This extinction is thought to have been caused by a period of unstable climate called the Carnian Pluvial Episode (CPE), in which the climate went from dry, to wet, to dry again four times over the course of 2m years.
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The upshot was that Dr Bernardi and his colleagues were able to establish accurate dates for the various ichno-associations they had catalogued, confirming, as they had suspected, that those associations precisely straddle the Carnian Pluvial Episode, thus matching the bone evidence from South America.
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This is what Wing's team found: The analysis shows that 40.8 million people (13.3% of the population) are currently exposed to a 1 in 23 year (1% annual exceedance probability) fluvial or pluvial flood in the [conterminous United States], which translates to a GDP exposure of $2.9 trillion (15.3% of total GDP).
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The Carnian Pluvial Event is sometimes called the Carnian Pluvial Episode and is also known as Reingrabener Wende (meaning Reingrabener turnover), or "Raibl event".
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Pleistocene pluvial lakes and rivers of the Mojave Desert Pluvial Lake Manix sediments (Pleistocene) in the Mojave Desert near Barstow, California. Ice Age pluvial lakes in the western United States A pluvial lake is a body of water that accumulated in a basin because of a greater moisture availability resulting from changes in temperature and/or precipitation. These intervals of greater moisture availability are not always contemporaneous with glacial periods. Pluvial lakes are typically closed lakes that occupied endorheic basins.
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With increased rainfall, the playa lakes enlarged and overflowed. Pluvial lakes were most extensive during glacial periods. During interglacial stages, with less rain, the pluvial lakes shrank to form small salt flats.
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Its natural habitats are very humid premontane and pluvial premontane forests.
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The Battle of the Frigidus was fought near the river, which was named Frigidus ('cold') by the Romans. It has the pluvial-nival regime in its upper course and the pluvial regime in its lower course.
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50,000 to 30,000 years ago), the Abbassia Pluvial brought wet and fertile conditions to what is now the Sahara Desert, which bloomed with lush vegetation fed by lakes, swamps, and river systems, many of which later disappeared in the drier climate that followed the pluvial. African wildlife that is now associated with the grasslands and woodlands south of the Sahara penetrated the entire North African region during the Abbassia Pluvial. Stone Age cultures (notably the Mousterian and the Aterian industries) flourished in North Africa during the Abbassia Pluvial. The shift to harsher climate conditions that came with the end of the pluvial may have promoted the emigration of modern Homo sapiens out of Africa to the rest of the globe.
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El Elegante contained a lake during the pluvial period preceding the last altithermal period.
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Also notably, there was a heightened rate of extinction during the Carnian Pluvial Event.
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This increased erosion at higher elevations with the introduction of alpine glaciers while mid-elevations were attacked by frost wedging and lower areas by more vigorous stream scouring. Pluvial lakes also formed during this time. Glaciers and pluvial lakes disappeared and the climate warmed and became drier with the start of Holocene epoch.
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The Tidal Mill of Corroios () is a 15th-century pluvial mill situated in the civil parish of Corroios, municipality of Seixal.
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Pluvial lakes that have since evaporated and dried out may also be referred to as paleolakes.Goudie, A.S., 2013. and semi-arid geomorphology. Cambridge University Press.
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This putative climatic event is called the "Carnian Pluvial Event", its age being between latest early Carnian (Julian) and the beginning of late Carnian (Tuvalian).
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Few, if any, Mousterian or Aterian tool makers survived in North Africa to witness them. Some older descriptions of the Mousterian Pluvial described it as a strong African Humid period.
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However, as the climate became drier, these large lakes shrank away. Goose Lake, Harney Lake, Malheur Lake, Summer Lake, Lake Abert, and the Warner Lakes are remnants of ancient pluvial lakes.
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Lower latitudes have even experienced major pluvials in early to mid-Holocene times. In geomorphology, pluvial refers to a geologic episode, change, process, deposit, or feature that is the result of the action or effects of rain. Sometimes it also refers to the fluvial action of rainwater flowing in a stream channel, including a flood, known as a pluvial flood, that is the direct result of excessive precipitation.Bradley, R.S. (2015) Paleoclimatology: reconstructing climates of the Quaternary.
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The climatic conditions that cause glaciation had an indirect effect on arid and semiarid regions far removed from the large ice sheets. The increased precipitation that fed the glaciers also increased the runoff of major rivers and intermittent streams, resulting in the growth and development of large pluvial lakes. Most pluvial lakes developed in relatively arid regions where there typically was insufficient rain to establish a drainage system leading to the sea. Instead, stream runoff flowed into closed basins and formed playa lakes.
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In geology and climatology, a pluvial is either a modern climate characterized by relatively high precipitation, or an interval of time of variable length – decades to thousands of years – during which a climate is characterized by either relatively high precipitation or humidity. Subdivisions of a pluvial, which are characterized by relatively high precipitation, are known as a subpluvials. Formally, pluvials were equated with glacial stages of the Quaternary. However, pluvials, as in equatorial regions, can also occur during interglacial stages.
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Its natural habitats are pluvial premontane and very humid premontane forests. Its altitudinal range is asl. It is threatened by habitat loss and degradation caused by agricultural expansion and logging; introduced species might also be a threat.
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The vaulted brick branches, most of them abandoned and sealed, date mostly from before 1910. The tunnel sections built up to 1918 are listed on the National Register of Historic Places as Alcantarilla Pluvial sobre la Quebrada Manzanares.
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Now Pluvial is an EP released in October 2006 by the British band These New Puritans. It was released on Angular Records and the catalogue number is ARC016. The EP was a self distributed limited edition of 500 numbered copies.
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The Soča ( in Slovene) or Isonzo ( in Italian; other names , , or ') is a long river that flows through western Slovenia () and northeastern Italy (). An Alpine river in character, its source lies in the Trenta Valley in the Julian Alps in northwestern Slovenia, at an elevation of . The river runs past the towns of Bovec, Kobarid, Tolmin, Kanal ob Soči, Nova Gorica (where it is crossed by the Solkan Bridge), and Gorizia, entering the Adriatic Sea close to the town of Monfalcone. It has a nival-pluvial regime in its upper course and pluvial-nival in its lower course.
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The Mousterian Pluvial is a mostly obsolete term for a prehistoric wet and rainy (pluvial) period in North Africa. It was described as beginning around 50,000 years before the present (B.P), lasting roughly 20,000 years, and ending ca. 30,000 B.P. In Africa the Mousterian industry was an archaeological term for a category of Middle Stone Age (or Middle Paleolithic) stone tool production. During the time that archaeological dates were determined by radiocarbon decay, the production of these tools was once thought to have occurred just before the limit of radiocarbon dating at 40 – 35 thousand years ago.
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Ammonoids and conodonts found in the formation constrain its age to the early Carnian. Reptiles of the Guanling biota include ichthyosaurs, thalattosaurs, placodonts, and Odontochelys (an early relative of turtles). Sedimentary events within this formation have been tied to the Carnian Pluvial Event.
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Fischer et al., 2007, p.42 The formation was deposited during the Carnian Pluvial Event (CPE), a global humid event leading to high extinction levels of various groups globally. The CPE led to anoxic conditions, most notably in the South China Block.
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Mud Lake and Harney Lake are also remnants of the original pluvial lake. The lakes as well as nearby marshes and playas are part of Harney Basin. The basin, a closed depression, covers , which makes it larger than the state of Connecticut.
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91, pp. 133-144. The following pluvial (rain) periods allowed the whipbirds on the western side to migrate east and take up areas near the Murray basin.Cracraft, J., 1986. Origin and evolution of continental biotas: speciation and historical congruence within the Australian avifauna. Evolution. Vol.
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The accumulation of conglomerates of Valensole spreads out for around 10 thousand years. Toward 3 Ma, the filling-in stopped. The rivers will rearrange their valleys through the poudingue and the pluvial, glacial, fluvial, erosion will cut the relief of the plateau in forming small valleys and hills.
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These New Puritans' first release was the extended play Now Pluvial, which was a three track long record released in October 2006 through independent record label Angular Records. Despite only being a limited release, the EP attracted good reception from Drowned in Sound, garnering a 9/10 review.
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Goose Lake is a large alkaline lake in the Goose Lake Valley on the Oregon- California border in the United States. Like many other lakes in the Great Basin, it is a pluvial lake that formed from precipitation and melting glaciers during the Pleistocene epoch.Grayson, p. 87, 93–94, 96Green, p.
