A particularly interesting form of surface wave is the surface acoustic wave (SAW).
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Their research, published in the journal Scientific Reports last week, demonstrates how a so-called "surface wave cloak" can make curved surfaces appear flat when they come in contact with electromagnetic waves.
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A surface wave can be imagined as an ocean wave, where the wave propagates along the surface of the body of water without having much of an effect on everything beneath it.
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So long as you have a smartphone with a working camera, all you have to do is point your phone at a flat surface, wave it in a circle, and voila—you, too, can have a virtual museum floating above your bed and nightstand.
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Ground wave refers to the propagation of radio waves parallel to and adjacent to the surface of the Earth, following the curvature of the Earth. This radiative ground wave is known as the Norton surface wave, or more properly the Norton ground wave, because ground waves in radio propagation are not confined to the surface. Another type of surface wave is the non-radiative, bound-mode Zenneck surface wave or Zenneck–Sommerfeld surface wave.The Physical Reality of Zenneck's Surface Wave.
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Beyond the horizon the direct and reflected waves are blocked by the curvature of the Earth, and the signal is purely made up of the diffracted surface wave. It is for this reason that surface wave is commonly called ground wave propagation.
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Hill, D. A., and J. R. Wait (1978), Excitation of the Zenneck surface wave by a vertical aperture, Radio Sci., 13(6), 969–977, .Goubau, G., "Über die Zennecksche Bodenwelle," (On the Zenneck Surface Wave), Zeitschrift für Angewandte Physik, Vol. 3, 1951, Nrs.
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The PHIVOLCS recorded the strongest earthquake later that afternoon that had a surface wave magnitude of 6.0. Another earthquake struck on August 11, with a surface wave magnitude of 6.3. Three years later, Taal Volcano, about 25 kilometers from the epicenter, erupted after 43 years of inactivity.
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A surface-wave-sustained discharge is a plasma that is excited by propagation of electromagnetic surface waves. Surface wave plasma sources can be divided into two groups depending upon whether the plasma generates part of its own waveguide by ionisation or not. The former is called a self-guided plasma. The surface wave mode allows the generation of uniform high-frequency-excited plasmas in volumes whose lateral dimensions extend over several wavelengths of the electromagnetic wave, e.g.
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The AWAC (Acoustic Wave and Currents) is a type of ADCP specifically designed for surface wave height and direction.
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E-field of a Zenneck surface wave at an air-silver interface. The Zenneck wave, Zenneck surface wave or Sommerfeld-Zenneck surface wave is a longitudinal, inhomogeneous or non-uniform electromagnetic plane wave incident at the complex Brewster's angle onto a planar or spherical boundary interface between two homogeneous media having different dielectric constants.Sommerfeld, Arnold, "Uber die Ausbreitung der Wellen in der Drahtlosen Telegraphie" (Tr. The Propagation of Waves in Wireless Telegraphy), Ann. Physik [4] 28, 665 (1909); 62, 95 (1920); 81, 1135 (1926).
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Seismic inversion involves the set of methods which seismologists use to infer properties through physical measurements.Menke, W., 1989, Geophysical data analysis: Discrete inverse theory. San Diego, Academic Press. Surface-wave inversion is the method by which elastic properties, density, and thickness of layers in the subsurface are obtained through analysis of surface-wave dispersion.
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In seismology, surface waves are collected along with other seismic data, but are traditionally considered noise and an impedance in interpreting deeper reflection and refraction information. Seismologists usually modify seismic equipment and experimental procedures to remove surface wave information from the data. Earthquake seismologists however require the information seismic surface waves provide and thus design their equipment to amplify and gather as much information on these waves as possible. The work by early earthquake seismologists to extract substantial information from surface wave data was the basis for surface wave inversion theory.
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The third seismic method, surface wave methods, look at the surface waves that seem to roll along the surface (ground roll).
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When the FSS is engineered for electromagnetic band gap (EBG) characteristics, the FSS is designed to enlarge its stop band properties in relation to dispersive, surface wave (SW) frequencies (microwave and radio frequencies). Furthermore, as an EBG it is designed to reduce its dependence on the propagating direction of the surface wave traveling across the surface (interface).
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There are many advantages to using surface waves to image the subsurface. For one, surface wave inversion readily images low-velocity zones. Refraction methods cannot see low-velocity zones because such a zone would bend the traversing wave deeper instead of towards the surface. Surface wave inversion is also non-invasive as well as cost effective.
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The earthquake was caused by movement on a convergent plate boundary. It created a tsunami disproportionately large for its surface wave magnitude.
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Knopoff’s method Schwab, F., Knopoff, L., 1970, Surface-wave dispersion computations: Bulletin of the Seismological Society of America, v. 60, p. 321-344. also uses Haskell’s equations to perform the surface wave data inversion, but it simplifies the equations for the fastest computation. The increased speed is mostly accomplished in programming as well as the lack of complex numbers in the calculations.
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Goubau, G., "Über die Zennecksche Bodenwelle," (Tr. On the Zenneck Surface Wave), Zeitschrift für Angewandte Physik, Vol. 3, 1951, Nrs. 3/4, pp. 103-107.
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Surface-wave-sustained plasmas (SWP) can be operated in a large variety of recipient geometries. The pressure range accessible for surface-wave-excited plasmas depends on the process gas and the diameter of the recipient. The larger the chamber diameter, the lower the minimal pressure necessary for the SWP mode. Analogously, the maximal pressure where a stable SWP can be operated decreases with increasing diameter.
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After the pioneering work by Kannai and Tanaka,Tokimatsu, K., 1997. Geotechnical Site Characterization Using Surface Wave. Proc., 1st International Conf. on Earthquake Geotechnical Engineering, 3, pp. 1333–1367.
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A change in density of 25% will cause a less than 10% change in surface wave velocity. A change in P-wave velocity will have even less effect (3%).
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A vast amount of the research on surface wave detection has been done in the surface-feeding topminnow/killfish Aplocheilus lineatus. Schwartz (1965) demonstrated that this species has exceptionally well-developed surface wave detection ability, and it is easily housed and trained in laboratories.Schwartz, E. (1965) "Bau und Funktion der seitenlinie des streifenhechtlings Aplocheilus lineatus". "Z Vergl Physiology A 50": 55-87, cited and translated in Coombs S., Görner P., and Münz H. eds.
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The magnitude of the earthquake has been estimated from intensity information and these estimates vary from 6.4 on the Me (Energy magnitude scale) to 7.3 on the surface wave magnitude scale.
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The 1976 Papua earthquake occurred on 26 June with a surface wave magnitude of 7.1 in Papua, Indonesia. Total deaths for the event amounted to 422, including 70 who died in subsequent landslides.
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Recent work has also revealed small ridges of tissue around each neuromast which direct water flow around it. The neuroanatomy beyond the receptor level for surface wave-detecting neuromasts has been minimally investigated.
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When the surface wave above them becomes unstable and breaks (when the surface wave amplitude reaches 1/7 its wavelength) most of the antidune bedform is destroyed and its sediment carried down stream. Antidunes are commonly observed in small streams that flow across beaches into the ocean. Flume studies have shown that they can also occur in submarine environments beneath density flows like turbidity currents. Antidunes produce sedimentary structures characteristic of their flow regime, which allow sedimentary geologists to understand past flow conditions.
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Two earthquakes occurred near the towns of Mabini and Tanauan on April 8. PHIVOLCS recorded the first earthquake which occurred near Mabini at 3:07 pm as having a surface wave magnitude of 5.6 while the second earthquake which happened in Talaga Proper, Mabini, Batangas, at 3:09 pm was recorded as having a surface wave magnitude of 6.0. The United States Geological Survey (USGS) recorded the first as a magnitude 5.7 earthquake while the second as a moment magnitude of 5.9 earthquake.
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PHIVOLCS recorded the earthquake which occurred at 1:28 pm as having a surface wave magnitude of 6.3. The United States Geological Survey (USGS) recorded the earthquake as a moment magnitude of 6.2 earthquake.
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Junji Yamauchi from the Hosei University, Koganei, Tokyo, Japan was named Fellow of the Institute of Electrical and Electronics Engineers (IEEE) in 2012 for contributions to electromagnetic waveguides and design of surface wave antennas.
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The pool on the right pulses over the vents about every two hours. Occasionally there will be vibrations, surface wave motion, and thumping; these effects are caused by collapsing gas and steam bubbles deep underground.
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The 1926 Kars earthquake occurred at 21:59 local time on 22 October. It had a surface wave magnitude of 6.0 and a maximum felt intensity of IX (Violent) on the Mercalli intensity scale, causing 360 casualties.
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The 1938 Kırşehir earthquake occurred at 12:59 local time on 19 April. It had an estimated surface wave magnitude of 6.7 and a maximum intensity of IX (Violent) on the Mercalli intensity scale, causing 224 casualties.
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The 1981 Dawu earthquake occurred on , in Sichuan, China. Registering a surface wave magnitude of 6.8, the earthquake killed about 150 people and injured roughly 300 more. It caused comprehensive damage within close range of its epicenter.
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Estimation of near-surface shear-wave velocities and quality factors, using multichannel analysis of surface-wave methods. J. Appl. Geophys. 103, 140–151. The fifth is a high-resolution Linear Radon transformation performed by Luo et al. (2008).
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With an estimated surface wave magnitude of 7.3, the earthquake killed 10,000–110,000. According to other local sources, two-thirds of a population of 176,000 inhabitants perished. In the 1950s, the 1375 kilometer long Qaraqum Canal was built.
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The magnitude of this earthquake has been variously calculated as 7.6 on the moment magnitude scale and 8.0-8.3 on the surface wave magnitude scale. The surface rupture caused by the earthquake was 23 km (14 mi) long.
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The 1957 Abant earthquake occurred at 8:33am on 26 May, in Turkey. The earthquake had an estimated surface wave magnitude of 7.1 and a maximum felt intensity of IX (Violent) on the Mercalli intensity scale, causing 52 casualties.
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MNSOP-2 . The MS7 scale used in China is a variant of Ms calibrated for use with the Chinese-made "type 763" long-period seismograph.. The MLH scale used in some parts of Russia is actually a surface wave magnitude..
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The 1942 Niksar–Erbaa earthquake in Turkey occurred at 16:03 local time on 20 December. It had an estimated surface wave magnitude of 7.0 and a maximum felt intensity of IX (Violent) on the Mercalli intensity scale, causing 3,000 casualties.
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The 1943 Adapazarı–Hendek earthquake occurred at 17:32 local time on 20 June in Sakarya Province, Turkey. It registered an estimated 6.6 on the surface wave magnitude scale with a maximum intensity of IX (Violent) on the Mercalli intensity scale.
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For the specific case of predicting wind wave statistics on the ocean, the term ocean surface wave model is used. Other applications, in particular coastal engineering, have led to the developments of wind wave models specifically designed for coastal applications.
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For earthquake with magnitudes smaller than M7.5, the different agencies mentioned above as issuing location estimates, usually distribute values of M within 0.2 units from each other. For these medium-sized earthquake, the average of the estimates is a reliable determination of the earthquake size. However, for great earthquakes approaching M8 and exceeding it, the initial estimate of M is often significantly too small. This is so because the surface wave M, which is quickly obtained, is defined as proportional to the 20 sec Reighly surface wave, and this wave has a wavelength of about 100 km.
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Ground conductivity is an extremely important factor in determining the field strength and propagation of surface wave (ground wave) radio transmissions. Low frequency (30–300 kHz) and medium frequency (300–3000 kHz) radio transmissions are particularly reliant on good ground conductivity as their primary propagation is by surface wave. It also affects the real world radiation pattern of high frequency (3-30 MHz) antennas, as the so called "takeoff angle" is not an inherent property of the antenna but a result of a ground reflection. For this reason ITU publishes an extensive world atlas of ground conductivities.
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In addition, as an artificial magnetic conductor it has a forbidden frequency band, over which surface waves and currents cannot propagate. Therefore, AMC surfaces have good radiation patterns without unwanted ripples based on suppressing the surface wave propagation within the band gap frequency range. The surface impedance is derived from the ratio of the electric field at the surface to the magnetic field at the surface, which extends far into the metal beyond the skin depth. When a texture is applied to the metal surface, the surface impedance is altered, and its surface wave properties are changed.
