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142-756: The Salton Sea is a shallow, landlocked, highly saline endorheic lake in Riverside and Imperial counties at the southern end of the U.S. state of California . It lies on the San Andreas Fault within the Salton Trough , which stretches to the Gulf of California in Mexico . The lake is about 15 by 35 miles (24 by 56 km) at its widest and longest. A 2023 report puts the surface area at 318 square miles (823.6 km). The Salton Sea became

284-606: A resort destination in the 20th Century, but saw die-offs of fish and birds in the 1980s due to contamination from farm runoff , and clouds of toxic dust in the current century as evaporation exposed parts of the lake bed. Over millions of years, the Colorado River had flowed into the Imperial Valley and deposited alluvium (soil), creating fertile farmland, building up the terrain, and constantly moving its main course and river delta . For thousands of years,

426-661: A type section , Global Boundary Stratotype Section and Point (GSSP), for the upper Pleistocene/Holocene boundary ( i.e. the upper boundary). The proposed section is the North Greenland Ice Core Project ice core 75° 06' N 42° 18' W. The lower boundary of the Pleistocene Series is formally defined magnetostratigraphically as the base of the Matuyama (C2r) chronozone , isotopic stage 103. Above this point there are notable extinctions of

568-611: A change from low-amplitude glacial cycles with a dominant periodicity of 41,000 years to asymmetric high-amplitude cycles dominated by a periodicity of 100,000 years. However, a 2020 study concluded that ice age terminations might have been influenced by obliquity since the Mid-Pleistocene Transition, which caused stronger summers in the Northern Hemisphere . Glaciation in the Pleistocene

710-469: A change was finally confirmed in 2009 by the International Union of Geological Sciences , the cutoff of the Pleistocene and the preceding Pliocene was regarded as being 1.806 million years Before Present (BP). Publications from earlier years may use either definition of the period. The end of the Pleistocene corresponds with the end of the last glacial period and also with the end of

852-588: A complex mixture of many different elements from different sources (not all from dissolved salts) in different molecular forms. The chemical properties of some of these forms depend on temperature and pressure. Many of these forms are difficult to measure with high accuracy, and in any case complete chemical analysis is not practical when analyzing multiple samples. Different practical definitions of salinity result from different attempts to account for these problems, to different levels of precision, while still remaining reasonably easy to use. For practical reasons salinity

994-574: A deviation from today's annual mean temperature, taken as zero. This sort of graph is based on another isotope ratio versus time. Ratios are converted to a percentage difference from the ratio found in standard mean ocean water (SMOW). The graph in either form appears as a waveform with overtones . One half of a period is a Marine isotopic stage (MIS). It indicates a glacial (below zero) or an interglacial (above zero). Overtones are stadials or interstadials. According to this evidence, Earth experienced 102 MIS stages beginning at about 2.588 Ma BP in

1136-490: A few percent (%). Physical oceanographers working in the abyssal ocean , however, are often concerned with precision and intercomparability of measurements by different researchers, at different times, to almost five significant digits . A bottled seawater product known as IAPSO Standard Seawater is used by oceanographers to standardize their measurements with enough precision to meet this requirement. Measurement and definition difficulties arise because natural waters contain

1278-421: A few regions had been studied and the names were relatively few. Today the geologists of different nations are taking more of an interest in Pleistocene glaciology. As a consequence, the number of names is expanding rapidly and will continue to expand. Many of the advances and stadials remain unnamed. Also, the terrestrial evidence for some of them has been erased or obscured by larger ones, but evidence remains from

1420-456: A measured density. Marine waters are those of the ocean, another term for which is euhaline seas . The salinity of euhaline seas is 30 to 35 ‰. Brackish seas or waters have salinity in the range of 0.5 to 29 ‰ and metahaline seas from 36 to 40 ‰. These waters are all regarded as thalassic because their salinity is derived from the ocean and defined as homoiohaline if salinity does not vary much over time (essentially constant). The table on

1562-655: A safe eating advisory for fish caught in the Salton Sea based on levels of mercury or PCBs found in local species. As of 2018, all species were considered acceptable for all populations. The Salton Sea has been termed a "crown jewel of avian biodiversity" by Milt Friend of the Salton Sea Science Office. It hosts "the most diverse and probably most significant populations of bird life in the continental United States, rivaled only by Big Bend, Texas ;" over 400 species have been documented. The Salton Sea

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1704-578: A team of Russian scientists in collaboration with Princeton University announced that they had brought two female nematodes frozen in permafrost , from around 42,000 years ago, back to life. The two nematodes, at the time, were the oldest confirmed living animals on the planet. The evolution of anatomically modern humans took place during the Pleistocene. At the beginning of the Pleistocene Paranthropus species were still present, as well as early human ancestors, but during

1846-464: A wide range of salinities is euryhaline . Salts are expensive to remove from water, and salt content is an important factor in water use, factoring into potability and suitability for irrigation . Increases in salinity have been observed in lakes and rivers in the United States, due to common road salt and other salt de-icers in runoff. The degree of salinity in oceans is a driver of

1988-465: Is about 44,000 mg/L, that is about 4.4% salt. The amount of salts that is deposited in the Imperial Valley agricultural land with irrigation water is about 4 million tons of salts annually. To maintain crop productivities, equal amount of salts must be leached from the root zone". Fertilizer runoffs have resulted in eutrophication , with large algal blooms and elevated bacterial levels. By