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They are the survivors of the desiccation and disappearance of the last pluvial lake that filled the Harney Basin during the Last Glacial Maximum.Bisson, P.A., and C.E. Bond (1971) Origin and Distribution of the Fishes of Harney Basin, Oregon. Copeia. 1971(2): 268-281.Behnke, R.J., and J.R. Tomelleri. (2002).
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The best studied of such episodes of humid climate, and probably the most intense and widespread, was the Carnian Pluvial Event. A 2020 study found bubbles of carbon dioxide in basaltic rocks dating back to the end of the Triassic, and concluded that volcanic activity helped trigger climate change in that period.
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The Quaternary of Nevada is typified by large pluvial lakes the largest being Lake Lahontan and Lake Bonneville. From deposits of this period come mammoths, a mastodon from Elko County, sabre-toothed cats, dire wolves, giant short-faced bears, and most of the animals still running around the Great Basin and Mojave Deserts today.
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The Dragonja (; ) is a long river in the northern part of the Istrian peninsula. It is a meandering river with a very branched basin and a small quantity of water. It has the pluvial regime and often dries up in summer. It features very diverse living environments and is home to a number of animal and plant species.
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Following the last Ice Age, melt water accumulated in the closed basins of what is now south-central Oregon. As a result, pluvial lakes covered much of Oregon's high desert country. This included the area around what is now Lake Abert. During this period, the area was home to mammoths, bison, horses, camels, and mountain sheep.
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Most members of the other main Neotropical subgenus, Urostigma begin life as hemiepiphytes. It grows in pluvial montane forest on the western slope of the Andes, 1800 to 2200 m (5900 to 6600 mft) above sea level. It has been classified as a Vulnerable species based on the fact that it is known from only three locations.
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The upper alluvial layers consist of partially stratified sand and silt mixed with layers of gravel. These deposits are permeable and provide the valley with groundwater. Calcium bicarbonate occurs in the groundwater throughout the basin. The entire valley was once covered by a single vast pluvial lake that may have been deep during the Pleistocene epoch.
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The major Carnian Pluvial Event stands as one focus point of many studies. Different hypotheses of the events occurrence include eruptions, monsoonal effects, and changes caused by plate tectonics. Continental deposits also support certain ideas relative to the Triassic period. Sediments that include red beds, which are sandstones and shales of color, may suggest seasonal precipitation.
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The formation and disappearance of Lake Tauca was a major hydrological event that was accompanied by several millennia of wetter climate. Its formation and the later Coipasa lake phase is associated with the Central Andean Pluvial Event (CAPE), which occurred from 18,000–14,000 to 13,800–9,700 BP. During this epoch, major environmental changes occurred in the Atacama as precipitation increased between 18° and 25° degrees south. In some areas, oases formed in the desert and human settlement began. The Central Andean Pluvial Event has been subdivided into two phases, a first one which began either 17,500 or 15,900 years ago and ended 13,800 years ago and a second phase which began 12,700 years ago and ended either 9,700 or 8,500 years ago; they were separated by a short dry period.
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The Great South American Chaco is a plain and its formation, millions of years ago, is very closely related to the formation of the Andes and the erosive process afterwards. Originally the Chaco was a basin, which within time, was filled with sediments of aerial origin (through wind action) and of pluvial origin (through rivers taking and depositing sediments in the Chaco).
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Parts of South East England received almost two and a half times the amount of rainfall that they would normally expect. The flood phenomena ranged from coastal flooding, pluvial flooding, fluvial flooding to groundwater flooding. The flooding took over most of the Somerset Levels and saw the main railway line to Cornwall and West Devon at Dawlish severed for several weeks.
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Pectoral fins are yellowish, while the pelvic and anal fins have white rays with red-orange membranes. The dorsal fin has seven rays, the anal fin has eight rays, and the pelvic fins usually seven. Size ranges up to 15 cm. The range is limited to a single cool spring and its overflow area in the upper pluvial White River.
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Cuchumatán may also be a derivation of the Nahuatl word kochmatlán, which means "place of the parrot hunters". The Cuchumatanes has a variety of different biomes, including pine-oak lower montane and montane humid forest, while lower montane wet forest and neotropic grass- and shrublands are present on higher slopes and plateaus,Steinberg & Taylor 2008 and subtropical pluvial forest in the northern piemonte.
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It contains large alkali lakes and tall cliffs, some with a prominence of more than . Steens Mountain, in Harney County, is the highest point within the region; its summit is above sea level.McArthur, p. 912"Pluvial Lakes: Oregon's Inland Seas", Oregon: A Geologic History To the east, the high desert country of the Columbia Plateau extends across the Snake River and into Idaho.
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Additional lake stands are recorded during the mid-Holocene, the Neoglacial and the Little Ice Age. These are dated to be 7,585 – 6,980, 4,795 – 4,220 and 495 – 230 years old before present, respectively. The reformation of the lake during these times was probably aided by its large catchment, seeing as other regional pluvial lakes do not frequently show lake stands at these timepoints.
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At various times during the Pleistocene epoch, both the southern and northern Altiplano were covered by vast pluvial lakes. Remnants are Lake Titicaca, straddling the Peru–Bolivia border, and Poopó, a salt lake that extends south of Oruro, Bolivia. Salar de Uyuni, locally known as Salar de Tunupa, and Salar de Coipasa are two large dry salt flats formed after the Altiplano paleolakes dried out.
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The Golden-chested Tanager can be found in a narrow elevational band of humid and heavily forested tropical lowland evergreen forests, pre-montane forests, forest borders and edges, and pluvial foothill forests in the Lower Tropical Zone in Ecuador and Colombia. Typically the species is seen in the mid-levels and subcanopy forest strata. Additional habitats used by this species include Montane Evergreen Forest.
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Aral Sea A map of Central Asia. The Karakum Desert is highlighted at the bottom. In the late Pleistocene, the Amu Dar'ya used to flow through the Karakum to the Aral Basin and Sarykamysh Depression, but flooding in the Amu Dar'ya valley during a pluvial period resulted in overflow to the Zeravshan River valley. The Amu Dar-ya merged with the Zeravshan and eventually reached Horezm Lake.
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Exceptionally hot in the summer, and cold in the winter, the late spring and early fall are popular times to visit. Malheur National Wildlife Refuge is home to one of the most extensive freshwater marsh ecosystems in the western United States. These marshes lie in the desiccated lake bed of a Pleistocene age pluvial lake.U.S. Fish and Wildlife Service (2013) Chapter 3 Physical Environment.
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The factors contributing to the formation of Lake Corcoran are not fully understood. The lake originally drained into Monterey Bay via the Salinas River, or at times not at all. Evaporation from this lake was a source of water for the Sierra Nevada and in lesser measure for the Basin and Range Province behind it. This contributed to the formation of large pluvial lakes in Nevada.
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The salt deposits of Salar de Uyuni were left by the lake The Viscachani culture around Lake Titicaca was contemporaneous with Lake Tauca. The earliest human dispersal in the region around Lake Tauca occurred towards the end of the Ticaña phase, with the Coipasa phase coinciding with the definitive establishment of humans in the region and also their spread through northwestern Argentina, where conditions were favourable. In the Atacama area, the end of the paleolake phase coinciding with Lake Tauca was accompanied by the end of the first phase of human settlement, which had occurred during the Central Andean Pluvial Event; now humans left the desert. Likewise in the Altiplano, the wet period that was contemporaneous to Lake Tauca allowed the settlement of Cerro Kaskio and Cueva Bautista close by, and the Central Andean Pluvial Event did the same in the Pampa del Tamarugal.
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The lake was about by wide and covered the present-day locations of Estancia, McIntosh, Progresso and Willard.The lake may have resembled Lake Tahoe in California, although Lake Tahoe is considerably deeper. Lake Estancia was the easternmost pluvial lake in Southwestern North America. Distinct shoreline landforms in the Estancia Valley occur at various elevations, including bars, beaches, gravel deposits, ridges, scarps, spits, swales, terraces and wave-cut cliffs.
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Oregon's mountain ranges were covered in large ice caps, although the Cordilleran Ice Sheet did not extend into the state. Evidence of ice cap increase and decrease is preserved in a series of glacial lakes, including Glacier Lake. Glacial erratics can be found across the northern half of the state, including sites such as the Erratic Rock State Natural Site. Pluvial lakes are also common across the state.
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Possible explanations include headward erosion or a broken natural dam of a lake or river. Whatever the cause, the Lower Colorado probably captured the landlocked Upper Colorado somewhere west of the Kaibab Uplift. The much larger drainage area and yet steeper stream gradient helped to further accelerate downcutting. Ice ages during the Pleistocene brought a cooler and wetter pluvial climate to the region starting 2 to 3 million years ago.