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Ripple in water is a surface wave. A mechanical wave is a wave that is an oscillation of matter, and therefore transfers energy through a medium.Giancoli, D. C. (2009) Physics for scientists & engineers with modern physics (4th ed.). Upper Saddle River, N.J.: Pearson Prentice Hall.
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The 1902 Andijan earthquake occurred on December 16 with a surface wave magnitude of 6.4 and a maximum perceived Mercalli intensity of IX (Violent). The shock claimed between 700 and 4,880 casualties and more than 40,000 homes were destroyed in the Andijan Region of Uzbekistan.
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The surface wave magnitude (M_s) scale is one of the magnitude scales used in seismology to describe the size of an earthquake. It is based on measurements in Rayleigh surface waves that travel primarily along the uppermost layers of the Earth. It is currently used in People's Republic of China as a national standard (GB 17740-1999) for categorising earthquakes. Surface wave magnitude was initially developed in the 1950s by the same researchers who developed the local magnitude scale ML in order to improve resolution on larger earthquakes: Recorded magnitudes of earthquakes during that time, commonly attributed to Richter, could be either M_s or M_L.
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4th world conf. earthquake eng. Santiago, Chile 2, A.3 (1969) 19-32. There are various phenomena that may lead to the earthquake rotational loading of structures, such as propagation of body wave, surface wave, special rotational wave, block rotation, topographic effect, and soil structure interaction.
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The occurred at 17:14 local time (08:14 UTC) on 12 June. It had a surface wave magnitude of 7.7, JMA magnitude 7.4, and triggered a small tsunami. The earthquake reached a maximum intensity of Shindo 5 in Sendai and caused 28 deaths and 1,325 injuries.
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The 1924 Pasinler earthquake occurred at 16:34 local time on 13 September in Pasinler, Erzurum, Eastern Anatolia Region of Turkey. It had a surface wave magnitude of 6.8 and reached a maximum felt intensity of IX (Violent) on the Mercalli intensity scale, causing 60 casualties.
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Cabanatuan was the epicenter of a very strong earthquake, 7.8 on the surface wave magnitude scale, at roughly 3 pm on July 16, 1990. It leveled some buildings, including the Christian College of the Philippines (Liwag Colleges) in the midst of class time, and killed 1,653 people.
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The estimated magnitude for the earthquake is 7.0 on the surface wave magnitude scale. It was followed by 18 months of aftershocks. Intensity estimates on the Mercalli scale are: VIII–IX for Antioch; VII for both Daphne, a suburb of Antioch, and the port town of Seleucia Pieria.
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The process of creating dispersion curves from raw surface wave data (distance vs. time plot) can be performed using five transformation processes. The first is known as the wave-field transformation (τ-p transformation), first performed by McMechan and Yedlin (1981).McMechan, G. A., and Yedlin, M. J., 1981.
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It can be found in scattered pockets throughout eastern African islands and coastline such as Madagascar, Eritrea, the Aldabran atoll, Réunion, Kenya, Mozambique, Mauritius, South Africa, and parts of the Red Sea in uncommon abundance. It prefers shallow coral reefs that are protected from strong surface wave action.
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It is native to the Indo-Pacific islands, distributed mostly in the Coral Triangle area, and also found in the American Samoa. It prefers environments protected from surface wave action on fringing reef crests, mid-slope terraces, and lagoons at depths of 2 to 25 meters (6–82 ft).
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There was a major foreshock on 15 March of that year. Following the mainshock on 3 May, earthquakes (presumably aftershocks) continued until January 1482, with large aftershocks on 5 May, 12 May, 3 October and 18 December. The estimated magnitude for the mainshock is 7.1 on the surface wave magnitude scale.
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The 1941 Van–Erciş earthquake occurred at 23:53 local time on 10 September. It had an estimated surface wave magnitude of 5.9 and a maximum intensity of VIII (Severe) on the Mercalli intensity scale. The earthquake has caused estimated casualties of between 190 and 430 people and also 600 buildings have collapsed.
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The multi-channel analysis of surface waves (MASW) technique can be performed similar to a traditional seismic acquisition whereby there is a geophone spread that is acquiring seismic data. The resulting data is processed by picking out the surface wave arrivals from the acquired distance vs. time plot. Based on the distance vs.
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There are a few disadvantages to this method as well. The resolution of the surface wave inversion method is not nearly as resolved as a seismic collection done in a wellbore. There is also the possibility for non-unique solutions to dispersion curves (several sets of parameters can yield the same dispersion curve).
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Arising from original analysis by Arnold Sommerfeld and Jonathan Zenneck of the problem of wave propagation over a lossy earth, it exists as an exact solution to Maxwell's equations. The Zenneck surface wave, which is a non-radiating guided-wave mode, can be derived by employing the Hankel transform of a radial ground current associated with a realistic terrestrial Zenneck surface wave source. Sommerfeld-Zenneck surface waves predict that the energy decays as R−1 because the energy distributes over the circumference of a circle and not the surface of a sphere. Evidence does not show that in radio space wave propagation, Sommerfeld-Zenneck surfaces waves are a mode of propagation as the path-loss exponent is generally between 20 dB/dec and 40 dB/dec.
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Geologic mapping and interpretation of geomorphology are typically completed in consultation with a geologist or engineering geologist. Geophysical exploration is also sometimes used. Geophysical techniques used for subsurface exploration include measurement of seismic waves (pressure, shear, and Rayleigh waves), surface-wave methods and/or downhole methods, and electromagnetic surveys (magnetometer, resistivity, and ground-penetrating radar).
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The 1932 Changma earthquake occurred at 10:04:27 local time (02:04:07 UTC) on 25 December. With an estimated magnitude of 7.6 on the surface wave magnitude scale, and a maximum felt intensity of X (Extreme) on the Mercalli intensity scale, the quake destroyed 1,167 houses and caused 275 deaths and 320 injuries.
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A type of FSS based metamaterial has the interchangeable nomenclature Artificial Magnetic Conductor (AMC) or High Impedance Surface (HIS). The HIS, or AMC, is an artificial, metallic, electromagnetic structure. The structure is designed to be selective in supporting surface wave currents, different from conventional metallic conductors. It has applications for microwave circuits and antennas.
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The 1949 Queen Charlotte Islands earthquake struck the sparsely populated Queen Charlotte Islands and the Pacific Northwest coast at 8:01 p.m. PDT on August 21. The shock had a surface wave magnitude of 8.1 and a maximum Mercalli Intensity of VIII (Severe). The interplate earthquake began in the ocean bottom just off the rugged coast of Graham Island.
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The 1925 Dali earthquake occurred at 14:42 UTC on 16 March. It had an estimated magnitude of 7.0 on the surface wave magnitude scale and a maximum perceived intensity of at least IX (Violent) on the Mercalli intensity scale. It had an epicenter in the province of Yunnan in southern China and killed an estimated 5,000 people.
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Richter's original "local" scale has been adapted for other localities. These may be labelled "ML", or with a lowercase "`l`", either M`l`, or M`l`., p. 59. (Not to be confused with the Russian surface-wave MLH scale..) Whether the values are comparable depends on whether the local conditions have been adequately determined and the formula suitably adjusted.
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The earthquake hit at 05:45 UTC, around 11:47 PM local time. It caused the most damage at Puerto BarriosAmbraseys and Adams, p. 198. in Izabal Department, Guatemala, and Puerto Cortes, Honduras, and it killed two people and measured between 6.4 and 6.7 surface wave magnitude. The quake was felt throughout Honduras, Belize, and parts of Guatemala.
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A recent theoretical model, proposed by Ahmed El Hady and Benjamin Machta, proposes that there is a mechanical surface wave which co- propagates with the electrical action potential. These surface waves are called "action waves". In the El Hady–Machta's model, these co-propagating waves are driven by voltage changes across the membrane caused by the action potential.
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The seismic wave interval measured on the time axis of an earthquake record - starting with the first seismic wave onset until the wavetrain amplitude diminishes to at least 10% of its maximum recorded value - is referred to as "earthquake duration". It is this concept that Bisztricsany first used to develop his Earthquake Duration Magnitude Scale employing surface wave durations.
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The 1930 Irpinia earthquake occurred at 00:08 UTC on 23 July, chiefly in an area known as Irpinia. It had a surface wave magnitude of 6.6 and a maximum intensity of X (Very destructive). The event caused 1,404 deaths and 4,624–7,000 injuries. The epicenter was near the boundaries between the regions of Basilicata, Apulia, and Campania.
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Branoner, F., Zhivkov, Z., Ziehm, U. and Behrend, O., (2012). Central representation of spatial and temporal surface wave parameters in the African clawed frog. Journal of Comparative Physiology A, 198: 797-815 It has been speculated that both Xenopus and the European grassfrog use their seismic sensory capabilities to locate conspecifics in breeding ponds.Narins, P.M., (1990).
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The occurred at about 21:30 local time on 8 May. It had a magnitude of 7.4 on the surface wave magnitude scale. It caused the destruction of many houses in Nagano and at least 8,600 people were killed. The earthquake triggered many landslides, the largest of which dammed the Sai River (a tributary of the Shinano River).
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Undular bore and whelps near the mouth of Araguari River in north-eastern Brazil. View is oblique toward mouth from airplane at approximately altitude.Figure 5 in: The undulations following behind the bore front appear as slowly modulated Stokes waves. In fluid dynamics, a Stokes wave is a nonlinear and periodic surface wave on an inviscid fluid layer of constant mean depth.
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The 1906 Meishan earthquake () was centered on Moe'akhe (), Kagi-cho, Japanese Taiwan (modern-day Meishan, Chiayi County, Taiwan) and occurred on March 17. Referred to at the time as the Great Kagi earthquake (), it is the third- deadliest earthquake in Taiwan's recorded history, claiming around 1,260 lives. The shock had a surface wave magnitude of 6.8 and a Mercalli intensity of IX (Violent).
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Surrounding the epicenter were several small towns built on flat glacial lake plains and low hills. (See this bulletin on the webpage of Earthquake Center of Saint Louis University) Scientists described the rupture as "strong". During the quake, surface wave and body wave magnitudes were measured at 5.2 and 5.54, respectively. The magnitude of the quake reached 5.4 on the Richter scale.
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There were 30 specific years where individual or multiple earthquakes were documented in Yemen for the 1,240 years prior to 1982. In 1909, a shock resulted in the deaths of 300 people and damaged 400 homes, and in 1941 two shocks (5.8 & 6.2 surface wave magnitude) killed 1,200 and destroyed 1,400 homes. Other minor events occurred in 1955 and again in 1959.
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ANFO, show reduced sensitivity under pressure. A transient pressure wave from a nearby detonation may compress the explosive sufficiently to make its initiation fail. This can be prevented by introducing sufficient delays into the firing sequence. A sympathetic detonation during mine blasting may influence the seismic signature of the blast, by boosting the P-wave amplitude without significantly amplifying the surface wave.
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Two main data gathering techniques are employed in gathering surface wave information. The two methods are spectral analysis of surface waves (SASW)Brown., L.T., Boore, D.M., Stokoe II, K.H., 2002, Comparison of Shear-Wave Slowness Profiles at 10 Strong-Motion Sites from Noninvasive SASW Measurements and Measurements Made in Boreholes: Bulletin of the Seismological Society of America, v. 92, p. 3116-3133.
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Overall, passive energy sources usually require more time when data gathering than active energy. Ambient noise is also more useful when it comes from random directions. The spectral analysis surface wave (SASW) technique requires the use of a spectral analyzer and at least two geophones. The spectral analyzer is used to study the frequency and phase of signals being recorded by the geophones.
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165 (5), 903–922. In performing a wave-field transformation, a slant stack is done, followed by a Fourier transform. The way in which a Fourier transform changes x-t data into x-ω (ω is angular frequency) data shows why phase velocity dominates surface wave inversion theory. Phase velocity is the velocity of each wave with a given frequency.