2130-679: Is also a major resting stop on the Pacific Flyway . A December 2018 report by the National Geographic Society stated: "Nearly all of California's population of eared grebes , for example, stop over at the lake, and at least a third of all the white pelicans living in North America ..." The report expressed concern about the reducing input of water into the Sea and the increasing salinity. "Without that extra water,

2272-781: Is estimated that, at maximum glacial extent, 30% of the Earth's surface was covered by ice. In addition, a zone of permafrost stretched southward from the edge of the glacial sheet, a few hundred kilometres in North America , and several hundred in Eurasia . The mean annual temperature at the edge of the ice was −6 °C (21 °F); at the edge of the permafrost, 0 °C (32 °F). Each glacial advance tied up huge volumes of water in continental ice sheets 1,500 to 3,000 metres (4,900–9,800 ft) thick, resulting in temporary sea-level drops of 100 metres (300 ft) or more over

2414-470: Is mainly responsible, as California lawmakers pledged to fund air-quality management projects to mitigate impacts from the 2003 water transfer agreement. Over the years, local, state and federal bodies have found minimal success dealing with the dust from the exposed playa. To reduce wind-borne dust, the district has a program known as vegetation enhancement and surface roughening, which includes plowing furrows on newly exposed playa within property owned by

2556-459: Is no systematic correspondence between pluvials to glacials, however. Moreover, regional pluvials do not correspond to each other globally. For example, some have used the term "Riss pluvial" in Egyptian contexts. Any coincidence is an accident of regional factors. Only a few of the names for pluvials in restricted regions have been stratigraphically defined. The sum of transient factors acting at

2698-425: Is now too saline for most species of fish. Massive fish kills involve the oxygen-depleting combination of summer sun and salt. The fish suffocate as salt water carries less oxygen than fresh water. Dead fish wash up in mass quantities on the beaches. Introduced tilapia (hybrid Mozambique × Wami ) can tolerate the high salinity levels and pollution. As of 2014, other fresh and brackish water fish species lived in

2840-649: Is on a railroad map from 1900, although this place had existed as a rail stop since the late 1870s. Until the advent of the modern sea, the Salton Sink was the site of a major salt-mining operation. In 1900, under Governor James Budd , the California Development Company began construction of irrigation canals to divert water from the Colorado River into the Salton Sink, a dry lake bed. After construction of these irrigation canals,

2982-520: Is pulled in to replace the sinking water, which in turn eventually becomes cold and salty enough to sink. Salinity distribution contributes to shape the oceanic circulation. Limnologists and chemists often define salinity in terms of mass of salt per unit volume, expressed in units of mg/L or g/L. It is implied, although often not stated, that this value applies accurately only at some reference temperature because solution volume varies with temperature. Values presented in this way are typically accurate to

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3124-651: Is referred to as brine . Salinity is an ecological factor of considerable importance, influencing the types of organisms that live in a body of water. As well, salinity influences the kinds of plants that will grow either in a water body, or on land fed by a water (or by a groundwater ). A plant adapted to saline conditions is called a halophyte . A halophyte which is tolerant to residual sodium carbonate salinity are called glasswort or saltwort or barilla plants. Organisms (mostly bacteria) that can live in very salty conditions are classified as extremophiles , or halophiles specifically. An organism that can withstand

3266-466: Is sometimes referred to as chlorinity. Operationally, dissolved matter is defined as that which can pass through a very fine filter (historically a filter with a pore size of 0.45 μm, but later usually 0.2 μm). Salinity can be expressed in the form of a mass fraction , i.e. the mass of the dissolved material in a unit mass of solution. Seawater typically has a mass salinity of around 35 g/kg, although lower values are typical near coasts where rivers enter

3408-470: Is usually related to the sum of masses of a subset of these dissolved chemical constituents (so-called solution salinity ), rather than to the unknown mass of salts that gave rise to this composition (an exception is when artificial seawater is created). For many purposes this sum can be limited to a set of eight major ions in natural waters, although for seawater at highest precision an additional seven minor ions are also included. The major ions dominate

3550-659: The Alpine ice sheet on the Alps . Scattered domes stretched across Siberia and the Arctic shelf. The northern seas were ice-covered. South of the ice sheets large lakes accumulated because outlets were blocked and the cooler air slowed evaporation. When the Laurentide Ice Sheet retreated, north-central North America was completely covered by Lake Agassiz . Over a hundred basins, now dry or nearly so, were overflowing in

3692-658: The California Natural Resources Agency finished the "Bruchard Road Dust Suppression Project" which, although only 112 acres (45 ha), was the first dust suppression project to be completed under the Salton Sea Management Program: Phase 1: 10 Year Plan (August 2018). Construction began on the ambitious 4,110-acre (1,660 ha) Species Conservation Habitat (SCH) Project in January 2021 on the small delta of

3834-462: The Colorado River "is facing an unprecedented water crisis due to prolonged drought, climate change and an overallocation of its resources". The water of the Salton Sea has a salinity of 44 grams of salt per liter, greater than that of the Pacific Ocean (35 g/L). The lack of an outflow means the Salton Sea does not have a natural stabilization system; it is very dynamic. Fluctuations in