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Historic rockfall on the north rim. The end of the Pleistocene ice ages and the start of the Holocene began to change the area's climate from a cool, wet pluvial one to dryer semi-arid conditions similar to that of today. With less water to cut, the erosive ability of the Colorado was greatly reduced. Mass wasting processes thus began to become relatively more important than they were before.
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These northern and western slopes of the Goose Lake basin are drained by Thomas Creek, Muddy Creek, Cottonwood Creek, and Drews Creek. All flow into Goose Lake. At the southern end of the basin, Willow Creek and Lassen Creek flow from the Warner Mountains into Goose Lake."Pluvial Lakes: Oregon's inland seas", Oregon: A Geologic History, Oregon Department of Geology and Mineral Industries, Portland, Oregon, 23 December 2009.
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Pluvial lakes represent changes in the hydrological cycle: wet cycles generate large lakes, and dry cycles cause the lakes to recede. Accumulated sediments show the variation in water level. During glacial periods, when the lake level is fairly high, mud sediments will settle out and be deposited. At times in between glaciers (interglacial), salt deposits may be present because of the arid climate and the evaporation of lakewater.
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"Le Grand Sault" (The Grand Canyon) at Sault de Hell Gates The watershed of Rimouski River covers an area of of which 98.6% are located in the Quebec and 1.4% in New Brunswick. The river has a Module of . The recorded maximum flow is and the minimum rate is . It has a nivo-pluvial regime with a flood in early May and another smaller at the end of October.
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During highstands the lake was about long and in some places wide. It covered a surface area possibly over during these highstands and at lowstands. At these sizes it was one of the largest pluvial lakes in the southwestern United States during the late Pleistocene. Most of the lake was located in Mexico, with only a bay between the West Potrillo Mountains and the Tres Hermanas Mountains extending into New Mexico.
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The Pluvial Lake Basins ecoregion contained vast lakes during the Pleistocene epoch that have now mostly disappeared. It is characterized by gently sloping, internally drained basins with lake terraces, playas, beach plains, stream terraces, intermittent lakes, fan skirts, and cool springs. Elevation varies from 4,200 to 6,200 feet (1,280 to 1,890 m). Some basin floor playas collect and evaporate water seasonally, but not as extensively as the High Desert Wetlands.
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Pico do Brejo do Cordeiro is a peak on the island of São Jorge in the Azores. It is located around the area of Norte Pequeno and is intimidatedly related with a peak mountain in the centre of the island. Its elevation is 739 m above sea level and is made up of a pluvial escarpment by the sea. It geological formation are volcanic and pyroclastic origin and is very old.
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Eventually an earthquake collapsed the overhang of the mouth. Lake Lahontan was a large Pleistocene pluvial lake that covered much of western Nevada. Due to drier Holocene climate the water elevation dropped and much smaller lakes remain such as Lake Humboldt, Pyramid Lake, and Carson Lake. The dry environment of the cave resulted in a wealth of well-preserved artifacts that provide a glimpse on how people lived in the area.
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During the Coipasa lake cycle, precipitation may have focused on the southern Altiplano and been transported there from the Chaco; the main Tauca cycle may have been accompanied by precipitation from the northeast. A glacial advance in the Turbio valley (a feeder of the Elqui River) between 17,000 and 12,000 years ago has been attributed to the Central Andean Pluvial Event. Other indicators point to dry conditions/lack of glacier advances in central Chile and the central Puna during the highstand of Lake Tauca, glaciers had already retreated from their maximum positions by the time it began and the Central Andean Pluvial Event may not have been synchronous between the southern Altiplano and the southern Atacama. Increased precipitation during the Tauca phase was probably triggered by the southern movement of the ITCZ and the strengthening of the South America monsoon, possibly caused by chilling in the northern hemisphere and North Atlantic, along with higher water temperatures off Northeastern Brazil.
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Wadia suggested that there was some thrust of Cambrian plates over Eocene plates in some areas. Wadia took an interest in soil science. In 1954, he suggested that the Pleistocene Ice Age of the northern hemisphere was a time of great rainfall (the Pluvial Age) in the semi-tropical and tropical latitudes. One of his early contributions was to explain the knee-bend or syntaxis in the mountain ranges around Nanga Parbat.
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Native Americans have lived in southeastern Oregon for at least 15,000 years, according to a 2012 find in the Paisley Caves. At that time, pluvial lakes filled many of the high desert basins. Little is known about the people who occupied the land at that time, except that they camped and hunted near the lakes. The earliest petroglyphs in southeastern Oregon may be as much as 15,000 years old or much older.
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The central scoria cone may be only a few thousand years old, possibly even of historical age. The arid climate may mislead as to its actual age, as there is little erosion in the desert. Early geological studies estimated an age of less than 800–1,000 years. Salty muds and rocks erupted by the scoria cone and the crater northwest of the main Waw an Namus caldera must have been emplaced after the last pluvial.
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It is part of the Sonoran Desert ecoregion and is the remnant of a Pleistocene era pluvial Lake Cochise. Portions of the dry lake bed have been used as a bombing range by the US military. It was designated a National Natural Landmark in 1966 for its fossil pollen captured underground, the thousands of sandhill cranes that roost in the area and the largest diversity of tiger beetles in the United States.
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About 7,500 years ago, the climate changed and the great pluvial lakes began to recede. As the lakes shrank, the mammoths, horses, and camels disappeared. Nevertheless, the area around Lake Abert and the marshes and meadows along the Chewaucan River, south and west of the lake, remained ideal habitat for wildlife including numerous small mammal species and many varieties of waterfowl. As a result, ancient people continued to occupy the area around Lake Abert.
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Lava flows reach lengths of and have thicknesses of and sometimes lava flows from separate cones overlap, such as in Papoose Canyon. In the past, pluvial lakes and glaciers extended over the Owens Valley. Volcanic activity occurred at the Big Pine volcanic field during that time and was influenced by these lakes and glaciers. Owens Lake spread through much of the valley during glacial times and cut shorelines into the lava flows.
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The basin has been filled with glacial deposits from the north and alluvial-pluvial sediments from the south. Fluid flows horizontally into the reservoir through the faults around the basin. A drill hole in the northern part of the field with a final depth of found thermal fluid with a maximum temperature of . Chemical analysis of the thermal fluid indicate that there is shallow-seated magmatic activity not far below the geothermal field.
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At that time, the Voltage Flow created the pluvial lake basin that the Malheur National Wildlife Refuge currently occupies by filling the paleovalley of and damming the prehistoric course of Malheur River at that time.Milliard, J.B.. (2010) Two-stage opening of the northwestern Basin and Range near Harney Basin, Oregon, USA: structural, sedimentological and volcanic constraints. unpublished Masters thesis, College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, Corvallis, Oregon. 80 pp.
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Bulletin no. 1475. U.S. Geological Survey, Reston, Virginia. Finally, Late Pleistocene, 22,000 year-old, fossil salmon bones have been reported being found in prehistoric gravel spawning beds that were uncovered near the connection between Malheur and Mud lakes. These fossils have been interpreted as indicating that the lake level of this prehistoric pluvial lake was high enough at this time that it was connected to and discharged directly into the Malheur River.
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An intense and permanent pluvial activity precipitates of 5,500 to 6,000 mm of water per year, flooding the plain, already saturated by the waters of the rivers San Juan, Colorado and Chirripó in its northern limit. To the south, the main rivers are the Suerre, Jiménez and Parismina, which feed the artificial channel of Tortuguero. The water covers much of the district, in the form of rivers, pipes, canals, lagoons or marshes.
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Abbassia and the nearby region, saw heavy rainfall during a period of time geological researchers call the Pluvial Abbassia. During this period, red, green and purple rocks or gravel became distributed all along the valley and Delta regions of the Nile. Gravel beds were formed, including a famous gravel bed at Abbassia. Photographed and described in 1926 by Paul Bovier-Lapierre, these gravel beds were as thick as 33 feet (10 metres/meters) in some areas.
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It occurs mainly on the Atlantic facing slopes of the Serra do Mar in southeastern Brazil. The distribution areas are located in the state of Rio de Janeiro to Santa Catarina, where they range from sea level to altitudes of 1500 m. Most are found in pluvial rainforests with an annual rainfall of up to 1600 mm. One finds plants of the kind on shady river banks and ravines, as well as in forests in damp, well draining soils.