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Haskell (1953) first performed the multilayer dispersion computation. Haskell’s work has been the basis for much of the current surface wave inversion theory. Since Rayleigh waves are composed of P and S-waves and Love waves are composed of only S waves, Haskell derived the elastic wave equations for both P and S-waves. These equations were modified to show Rayleigh wave motion.
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Ground shock, or water shock will result from nuclear explosions on (or near) the surface of ground or water. The ground shock can damage or destroy hardened structures. In water, the shock is damaging to nearby vessels and may also produce a surface wave to limited ranges. A crater is formed by an explosion at (or near) the ground surface.
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S- and surface wave data are used in global models when this coverage is not sufficient, such as in ocean basins and away from subduction zones. First-arrival times are the most widely used, but models utilizing reflected and refracted phases are used in more complex models, such as those imaging the core. Differential traveltimes between wave phases or types are also used.
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The 1877 Iquique earthquake occurred at 21:16 local time on 9 May (0:59 on 10 May UTC). It had a magnitude of 8.5 on the surface wave magnitude scale. Servicio sismológico Universidad de Chile, Sismos importantes o destructivos desde 1570. Other estimates of its magnitude have been as high as 8.9 and 9.0 (based on the size of the tsunami).
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In telecommunication, ground constants are the electrical parameters of earth: electrical conductivity, σ, electrical permittivity, ε, and magnetic permeability, μ. The values of these parameters vary with the local chemical composition and density of the Earth. For a propagating electromagnetic wave, such as a surface wave propagating along the surface of the Earth, these parameters vary with frequency and direction.
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Most research on the detection of surface waves has been done on the striped panchax, Aplocheilus lineatus Surface wave detection by animals is the process by which animals, such as surface-feeding fish are able to sense and localize prey and other objects on the surface of a body of water by analyzing features of the ripples generated by objects' movement at the surface. Features analyzed include waveform properties such as frequency, change in frequency, and amplitude, and the curvature of the wavefront. A number of different species are proficient in surface wave detection, including some aquatic insects and toads, though most research is done on the topminnow/surface killifish Aplocheilus lineatus. The fish and other animals with this ability spend large amounts of time near the water surface, some just to feed and others their entire lives.
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The massive root systems of mangroves are efficient at dissipating wave energy.Massel, S. R.; Furukawa, K.and Brinkman R. M. (1999) "Surface wave propagation in mangrove forests" Fluid Dynamics Research 24(4): pp. 219–249 Mangroves retard the tidal movement of water, allowing sediment to be deposited as the tide comes in, and leaving all except fine particles when the tide ebbs.Mazda, Yoshihiro et al.
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The 1893 Quchan earthquake occurred at about 19:30 local time (15:06 UTC) on 17 November. It had an estimated magnitude of 6.6 on the surface wave magnitude scale and a maximum perceived intensity of X (Extreme) on the Mercalli intensity scale. It caused severe damage in Quchan County, particularly to the town of Quchan itself and there were an estimated 18,000 casualties.
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The 1983 Luzon earthquake struck the Philippines at 20:17 PST (UTC+08:00) on August 17. The shock had a surface wave magnitude of 6.5 and a maximum Mercalli intensity of VII (Very strong), killing 16 people and injuring 47. Seven towns were damaged, several buildings collapsed, and electricity was cut off in Laoag. Features like sand volcanoes and cracks formed during the quake.
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The quake had a surface wave magnitude of 7.3 and it killed at least 1070; 998 of those deaths were in Yenice, with another 50 in Gönen, 20 in Çan, and 3 in Manyas. The cost of repair was estimated at US$3,570,000. Several thousand buildings were affected in the Can-Yenice-Gonen area. Damage of intensity VI occurred at Sakarya (Adapazari), Bursa, Edirne, Istanbul and Izmir.
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The 1983 Biga earthquake hit northwestern Turkey on 5 July 1983. Responsible for five deaths and approximately twenty-six casualties throughout Biga and Erdek and damage in Istanbul, the earthquake measured 6.1 on the surface wave magnitude scale. It shook places as far away as eastern Greece. The United States Geological Survey listed the earthquake among the "Significant Earthquakes of the World" for 1983.
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Considering the large surface wave magnitude (7.1) and widespread surface rupturing, structural damage to buildings was surprisingly small; variations in damage were related to the materials used and construction method of individual buildings, rather than the proximity to the fault break.. Some villages suffered 70% destruction of property, while others nearby with fault lines running right through them had only a few houses damaged.
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The 1939 Chillán earthquake occurred in south-central Chile on 24 January with a surface wave magnitude of 8.3 and a maximum Mercalli intensity of X (Extreme). With a death toll of around 28,000, compared to the 2,231–6,000 (official estimates vary greatly) (Exact data location missing from URL) of the Great Chilean earthquake of 1960, it is the single deadliest earthquake in Chile.
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The direct search algorithm matches a data driven model to the synthetic dispersion curve (Wathelet et al., 2004).Wathelet, M., Jongmans, D., Ornberger, M., 2004, Surface-wave inversion using a direct search algorithm and its application to ambient vibration measurements: Near Surface Geophysics, p. 211-221. This algorithm creates a theoretical dispersion curve by guessing parameters such as shear wave velocity, compressional wave velocity, density, and thickness.
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The 1905 Kangra earthquake occurred in the Kangra Valley and the Kangra region of the Punjab Province (modern day Himachal Pradesh) in India on 4 April 1905. The earthquake measured 7.8 on the surface wave magnitude scale and killed more than 20,000 people. Apart from this, most buildings in the towns of Kangra, Mcleodganj and Dharamshala were destroyed. Dharamsala Earthquake 1905 – ImagesHistory Kangra district Official website.
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The 2008 Yingjiang earthquakes were a series of major earthquakes ranging from surface wave magnitude (Ms) 4.1 to 5.9 that struck Yingjiang County, Yunnan province, China between August 19 (in UTC; August 20 local time) and September 3. It caused 5 deaths, 21 serious injuries, and RMB 2.7 billion in direct economic damage. USGS put the magnitude of the strongest one to Mw 6.0.
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Microwave induced plasma ion sources are capable of exciting electrodeless gas discharges to create ions for trace element mass spectrometry. A microwave plasma is a type of plasma, that has high frequency electromagnetic radiation in the GHz range. It is capable of exciting electrodeless gas discharges. If applied in surface-wave- sustained mode, they are especially well suited to generate large-area plasmas of high plasma density.
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Seismic methods utilize elastic energy created by natural and artificial sources to create an image of the subsurface. Seismic waves are recorded on geophones. Seismic methods are split up into three different methods, reflection, refraction, and surface wave, based on the physical property of the waves being considered. The reflection method looks at reflected energy from sharp boundaries to determine contrasts in density and velocity.
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Species in this order typically have four to six flagella at the cell's apical pole, one of which is recurrent - that is, it runs along a surface wave, giving the aspect of an undulating membrane. Like other parabasalids, they typically have an axostyle, a pelta, a costa, and parabasal bodies. In Histomonas only one flagellum and a reduced axostyle are found, and in Dientamoeba, both are absent.
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If a corresponding solution for an isotropic case can be formulated, then the anisotropic case can be arrived at with more calculations. The correct identification of body and surface wave polarizations is the key to determining the degree of anisotropy. The modeling of many two-phase materials can be simplified by the use of anisotropic elastic-constants. These constants can be found by looking at recorded data.
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In this case the dispersion relation allows for two modes: a barotropic mode where the free surface amplitude is large compared with the amplitude of the interfacial wave, and a baroclinic mode where the opposite is the case – the interfacial wave is higher than and in antiphase with the free surface wave. The dispersion relation for this case is of a more complicated form.
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The 1979 Bali earthquake occurred at with a surface wave magnitude of 6.3. The shock occurred southeast of the coast of Karangasem Regency in the Lombok Strait, and about east-northeast of Denpasar. Up to 80 percent of the buildings in Karangasem Regency were damaged, between 15,000 and 500,000 people were displaced, and road links to the provincial capital of Denpasar were briefly severed.
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The 1942 Guatemala earthquake occurred at on August 6 and had ratings of 7.7 on the moment magnitude scale and 7.9 on the surface wave magnitude scale. The epicenter was located off the southern coast of Guatemala, and it was one of the strongest earthquakes ever recorded there. The earthquake caused widespread damage in the west-central highlands of Guatemala. Thirty-eight people died in the earthquake.
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The 1974 Zhaotong earthquake occurred at 19:25 UTC on 10 May. It had a magnitude that was measured at 7.0 on the moment magnitude scale and 7.1 on the surface wave magnitude scale. It had a maximum perceived intensity of IX (Violent) on the Mercalli intensity scale. The epicenter was located in Zhaotong prefecture in Yunnan province and it caused between 1,641 and 20,000 deaths.
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A diving thumb In physics, a surface wave is a mechanical wave that propagates along the interface between differing media. A common example is gravity waves along the surface of liquids, such as ocean waves. Gravity waves can also occur within liquids, at the interface between two fluids with different densities. Elastic surface waves can travel along the surface of solids, such as Rayleigh or Love waves.
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There will also be a reflected signal as the transmission will be reflected by a number of objects including the earth's surface and any hills, or large buildings that may be present. In addition to this there is a surface wave. This tends to follow the curvature of the Earth and enables coverage beyond the horizon. It is the sum of all these components that is known as the ground wave.
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Systems using an alternate technology have also been developed for over-the-horizon detection. Due to diffraction, electromagnetic surface waves are scattered to the rear of objects, and these signals can be detected in a direction opposite from high-powered transmissions. Called OTH- SW (SW for Surface Wave), Russia is using such a system to monitor the Sea of Japan, and Canada has a system for coastal surveillance.
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The 1981 Sirch earthquake occurred at 00:22 local time (17:22 UTC) on July 28. It had a magnitude of 7.1 on the surface wave magnitude scale and a maximum perceived intensity of IX (Violent) on the Mercalli intensity scale. The epicentre was in the province of Kerman in eastern Iran. The earthquake caused the destruction of Kerman and serious damage to towns and villages in the surrounding area.
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Another application is as stop band device for surface wave propagation along the interface. This is because surface waves are a created as a consequence of an interface between two media having dissimilar refractive indices. Depending on the application of the system that includes the two media, there may be a need to attenuate surface waves or utilize them. An FSS based metamaterial employs a (miniature) model of equivalent LC circuitry.
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Surface wave inversion is becoming a valuable tool in evaluating the near subsurface. Surface waves found on seismograms can now be a useful by product of seismic exploration surveys instead of a waste product. Furthermore, it is more budget friendly because the use of an active energy source is not needed. Also, it is useful in detecting low velocity zones in the subsurface that are undetectable by refraction methods.
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Response towards prey typically follows the pattern orientation towards prey, swimming towards prey, and then prey capture. This ability is sometimes referred to as a sense of "distant touch."Schwarz, J.S., Reichenbach, T., and Hudspeth, A. J. (2011) "A hydrodynamic sensory antenna used by killifish for nocturnal hunting". The Journal of Experimental Biology 214:1857-1866 Several species have been shown to use surface wave detection for prey capture.
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If they are both in surface-wave and resonator mode, they can exhibit a high degree of spatial localization. This allows to spatially separate the location of plasma generations from the location of surface processing. Such a separation (together with an appropriate gas-flow scheme) may help reduce the negative effect, that particles released from a processed substrate may have on the plasma chemistry of the gas phase.
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The 1917 Bali earthquake occurred at 06:50 local time on 21 January (23:11 on 20 January UTC). It had an estimated magnitude of 6.6 on the surface wave magnitude scale and had a maximum perceived intensity of IX (Violent) on the Mercalli intensity scale. It caused widespread damage across Bali, particularly in the south of the island. It triggered many landslides, which caused 80% of the 1500 casualties.
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Some geophysical imaging techniques for the Earth's lithosphere and upper mantle include teleseismic tomography, surface-wave tomography, gravity modeling, and electromagnetic methods. Geophysical imaging techniques can be combined to create a more accurate image of the lithosphere. The techniques used to image the lithosphere can be used to map out the thermostructure of the Earth. In turn, the thermostructure reveals near surface processes such as seismicity, magma emplacement, and mineralization events.