3976-406: The Gulf of California . Most of these gulls are only present in the summer months. According to the A. W. Kuchler U.S. potential natural vegetation types, the area roughly within 3 miles (4.8 km) of the sandy shoreline of the Salton Sea would have a saltbush / greasewood ( 40 ) vegetation type and a Great Basin shrubland ( 7 ) vegetation form. This saline , endorheic rift lake on

4118-449: The Pacific Flyway . In the 1970s, scientists issued warnings that the lake would continue to shrink and become more inhospitable to wildlife. In the 1980s, contamination from farm runoff promoted the outbreak and spread of wildlife diseases. Massive die-offs of the avian populations have occurred, especially after the loss of several species of fish on which they depend. Salinity rose so high that large fish kills occurred, often blighting

4260-542: The Paleolithic age used in archaeology . The name is a combination of Ancient Greek πλεῖστος ( pleîstos ) 'most' and καινός ( kainós ; Latinized as cænus ) 'new'. At the end of the preceding Pliocene, the previously isolated North and South American continents were joined by the Isthmus of Panama , causing a faunal interchange between the two regions and changing ocean circulation patterns, with

4402-513: The Quantification Settlement Agreement of 2003, the surface area of the sea had been expected to decrease by 60% between 2013 and 2021. Salinity Salinity is an important factor in determining many aspects of the chemistry of natural waters and of biological processes within it, and is a thermodynamic state variable that, along with temperature and pressure , governs physical characteristics like

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4544-662: The Ruwenzori Range in east and central Africa were larger. Glaciers existed in the mountains of Ethiopia and to the west in the Atlas Mountains . In the northern hemisphere, many glaciers fused into one. The Cordilleran Ice Sheet covered the North American northwest; the east was covered by the Laurentide . The Fenno-Scandian ice sheet rested on northern Europe , including much of Great Britain;

4686-629: The San Andreas Fault at the southern end of the U.S. state of California lies between and within the Imperial and Coachella valleys, all of which lie within the larger Salton Trough , a pull-apart basin that stretches to the Gulf of California in Mexico. The lake occupies the lowest elevations of the trough, known as the Salton Sink , where the lake surface is 236.0 ft (71.9 m) below sea level as of January 2018. The deepest point of

4828-437: The calcareous nannofossils : Discoaster pentaradiatus and Discoaster surculus . The Pleistocene covers the recent period of repeated glaciations. The name Plio-Pleistocene has, in the past, been used to mean the last ice age. Formerly, the boundary between the two epochs was drawn at the time when the foraminiferal species Hyalinea baltica first appeared in the marine section at La Castella, Calabria, Italy. However,

4970-459: The coot ), black-tailed jackrabbit , black-tailed cottontail rabbit , and sometimes deer and bighorn sheep . Among the plants they used were bulrush , cattail , mesquite , and saltbush . The Cahuilla people have an oral memory of the last lake, which existed in the 17th century and dried up soon after 1700. Throughout the Spanish period of California's history, the area was referred to as

5112-529: The density and heat capacity of the water. A contour line of constant salinity is called an isohaline , or sometimes isohale . Salinity in rivers, lakes, and the ocean is conceptually simple, but technically challenging to define and measure precisely. Conceptually the salinity is the quantity of dissolved salt content of the water. Salts are compounds like sodium chloride , magnesium sulfate , potassium nitrate , and sodium bicarbonate which dissolve into ions. The concentration of dissolved chloride ions

5254-564: The hydrography is such that a possible cause of reduced circulation is the production of stratified oceans. In such cases, it is more difficult to subduct water through the thermohaline circulation. Not only is salinity a driver of ocean circulation, but changes in ocean circulation also affect salinity, particularly in the subpolar North Atlantic where from 1990 to 2010 increased contributions of Greenland meltwater were counteracted by increased northward transport of salty Atlantic waters. However, North Atlantic waters have become fresher since

5396-477: The last glacial period ended about 10,000 years ago. Over 11 major glacial events have been identified, as well as many minor glacial events. A major glacial event is a general glacial excursion, termed a "glacial." Glacials are separated by "interglacials". During a glacial, the glacier experiences minor advances and retreats. The minor excursion is a "stadial"; times between stadials are "interstadials". These events are defined differently in different regions of

5538-599: The woolly rhinoceros , various giraffids , such as the Sivatherium ; ground sloths , Irish elk , cave lions , cave bears , Gomphotheres , American lions , dire wolves , and short-faced bears , began late in the Pleistocene and continued into the Holocene. Neanderthals also became extinct during this period. At the end of the last ice age, cold-blooded animals, smaller mammals like wood mice , migratory birds, and swifter animals like whitetail deer had replaced

5680-413: The world's ocean circulation , where density changes due to both salinity changes and temperature changes at the surface of the ocean produce changes in buoyancy, which cause the sinking and rising of water masses. Changes in the salinity of the oceans are thought to contribute to global changes in carbon dioxide as more saline waters are less soluble to carbon dioxide. In addition, during glacial periods,

5822-568: The " Colorado Desert " after the Colorado River. In a railroad survey completed in 1855, it was called "the Valley of the Ancient Lake". On several old maps from the Library of Congress , it has been found labeled "Cahuilla Valley" (after the local Indian tribe) and "Cabazon Valley" (after a local Indian chief – Chief Cabazon). " Salt Creek " first appeared on a map in 1867, and "Salton Station"