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Oregon Pleistocene geography. Blue areas are pluvial lakes, purple areas are Missoula Flood deposits, and white areas indicate maximum ice extent during the Glacial Maximum. The Fort Rock Basin is an endorheic basin. Increased moisture in this semiarid environment during the Pleistocene through increased cloud cover and cooler temperatures resulted in higher lake levels. At its maximum, the lake filled the basin up to 75 m deep (245 ft), with a surface area of over 2,300 km2 (900 mi2).
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The pupfish is a member of the genus Cyprinodon. Most divergence of Cyprinodon species likely took place during the early-to-mid Pleistocene, a time when pluvial lakes intermittently filled the now-desert region, though some may have occurred during the last 10,000 years. The evaporation of the lakes resulted in the geographic isolation of small Cyprinodon populations and the speciation of C. nevadensis. Ichthyologists Rosa Smith Eigenmann and Carl H. Eigenmann first identified Cyprinodon nevadensis in 1889.
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Location of the former Lake Condon. During the last Ice Age (18,000 to 12,000 years ago), and in multiple previous Ice Ages, cataclysmic floods inundated portions of the Pacific Northwest from Glacial Lake Missoula, pluvial Lake Bonneville, and perhaps from subglacial outbursts. Glacial Lake Missoula was a body of water as large as some of the USA's Great Lakes. This lake formed from glacial meltwater that was dammed by a lobe of the Canadian ice sheet.
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Prehistoric stone tools, facies with rare bifaces, have been found in the region dating from the Early Pleistocene (over 780,000 years ago) to the present Holocene epoch. During that period the climate alternated several times between arid or semi-arid and pluvial. The English explorer Richard Francis Burton visited the region in 1857–59. At that time Marungu was one of the sources of slaves collected by the Arabs and taken to the great slave market at Ujiji.
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It has been known for over a century that large lakes previously existed in the Western United States, most notably Nevada's Lake Lahontan and Utah's Lake Bonneville. Such lakes also formed in eastern Oregon, where present-day Malheur Lake and Goose Lake are remnants of former pluvial lakes. Lake Modoc was so named by Samuel N. Dicken, professor of geography at the University of Oregon. The region of Lake Modoc was first described during the early and mid-19th century.
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By Jamarimutt. From 1942 to 1956 he worked as official architect for the engineering division of the Autoridad de Fuentes Fluviales (Pluvial Fountains Authority), today the Autoridad de Energía Eléctrica (Electric Power Authority). During this time he also designed a church in Hato Rey, and the home residence of Antonio S. Luchetti, the director of the Authority. This last one, commissioned by the government of Puerto Rico, caused so much public criticism that the home was sold without Luchetti ever living it.
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Red Rock Pass, Idaho. About 14,500 years ago, pluvial Lake Bonneville in northern Utah reached its highest water level since its formation. The lake occupied the present-day basin of the Great Salt Lake, but was far larger, covering about . As it rose the lake level caused seepage at, then breached, the ancient level of Red Rock Pass, a mountain pass at the headwaters of the Portneuf River, a tributary of the Snake River above present-day American Falls Reservoir.
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Following the retreating glaciers of the last glaciation period of the Ice Age, melt water accumulated in the closed basins of what now is south central Oregon. As a result, pluvial lakes covered much of the high desert. This included the Summer Lake basin south of Picture Rock Pass and the Silver Lake basin north of the pass. The marshes and meadows that surrounded these lakes were ideal habitat for wildlife including bison, deer, antelope, mountain sheep, and many varieties of waterfowl.
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Several pluvial lakes formed in what is now the southwestern United States during the glaciation of the late Pleistocene. One of these was Lake Bonneville in western Utah, which covered roughly . When Lake Bonneville was at its maximum water level, it was higher than the Great Salt Lake. Fresh water mollusks have been found in mud deposits from Searles Lake in California and suggest that the water temperature was about 7 degrees Fahrenheit (or 4 degrees Celsius) cooler than current temperatures.
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"Rift Volcanoes: Aftermath of the Yellowstone Hot Spot", Oregon: A Geologic History"High Desert Volcanoes: Sleeping Giants of Eastern Oregon", Oregon: A Geologic History During the last 2 million years, a series of ice ages altered the landscape. As each ice sheet melted, runoff and increased rainfall filled many of the region's closed basins, forming large pluvial lakes. The Goose Lake, Harney, and Klamath basins were filled along with many other smaller basins. Some of the lakes covered as much as .
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The nearly level High Desert Wetlands ecoregion consists of high desert lakes and surrounding wetlands that provide critical habitat for nesting and migratory birds and associated upland birds and mammals. Elevation varies from 4,000 to 5,200 feet (1,219 to 1,646 m). The fine-textured soils are poorly drained, and basins collect water seasonally. Although water levels fluctuate from year to year, lakes and wetlands in this region hold water more consistently than on the coarser, better drained soils of the Pluvial Lake Basins.
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The lake briefly returned during the Younger Dryas and eventually desiccated during the Holocene. Wind-driven erosion has excavated depressions in the former lakebed that are in part filled with playas. The lake is only one of several pluvial lakes in southwestern North America that developed during the late Pleistocene. Their formation has been variously attributed to decreased temperatures during the ice age and increased precipitation; a shutdown of the thermohaline circulation and the Laurentide Ice Sheet altered atmospheric circulation patterns and increased precipitation in the region.
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The Missoula Floods of Oregon and Washington states were also caused by breaking ice dams, resulting in the Channeled Scablands. Lake Bonneville, a pluvial lake, burst catastrophically in the Bonneville Flood about 14,500 years ago, due to its water overflowing and washing away a sill composed of two opposing alluvial fans which had blocked a gorge. Lake Bonneville was not a glacial lake, but glacial age climate change determined the lake level and its overflow. The first scientific report of a megaflood (Gilbert, 1890) describes this event.
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The Stansbury expedition to Utah was a huge scientific success. He was the first to determine that the lake was actually a remnant of a larger inland freshwater pluvial lake (today called Lake Bonneville). The method of triangulation used to map the lake was a first for the Topographical Corps, and the method was put into standard use by the Corps and later by the US Geological Survey. The expedition collected many different species of birds, plants, lizards and mammals as well as rock samples and fossils.
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The Tecopa pupfish is member of the genus Cyprinodon of the pupfish family Cyprinodontidae, a taxon of killifish most diverse in North America. Most divergence of local Cyprinodon species likely took place during the early-to-mid Pleistocene, a time when pluvial lakes intermittently filled the now-desert region, though some may have occurred during the last 10,000 years. The evaporation of the lakes resulted in the geographic isolation of small Cyprinodon populations in remnant wetlands and the speciation of C. nevadensis. C. n.
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The dating techniques of the day were limited, but the Grimaldi people were believed to be of the late Palaeolithic period. An inference of the true age can be made from the layering. The more tropical fauna of the lower levels below the Grimaldi man skeletons had rhinoceros, hippopotamus and elephants, are known from the Mousterian Pluvial, a moist period from 50,000 to 30,000 years before present. The Aurignacian is 47,000 to 41,000 years old using the most recent calibration of the radiocarbon timescale.
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He leaves that position in 1993, and appointed Secretary of Urban Infrastructure and Ecology, under the same administration. On this position, he boosted the work on the modernization of Hermosillo, among them, the Vado del Río Zone, the vaulting if Yucatán Street (among other pluvial modernization works), which included a 20 million pesos investment during the first three years of the Manlio Fabio Beltrones state administration; he also boosted the development of the Solidaridad Boulevard, as well as the creation of a vehicle inspection program.Redacción.
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Speleothem records indicate an increase in precipitation in southern Oregon, the timing of which coincides with increased sizes of pluvial lakes in the northern Great Basin. A pollen record from the Siskiyou Mountains suggests a lag in timing of the Younger Dryas, indicating a greater influence of warmer Pacific conditions on that range, but the pollen record is less chronologically constrained than the aforementioned speleothem record. The Southwest appears to have seen an increase in precipitation, as well, also with an average 2° of cooling.
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The geologist Erik Nilsson claimed to have identified traces of glaciation on Chilalo, as well as on its neighbor Mount Kaka down to about 3400 meters, which he dated to the "Last Pluvial Period".Erik Nilsson, "Traces of Ancient Changes of Climate in East Africa: Preliminary Report", Geografiska Annaler, 17 (1935), pp. 13f Although this mountain is located south of the East African Rift, along with Mount Gugu to the north and Mount Kaka to the south, it is considered, geologically speaking, part of the Ethiopian Highlands.