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In the radar role, the creeping waves in question are diffracting around the Earth, although processing the returned signal is difficult. Development of such systems became practical in the late 1980s due to the rapidly increasing processing power available. Such systems are known as OTH-SW, for Surface Wave. The first OTH-SW system deployed appears to be a Soviet system positioned to watch traffic in the Sea of Japan.
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They are typically made from glass composites (mixtures of carbon fiber, Kevlar and fiberglass) or rotomolded plastic. Many kayaks, such as those used in whitewater kayaking on rivers or tidal rapids, are used. Many whitewater designs can be fitted with fins, to assist in control on moving surf waves. (See: Ocean surface wave, Whitewater) Sea kayaks, generally used for day-trip, to expedition kayaking, are used in surf kayaking.
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Shakemap in Kyrgyzstan The 1992 Suusamyr earthquake occurred at 02:04 UTC on 19 August near Toluk in the border area of Kyrgyzstan. The shock had a surface wave magnitude of 7.5 and a maximum felt intensity of IX (Violent) on the Mercalli intensity scale. It was a result of reverse faulting. The death toll from the event amounted to about 75, including 14 people who were killed by landslides.
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Recent emphasis has focused on developing methods for exploiting ambient noise and earthquakes in surface wave tomography and combining this information to produce 3-D models of the crust and uppermost mantle. In addition, he has developed Monte Carlo methods for seismic inversions and has worked on applying physical constraints from geodynamical models and thermodynamics into seismic inversions. He has published numerous articles with an h-index of 50 (updated on 23 August 2015).
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The 1958 Ecuador–Colombia earthquake struck the coastal regions of Ecuador and Colombia on January 19 with a surface wave magnitude of 7.6 at 9:07 local time. Approximately 30 percent of Esmeraldas (Ecuador) was destroyed, including the children's department of the hospital, where three children died. In all, 111 persons died and 45 were injured as a result of the earthquake. Water mains were broken and power transmission lines were damaged.
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The 5.7 magnitude Little Skull Mountain (LSM) earthquake the following day, June 29, 1992, at 10:14 UTC near Yucca Mountain, Nevada, is also considered part of the regional sequence and may have been triggered by surface wave energy produced by the Landers earthquake. Foreshock activity, in the form of a significant increase in micro-earthquakes, was observed at Little Skull Mountain following the Landers earthquake, and the activity continued until the main LSM earthquake.
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The 1946 Dominican Republic earthquake occurred on August 4 at 17:51 UTC near Samaná, Dominican Republic. The mainshock measured 8.1 on the surface wave magnitude scale and an aftershock occurred four days later on August 8 at 13.28 UTC with a magnitude of 7.6. A tsunami was generated by the initial earthquake and caused widespread devastation across Hispaniola. The tsunami was observed in much of the Caribbean and the northwestern Atlantic Ocean.
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The 1975 Near Islands earthquake occurred at 08:43 UTC on February 2 off the coast of Attu Island, Alaska. The earthquake had a surface wave magnitude of 7.6 and a maximum Mercalli intensity of IX (Violent). It caused heavy damage on Shemya Island, injuring 15 residents. The runways of Shemya Air Force Base sustained cracks up to wide, and crevices with as much as of displacement were observed on the island.
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There are sufficient instrumental recordings preserved for this earthquake to allow an estimate of its magnitude. A range of 7.5–8.0 has been estimated from the seismographs, a magnitude that is insufficient to explain the observed tsunami. The surface wave magnitude for this earthquake was calculated from seismic waves with a period up to 40 seconds. For a tsunami earthquake however, a large part of the energy release is at much longer periods (lower frequencies).
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The earthquake struck at 8:18 PM and surface wave magnitude of 6.5. It was the most powerful earthquake to strike the Philippines in seven years. Shaking lasted 20 seconds and damaged seven towns extensively, its greatest damage occurring near Pasuquin, Laoag, Sarrat, and Batac in the Ilocos Norte province. Early reports claimed that 17 were killed and 80 were injured, but these numbers were later revised to 16 and 47, respectively.
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The 2008 Panzhihua earthquake struck southern Sichuan province, China on August 30 at with a surface wave magnitude of 6.1 (5.7 ). It is also cited as the Renhe-Huili earthquake, especially in SCEA reports and early CEA reports. It was not an aftershock of the Sichuan earthquake that occurred several months prior. With more than 400 aftershocks, it caused over 40 deaths, the collapse of 10,000 homes and damage to other infrastructure in the area.
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Frequency selective surfaces (FSS) materials can be utilized as band gap material in the surface wave domain, at microwave and radio frequency wavelengths. Support of surface waves is a given property of metals. These are propagating electromagnetic waves that are bound to the interface between the metal surface and the air. Surface plasmons occur at optical frequencies, but at microwave frequencies, they are the normal currents that occur on any electrical conductor.
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Dorman and Ewing (1962)Dorman, J., Ewing, M., 1962, Numerical Inversion of Seismic Surface Wave Dispersion Data and Crust-Mantle Structure in the New York- Pennsylvania Area: Journal of Geophysical Research, v. 16, p. 5227-5241. came up with an algorithm based on Haskell’s earlier work. Their method used an iterative technique that enabled the user to input parameters and the computer to find which exact parameters best fit the experimental data.
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This type of wave travels along the surface or interface between two media. An example of a surface wave would be waves in a pool, or in an ocean, lake, or any other type of water body. There are two types of surface waves, namely Rayleigh waves and Love waves. Rayleigh waves, also known as ground roll, are waves that travel as ripples with motion similar to those of waves on the surface of water.
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Species of the order Trichomonadida typically have four to six flagella at the cell's apical pole, one of which is recurrent - that is, it runs along a surface wave, giving the aspect of an undulating membrane. Mixotricha paradoxa have four weak flagella that serve as rudders. It has four large flagella at the front end, three pointing forwards and one backward. The basal bodies are also bacteria, not spirochaetes but oval, pill-shaped bacteria.
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The frequency range used is from 6 to 30 MHz. Launched officially in 2009, the French STRADIVARIUS research project developed a new over-the-horizon radar (High Frequency Surface Wave Radar – HFSWR) capable of monitoring maritime traffic up to 200 nautical miles offshore. A demonstration site, DIGINEXT is operational since January 2015 on the French Mediterranean coast to showcase the 24/7 capabilities of the system that is now offered for sale by DIGINEXT.
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The theory underlying the prism coupler was first published in the Soviet Union.L.V. Iogansen, “Theory of resonant electromagnetic systems with total internal reflection III,” Sov. Phys. Tech. Phys., vol. 11, pp. 1529–1534, May 1967. This work was not known in the US. Starting in 1969, Shubert, Harris, and Polky at the University of Washington,J.H. Harris and R. Shubert,”Optimum power transfer from a beam to a surface wave,” Conf. Abs., URSI Spr.
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Troppy effect – a phenomenon of formation of irregular residual surface wave- like damages resulting from a non-stationary process of cyclic elastoplastic deformation in the zone of contact at rolling friction. It was openly and studied by professor L. A. Sosnovskiy with staff in the framework of Tribo- Fatigue.Sosnovskiy, L. A. "Troppy Phenomenon" / L. A. Sosnovskiy, S. S. Shcharbakou // Proc. of World Tribology Congress III [Electronic resource] : Washington, D.C. USA, September 12–16, 2005.
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Vernègues after the earthquake Street in Salon-de-Provence after the earthquake The 1909 Provence earthquake occurred on June 11 in Provence. Measuring 6.2 on the surface wave magnitude scale, it is the largest ever recorded earthquake in metropolitan France.Dominique Chardon and Olivier Bellier, "Geological boundary conditions of the 1909 Lambesc (Provence, France) earthquake : structure and evolution of the Trévaresse ridge anticline", Bulletin de la Société Géologique de France, 2003, t. 174, no.
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In research at Physikalisch-Chemisches-Institut, Heidelberg, Germany, axicon lenses have been used in laser diagnostics of mechanical properties of thin films and solids by surface-wave spectroscopy. In these experiments, laser radiation is focused on the surfaces in a concentric ring. The laser pulse generates concentric surface acoustic waves, with amplitude that reaches a maximum in the center of the ring. This approach makes it possible to study mechanical properties of materials under extreme conditions.
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Michael H. Ritzwoller (born July 29, 1954) is an observational seismologist and professor of physics at University of Colorado Boulder. He is also the director of the Center for Imaging the Earth's Interior at University of Colorado Boulder. His early work was mainly in normal mode seismology and helioseismology. Research in the last decade has concentrated on developing methods to focus seismic models derived from surface wave dispersion information to tectonic scales, particularly in the US and China.
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The earthquake occurred at 22:00 local time on 11 November. It had an epicenter close to Edo (now Tokyo), causing considerable damage in the Kantō region from the shaking and subsequent fires, with a death toll of 7,000–10,000 people and destroyed around 14,000 buildings. The earthquake had a magnitude of 7.0 on the surface wave magnitude scale and reached a maximum intensity of XI (Extreme) on the Mercalli intensity scale. The earthquake triggered a minor tsunami.
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In the resonator mode, the plasma density does not exceed the critical density. A standing electromagnetic wave, which is confined by a resonator cavity, penetrates the plasma and sustains it in the regions of highest field intensity. The geometry of this region determines the spatial distribution of the plasma. Plasmas excited in resonator mode are less resistant against detuning, for instance by the insertion of electric probes (Langmuir probes) or electrically conducting samples compared to surface-wave plasmas.
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Diffraction depends on the relationship between the wavelength and the size of the obstacle. In other words, the size of the obstacle in wavelengths. Lower frequencies diffract around large smooth obstacles such as hills more easily. For example, in many cases where VHF (or higher frequency) communication is not possible due to shadowing by a hill, it is still possible to communicate using the upper part of the HF band where the surface wave is of little use.
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Surface waves propagate along the Earth's surface, and are principally either Rayleigh waves or Love waves.. See especially figure 1-10. For shallow earthquakes the surface waves carry most of the energy of the earthquake, and are the most destructive. Deeper earthquakes, having less interaction with the surface, produce weaker surface waves. The surface-wave magnitude scale, variously denoted as Ms, MS, and Ms, is based on a procedure developed by Beno Gutenberg in 1942; based on work by .
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The 1903 Manzikert earthquake struck Manzikert of nowadays Muş Province in eastern Turkey on 28 April. Registering a surface wave magnitude of 7.0, the earthquake originated from a highly active seismic zone. It killed 3,500 people and 20,000 animals, destroyed 12,000 homes, and is now listed among Turkey's deadliest earthquakes in recorded history. To this day, Turkey is threatened by major earthquakes – more than 100 earthquakes over 7.0 have taken place in the country's known history.
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Rotman invented many types of surface wave antennas including the trough waveguide, the channel waveguide, and the sandwich wire antenna. These periodic structures which he analyzed together with Arthur Oliner allow antennas to scan in various directions by changing frequencies. The sandwich wire antenna was one of the first attempts to use the then-new techniques of microstrip and stripline to create an antenna. W. Rotman and N. Karas, "The Sandwich Wire Antenna," August 1965, Microwave Journal , vol.
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Hallicrafters SX-28 shortwave receiver analog tuning dial, circa 1944 Amateur radio operators also discovered that long-distance communication was possible on shortwave bands. Early long-distance services used surface wave propagation at very low frequencies, which are attenuated along the path at wavelengths shorter than 1,000 meters. Longer distances and higher frequencies using this method meant more signal loss. This, and the difficulties of generating and detecting higher frequencies, made discovery of shortwave propagation difficult for commercial services.
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The 1953 Ionian islands earthquake occurred with a surface wave magnitude of 7.2 and a maximum Mercalli intensity of X (Extreme) on August 12, 1953. Building damage was extensive and the southern islands of Kefalonia and Zakynthos were practically levelled. The islands were reconstructed from the ground up over the following years under a strict building code. The code has proven extremely effective, as many earthquakes since that time have caused no damage to new buildings.
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The 115 Antioch earthquake occurred on 13 December 115 AD. It had an estimated magnitude of 7.5 on the surface wave magnitude scale and an estimated maximum intensity of XI (Extreme) on the Mercalli intensity scale. Antioch and surrounding areas were devastated with a great loss of life and property. It triggered a local tsunami that badly damaged the harbour at Caesarea Maritima. The Roman Emperor Trajan was caught in the earthquake, as was his successor Hadrian.