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5964-654: The "Tarantian"). In addition to these international subdivisions, various regional subdivisions are often used. In 2009 the International Union of Geological Sciences (IUGS) confirmed a change in time period for the Pleistocene, changing the start date from 1.806 to 2.588 million years BP, and accepted the base of the Gelasian as the base of the Pleistocene, namely the base of the Monte San Nicola GSSP . The start date has now been rounded down to 2.580 million years BP. The IUGS has yet to approve

6106-405: The 1970s, the runoff which was full of salty chemicals led to a warning that the salinity of the lake would no longer sustain wildlife. Both the hypersalinity and the presence of contaminants in the Salton Sea triggered massive die-offs in the fish and avian populations; salt water carries less oxygen than fresh water , which was further depleted by algal blooms and by extreme temperatures during

6248-408: The 1980s. Titration with silver nitrate could be used to determine the concentration of halide ions (mainly chlorine and bromine ) to give a chlorinity . The chlorinity was then multiplied by a factor to account for all other constituents. The resulting 'Knudsen salinities' are expressed in units of parts per thousand (ppt or ‰ ). The use of electrical conductivity measurements to estimate

6390-650: The 2013 USGS Salton Sea Ecosystem Monitoring and Assessment Plan. The first state-funded project was the Torres-Martinez Wetland Project, in which the Torres Martinez Desert Cahuilla Indians partnered with the state to restore shallow wetlands along the northern edge of the sea that was destroyed by a massive storm in 2012. This prototype project was completed in April 2018. In November 2019, an emergency

6532-569: The Early Pleistocene Gelasian . Early Pleistocene stages were shallow and frequent. The latest were the most intense and most widely spaced. By convention, stages are numbered from the Holocene, which is MIS1. Glacials receive an even number and interglacials receive an odd number. The first major glacial was MIS2-4 at about 85–11 ka BP. The largest glacials were 2, 6, 12, and 16. The warmest interglacials were 1, 5, 9 and 11. For matching of MIS numbers to named stages, see under

6674-409: The Earth's surface is cyclical: climate, ocean currents and other movements, wind currents, temperature, etc. The waveform response comes from the underlying cyclical motions of the planet, which eventually drag all the transients into harmony with them. The repeated glaciations of the Pleistocene were caused by the same factors. The Mid-Pleistocene Transition , approximately one million years ago, saw

6816-594: The Imperial County Air Pollution Control District. Local activists ask if this is an issue of environmental justice , since the area most impacted is 85% Latinos. Some 650,000 people, many who are farmworkers, live where there is significant exposure to the dust. The public health impacts of continuing not to meet federal air quality standards include the treatment of child and adult asthma, cardiac disease , lung cancer , and increased mortality rates . Lower concentrations of

6958-661: The Interior prepared a draft Environmental Impact Report in compliance with the Reclamation Act and working in partnership with the Salton Sea Authority . A Strategic Science Plan and the Bureau of Reclamation's Alternatives Appraisal Report were also added to the voluminous studies of the lake. Before the legislative and scientific recommendations were implemented, priorities shifted away from activities at

7100-519: The Mexican border and then north into 1,700 miles (2,700 km) of irrigation channels that crisscross the farms. Gravity carries the agricultural runoff downhill through the New and Alamo rivers to the lake. The water is full of salts, selenium , and fertilizers (mainly nitrates ). As it drains through the soil, the water leaches out ancient salt deposits that also raise the salinity. Evaporation in

7242-611: The New River. The project is building ponds and wetlands on both sides of the mouth of this highly polluted river on the southern bank of the sea. Water from the Salton Sea will be combined with the river water to control salinity and naturally occurring selenium . While creating a dust reducing wetlands, the blended water will achieve the proper conditions for the desert pupfish and other aquatic life. Federal government said in November 2022, it will spend $ 250 million over four years for

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7384-479: The North American west. Lake Bonneville , for example, stood where Great Salt Lake now does. In Eurasia, large lakes developed as a result of the runoff from the glaciers. Rivers were larger, had a more copious flow, and were braided . African lakes were fuller, apparently from decreased evaporation. Deserts, on the other hand, were drier and more extensive. Rainfall was lower because of the decreases in oceanic and other evaporation. It has been estimated that during

7526-496: The Pleistocene's overall climate could be characterised as a continuous El Niño with trade winds in the south Pacific weakening or heading east, warm air rising near Peru , warm water spreading from the west Pacific and the Indian Ocean to the east Pacific, and other El Niño markers. Pleistocene climate was marked by repeated glacial cycles in which continental glaciers pushed to the 40th parallel in some places. It

7668-805: The Pleistocene, the East Antarctic Ice Sheet thinned by at least 500 meters, and that thinning since the Last Glacial Maximum is less than 50 meters and probably started after ca 14 ka. During the 2.5 million years of the Pleistocene, numerous cold phases called glacials ( Quaternary ice age ), or significant advances of continental ice sheets, in Europe and North America, occurred at intervals of approximately 40,000 to 100,000 years. The long glacial periods were separated by more temperate and shorter interglacials which lasted about 10,000–15,000 years. The last cold episode of

7810-411: The Pleistocene, the plates upon which they sit probably having moved no more than 100 km (62 mi) relative to each other since the beginning of the period. In glacial periods, the sea level would drop by up to 120 m (390 ft) lower than today during peak glaciation, exposing large areas of the present continental shelf as dry land. According to Mark Lynas (through collected data),