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The Yangbajing Basin lies between the Nyainquentanglha Range to the northwest and the Yarlu-Zangbo suture to the south. The Yangbajain Geothermal Field is in the central part of a half-graben fault-depression basin caused by the foremontane fault zone of the Nyainqentanglha Mountains. The SE-dipping detachment fault began to form about 8 Ma. The geothermal reservoir is basically a Quaternary basin underlaid by a large granite batholith. The basin has been filled with glacial deposits from the north and alluvial-pluvial sediments from the south.
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Just like the Lake Tauca highstand may have coincided with the first Heinrich event, the Younger Dryas may be associated with the Coipasa highstand and the second Central Andean Pluvial Event although the Younger Dryas ended two millennia before the CAPE. The second CAPE was caused either by changes in the South American monsoon or by changes in the atmospheric circulation over the Pacific Ocean, and its end has been attributed to a warming North Atlantic drawing the ITCZ northward. Today, the average temperature at stations at an altitude of is .
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Unlike other pluvial lakes, Lake Modoc had a steady inflow of surface water, owing to its proximity to snow- and glacier-covered mountains of the Cascade Range. Its watershed extended over present-day Modoc and Siskiyou counties (both in California), and Jackson, Klamath and Lake counties (all in Oregon), including the Williamson River, Sprague River and Lost River. Cinder, pumice and volcanic ash from the Cascades filled the lake. Lake Modoc also featured an outflow, at first to the south before a lava flow blocked it, although seepage continued from there to this day.
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Abundant red beds and evaporites such as halite support these conclusions, but some evidence suggests the generally dry climate of was punctuated by episodes of increased rainfall. The most important humid episodes were the Carnian Pluvial Event and one in the Rhaetian, a few million years before the Triassic–Jurassic extinction event. Sea levels began to rise during the Jurassic, probably caused by an increase in seafloor spreading. The formation of new crust beneath the surface displaced ocean waters by as much as above today's sea level, flooding coastal areas.
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Summer temperatures at the Ubehebe Craters can be quite high while winter temperatures often fall below freezing. During the Little Ice Age, temperatures were low enough to allow the development of snow patches in the Ubehebe Craters, which then left nivation landforms. Present-day precipitation in Death Valley is about with large year-to-year variability but was higher during past pluvial periods such as between 17,500 and 15,000 years ago. Today, precipitation usually occurs in the form of sudden rainfall that can trigger substantial erosion and sometimes generates ephemeral lakes in the craters.
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Rivers State is a predominantly low-lying pluvial state in southern Nigeria, located in the eastern part of the Niger Delta on the oceanward extension of the Benue Trough. The inland part of the state consists of tropical rainforest, and towards the coast, the typical Niger Delta environment features many mangrove swamps. Rivers State has a total area of 11,077 km² (4,277 mi²), making it the 26th largest state in Nigeria. Surrounding states are Imo, Abia and Anambra to the north, Akwa Ibom to the east and Bayelsa, Delta to the west.
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The climate is dry, with precipitation averaging and at above elevation. Moisture originates from the Atlantic Ocean, the equatorial Pacific and the Gran Chaco in Argentina; it falls mostly during winter unlike the rest of the Altiplano where summer precipitation dominates. Precipitation is variable both over annual and millennial timescales, with complex regional variations during El Nino and La Nina years and with past increases during the Central Andean Pluvial Events between 18,00014,100 and 13,60010,600 years ago, during which Lake Tuyajto rose. Conversely, during some future climate change scenarios it might dry up altogether.
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The Carnian Pluvial Event (CPE) was a time of major change in global climate and of biotic turnover that occurred during the Carnian, early Late Triassic, between about 234 and 232 million years ago. The base of the CPE is marked by a ≈4‰ negative shift in carbon stable isotopes () of fossil molecules (n-alkanes) from higher plants and total organic carbon. A ≈1.5‰ negative shift in oxygen stable isotopes () of conodont apatite suggests a global warming. Major changes in organisms responsible for calcium carbonate production occurred during the CPE.
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Proposed & Existing Access points for the Bonneville Shoreline Trail Bonneville Shoreline Trail marker. The Bonneville Shoreline Trail is a mixed use (biking/hiking) recreation trail in Utah that roughly follows the shoreline of the ancient Lake Bonneville, a prehistoric pluvial lake which existed in northern Utah before naturally draining about 14,000 years ago. Some sections of the trail are complete while other parts are still being developed. The Bonneville Shoreline Trail hopes to one day stretch from the Idaho border (north of Logan, Utah) and run southward all the way to Nephi, Utah.
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Revista Así. Dispone Beltrones cambios y enroques en su equipo. julio de 1993, No. 302, pag. 21Redacción. Revista Así. Prorrogan plazo para verificación vehicular. agosto de 1993, No. 303, Pag. 18Ortíz, Luis Enrique. Revista Así. Casi una realidad el drenaje pluvial. agosto de 1993, No. 304, pag. 45.Redacción. Revista Así. Agua potable, inversión sin precedente para los habitantes de Hermosillo. junio de 1994, No. 324, Pag. 44. He also upgraded the modernization of the north and northwest area of the Sonora state, mainly the Puerto Peñasco, San Luis Rio Colorado, Sonoyta, and Nogales counties.
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Fort Rock looking east from the Fort Rock Road Winter view looking northwest into open side Previous age estimates of Fort Rock ranged upwards to 1.8 million years. Recently, the age of Fort Rock has been estimated at 50,000 to 100,000 years. This coincides with a period of time when large pluvial lakes filled the valleys of central Oregon and much of the Great Basin of the western United States. At its maximum, the water in Fort Rock Lake was estimated to cover nearly and was about deep where the Fort Rock tuff ring formed.
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The Sahara pump theory describes this cycle. During periods of a wet or "Green Sahara", the Sahara becomes a savanna grassland and various flora and fauna become more common. Following inter-pluvial arid periods, the Sahara area then reverts to desert conditions and the flora and fauna are forced to retreat northwards to the Atlas Mountains, southwards into West Africa, or eastwards into the Nile Valley. This separates populations of some of the species in areas with different climates, forcing them to adapt, possibly giving rise to allopatric speciation.
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The lake is the largest remnant of Lake Bonneville, a prehistoric pluvial lake that once covered much of western Utah. The three major tributaries to the lake, the Jordan, Weber, and Bear rivers together deposit approximately 1.1 million tons of minerals in the lake each year. As it is endorheic (has no outlet besides evaporation), it has very high salinity (far saltier than seawater) and its mineral content is steadily increasing. Due to the high density resulting from its mineral content, swimming in the Great Salt Lake is similar to floating.
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Lacustrine system of the Mojave Desert The size of pluvial lakes, such as Lake Manly, is governed by the balance between inflow by precipitation or rivers or streams and evaporation, if one assumes that seepage and overflow are not important. This can make the surface of such lakes a useful gauge for paleoclimatic conditions. The principal water supplies to Lake Manly were the Amargosa River, the Mojave River and the Owens River, which yielded a large integrated drainage system over the southwestern Great Basin. The total surface area of Lake Manly's catchment was about .
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The outflow mostly consists of evaporation, and a very small amount seeps through the sandspit that impounds it from the main Great Salt Lake valley. The lake was isolated from Lake Bonneville approximately 15,000-17,000 years ago after evaporation lowered the lake level to below the natural Stockton Bar barrier between Rush Valley and Tooele Valley. During the ice ages, Rush Valley was merely one of many arms of Lake Bonneville. After Bonneville dried up, Rush Valley contained several pluvial lakes – Shambip, Smelter, and Rush – of which only Rush Lake remains today.
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During the fall of 1994 both levels were severely damaged by the natural phenomenon of salt dissolution due to infiltration of ground and pluvial waters, which flooded the Unirea mine. The catastrophic aggressiveness of waters flowing down the shaft gradually created huge cavities and the specialists who evaluated the full scope of the disaster decided to close down the mine. Eugen Scrob, an I.S.P.H. researcher, came up with an idea which was to keep the mine from completely collapsing. He immediately applied a new experimental method, helped by the miners of the Slanic mine.
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As soil starts to slowly form, new plant species colonize the stable dunes ultimately developing more extensive root structures and plant diversity. When the dune has become continuously vegetated, lichen and moss grows in the understory, providing a water-repellent surface that reduces erosion (through rainfall and wind), this results in the official formation of the grey dune. Pluvial processes dominate the geomorphology of grey dunes, with rain splash and slope wash being the most common processes taking place. Erosion can take place in the form of rain splash and slope wash.