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Examples are the waves at the surface of water and air (ocean surface waves). Another example is internal waves, which can be transmitted along the interface of two water masses of different densities. In theory of hearing physiology, the traveling wave (TW) of Von Bekesy, resulted from an acoustic surface wave of the basilar membrane into the cochlear duct. His theory purported to explain every feature of the auditory sensation owing to these passive mechanical phenomena.
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On 31 March 1969 the island was the site of an earthquake measuring 6.6 on the surface wave magnitude scale. The earthquake caused some damage including numerous rock falls. On 9 April 1996 a station of the Hurghada Seismological Network began operating on the island with the aim of gaining information on the seismotectonics of the southern Gulf of Suez region. The station is operated by solar batteries and the seismic data is transmitted by telemetry to the Hurghada Seismological Center in Hurghada.
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Cross sea of shallow-water swell waves near the Whales Lighthouse (Phare des Baleines), Île de Ré Wind waves are generated by many kinds of disturbances such as seismic events, gravity, and crossing wind. The generation of wind waves is initiated by the disturbances of the crosswind field on the surface of the water. Two major mechanisms of surface wave formation by winds (the Miles-Phillips mechanism) and other sources (e.g. earthquakes) of wave formation can explain the generation of wind waves.
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The horizontal loop radiated most of its energy in the form of a surface wave, thereby minimising any unwanted interference. In practical terms, erecting a horizontal loop antenna on a ship caused several problems. The loop was supported by guy wires from a central mast. It was too wide for the ship to pass through Dutch ship canals, so the side sections had to be hinged so they could be raised to a vertical position until the ship was at sea.
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The ISC- GEM Global Instrumental Earthquake Catalogue (1900-2013) (prepared at the request of the GEM Foundation) catalogs magnitude 5.5 or greater earthquakes suitable for modeling and assessing seismic hazard and risk. Epicentral locations and hypocentral depths were recalculated from original travel time data using a consistent velocity model. Magnitudes are expressed as moment magnitude scale (Mw), taken either from reliable published values of seismic moment or from recalculated values of surface wave or body wave magnitude, converted to Mw using empirical relationships.
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In two most recent investigations using statistically stable samples for Italian earthquakes [approximately 100,000 events over the period 1981-2002 in the Richter local [ML] magnitude range of 3.5-5.8] Castello, B., Olivieri, M. & G. Selvaggi, 2007. Local and duration magnitude determination for the Italian earthquake catalog, 1981-2002. and for Indian earthquakes exemplified by an aftershock sequence of 121 events with (surface wave magnitude) > 4.0 in 2001 in the Bhuj area of northwestern India,Mandal et al. 2004 (op.
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The 2017 Batangas earthquakes were an earthquake swarm that occurred from early April to mid-August 2017, affecting the province of Batangas in the Philippines and other nearby areas. The first major earthquake occurred on April 4 at 8:58pm Philippine Standard Time, with a surface wave magnitude of 5.5 off the coast of Batangas. According to the PHIVOLCS Earthquake Intensity Scale, the earthquake had an intensity of VI (Very Strong). On April 8, stronger earthquakes occurred in the province.
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The 1914 Burdur earthquake occurred at 00:07 local time (22:07 UTC) on 4 October. It was estimated to be 7.0 on the surface wave magnitude scale with a maximum intensity of IX (Violent) on the Mercalli intensity scale. It was centered near Lake Burdur in southwestern Turkey and the mainshock and subsequent fire destroyed more than 17,000 homes, and caused 2,344 casualties. In Burdur nearly 100 percent of the homes were destroyed along with other significant and historical monuments.
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The 1948 Ashgabat earthquake (; 1948 Aşgabat ýertitremesi; ) occurred on 6 October with a surface wave magnitude of 7.3 and a maximum Mercalli intensity of X (Extreme). The shock occurred in Turkmenistan near Ashgabat. Due to censorship by the Turkmen government, the event was not widely reported in the USSR's media. Historians tend to agree that the ban on reporting the extent of the casualties and damage did not allow the Soviet government to allocate enough financial resources to adequately respond.
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The 1982 El Salvador earthquake occurred southeast of San Salvador on 19 June at 00:21 local time (06:21 UTC). This undersea earthquake struck offshore in the Pacific Ocean and had a surface wave magnitude of 7.2 and a maximum Mercalli intensity of VII (Very strong). Occurring adjacent to a subduction zone at the Middle America Trench, this normal-slip shock left at least 16 and as many as 43 people dead, and many injured, and also inflicted $5 million in damage.
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The area between Greenland and Baffin Island is one of the most seismically active regions in eastern Canada. It was not known as a seismic zone until November 20, 1933, when an earthquake with a surface wave magnitude of 7.3 occurred beneath Baffin Bay. This is the largest instrumentally recorded earthquake to have occurred along the passive margin of North America and possibly the largest passive-margin earthquake worldwide. Coincidentally, it is also the largest north of the Arctic Circle.
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The epicenter was pinpointed to Dawu County in Sichuan. Its official magnitude was 6.8 and its surface wave magnitude reached 6.6. A moderately well controlled focal mechanism indicates that the earthquake was probably a result of left lateral strike-slip faulting on the Daofu fault. The Daofu fault forms part of the Xianshuihe fault system, which experienced a sequence of four earthquakes greater than 6.0 between 1973 and 1982, with each event triggering the next in the sequence by changing the stress state.
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The 1575 Valdivia earthquake occurred at 14:30 local time on December 16. It had an estimated magnitude of 8.5 on the surface wave magnitude scale and led to the flood of Valdivia, Chile. Pedro Mariño de Lobera, who was corregidor of Valdivia by that time, wrote that the waters of the river opened like the Red Sea, one part flowing upstream and one downstream. Mariño de Lobera also evacuated the city until the dam at Laguna de Anigua (nowadays Riñihue Lake) burst.
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The 1951 Kurşunlu earthquake occurred at 18:33 GMT (20:33 local time) on 13 August near Kurşunlu, Çankırı Province, Central Anatolia Region, Turkey. The earthquake was one of a series of major and intermediate quakes that have occurred in modern times along the North Anatolian Fault since 1939. It had a magnitude of 6.9 on the surface wave magnitude scale and a maximum felt intensity of IX (Violent) on the Mercalli intensity scale. There were 50 casualties and 3,354 injuries.
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The earthquake was felt over a wide area from Alexandria in the southwest to Antioch in the north previously damaged by the earthquake of 526. The area of felt intensity of VIII or more extends from Tripoli in the north to Tyre in the south. Estimates for the magnitude vary from 7.2 on the surface wave magnitude scale to a possible 7.5 on the moment magnitude scale. The rupture length is estimated to be greater than and possibly as long as .
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This earthquake was the first tsunami earthquake to be recorded using modern broadband instruments. The initial surface wave magnitude, which uses only waves of a period of 20 seconds, was estimated at 7.0–7.2. The part of the Middle America Trench off Nicaragua contains relatively little sediment, allowing the slip to propagate up-dip all the way to the trench bottom, which tends to generate large tsunamis. The trench sediment here has been subducted and this soft material lies along the plate interface.
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The threads represented prevailing ocean surface wave-crests and directions they took as they approached islands and met other similar wave-crests formed by the ebb and flow of breakers. Individual charts varied so much in form and interpretation that the individual navigator who made the chart was the only person who could fully interpret and use it. The use of stick charts ended after World War II when new electronic technologies made navigation more accessible and travel among islands by canoe lessened.
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The surface wave is also very dependent upon the nature of the ground over which the signal travels. Ground conductivity, terrain roughness and the dielectric constant all affect the signal attenuation. In addition to this the ground penetration varies, becoming greater at lower frequencies, and this means that it is not just the surface conductivity that is of interest. At the higher frequencies this is not of great importance, but at lower frequencies penetration means that ground straight down to 100 meters may have an effect.
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The 1935 Helena earthquake occurred at in Montana, with an epicenter near Helena. It had a magnitude of 6.2 on the surface wave magnitude scale and a maximum perceived intensity of VIII (Severe) on the Mercalli intensity scale. The temblor on that date was the largest of a series of earthquakes that also included a large aftershock on October 31 of magnitude 6.0 and a maximum intensity of VIII. Two people died in the mainshock and two others died as a result of the October 31 aftershock.
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The estimated magnitude of the earthquake as 8.6 on the surface wave magnitude scale, has been taken from modelling of the tsunami. A source area of long by wide with a displacement of is consistent with the observed distribution and degree of flooding. Analysis of the tsunami deposits associated with the 2011 earthquake suggests that the extent of sand deposition in the earlier events underestimated the degree of inundation. A muddy deposit was found to extend half as far again as the sand sheet.
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The proposed device is characterized from a continuously tunable gain spectrum that selectively amplifies mechanical modes from radio frequency to microwave rates. Viewed as Brillouin process, the system accesses a regime in which the phonon plays the role of Stokes wave. Stokes wave refers to a non-linear and periodic surface wave on an inviscid fluid (ideal fluid assumed to have no viscosity) layer of constant mean depth. For this reason it should be also possible to controllably switch between phonon and phonon laser regimes.
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Antennas are usually created by modifying ordinary circuitry into transmission line configurations. The required antenna for any given application is dependent on the bandwidth employed, and range (power) requirements. In the microwave to millimeter-wave range – wavelengths from a few meters to millimeters – the following antennas are usually employed: Dipole antennas, short antennas, parabolic and other reflector antennas, horn antennas, periscope antennas, helical antennas, spiral antennas, surface-wave and leaky wave antennas. Leaky wave antennas include dielectric and dielectric loaded antennas, and the variety of microstrip antennas.
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Ynang Maria: A Celebration of the Blessed Virgin Mary in the Philippines. Edited by Consuelo B. Estepa, Ph.D. Pasig City: Anvil Publishing, Inc, 2004. The original edifice was among the many structures destroyed in the Lady Caycay earthquake, an 8.2 surface wave magnitude tremor which struck Panay Island on 25 January 1948. Pope Pius XII elevated Jaro to an archdiocese on 29 June 1951 via a papal bull, and the cathedral was fully restored by 1956 under José María Cuenco, the first Archbishop of Jaro.
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The magnitude for great earthquakes is often underestimated, at first. The standard teleseismic measure of the ‘size’ of an earthquake is the surface wave magnitude, , which has to be derived by definition from the surface waves with 20 second period. A more reliable and more modern scale is that of the moment magnitude, . Variations of the amplitudes recorded at different seismograph stations are due to many reasons, but the mean magnitude derived from reports by many stations that have recorded the earthquake should be fairly stable.
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The 1895 Quchan earthquake occurred at about 11:30 local time (08:30 UTC) on 17 January. It had an estimated magnitude of 6.8 on the surface wave magnitude scale and a maximum perceived intensity of VIII (Severe) on the Mercalli intensity scale. It caused severe damage in Quchan County, particularly to the town of Quchan itself and there were an estimated 1,000-11,000 casualties. It was the last in a sequence of major damaging earthquakes that struck the area between 1851 and 1895.
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This process applies a load downwards on the test pile. During the loading sequence the load applied to the test pile is monitored by a calibrated load cell incorporated in the base of the combustion piston. Pile settlement is measured using a remote laser reference source that falls on a photovoltaic cell incorporated in the piston. The laser reference source should be placed at least 15 m from the test pile to avoid the influence of test-induced ground surface wave disturbance (Brown & Hyde, 2006).
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13083-13099 and showed the existence of long-range correlations in multiply diffracted seismic wave fields and paved the way for the use of ambient noise for seismic imaging.Campillo, M., & Paul, A., « Long range correlations in the diffuse seismic coda », Science, (2003), 299, p. 547-549 Michel Campillo and Anne Paul have shown the existence of long-range correlations in multiply diffracted seismic wave fieldsNM. Shapiro, M. Campillo, L. Stehly and M. Ritzwoller, « High Resolution Surface-Wave Tomography from Ambient Seismic Noise », Science, (2005), 307, p.