7952-633: The Pleistocene. The climate was strongly variable depending on the glacial cycle, with the sea levels being up to 120 metres (390 ft) lower than present at peak glaciation, allowing the connection of Asia and North America via Beringia and the covering of most of northern North America by the Laurentide Ice Sheet . Charles Lyell introduced the term "Pleistocene" in 1839 to describe strata in Sicily that had at least 70% of their molluscan fauna still living today. This distinguished it from

8094-900: The Salton Sea Restoration Act. It stated that it was the "intent of the Legislature that the State of California undertake the restoration of the Salton Sea ecosystem and the permanent protection of the wildlife dependent on that ecosystem". The restoration plan was not implemented as state lawmakers found it too expensive and the Great Recession hit the economy. Repeated delays and dwindling public interest precluded any real change. The lake continued to dry up, exposing more lake bed known as playa , and sending nearby communities clouds of toxic dust. A haze incorporating pesticide plumes, exhaust fumes, factory emissions, and

8236-403: The Salton Sea by the year 2028. This would improve conditions for residents and wildlife. The initial 10-year plan will cover less than half of the dry lakebed that researchers say will be exposed during that time. The state initially budgeted $ 80.5 million to begin designing the wetlands without a commitment that the program will ever be fully funded. The projected cost to design and construct

8378-545: The Salton Sea to compensate for the loss of agricultural runoff needed to replenish the sea. As the 2017 deadline for ending the additional mitigation water approached, the district, along with Imperial County, petitioned the California State Water Resources Control Board in 2014 with a demand for state action to fulfill its obligation after years of delays and unfulfilled plans. Pacific Institute , an environmental think tank ,

8520-408: The Salton Sea" would be lower and achievable using existing infrastructure. The aqueduct proposal, and others, hung on the outcome of a feasibility study. After a yearlong review, in 2022 a state-appointed panel of experts rejected the idea "based on its high cost, environmental damage, minimal benefits to Mexico" and other factors, recommending instead that fresh water be diverted to the sea. However,

8662-442: The Salton Sea. The body was initially a freshwater lake and was stocked with tilapia , gulf croaker , orangemouth corvina , and sargo , which sustained an important sport fishery and provided food for birds. By the 1960s, its rising salinity had begun to jeopardize some of these species. A September 2019 report stated that 20 years earlier, "there were some 100 million fish in the Sea. Now, more than 97% of those fish are gone". It

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8804-575: The Salton Sink became fertile, allowing farmers to plant crops. Within two years, the Alamo Canal became filled with silt from the Colorado River. Engineers tried to alleviate the blockages to no avail. Imperial Valley farmers, under considerable financial stress, pressured the California Development Company to resolve the problem. Engineer Charles Rockwood , faced with bankruptcy and "after mature deliberation", directed

8946-563: The United Arab Emirates, Saudi Arabia, and Japan. Most of exported hay feeds dairy cows, while Japan uses it for Kobe beef production. On January 1, 2018, 40% less water began flowing into the sea as the 15-year mitigation period ended per the 2003 water transfer agreement. A court decision also forced the Imperial Irrigation District to end a program that had allowed it to equally distribute and cap

9088-535: The Younger Dryas is the official start of the current Holocene Epoch . Although it is considered an epoch, the Holocene is not significantly different from previous interglacial intervals within the Pleistocene. In the ICS timescale, the Pleistocene is divided into four stages or ages , the Gelasian , Calabrian , Chibanian (previously the unofficial "Middle Pleistocene"), and Upper Pleistocene (unofficially

9230-408: The amount of water its members receive. Although it had been shrinking for years, this began to lower the water level significantly. As the shore recedes, at least 75 square miles (190 km) of playa will be exposed by 2045, with additional dust becoming wind blown as the exposed playa dries out. A vertical drop of one foot in the water level can expose thousands of feet of horizontal playa. The state

9372-706: The appearance of Homo sapiens about 300,000 years ago. Artifacts associated with modern human behavior are unambiguously attested starting 40,000–50,000 years ago. According to mitochondrial timing techniques, modern humans migrated from Africa after the Riss glaciation in the Middle Palaeolithic during the Eemian Stage , spreading all over the ice-free world during the late Pleistocene. A 2005 study posits that humans in this migration interbred with archaic human forms already outside of Africa by

9514-411: The area, and as of 2020 was developing a seawater desalination proposal. In 2018, the California Natural Resources Agency requested proposals to increase waterflow to the sea to reduce dust and dust-borne toxins. The 11 proposals ranged in cost from $ 300 million to several billion dollars. Alternatively, a 2020 research report stated that the cost of "transferring water from agricultural users to

9656-527: The articles for those names. Both marine and continental faunas were essentially modern but with many more large land mammals such as Mammoths , Mastodons , Diprotodons , Smilodons , tigers , lions , Aurochs , short-faced bears , giant sloths , species within Gigantopithecus and others. Isolated landmasses such as Australia , Madagascar , New Zealand and islands in the Pacific saw

9798-456: The avian population depended on for food increased their risk of starvation, exacerbating their decline. Birdwatchers in 2017 reported that most of the American white pelicans , double-crested cormorants , and eared grebes have disappeared. The Salton Sea is notable as the only part of the United States to host a significant population of Yellow-footed gulls , a species otherwise endemic to