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By 50 kybp (thousand years before present), the Wisconsin glaciation ("Würm glaciation" in Europe) was well-advanced; growing ice sheets in North America and Europe displaced the standard climatic zones of the northern hemisphere southward. The temperate zones of Europe and North America acquired an Arctic or tundra climate, and the rain bands typical of the temperate zones dropped to the latitudes of northern Africa. Curiously, the same influences that created the Mousterian Pluvial were thought to have brought it to a close. In the period of its fullest development, c.
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According to a 1984 report, the mountains supported abundant wildlife, including healthy populations of colobus and blue monkey, bush-pig and a local sub-species of bushbuck. The south eastern Kipia and Lomwaga Uplands were least visited by hunters and had the largest populations of elephant, buffalo, duiker's, hyaena and leopard. Mammals that normally inhabit a forest environment show greatest differentiation from similar mammals elsewhere, probably due to isolation of the Imatong forests from other forests by wide areas of semi-arid savanna. This isolation dates back to the last Pleistocene Pluvial period about 12,000 years ago.
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Paleo-Indians were present in southwestern Utah as early as 10,000 BC, when the climate was much wetter during the Pleistocene ice age and the Sevier basin was partially occupied by pluvial Lake Bonneville. Wetlands along the shoreline and a much fuller Sevier River provided abundant habitat for fish and wildlife, supporting a larger human population. Lake Bonneville had dried up by about 7000 BC, and the aridifying climate limited plant and animal resources. The Desert Archaic culture, characterized by small semi- nomadic bands, succeeded the Paleo-Indians but it is not known whether they are the descendants or an entirely different group.
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Lake Modoc was a pluvial lake that existed during the Pleistocene in basins formed by faulting and volcanism, which left. It covered a length of from south of Tule Lake in California to near present-day Fort Klamath in Oregon, its waters reaching an elevation of about above sea level and covering an area of about with a highly irregular shape. Several islands formed in the lake, such as the Klamath Hills, present-day Miller Hill close to Klamath Falls and Turkey Hill close to Malin. The shoreline of Lake Modoc is well visible close to Tule Lake.
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The 1970s had been an exceptionally wet decade over eastern Australia,Pluvial period of the 1970s despite short-term droughts from April to August 1976 and June to December 1977. 1978 was especially wet in the southern coast districts of New South Wales and East Gippsland because southern low pressure systems consistently redeveloped over the east coast. Orbost's 1978 rainfall of is as much as 256 mm (10 inches) above its previous record from 1935. In the winter, unseasonal rains struck normally bone-dry areas of northern Australia, and the wet season arrived early in the north in October.
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The climate of this region has varied greatly in the past, with pluvial and dry periods alternating; the current arid phase averages less than of precipitation per year. During its geologic history, the Fazzan Basin has on at least four occasions during the Pleistocene been inundated with water to form a large lake. On each occasion, a thick layer of limestone was deposited. Armitage et al. (2007) estimated that two of these events occurred earlier than 400,000 years ago, another one was in MIS 11 (~400,000 years ago) and a further one in MIS 5 (between 130,000 and 80,000 years ago).
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An irregularly-shaped pit crater at the top of the shield marks the site where lava flowed in all directions to create the Badlands.Badlands Natural History - Oregon Natural Desert Association Lava tubes acted as conduits for the lava in some instances and are evidenced on the surface by tumuli, also known as pressure ridges. Soils in the Badlands were largely formed from ash associated with the eruption of Mount Mazama some 7,700 years ago. It is the northwesternmost part of the Northern Basin and Range ecoregion, described as Pluvial Lake Basin, and shares many characteristics of the Great Basin.
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Hall, W.E., Van Devender, T.R. and Olson, C.A., Late Quaternary arthropod remains from Sonoran desert packrat middens, southwestern Arizona and northwestern Sonora, Quaternary Research, in press, 1988. All have concluded that the Gran Desierto has been an ecological refuge for desert plants since at least the late Pleistocene. The Gran Desierto has served as a refuge for most dominant Mojave Desert plant species during cooler pluvial epochs as well. Carbon-14 dating for a midden from the Tinajas Altas Mountains shows assemblages of juniper and Joshua trees coexisting with contemporary Gran Desierto flora and fauna more than 43,000 years before present.
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The Klamath/Goose Lake Warm Wet Basins ecoregion (named for Upper Klamath and Goose lakes) is drier than elsewhere in the eastern Cascades, yet it contains floodplains, terraces, and a pluvial lake basin. Elevation varies from . A variety of wildrye, bluegrass, and wheatgrass species once covered the basins, but most of the wet meadows and wetlands have been drained for rural residential development, pasture, and cropland, including alfalfa, potatoes, and small grains. Potential vegetation includes bluebunch wheatgrass, Idaho fescue, antelope bitterbrush, big sagebrush, and low sagebrush on the steppes, with tules, cattails, and sedges in the wetlands.
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Groundwater sapping is a geomorphic erosion process that results in the headward migration of channels in response to near constant fluid discharge at a fixed point. The consistent flow of water displaces fine sediments which physically and chemically weathers rocks. Valleys that appear to have been created by groundwater sapping occur throughout the world in areas such as England, Colorado, Hawai’i, New Zealand, and many other places. However, it is difficult to characterize a landform as being formed exclusively by groundwater sapping due to phenomena such as pluvial runoff, plunge-pool undercutting, changes in water table level, and inconsistent groundwater flow.
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The Warner Range is not part of the Sierra Nevada range or the Cascade Range, but part of the Great Basin Ranges. It is in the semi-arid, sparsely-populated northeastern corner of California and the south-central portion of Oregon. The range is a classic example of horst and graben (fault-block) topography with pluvial (ephemeral) lakes occupying the graben basins. The eastern escarpment of the range overlooks the Surprise Valley in California and Warner Valley in Oregon, enclosed basins that contain Upper Alkali Lake, Middle Alkali Lake, and Lower Alkali Lake along the California–Nevada border, and the Warner Lakes (Crump and Hart lakes) in Oregon.
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Late Triassic (220 Ma) The arid climate of the Late Triassic was interrupted by the markedly more humid conditions of the Carnian Pluvial Event (CPE). Evidences of increased rainfall during the CPE are 1) the development of palaeosols (histic and spodic soils) typical of tropical humid climate with a positive water budget throughout the year; 2) hygrophytic palynological assemblages that reflect a vegetation more adapted to humid climate; 3) siliciclastic sediment input into the basins due to increased continental weathering and runoff; 4) the widespread presence of amber. However, wet climate was periodically interrupted by dry climate. Oxygen isotope analyses performed on conodont apatite show a ≈1.5‰ negative shift.
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During periods of a wet or Green Sahara, the Sahara and Arabia become a savanna grassland and African flora and fauna become common. Following inter-pluvial arid periods, the Sahara area then reverts to desert conditions, usually as a result of the retreat of the West African Monsoon southwards. Evaporation exceeds precipitation, the level of water in lakes like Lake Chad falls, and rivers become dry wadis. Flora and fauna previously widespread as a result retreat northwards to the Atlas Mountains, southwards into West Africa, or eastwards into the Nile Valley and thence either southeast to the Ethiopian Highlands and Kenya or northeast across the Sinai into Asia.
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Between about 133 and 122 thousand years ago (kya), the southern parts of the Saharan-Arabian Desert experienced the start of the Abbassia Pluvial, a wet period with increased monsoonal precipitation, around 200–100 mm/year. This allowed Eurasian biota to travel to Africa and vice versa. The growth of speleothems (which requires rainwater) was detected in Hol-Zakh, Ashalim, Even-Sid, Ma'ale-ha-Meyshar, Ktora Cracks, Nagev Tzavoa Cave. In Qafzeh and Es Skuhl caves, where at that time precipitation was 600–1000 mm/year, the remains of Qafzeh-Skhul type anatomically modern humans are dated from this period, but human occupation seems to end in the later arid period.
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It is believed that a sub-population of Lahontan cutthroats became isolated in Silver King Creek above Silver King Canyon Gorge after erosion made the gorge impassable to trout swimming upstream, probably between 5,000 and 8,000 years ago. The upstream population then adapted to local conditions independent of the larger population below that had evolved in pluvial Lake Lahontan during the Pleistocene. Although Lahontan cutthroats are heavily spotted, the isolated sub-population lost virtually all spotting, perhaps because spots made fish more visible and susceptible to predation in the ultra-clear and shallow mountain stream. Paiute cutthroats are also notable for a purple coloration, whereas Lahontan cutthroats have bronze coloration.