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Some ADCPs can be configured to measure surface wave height and direction. The wave height is estimated with a vertical beam that measures the distance to the surface using the echo from short pulses and simple peak estimation algorithms. The wave direction is found by cross correlating the along-beam velocity estimates and the wave height measurement from the vertical beam. Wave measurements are typically available for seafloor-mounted instruments but recent improvements permit the instrument to be mounted also on rotating subsurface buoys.
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Surface plasmon polaritons (SPPs) are electromagnetic waves that travel along a metal–dielectric or metal–air interface, practically in the infrared or visible-frequency. The term "surface plasmon polariton" explains that the wave involves both charge motion in the metal ("surface plasmon") and electromagnetic waves in the air or dielectric ("polariton"). They are a type of surface wave, guided along the interface in much the same way that light can be guided by an optical fiber. SPPs are shorter in wavelength than the incident light (photons).
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The 2008 Qeshm earthquake occurred on 10 September in the Hormozgān Province of southern Iran, south of Tehran. Its epicenter was near the port city of Bandar Abbas, where an earthquake two years prior had caused damage. The earthquake measured 5.9 on the moment magnitude scale and 6 on the surface wave scale, killing seven people and injuring up to 45. Causing both catastrophic and minor damage, the earthquake devastated up to 200 villages throughout southern Iran, but left the port city of Bandar Abbas almost unscathed.
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The 1976 Bali earthquake occurred at with a surface wave magnitude of 6.5. The shock occurred south of the Bali Sea coast of the Buleleng Regency, and about northwest of Denpasar. Up to ninety percent of houses in Buleleng Regency were seriously damaged or destroyed and the Seririt sub-district was almost completely destroyed, where a school building collapsed and trapped at least 200 students. 573 people are believed to have died; at least 544 in Buleleng Regency, 24 in Jembrana and 5 in Tabanan.
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Earthquakes M5.5+ around Japan (1900–2016) M7.0–7.9=163 EQs, M8.0+=14 EQs.USGS Earthquake Catalog Search This is a list of earthquakes in Japan with either a magnitude greater than or equal to 7.0 or which caused significant damage or casualties. As indicated below, magnitude is measured on the Richter magnitude scale (ML) or the moment magnitude scale (Mw), or the surface wave magnitude scale (Ms) for very old earthquakes. The present list is not exhaustive, and reliable and precise magnitude data is scarce for earthquakes that occurred before the development of modern measuring instruments.
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The struck the former Japanese provinces of Mino and Owari (present-day Gifu Prefecture) in the Nōbi Plain in the early morning of October 28 with a surface wave magnitude of 8.0. The event, also referred to as the , the , or the , is the strongest known inland earthquake to have occurred in the Japanese archipelago. The earthquake came at a time when Japan was undergoing a transformation into a more industrial nation and while advancing its scientific understanding in many fields. Damage from the event was widespread and the loss of life was significant.
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The 1949 Queen Charlotte Islands earthquake was caused by a rupture on the Queen Charlotte Fault, which forms part of the boundary between the Pacific and North American plates. This fault runs from northern Vancouver Island, west of the Queen Charlotte Islands, up to the Gulf of Alaska. The earthquake ruptured the fault for a distance more than . Because this quake occurred before the modern surface wave magnitude scale was developed and widely implemented, this earthquake may have only had the same overall intensity as the 2012 Haida Gwaii earthquake.
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In many cases one cannot simply say that a field is or is not evanescent. For instance, in the above illustration, energy is indeed transmitted in the horizontal direction. The field strength drops off exponentially away from the surface, leaving it concentrated in a region very close to the interface, for which reason this is referred to as a surface wave. However, there is no propagation of energy away from (or toward) the surface (in the z direction), so that one could properly describe the field as being "evanescent in the z direction".
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The 1605 Nankai earthquake occurred at about 20:00 local time on 3 February. It had an estimated magnitude of 7.9 on the surface wave magnitude scale and triggered a devastating tsunami that resulted in thousands of deaths in the Nankai and Tōkai regions of Japan. It is uncertain whether there were two separate earthquakes separated by a short time interval or a single event. It is referred to as a tsunami earthquake, in that the size of the tsunami greatly exceeds that expected from the magnitude of the earthquake.
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Iran experiences regular earthquakes, with 200 reported in 1996 alone. Like dozens that had preceded it, the 1997 Qayen event was of significant magnitude. It occurred on Saturday, May 10, 1997 at 12:57 IRST in the Sistan region, one of the most seismically active areas of the country. The first major earthquake in that region since 1979, it registered 7.3 on the moment magnitude scale (), 7.2 on the surface wave magnitude scale (), 7.7 on the energy magnitude scale (Me), and had a maximum perceived intensity of X, or Extreme on the Mercalli intensity scale.
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The "g" subscript refers to the granitic layer through which Lg waves propagate. . See also J. R. Kayal, "Seismic Waves and Earthquake Location", here, page 5. a complex form of the Love wave which, although a surface wave, he found provided a result more closely related to the scale than the scale.. Lg waves attenuate quickly along any oceanic path, but propagate well through the granitic continental crust, and MbLg is often used in areas of stable continental crust; it is especially useful for detecting underground nuclear explosions..
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Key Monastery and the Spiti Valley, seriously affected by the Kinnaur earthquake The 1975 Kinnaur earthquake occurred in the early afternoon (local time) (08:02 UTC) of 19 January. It had a magnitude of 6.8 on the surface wave magnitude scale and a maximum perceived intensity of IX (Violent) on the Mercalli intensity scale, causing extensive damage in Himachal Pradesh, in northern India. Its epicentre was in Kinnaur district in the southeastern part of Himachal Pradesh and caused 47 casualties. Landslides, rock falls and avalanches caused major damage to the Hindustan-Tibet Road.
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First, AMC or HIS surfaces are designed to have an allotted set of frequencies over which electromagnetic surface waves and currents will not be allowed to propagate. These materials are then both beneficial and practical as antenna ground planes, small flat signal processing filters, or filters as part of waveguide structures. For example, AMC surfaces as antenna ground planes are able to effectively attenuate undesirable wave fluctuations, or undulations, while producing good radiation patterns. This is because the material can suppress surface wave propagation within the prescribed range of forbidden frequencies.
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The 1897 Mindanao earthquakes occurred on 20 September at 19:06 UTC and 21 September at 05:12 UTC. The estimated epicentres of the two earthquakes are identical, lying just off the southwestern coast of Mindanao in the Philippines, south of Basilan island. The earthquakes were originally given estimated magnitudes of 8.6 and 8.7 on the surface wave magnitude scale by Charles Richter, but these were revised downwards by Katsuyuki Abe to 7.4 and 7.5 , respectively. Contemporary reports noted that with few exceptions, all the masonry buildings in Zamboanga and Basilan were left in ruins.
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A lineatus and other surface wave detecting fish have a limited range in which they can detect surface waves. The ratio of source distance/swim distance ranges between 0.84 and 1.20, and the means range from 0.98 to 1.07. This translates to an accuracy of 85% or higher when stimuli are 6–19 cm from the fish, decreasing to 76% at 14 cm. As the wave source gets farther from a fish, the fish's ability to accurately determine distance decreases until it can no longer detect the waves.
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Guyots show evidence of having once been above the surface, with gradual subsidence through stages from fringed reefed mountain, coral atoll, and finally a flat-topped submerged mountain. Seamounts are made by extrusion of lavas piped upward in stages from sources within the Earth's mantle, usually hotspots, to vents on the seafloor. The volcanism invariably ceases after a time, and other processes dominate. When an undersea volcano grows high enough to be near or breach the ocean surface, wave action and/or coral reef growth tend to create a flat-topped edifice.
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The Kythira Strait, located within the Western Hellenic arc, is subject to submergence on account of normal faulting which results in "extensional deformation and rotation" between two major segments of the external arc. According to Papadopoulos and Kijko, the Western Hellenic arc has high seismic activity, resulting in deformations in the strait which are active. Here the "seismic slip" recorded is on the order of 0.3 cm/year. Also reported in the strait are earthquakes at shallow and intermediate depths, with surface-wave magnitudes of up to 8.0.
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Operation of SAW devices is based on the transformation of the initial electric signal into a surface wave that, after achieving the required changes to the spectrum of the initial electric signal as a result of its interaction with different types of surface inhomogeneity, is transformed back into a modified electric signal. The transformation of the initial electric energy into mechanical energy (in the form of SAW) and back is usually accomplished via the use of piezoelectric materials for both generation and reception of Rayleigh waves as well as for their propagation.
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Incoming wave (red) reflected at the wall produces the outgoing wave (blue), both being overlaid resulting in the clapotis (black). In hydrodynamics, a clapotis (from French for "lapping of water") is a non-breaking standing wave pattern, caused for example, by the reflection of a traveling surface wave train from a near vertical shoreline like a breakwater, seawall or steep cliff. The resulting clapotic wave does not travel horizontally, but has a fixed pattern of nodes and antinodes. These waves promote erosion at the toe of the wall, and can cause severe damage to shore structures.
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The Luzon earthquake occurred on Monday, July 16, 1990, at 4:26 PM local time in the Philippines. The densely populated island of Luzon was struck by an earthquake with a 7.8 Ms (surface-wave magnitude). The earthquake produced a 125 km-long ground rupture that stretched from Dingalan, Aurora to Cuyapo, Nueva Ecija as a result of strike-slip movements along the Philippine Fault and the Digdig Fault within the Philippine Fault System. The earthquake epicenter was placed at 15° 42' N and 121° 7' E near the town of Rizal, Nueva Ecija, northeast of Cabanatuan City.
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These tsunami earthquakes are dangerous because most of the energy release happens at lower frequencies than normal earthquakes and they lack the peaks of seismic wave activity that would alert coastal populations to a possible tsunami risk. Typically the surface wave magnitude for such an event is much smaller than moment magnitude as the former does not capture the longer wavelength energy release. The 1896 Sanriku earthquake went almost unnoticed, but the associated tsunami killed more than 22,000 people. Extremely slow ruptures take place on a time scale of hours to weeks, giving rise to slow earthquakes.
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The 1968 Inangahua earthquake struck west of Murchison, New Zealand, near the small town of Inangahua Junction at 5:24 am NZDT on 24 May 1968. The earthquake had a moment magnitude of 7.1, a local magnitude of 6.7, a surface wave magnitude of 7.4 and a maximum Mercalli intensity of X (Very Destructive). It occurred at a depth of , being extremely shallow for an earthquake of its size. It resulted in the deaths of three people, with a further 14 people injured, making it the fifth deadliest earthquake in New Zealand's recorded history (tied with the 1848 Marlborough earthquake).
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Hindcasting usually refers to a numerical-model integration of a historical period where no observations have been assimilated. This distinguishes a hindcast run from a reanalysis. Oceanographic observations of salinity and temperature as well as observations of surface-wave parameters such as the significant wave height are much scarcer than meteorological observations, making hindcasting more common in oceanography than in meteorology. Also, since surface waves represent a forced system where the wind is the only generating force, wave hindcasting is often considered adequate for generating a reasonable representation of the wave climate with little need for a full reanalysis.
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However, above a certain cutoff frequency, transverse electric (TE) or transverse magnetic (TM) modes can also propagate, as they do in a hollow waveguide. It is usually undesirable to transmit signals above the cutoff frequency, since it may cause multiple modes with different phase velocities to propagate, interfering with each other. The outer diameter is roughly inversely proportional to the cutoff frequency. A propagating surface-wave mode that does not involve or require the outer shield but only a single central conductor also exists in coax but this mode is effectively suppressed in coax of conventional geometry and common impedance.
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Tectonic map of the Anatolian Plate showing the main fault zones. The Yenice–Gönen Fault is the southernmost splay at the western end of the 260px The 1953 Yenice–Gönen earthquake occurred at 21:06 local time (19:06 UTC on 18 March in the province of Çanakkale and Balıkesir in the Marmara Region at western Turkey. It had a magnitude 7.5 on the surface wave magnitude scale and a maximum felt intensity of IX (Violent) on the Mercalli intensity scale. It caused widespread damage, killing 1,070 and causing damage that was estimated at US$3,570,000 repair value.