9940-641: The basin resulted in the formation of the Salton Sea. On February 11, 1907, the breach was finally closed after substantial intervention by the Southern Pacific Transportation Company . In the 1920s, agriculture had boomed in the valley as the Imperial Irrigation District delivered large quantities of Colorado River water to irrigate the crops. The lake would have dried up naturally, but with flood irrigation being commonly used, plenty of water ran off

10082-450: The beaches of the sea with their carcasses. Tourism was drastically reduced. After 1999, the lake began to shrink as local agriculture used the water more efficiently, so less runoff flowed into the lake. As the lake bed became exposed, the winds sent clouds of toxic dust into nearby communities. The state is mainly responsible for fixing the problems. California lawmakers pledged to fund air-quality management projects in conjunction with

10224-626: The breach was later described as a "blunder so serious as to be practically criminal." In 1905, heavy rainfall and snowmelt caused the Colorado River to swell, overrunning the third intake cut into the bank of the river and sending the flood into the Alamo Canal. The resulting flood poured down the canal and down two formerly dry arroyos , the New River in the west and the Alamo River in the east, each about 60 mi (97 km) long. Over about two years, these two newly created rivers carried

10366-480: The children in the region have asthma (with the national rate being less than 10%). Scientists are studying how much of this is caused by the Salton Sea dust and what is actually in the windblown particles. Ten schools in the Imperial Valley use green, yellow, and red flags signaling air quality for the many children who have asthma. Green means they join their friends on the playground, whereas red means they stay inside all day. Parents can also receive emailed alerts from

10508-538: The climate variation more extreme. The Late Pleistocene witnessed the spread of modern humans outside of Africa as well as the extinction of all other human species. Humans also spread to the Australian continent and the Americas for the first time, co-incident with the extinction of most large-bodied animals in these regions. The aridification and cooling trends of the preceding Neogene were continued in

10650-417: The composition of seawater. They can also be determined by making direct density measurements. A sample of seawater from most locations with a chlorinity of 19.37 ppt will have a Knudsen salinity of 35.00 ppt, a PSS-78 practical salinity of about 35.0, and a TEOS-10 absolute salinity of about 35.2 g/kg. The electrical conductivity of this water at a temperature of 15 °C is 42.9 mS/cm. On

10792-552: The construction of a breach in the bank of the Colorado River approximately 4 miles (6.4 km) south of the existing wooden headgates (the Chaffey Gate). The breach, known as the Lower Mexican Intake and constructed without headgates and without the permission of the Mexican authorities, allowed the Colorado River to flow unimpeded into the canal and then to Imperial Valley farms. Rockwood's action in ordering

10934-433: The desert heat further concentrates the salt. The transformation of the lake made it increasingly inhospitable to wildlife. By the late 1970s, fish started dying off and bird populations declined. In the late 1970s, a series of heavy tropical storms caused the water level to rapidly rise and flood its banks. The surrounding towns and businesses were severely damaged, many beyond repair. In 1976, Hurricane Kathleen inundated

11076-678: The district. Fugitive dust , consisting of very small particles suspended in the air, is being studied to distinguish between playa dust and desert emissions that are primarily made up of mineral dust from soil. The Imperial County Air Quality Management District , the South Coast Air Quality Management District, and the University of California at Riverside School of Medicine along with the environmental justice group Comite Civico Del Valle are using mobile and stationary air quality monitoring units in

11218-563: The effort to protect the health of the nearby residents. The Salton Sea Task Force was formed by the state in 2015 by Governor Jerry Brown 's administration. The Natural Resources Agency released the Salton Sea Management Program (SSMP) in March 2017. The SSMP proposed constructing 29,800 acres (12,100 ha) of habitat restoration and dust suppression projects on lakebed areas that have been, or will be, exposed at

11360-416: The end of mitigation flows at the start of 2018), there will not be any species of fish left that will be able to survive in the sea's main body. As the decline of tilapia populations continues, there has been an immense proliferation of the water boatman population which do serve as feed for "a limited number of aquatic and shorebird species". A direct concern of the potential eradication of fish species from

11502-618: The entire surface of the Earth. During interglacial times, such as at present, drowned coastlines were common, mitigated by isostatic or other emergent motion of some regions. The effects of glaciation were global. Antarctica was ice-bound throughout the Pleistocene as well as the preceding Pliocene. The Andes were covered in the south by the Patagonian ice cap. There were glaciers in New Zealand and Tasmania . The current decaying glaciers of Mount Kenya , Mount Kilimanjaro , and

11644-411: The entire volume of the Colorado River into the Salton Sink. The Southern Pacific Railroad tried to stop the flooding by dumping earth into the canal's headgates area, but the effort was not fast enough, and the river eroded deeper and deeper into the dry desert sand of the Imperial Valley. A large waterfall formed as a result and began cutting rapidly upstream along the path of the Alamo Canal that now

11786-782: The evolution of large birds and even reptiles such as the Elephant bird , moa , Haast's eagle , Quinkana , Megalania and Meiolania . The severe climatic changes during the Ice Age had major impacts on the fauna and flora. With each advance of the ice, large areas of the continents became depopulated, and plants and animals retreating southwards in front of the advancing glacier faced tremendous stress. The most severe stress resulted from drastic climatic changes, reduced living space, and curtailed food supply. A major extinction event of large mammals ( megafauna ), which included mammoths , mastodons , saber-toothed cats , glyptodons ,