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Lake Manly was a pluvial lake in Death Valley, California, covering much of Death Valley with a surface area of during the so-called "Blackwelder stand". Water levels varied through its history, and the chronology is further complicated by active tectonic processes that have modified the elevations of the various shorelines of Lake Manly; during the Blackwelder stage they reached above sea level. The lake received water mainly from the Amargosa River and at various points from the Mojave River and Owens River. The lake and its substantial catchment favoured the spread of a number of aquatic species, including some lizards, pupfish and springsnails.
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Evidence for the lake's existence includes wavecut terraces observed by geologists in 1925, pebbles and tufa, layers of clay and salt on its former lake bed, and calcium carbonate deposits that were probably formed by algae in the lake. These clues are dispersed across Death Valley, especially within the more researched areas of Beatty Junction and Desolation Canyon. While the deposits were once attributed to a single lake stand, later evidence was found of various lake cycles going back to the Pliocene. The history of Lake Manly is not as well understood as that of Lake Lahontan and Lake Bonneville, the two largest pluvial lakes recorded in the Great Basin.
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The conjecture proposed by linguist and historian Igor M. Diakonoff may be summarized. From a prehistoric homeland near Darfur, which was better watered,At about this time the surface water level of Lake Chad to the west was 12 meters higher than it is today. R. Said, "Chronological framework: African pluvial and glacial epics" at 146-166, 148, in General History of Africa, volume I, Methodology and African Prehistory (UNESCO 1990), Abridged Edition.A drying out of the Sahara during the fourth and third millennium B.C.E. (6 kya to 4 kya) is accounted for and described by the Sahara Pump Theory, in its most recent cycle.
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Exceptions aside, in the South of the Sahara, risk assessment is not yet an institutionalized practice. The exposure of human settlements to multiple hazards (hydrological and agricultural drought, pluvial, fluvial and coastal floods) is frequent and requires risk assessments on a regional, municipal and sometimes individual human settlement scale. The multidisciplinary approach and the integration of local and technical- scientific knowledge is necessary from the first steps of the assessment. Local knowledge remains unavoidable to understand the hazards that threaten individual communities, the critical thresholds in which they turn into disasters, for the validation of hydraulic models and in the decision-making process on risk reduction.
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During earlier strong African Humid periods, the now-desiccated regions of northern Africa were well-watered, bearing lakes, swamps, and river systems that no longer exist. What is now the Sahara desert supported typical African wildlife of grassland and woodland environments: herbivores from gazelle to giraffe to ostrich, predators from lion to jackal, even hippopotamus and crocodile, as well as extinct forms like the Pleistocene camel. The humid periods of 52.5–50.5 kybp and 37.5–33 kybp were not has strong as those of the earlier Eemian humid period. The old theory was that the Mousterian Pluvial was caused by large- scale climatic changes during the last ice age.
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The Neopluvial is in part correlative to the Neoglacial, and might have been caused by a change in winter conditions over the North Pacific. This cooling is primarily explained by steadily declining summer insolation, though synchronous patterns in hydrological responses at sub-millennial scales may be linked to atmospheric circulation shifts driven by factors such as internal variability in ocean-atmosphere teleconnections. Strengthening ENSO variability, a cooling of the North Pacific and a southward shift of the Pacific jet stream also coincided with the Neopluvial. The neopluvial resembles the Pluvial period that occurred in western North America during the late Last Glacial Maximum, but was much weaker than the LGM wet period.
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According to an alternative hypothesis, the Carnian Pluvial Event was a regional climatic perturbation mostly visible in the western Tethys and related to the uplift of a new mountain range, the Cimmerian Orogen, which resulted from the closing of a tethyan northern branch, east of the present European continent. The new mountain range was forming on the southern side of Laurasia, and acted then as the Himalayas and Asia do today for the Indian Ocean, maintaining a strong pressure gradient between the ocean and continent, and thus generating a monsoon. Summer monsoonal winds were thus intercepted by the Cimmerian mountain range and generated strong rain, thus explaining the switch to humid climate recognized in western Tethys sediments.
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While the Atacama Desert was once considered an obstacle to human habitation, many traces of past human activity have been found in it. Between 12,800 and 9,700 years ago the "Central Andean Pluvial Event" led to the formation of large lakes in the Altiplano and of wetlands in the lowlands; these wetlands acted as oases of life and also as stepping stones for the spread of early humans. During the later Holocene the climate became more arid again, the lakes and many of these wetlands disappeared again. The latest Pleistocene-early Holocene was also the time by which humans in South America had colonized all available spaces with various technological strategies; in the case of the Atacama region, this included the then-existing wetlands.
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Most of the rocks underlying the Snake River Plain originated from massive lava flows related to eruptions of the Yellowstone hotspot over many millions of years. Shoshone Falls flows over a 6-million-year-old rhyolite or trachyte lava flow that intersects the weaker basalt layers comprising the surrounding Snake River Plain, creating a natural knickpoint that resists water erosion. The falls themselves were created quite suddenly during the cataclysmic Bonneville Flood at the end of the Pleistocene ice age about 14,500–17,500 years ago, when pluvial Lake Bonneville, an immense freshwater lake that covered much of the Great Basin, overflowed through Red Rock Pass into the Snake River. About of water were released–1500 times the average annual flow of the Snake River at Twin Falls.
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Remote Sensing of Environment. 282–297 global snow cover trends,DIETZ, A., KUENZER, C., and C. CONRAD, 2013: Snow cover variability in Central Asia between 2000 and 2011 derived from improved MODIS daily snow cover products. International Journal of Remote Sensing 34 (11), 3879–3902DIETZ, A., WOHNER, C., and C. KUENZER, 2012: European snow cover characteristics between 2000 and 2011 derived from improved MODIS daily snow cover products. Remote Sensing, 4, 2432–2454, doi:10.3390/rs4082432 water inundation from pluvial, riverine, or sea level rise flooding in coastal areas,KUENZER, C, KLEIN, I., ULLMANN; T., FOUFOULA- GEORGIOU, E., BAUMHAUER, R., DECH, S., 2015: Remote Sensing of River Delta Inundation: exploiting the Potential of coarse spatial Resolution, temporally- dense MODIS Time Series.
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Lake Bonneville and other ice age pluvial lakes (17,500 years BP), and modern remnants A significant amount of the physical evidence used by Kristan-Tollmann and Tollmann, as supporting their hypothesis, is either too old or too young to have been created by this hypothesized impact. In many cases, it is hundreds to thousands, and in one case hundreds of thousands, of years too old to be credible evidence of a Holocene impact. The research that dates the tektites, which Tollmann's bolide hypothesis regards as indicative for the timing of the impact, is outdated. Later research,Schneider, D.A., D.V. Kent, G.A. Mello, 1992, A detailed chronology of the Australasian impact event, the Brunhes–Matuyama geomagnetic polarity reversal, and global climatic change.
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Snowmelt from alpine glaciers on the nearby Sierra Nevada during glacial periods fed rivers that flowed into the valleys of the region year round. Since the topography of the Basin and Range region was largely formed by faulting, not by river erosion, many of the basins have no outlets, meaning they will fill up with water like a bathtub until they overflow into the next basin. So during the cooler and wetter pluvial climates of the glacial periods, much of eastern California, all of Nevada, and western Utah were covered by large lakes separated by linear islands (the present day ranges). Shoreline Butte showing Lake Manly shorelines The Lake Manly lake system as it might have looked during its last maximum extent 22,000 years ago.
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A reexamination of old radiocarbon dates and interpretation of paleomagnetic data and new radiocarbon dates limits the eruption of volcanic vents in this volcanic field to the time period between 7320 and 7790 calendar years B.P.Sherrod, D.R., D.E. Champion, and J.P. McGeehin (2012) Age and duration of volcanic activity at Diamond Craters, southeastern Oregon. Journal of Volcanology and Geothermal Research. 247–248:108–114 North of Diamond Craters, a late Pleistocene basaltic lava flow, called the Voltage Flow, forms a high- standing subdued ridge that marks the eastern boundary of the pluvial lake basin that is now occupied by Malheur, Mud, and Harney lakes. The Voltage Flow was erupted about 1.9 million years ago from several volcanic vents located north of Diamond Craters.
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Conodonts were a major vertebrate group which died out at the end of the Triassic Fish did not suffer a mass extinction at the end of the Triassic. The late Triassic in general did experience a gradual drop in actinopterygiian diversity after an evolutionary explosion in the middle Triassic. Though this may have been due to falling sea levels or the Carnian pluvial event, it may instead be a result of sampling bias considering that middle Triassic fish have been more extensively studied than late Triassic fish. Despite the apparent drop in diversity, neopterygiians (which include most modern bony fish) suffered less than more "primitive" actinopterygiians, indicating a biological turnover where modern groups of fish started to supplant earlier groups.