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The 1989 Ungava earthquake occurred at 09:24 local time (14:24 UTC) on 25 December to the north of Lac Bécard in a remote part of the Ungava Peninsula in northern Quebec. It had a magnitude of 6.3 on the surface wave magnitude scale and 6.2–6.5 on the moment magnitude scale and a maximum felt intensity of only IV (Light) on the Mercalli intensity scale, due to its remoteness from any inhabited areas. The mainshock was preceded by a magnitude 5.1 foreshock ten hours earlier. It was the first earthquake in eastern North America known to be associated with ground rupture.
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In 1946, the Government of Canada, through an Order in Council, granted the Department of National Defence the power to administer and maintain facilities to collect data for communications research. The Royal Canadian Navy was allotted forty positions, seven of which were in Prince Rupert. In either 1948 or 1949, Prince Rupert ceased operations, and the positions were relocated to RCAF Whitehorse, Yukon. The 1949 Queen Charlotte earthquake, with a surface wave magnitude of 8.1 and a maximum Mercalli intensity of VIII (Severe), broke windows and swayed buildings on August 22. In Summer 1958, Prince Rupert endured a riot over racial discrimination.
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EMATs are suitable to generate all kinds of waves in metallic and/or magnetostrictive materials. Depending on the design and orientation of coils and magnets, shear horizontal (SH) bulk wave mode (norm-beam or angle-beam), surface wave, plate waves such as SH and Lamb waves, and all sorts of other bulk and guided-wave modes can be excited.R.B. Thompson, Physical Principles of Measurements with EMAT Transducers,Ultrasonic Measurement Methods, Physical Acoustics Vol XIX, Edited by R.N. Thurston and Allan D. Pierce, Academic Press, 1990B.W. Maxfield, A. Kuramoto, and J.K. Hulbert, Evaluating EMAT Designs for Selected Applications, Mater. Eval.
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Rayleigh waves are much slower than body waves, at roughly 90% of the velocity of for a typical homogeneous elastic medium. Rayleigh waves have energy losses only in two dimensions and are hence more destructive in earthquakes than conventional bulk waves, such as P-waves and S-waves, which lose energy in all three directions. A Love wave is a surface wave having horizontal waves that are shear or transverse to the direction of propagation. They usually travel slightly faster than Rayleigh waves, at about 90% of the body wave velocity, and have the largest amplitude.
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Georg von Békésy (, ; born in Budapest, Hungary on 3 June 1899 – 13 June 1972) was a Hungarian biophysicist. By using strobe photography and silver flakes as a marker, he was able to observe that the basilar membrane moves like a surface wave when stimulated by sound. Because of the structure of the cochlea and the basilar membrane, different frequencies of sound cause the maximum amplitudes of the waves to occur at different places on the basilar membrane along the coil of the cochlea. High frequencies cause more vibration at the base of the cochlea while low frequencies create more vibration at the apex.
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Békésy contributed most notably to our understanding of the mechanism by which sound frequencies are registered in the inner ear. He developed a method for dissecting the inner ear of human cadavers while leaving the cochlea partly intact. By using strobe photography and silver flakes as a marker, he was able to observe that the basilar membrane moves like a surface wave when stimulated by sound. Because of the structure of the cochlea and the basilar membrane, different frequencies of sound cause the maximum amplitudes of the waves to occur at different places on the basilar membrane along the coil of the cochlea.
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Conversely, the operator knew the characteristics of groups of transmissions which were being followed as commitments and tended to search for these frequencies, or signals of those types. This enabled loopholes in the search procedures to be created. An example of a loophole was when an Oslo transmission continued for a whole year, without being reported by any Funkabwehr station, although the intercept station in Oslo was with the surface wave of the transmitter. The transmission used procedure which was unlike that of the usual clandestine groups covered, and so was ignored by the search operation.
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The operating principle of the Ocean Grazer wave energy converter is to store potential energy by creating a hydraulic head, due to the differences in pressure between two reservoirs. All three concepts rely on this principle to function. The hydraulic head is created by circulating internal fluid from the lower to the upper reservoir via a novel hydro-mechanical power take off system, composed of distributed and coupled floaters. Each floater is linked to a separate multi-piston pumping system, consisting of differently sized pistons that regulate the amount of pumped fluid and that can be adapted to the surface wave conditions.
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Merchant ship labouring in heavy seas as a huge wave looms astern In fluid dynamics, the wave height of a surface wave is the difference between the elevations of a crest and a neighbouring trough. Wave height is a term used by mariners, as well as in coastal, ocean and naval engineering. At sea, the term significant wave height is used as a means to introduce a well-defined and standardized statistic to denote the characteristic height of the random waves in a sea state. It is defined in such a way that it more or less corresponds to what a mariner observes when estimating visually the average wave height.
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The earthquake lasted between 25 and 30 seconds and had an estimated magnitude of 6.75 on the surface wave magnitude scale. The calculated focal mechanism is consistent with slightly oblique dextral (right lateral) strike-slip on a NW-SE trending fault plane, matching the orientation of other fault planes measured in the area and a marked bathymetric lineament. The fault parameters calculated for the earthquake are a length of 30 km, a width of 27 km and a slip of one metre. The NW trending nodal plane of this earthquake coincides with the strike of the NW trending Naqara Fault on the southeast coast of Viti Levu.
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The middle legs used for rowing have particularly well developed fringe hairs on the tibia and tarsus to help increase movement through the ability to thrust. The hind pair of legs are used for steering When the rowing stroke begins, the middle tarsi of gerrids are quickly pressed down and backwards to create a circular surface wave in which the crest can be used to propel a forward thrust. The semicircular wave created is essential to the ability of the water strider to move rapidly since it acts as a counteracting force to push against. As a result, water striders often move at 1 meter per second or faster.
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The city hall Folklore museum (Kyriakou mansion) The archaeological museum In independent Greece, Kalamata was rebuilt and became one of the most important ports in the Mediterranean sea. It is not surprising that the second-oldest Chamber of Commerce in the Mediterranean, after that of Marseille, exists in Kalamata. During World War II on 29 April 1941, a battle was fought near the port between the invading German forces and the 2nd New Zealand Division, for which Jack Hinton was later awarded the Victoria Cross. Kalamata was again in the news on 13 September 1986, when it was hit by an earthquake that measured 6.2 on the surface wave magnitude scale.
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Capillary wave ripples on Lifjord in Øksnes, Norway The ripples which surface-feeding fish detect are known more technically as capillary waves. Capillary waves are generated by movement of an object at the surface of the water or from the brief contact of an object with the surface from either medium (air or water). Waves radiate outward in concentric circles from the source, and the waveform of each train of waves changes in very specific and predictable waves, as dictated by surface tension and gravity.Bleckmann H, and Kase R. H. (1987) "Prey localization by surface wave ray-tracing: fish track bugs like oceanographers track storms".
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Xenopus has approximately 200 lateral-line organs located along the sides of its body, and also around its eyes, head and neck. It is claimed these are used to navigate and detect prey either striking the water or struggling but the role of these organs in surface wave detection is not entirely clear; Xenopus with all of their lateral line organs destroyed are still able to respond to surface waves in an oriented fashion. Compared to animals with an intact system they respond somewhat less accurately to anterior stimuli and much less accurately to stimuli from behind. Areas of the Xenopus brain responding to surface waves have been identified.
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The Richter and MMS scales measure the energy released by an earthquake; another scale, the Mercalli intensity scale, classifies earthquakes by their effects, from detectable by instruments but not noticeable, to catastrophic. The energy and effects are not necessarily strongly correlated; a shallow earthquake in a populated area with soil of certain types can be far more intense in effects than a much more energetic deep earthquake in an isolated area. Several scales have historically been described as the "Richter scale", especially the local magnitude and the surface wave scale. In addition, the body wave magnitude, , and the moment magnitude, , abbreviated MMS, have been widely used for decades.
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This type of radar, surface-wave OTH, is used for surveillance, and operates most commonly between 4 and 20 MHz. Lower frequencies enjoy better propagation but poorer radar reflection from small targets, so there is usually an optimum frequency that depends on the type of target. A different approach to over-the-horizon radar is to use creeping waves or electromagnetic surface waves at much lower frequencies. Creeping waves are the scattering into the rear of an object due to diffraction, which is the reason both ears can hear a sound on one side of the head, for instance, and was how early communication and broadcast radio was accomplished.
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Siting the antenna on a high mountain can increase the range somewhat; but, in general, it is impractical to build radar systems with line-of-sight ranges beyond a few hundred kilometres. OTH radars use various techniques to see beyond that limit. Two techniques are most commonly used; shortwave systems that refract their signals off the ionosphere for very long-range detection, and surface wave systems, which use low frequency radio waves that, due to diffraction, follow the curvature of the Earth to reach beyond the horizon. These systems achieve detection ranges of the order of a hundred kilometres from small, conventional radar installations.
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In general understanding, the physics of wave dissipation can be categorized by considering with its dissipation sources, such as 1) wave breaking 2) wave–turbulence interaction 3) wave–wave modulation respectively. (descriptions below of this chapter also follow the reference ) 1) dissipation by "wave breaking" Wind-wave breaking at coastal area is a major source of the wind-wave dissipation. The wind waves lose their energy to the shore or sometimes back to the ocean when those break at the shore. (see more explains -> “Ocean surface wave breaking”) 2) dissipation by "wave–turbulence interaction" The turbulent wind flows and viscous eddies inside waves can both affect wave dissipation.
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The 1766 Istanbul earthquake was a strong earthquake with epicenter in the eastern part of the Sea of Marmara, in the Çınarcık Basin (or near the Princes' Islands, north of the basin) which occurred in the early hours of Thursday morning, 22 May 1766. The earthquake had an estimated magnitude of 7.1 on the surface wave magnitude scale, and caused effects in a vast area extending from Izmit to Tekirdağ. In this area, the earthquake was followed by a tsunami which caused significant damage. The earthquake of 1766 was the last major earthquake to rock Istanbul because of a rupture of the North Anatolian Fault in the Marmara region.
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In certain circumstances, waves of unchanging shape also can occur in nonlinear media; for example, the figure shows ocean waves in shallow water that have sharper crests and flatter troughs than those of a sinusoid, typical of a cnoidal wave, a traveling wave so named because it is described by the Jacobi elliptic function of m-th order, usually denoted as . Large-amplitude ocean waves with certain shapes can propagate unchanged, because of properties of the nonlinear surface-wave medium. Wavelength of a periodic but non-sinusoidal waveform. If a traveling wave has a fixed shape that repeats in space or in time, it is a periodic wave.
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Most of the casualties and damage were caused by a tsunami affecting the west coasts of Nicaragua and Costa Rica, and it was one of three tsunamis to occur within a span of six months. Runup heights were measured shortly after the earthquake and reached heights of up to 9.9 meters, though the average height was 3 to 8 meters. The tsunami was disproportionately large for its surface wave magnitude, or , and the duration of the rupture process was 100 s, unusually long for its size. The moment magnitude was 7.6, larger than the 20-s of 7; this – difference is a characteristic of tsunami earthquakes.
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Seasat carried five major instruments designed to return the maximum information from ocean surfaces: # Radar altimeter to measure spacecraft height above the ocean surface # Microwave scatterometer to measure wind speed and direction # Scanning multichannel microwave radiometer to measure sea surface temperature # Visible and infrared radiometer to identify cloud, land and water features # Synthetic aperture radar (SAR) L-band, HH polarization, fixed look angle to monitor the global surface wave field and polar sea ice conditions {the antenna is the light parallelogram in the picture}. The SAR support structure was designed and manufactured by Northrop Grumman Astro Aerospace in Carpinteria, California. The structure deployed on orbit. Many later remote sensing missions benefited from Seasat's legacy.
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The surface plasmon polariton is a non- radiative electromagnetic surface wave that propagates in a direction parallel to the negative permittivity/dielectric material interface. Since the wave is on the boundary of the conductor and the external medium (air, water or vacuum for example), these oscillations are very sensitive to any change of this boundary, such as the adsorption of molecules to the conducting surface. To describe the existence and properties of surface plasmon polaritons, one can choose from various models (quantum theory, Drude model, etc.). The simplest way to approach the problem is to treat each material as a homogeneous continuum, described by a frequency-dependent relative permittivity between the external medium and the surface.