11928-404: The farms into the lake and kept it full. The district holds senior rights to water from the Colorado River according to Doctrine of Prior Appropriation , which states that whoever first puts a quantity of water from a given source to beneficial use gains the right to use that quantity of water from that source in future. In 1930, a wildlife refuge was established on some wetlands along the edge of

12070-491: The form of silicic acid , which usually appears as a neutral molecule in the pH range of most natural waters, may also be included for some purposes (e.g., when salinity/density relationships are being investigated). The term 'salinity' is, for oceanographers, usually associated with one of a set of specific measurement techniques. As the dominant techniques evolve, so do different descriptions of salinity. Salinities were largely measured using titration -based techniques before

12212-414: The glacial range, which have their own glacial history depending on latitude, terrain and climate. There is a general correspondence between glacials in different regions. Investigators often interchange the names if the glacial geology of a region is in the process of being defined. However, it is generally incorrect to apply the name of a glacial in one region to another. For most of the 20th century, only

12354-411: The global scale, it is extremely likely that human-caused climate change has contributed to observed surface and subsurface salinity changes since the 1950s, and projections of surface salinity changes throughout the 21st century indicate that fresh ocean regions will continue to get fresher and salty regions will continue to get saltier. Salinity is serving as a tracer of different masses. Surface water

12496-440: The growing communities they serve. Local agriculture became more efficient at using water which resulted in the shoreline retreating as less run-off flowed into the lake. Farmers installed sprinklers to replace flood irrigation and used soil measurement devices that tell them when to water. As the Salton Sea shrank, it became saltier than ocean water. The California State Legislature , by legislation enacted in 2003 and 2004, directed

12638-450: The historical terminology was established. Corresponding to the terms glacial and interglacial, the terms pluvial and interpluvial are in use (Latin: pluvia , rain). A pluvial is a warmer period of increased rainfall; an interpluvial is of decreased rainfall. Formerly a pluvial was thought to correspond to a glacial in regions not iced, and in some cases it does. Rainfall is cyclical also. Pluvials and interpluvials are widespread. There

12780-468: The improvements is $ 383 million. The focus was no longer on restoring the lake but presenting a feasible plan with a budget that legislators would gradually fund over the ten-year period. The 10-year plan will not fix everything so state and local officials continue to seek ways to deal with the problems. Salton Sea Management Program Monitoring and Adaptive Management Implementation Plan is being developed that will prioritize and phase-in implementation of

12922-421: The inorganic composition of most (but by no means all) natural waters. Exceptions include some pit lakes and waters from some hydrothermal springs . The concentrations of dissolved gases like oxygen and nitrogen are not usually included in descriptions of salinity. However, carbon dioxide gas, which when dissolved is partially converted into carbonates and bicarbonates , is often included. Silicon in

13064-412: The ionic content of seawater led to the development of the scale called the practical salinity scale 1978 (PSS-78). Salinities measured using PSS-78 do not have units. The suffix psu or PSU (denoting practical salinity unit ) is sometimes added to PSS-78 measurement values. The addition of PSU as a unit after the value is "formally incorrect and strongly discouraged". In 2010 a new standard for

13206-646: The irrigation canals. In the 1950s and into the 1960s, the communities expanded as the area's reputation as a resort destination and sport fishery grew. Hotels and yacht clubs were built on the shore along with homes and schools. Resorts in communities like Bombay Beach hosted entertainers such as Frank Sinatra , The Beach Boys and Bing Crosby . Yacht clubs held parties at night and golf courses provided recreation. Many people came for boating activities such as water skiing and fishing as stocked fish proliferated. Lakeshore communities grew as vacation homes were built. More than 1.5 million visitors visited annually at

13348-686: The lake after the September 11 attacks in 2001. In 2003, the Imperial Irrigation District signed the largest agriculture-to-urban water transfer agreement in US history. Much of its water allocation would go to communities along the California coast at a profit. With a 45-year term, the Quantification Settlement Agreement was a means for the San Diego County Water Authority and other districts to obtain additional water for

13490-408: The lake is only 5 ft (1.5 m) higher than the lowest point of Death Valley . The Salton Sea is about 15 by 35 miles (24 by 56 km) at its widest and longest, though it varies in dimensions and area with fluctuations in agricultural runoff and rainfall. A 2023 report puts surface area at 318 square miles. The New , Whitewater , and Alamo rivers, combined with agricultural runoff , are

13632-419: The lake that had attracted many birds. The fish flourished in the lake and provided a source of food for massive populations of migratory birds. Birdwatchers flocked to this new refuge in the middle of a desert. The continuing intermittent flooding of the Imperial Valley from the Colorado River ended with the construction of Hoover Dam . Imperial Dam , built in 1938, serves as a desilting dam for water entering

13774-411: The lake's shrinking will start to accelerate—making it saltier, smaller, less welcoming to the birds that rely on it during migration". Both the hypersalinity and presence of contaminants in the Salton Sea triggered massive die-offs in the fish and avian populations and the contamination promoted the outbreak and spread of diseases such as avian cholera . In turn, the loss of several species of fish that