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Other ice sheets, such as the Laurentide Ice Sheet, formed during glacial periods, had completely melted and disappeared during interglacials. The major effects of the Quaternary glaciation, have been the erosion of land and the deposition of material, both over large parts of the continents; the modification of river systems; the creation of millions of lakes, including the development of pluvial lakes far from the ice margins; changes in sea level; the isostatic adjustment of the Earth's crust; flooding; and abnormal winds. The ice sheets themselves, by raising the albedo (the extent to which the radiant energy of the Sun is reflected from Earth) created significant feedback to further cool the climate. These effects have shaped entire environments on land and in the oceans, and in their associated biological communities.
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Traces of the Tauca humid episode have been found at Salar Pedernales, past 26° south latitude. Lake Tauca's highstand correlates with river terraces in Peru's Pisco River; terraces dated 24,000–16,000 BP in its tributary, the Quebrada Veladera; enlarged drainage systems in the Quebrada Veladera; a humid period at Lake Junin, and new soil formation in the pampas south of the Quinto River in Argentina. During the second Central Andean Pluvial Event, soils also formed in a wetland of northern Chile. During the Tauca phase, water levels in Laguna Miscanti were higher than today; shorelines formed from an event in Ch'iyar Quta and Lake Tuyajto; saline lakes formed in the Lipez area, and water levels rose in the Guayatayoc-Salinas Grandes basin, in Laguna de Suches in Peru and lakes at Uturuncu and Lazufre.
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Carvings of fauna common in the Sahara during the wet phase, found at Tassili in the central Sahara The Sahara pump theory is a hypothesis that explains how flora and fauna migrated between Eurasia and Africa via a land bridge in the Levant region. It posits that extended periods of abundant rainfall lasting many thousands of years (pluvial periods) in Africa are associated with a "wet-Sahara" phase, during which larger lakes and more rivers existed. This caused changes in the flora and fauna found in the area. Migration along the river corridor was halted when, during a desert phase 1.8–0.8 million years ago (mya), the Nile ceased to flow completely and possibly flowed only temporarily in other periods due to the geologic uplift (Nubian Swell) of the Nile River region.
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Lake Condon was a temporary lake in the Pacific Northwest region of North America, formed periodically by the Missoula Floods from 15,000 to 13,000 BC. The restricted flow of watersFlow was restricted by a hydraulic dam—a restriction to the flow rate caused by a narrowed reach in a river valley. from cataclysmic floods from Glacial Lake Missoula, and pluvial Lake Bonneville through the constriction of the Wallula Gap in the Horse Heaven Hills flowed into south-central Washington and north-central Oregon, and were backed up by the Columbia River Gorge, forming Lake Condon. The water remained for a period of 5–7 days before the flood waters drained through the Columbia River Gorge. Lake Condon reached an elevation of about 1200 feet above sea level (today's sea level) before subsiding.
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Monthly flows of the Aude near its outlet represented as a histogram In its upper reaches the Aude has a nivo-pluvial regime (with a maximum flow in spring linked to snowmelt). Then from CarcassonneData from the hydrological station at Carcassonne (Pont-neuf) Navigate on the page to obtain the different hydrological data, the Station Code is: Y1232010. where the average flow rate reaches , the system is almost entirely rainfed (The flow at Grau de VendresTotal Encyclopedia EnCarta 2006, article on the Aude. where it meets the Mediterranean is around .) The Aude is thus characterized in its lower course by a pluvio-nival regime of meridional type with high baseflow in summer, in August at Moussan in the lower alluvial plain not far from the river mouth, against an average of .
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In 1982, a sub-fossil right middle phalanx was found in a prehistoric midden near Kuruwita in Sri Lanka, which is dated to about 16,500 ybp and tentatively considered to be of a tiger. Tigers appear to have arrived in Sri Lanka during a pluvial period, during which sea levels were depressed, evidently prior to the last glacial maximum about 20,000 years ago. The tiger probably arrived too late in southern India to colonise Sri Lanka, which earlier had been connected to India by a land bridge. Results of a phylogeographic study using 134 samples from tigers across the global range suggest that the historical northeastern distribution limit of the Bengal tiger is the region in the Chittagong Hills and Brahmaputra River basin, bordering the historical range of the Indochinese tiger.
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30 to 18 kybp, the Laurentide Ice Sheet not only covered an enormous geographic area, but increased its altitude to 1750 meters (more than 1 mile). It generated its own long term weather patterns, which affected the jet stream passing over the North American continent. The jet stream effectively split in two, creating a new dominant weather pattern over the northern hemisphere that brought harsher conditions to several regions (including parts of Central Asia and the Middle East) -- changes that included an end to the Mousterian Pluvial and a return to a more arid climate in northern Africa. It is now understood that the major African Humid period events are caused by increased insolation in the northern hemisphere and the impact of continental surface warming on the tropical monsoons.
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The water would have reached the Culebra Creek and eventually the Red River at La Junta Point; the Red River constituted the headwater of the Rio Grande during that time. The overflow of Lake Alamosa into the Rio Grande expanded its catchment by about -, adding the high, glaciated San Juan Mountains, Sangre de Cristo Mountains and Sawatch Range to its watershed. Water levels dropped quickly after the overflow began, preventing the formation of the repeated shorelines that are common at shrinking pluvial lakes where the decline in water levels is paced by evaporation. The decline probably was not as quick as during the Bonneville flood of Lake Bonneville, another example of a lake overflow event in North America, as the rocks at Lake Alamosa were more solid and there is no clear indication of a catastrophic overflow flood.
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To avoid confusion about the makers, the Mousterian and Alterian tools are now sometimes grouped as Aterian. With more recent dating methods, these tools are now understood to have been mostly produced during the humid Eemian interglacial and later phases of MIS 5, from 130 kybp to 72 kybp. Mousterian tools are frequently older than the Aterian tools. During the dry period that followed in Northern Africa, from 71 to 14.5 kybp, recent research has found that there were 3 semi-humid interruptions: 65–61 kybp, 52.5–50.5 kybp and 37.5–33 kybp. The later 2 have sometimes been grouped to constitute a “Mousterian Pluvial.” They are not associated with strong “Green Sahara” events line the ones of the Eemian in early MIS 5; the late MIS 5 humid period (from 105 – 75 kybp); or the early Holocene.
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It has been suggested that this second group possibly possessed a more sophisticated "big game hunting" tool technology and was less dependent on coastal food sources than the original group. Much of the evidence for the first group's expansion would have been destroyed by the rising sea levels at the end of each glacial maximum. The multiple dispersal model is contradicted by studies indicating that the populations of Eurasia and the populations of Southeast Asia and Oceania are all descended from the same mitochondrial DNA L3 lineages, which support a single migration out of Africa that gave rise to all non-African populations. On the basis of the early date of Badoshan Iranian Aurignacian, Oppenheimer suggests that this second dispersal may have occurred with a pluvial period about 50,000 years before the present, with modern human big-game hunting cultures spreading up the Zagros Mountains, carrying modern human genomes from Oman, throughout the Persian Gulf, northward into Armenia and Anatolia, with a variant travelling south into Israel and to Cyrenicia.
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There is significant variation within the city, with rainfall at the lower- elevation Pudahuel site near the airport being about 20 percent lower than at the older Quinta Normal site near the city centre. Santiago's rainfall is highly variable and heavily influenced by the El Niño Southern Oscillation cycle, with rainy years coinciding with El Niño events and dry years with La Niña events.Rutllant, Josè and Fuenzalida, Humberto; "Synoptic Aspects of the Central Chile Rainfall Variability Associated with the Southern Oscillation," International Journal of Climatology, vol. 11 (1991), pp. 63–76 The wettest year since records began in 1866 was 1900 with Paskoff, Roland P.; "Geomorphological Processes and Characteristic Landforms in the Mediterranean Regions of the World," Mediterranean Type Ecosystems; in Ecological Studies, Volume 7, 1973, pp. 53–60 – part of a "pluvial" from 1898 to 1905 that saw an average of over eight yearsLliboutry, Louis; "Studies of the shrinkage after a sudden advance, blue bands and wave ogives on Glaciar Universidad (central Chilean Andes)," Journal of Glaciology; vol. 3, Issue 24, pp. 261–270 incorporating the second wettest year in 1899 with – and the driest 1924 with .
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