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Corum, K. L., and J. F. Corum, "The Zenneck surface wave", Nikola Tesla, Lightning Observations, and stationary waves, Appendix II. 1994. In the development of modern physics, Alexandru Proca (1897-1955) was known for developing relativistic quantum field equations bearing his name (Proca's equations) which apply to the massive vector spin-1 mesons. In recent decades some other theorists, such as Jean-Pierre Vigier and Bo Lehnert of the Swedish Royal Society, have used the Proca equation in an attempt to demonstrate photon mass as a longitudinal electromagnetic component of Maxwell's equations, suggesting that longitudinal electromagnetic waves could exist in a Dirac polarized vacuum. However photon rest mass is strongly doubted by most physicists.
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The sequence of events in 1759 began on October 30, with the smaller of the two severe main shocks that year, causing the deaths of 2000 people in Safed and other settlements. This initial event was estimated at 6.6 on the surface wave magnitude scale and given a rating of VIII (Severe) to IX (Violent) on the Mercalli intensity scale. This was followed by a more significant earthquake (7.4 and IX) on November 25 that destroyed all the villages in the Beqaa Valley. The areas that experienced damage were roughly the same for both the thirteenth and eighteenth-century earthquakes, with the cities of Nablus, Acre, Tyre, Tripoli and Hama being affected.
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Further, the family of such scans is given depending on the values of FN and N (measurements were carried out at six marked points). It is clearly seen that the influence of the anisotropy of the local properties of the metal is detected at FN=100 and 200 H after N=50,000 cycles. alt= Figure 7, a shows photographs of residual surface wave-like damage in the vicinity of the shaft roller track. In the case when the roller and shaft are made of the same steel and have the same surface properties, residual wave-like damages under certain test conditions are formed on the working surfaces of both elements simultaneously (see Figure 7, b).
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Unlike the NNIIRT, this design bureau focused on higher frequency radars like the P-20, P-30, P-30M, P-35, P-32D2 and the P-50 (NATO: E/F-bands). These radars have better accuracy and faster scan rates, and are thus more suited for ground control of fighter aircraft, which complement the lower frequency radars developed by the NNIIRT design bureau. NNIDAR has in recent years expanded their product range to include innovative radar designs like the Podsolnukh-E over-the-horizon (OTH) surface-wave radar and the 29B6 Konteyner. The latter, while also being an OTH-radar, has separate locations for the transmitter and the receiver making it a bi-static system.
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E-field of a surface plasmon polariton at an silver–air interface, at a frequency corresponding to a free-space wavelength of 10μm. At this frequency, the silver behaves approximately as a perfect electric conductor, and the SPP is called a Sommerfeld–Zenneck wave, with almost the same wavelength as the free-space wavelength. The surface plasmon polariton (SPP) is an electromagnetic surface wave that can travel along an interface between two media with different dielectric constants. It exists under the condition that the permittivity of one of the materials forming the interface is negative, while the other one is positive, as is the case for the interface between air and a lossy conducting medium below the plasma frequency.
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When the 1989 World Series began, it was notable chiefly for being the first ever World Series matchup between the two San Francisco Bay Area teams, the San Francisco Giants and Oakland Athletics. Oakland won the first two games at home, and the two teams crossed the bridge to San Francisco to play Game 3 on Tuesday, October 17. ABC's broadcast of Game 3 began at 5 pm local time, approximately 30 minutes before the first pitch was scheduled. At 5:04, while broadcasters Al Michaels and Tim McCarver were narrating highlights and the teams were warming up, the Loma Prieta earthquake occurred (having a surface-wave magnitude of 7.1 with an epicenter ten miles (16 km) northeast of Santa Cruz, California).
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The distinguishing feature for a tsunami earthquake is that the release of seismic energy occurs at long periods (low frequencies) relative to typical tsunamigenic earthquakes. Earthquakes of this type do not generally show the peaks of seismic wave activity associated with ordinary events. A tsunami earthquake can be defined as an undersea earthquake for which the surface wave magnitude Ms differs markedly from the moment magnitude Mw, because the former is calculated from surface waves with a period of about 20 seconds, whereas the latter is a measure of the total energy release at all frequencies. The displacements associated with tsunami earthquakes are consistently greater than those associated with ordinary tsunamigenic earthquakes of the same moment magnitude, typically more than double.
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In May 2008 Cyclone Nargis sent a storm surge 40 kilometers up Myanmar's densely populated Irrawaddy river delta, causing catastrophic destruction and at least 138,000 fatalities. It was the worst natural disaster in the country's history, with allegations that government officials stopped updating the death toll after 138,000 to minimize political fallout. Relief efforts were slowed for political reasons as Myanmar's military rulers initially resisted large-scale international aid. Hampering the relief efforts, only ten days after the cyclone, nearby central China was hit by a massive earthquake, known as the Sichuan earthquake. The powerful earthquake in Sichuan Province in May 2008 measured 8.0 Mw (surface wave magnitude), killing more than 69,000 people and leaving some 4.8 million people homeless, though the number may have been as high as 11 million.
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The Spectral-Analysis-of-Surface-Waves (SASW) method is another non-invasive technique, which is widely used in practice to image the shear wave velocity profile of the soil. The SASW method relies on the dispersive nature of Raleigh waves in layered media, i.e., the wave-velocity depends on the load's frequency. A material profile, based on the SASW method, is thus obtained according to: a) constructing an experimental dispersion curve, by performing field experiments, each time using a different loading frequency, and measuring the surface wave-speed for each frequency; b) constructing a theoretical dispersion curve, by assuming a trial distribution for the material properties of a layered profile; c) varying the material properties of the layered profile, and repeating the previous step, until a match between the experimental dispersion curve, and the theoretical dispersion curve is attained.
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The other is continuous wave stimuli, which will contain many frequencies and in the wild are generated by fallen prey struggling at the water surface. It has been pointed out that A lineatus and other surface feeding fish are able to locate prey even if the waveform is only in click form (just touching the surface once, as when surfacing for air or when a mosquito larva is hatching), which takes less time to complete than the fish will take to swim over.Lang, H.H. (1980a) Surface wave discrimination between prey and nonprey by the back swimmer Notonecta glauca L. (Hemiptera, Heteroptera). Behavioral Ecology and Sociobiology 6:233-246, cited in Bleckmann, H, and Schwartz, E. (1982) "The functional significance of frequency modulation within a wave train for prey localization in the surface- feeding fish Aplocheilus lineatus".
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The authors of the study conclude that if the 464 BC event took place along the fault whose scarp they identified, its magnitude would have been approximately 7.2 on the surface wave magnitude scale. Due to the lack of proper infrastructure and seismic engineering knowledge during this time casualties were originally thought to be very high with some contemporary sources believing the death toll to be around 20,000. However, modern scholars believe this might be an exaggeration due to the fact that at the time the city was relatively small and spread out, with most buildings being one floor and constructed from wood or sun-baked brick making it hard to believe that casualties could have been so high. The lack of detailed population records, coupled with flight of survivors to other areas, may have contributed to the uncertainty, as it can today.
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However, there is no evidence of a neural circuit that performs this calculation, and other researchers suggest that the distance between any pair of surface wave neuromasts is too small (A lineatus's head is only 1 cm wide) for the calculation to be made accurately, and then at distances from the stimulus less than 7 cm.Bleckmann, H, and Schwartz, E. (1982) "The functional significance of frequency modulation within a wave train for prey localization in the surface-feeding fish Aplocheilus lineatus". Journal of Comparative Physiology 145: 331-339 The accuracy predicted by a time- difference mechanism (using triangulation of the wave source based on curvature of wave front) doesn't match actual accuracy. Additionally it has been shown that if all neuromasts are removed except for one, direction detection still occurs to some degree,Müller, U. (1981) "Der Einflulb einzelner Neuromasten des Seitenliniensystems auf die Lokalisationsleistung des Streifenhechtlings Aplocheilus Lineatus".
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This causes a variation in the tidal force and theoretical amplitude of about ±18% for the Moon and ±5% for the Sun. If both the Sun and Moon were at their closest positions and aligned at new moon, the theoretical amplitude would reach . Real amplitudes differ considerably, not only because of depth variations and continental obstacles, but also because wave propagation across the ocean has a natural period of the same order of magnitude as the rotation period: if there were no land masses, it would take about 30 hours for a long wavelength surface wave to propagate along the Equator halfway around the Earth (by comparison, the Earth's lithosphere has a natural period of about 57 minutes). Earth tides, which raise and lower the bottom of the ocean, and the tide's own gravitational self attraction are both significant and further complicate the ocean's response to tidal forces.
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The meizoseismal areas of both of these Jordan Rift Valley events were along a north–south line near the fault zone. Several other previous events occurred in the same region, and by comparison both the 1202 Syria earthquake and the Near East earthquakes of 1759 had larger magnitudes than the 1837 event and have been associated with the Yammouneh fault in Lebanon. However, no other earthquakes of similar size occurred in the Dead Sea zone after seismometers began being used around the turn of the twentieth century, so Nicholas Ambraseys mapped the intensity values reported from more than 120 locations within the affected area and used the values to create a relationship with a group of 158 earthquakes in nearby Turkey and northern Syria with known intensities and magnitudes to predict the surface wave magnitude for this event. The average radius of the isoseismals in the area helped to estimate a magnitude of 7.0 to 7.1 for the event.
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Professor Jeff Collins (22 April 1930 – 23 September 2015) was a British electrical engineer who directed and researched experimental physics, robotics, microelectronics, communications technologies and parallel computing. Moving between academia, commercial and military research throughout his diverse career, he proved to be an enthusiastic leader demonstrated in his numerous directorships, successful fund-raising and his recreational interests of sports. Institutions he worked for included Automation & Robotics Research Institute at the University of Texas at Arlington, Rockwell International, University of Edinburgh, University of Glasgow, GEC, Ferranti, Hansen Experimental Physics Laboratory at Stanford University, Wolfson Microelectronics Institute, Advent Technology Venture Capital Group, Artemis Intelligent Power, Lothian Regional Council and Edinburgh Napier University. He contributed to many academic papers, such as Surface Wave Transducers and Microwave magnetostatics In the 1970s and 80s working for University of Edinburgh he secured funding for Surface acoustic wave devices research and then used them in a Skynet (satellite) receiver which achieved faster synchronisation.
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The Sommerfeld–Zenneck wave or Zenneck wave is a non-radiative guided electromagnetic wave that is supported by a planar or spherical interface between two homogeneous media having different dielectric constants. This surface wave propagates parallel to the interface and decays exponentially vertical to it, a property known as evanescence. It exists under the condition that the permittivity of one of the materials forming the interface is negative, while the other one is positive, as for example the interface between air and a lossy conducting medium such as the terrestrial transmission line, below the plasma frequency. Its electric field strength falls off at a rate of e-αd/√d in the direction of propagation along the interface due to two-dimensional geometrical field spreading at a rate of 1/√d, in combination with a frequency-dependent exponential attenuation (α), which is the terrestrial transmission line dissipation, where α depends on the medium’s conductivity.
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A tsunami surge of occurred near Pameungpeuk (2008 image) Tsunami earthquakes can be influenced by both the presence of (and lack of) sediment at the subduction zone, and can be categorized as either aftershocks of megathrust earthquakes, like the M7 June 22, 1932 Cuyutlán event in Mexico, or as standalone events that occur near the upper portion of a plate interface. Northwestern University professor Emile Okal imparts that in the aftershock scenario, they can occur as a result of stress transfer from a mainshock to an accretionary wedge or a similar environment with "deficient mechanical properties", and as standalone events they can occur in the presence of irregular contacts at the plate interface in a zone that lacks sediment. One of the initial characterizations of tsunami earthquakes came from seismologist Hiroo Kanamori in the early 1970s, and additional clarity materialized following the 1992 Nicaragua earthquake and tsunami, which was evaluated to have a surface wave magnitude of 7.0 when analyzing short period seismic signals. When longer period signals of around 250 seconds were investigated, the shock was reevaluated to have a moment magnitude of 7.6, with a hypothesis that the slow nature of the slip of the event may have concealed its substantial extent.
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