13916-481: The lake, botulism spread among the dying tilapia , which were eaten by the birds. During a four-month long period in 1996, 14,000 birds died from eating the fish, nearly 10,000 of which were pelicans. The carcasses were burned in an incinerator 24 hours per day for weeks. The resulting news coverage conveyed a simplified story that implied the lake was a toxic catastrophe filled with water that could be deadly. In 1995, Congressman Sonny Bono advocated for attention to

14058-439: The lakeshore communities and put Bombay Beach completely underwater. Tourism was drastically reduced, and many of the resorts and associated infrastructure were abandoned. The state began to issue odor advisories as the lake began to stink. In the 1990s, the shores were littered with dead fish as the lake had gotten so salty that large die-offs occurred. Fertilizers in the runoff caused massive blooms of algae . When storms churned

14200-622: The large amounts of material moved about by glaciers. Less common are cave deposits, travertines and volcanic deposits (lavas, ashes). Pleistocene marine deposits are found primarily in shallow marine basins mostly (but with important exceptions) in areas within a few tens of kilometres of the modern shoreline. In a few geologically active areas such as the Southern California coast, Pleistocene marine deposits may be found at elevations of several hundred metres. The modern continents were essentially at their present positions during

14342-470: The lower Palaeolithic they disappeared, and the only hominin species found in fossilic records is Homo erectus for much of the Pleistocene. Acheulean lithics appear along with Homo erectus , some 1.8 million years ago, replacing the more primitive Oldowan industry used by A. garhi and by the earliest species of Homo . The Middle Paleolithic saw more varied speciation within Homo , including

14484-409: The measured conductivity at 5 °C might only be in the range of 50–80 μS/cm. Direct density measurements are also used to estimate salinities, particularly in highly saline lakes . Sometimes density at a specific temperature is used as a proxy for salinity. At other times an empirical salinity/density relationship developed for a particular body of water is used to estimate the salinity of samples from

14626-478: The megafauna and migrated north. Late Pleistocene bighorn sheep were more slender and had longer legs than their descendants today. Scientists believe that the change in predator fauna after the late Pleistocene extinctions resulted in a change of body shape as the species adapted for increased power rather than speed. The extinctions hardly affected Africa but were especially severe in North America where native horses and camels were wiped out. In July 2018,

14768-469: The mid-2010s due to increased Greenland meltwater flux. Pleistocene The Pleistocene ( / ˈ p l aɪ s t ə ˌ s iː n , - s t oʊ -/ PLY -stə-seen, -⁠stoh- ; referred to colloquially as the Ice Age ) is the geological epoch that lasted from c.  2.58 million to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations . Before

14910-402: The modern lake. During the early 20th century, the lake would have dried up, except that farmers used generous amounts of Colorado River water for irrigation and let the excess flow into the lake. In the 1950s and into the 1960s, the area became a resort destination , and communities grew with hotels and vacation homes. Birdwatching was also popular as the wetlands were a major resting stop on

15052-461: The northern edge of the sea in 2018. Construction began in 2021 on a 4,110-acre (1,660 ha) habitat restoration and dust suppression project. The Gulf of California would extend as far north as the city of Indio , some 150 miles (240 km) northwest of its current limits, were it not for the delta created by the Colorado River. Over three million years, through all of the Pleistocene ,

15194-422: The ocean. Rivers and lakes can have a wide range of salinities, from less than 0.01 g/kg to a few g/kg, although there are many places where higher salinities are found. The Dead Sea has a salinity of more than 200 g/kg. Precipitation typically has a TDS of 20 mg/kg or less. Whatever pore size is used in the definition, the resulting salinity value of a given sample of natural water will not vary by more than

15336-581: The older Pliocene Epoch , which Lyell had originally thought to be the youngest fossil rock layer. He constructed the name "Pleistocene" ('most new' or 'newest') from the Greek πλεῖστος ( pleīstos ) 'most' and καινός ( kainós ( Latinized as cænus ) 'new'). This contrasts with the immediately preceding Pliocene ("newer", from πλείων ( pleíōn , "more") and kainós ) and the immediately subsequent Holocene ("wholly new" or "entirely new", from ὅλος ( hólos , "whole") and kainós ) epoch , which extends to

15478-700: The onset of glaciation in the Northern Hemisphere occurring around 2.7 million years ago. During the Early Pleistocene (2.58–0.8 Ma), archaic humans of the genus Homo originated in Africa and spread throughout Afro-Eurasia . The end of the Early Pleistocene is marked by the Mid-Pleistocene Transition , with the cyclicity of glacial cycles changing from 41,000-year cycles to asymmetric 100,000-year cycles, making

15620-491: The order of 1%. Limnologists also use electrical conductivity , or "reference conductivity", as a proxy for salinity. This measurement may be corrected for temperature effects, and is usually expressed in units of μS/cm . A river or lake water with a salinity of around 70 mg/L will typically have a specific conductivity at 25 °C of between 80 and 130 μS/cm. The actual ratio depends on the ions present. The actual conductivity usually changes by about 2% per degree Celsius, so

15762-470: The peak. In the 1970s, scientists issued warnings about the changes coming to this lake with no outlet. Studies that started in the 1960s found a complex problem for which any remediation would be expensive. The Imperial Valley has about 500,000 acres (200,000 ha) of farmland for which flood irrigation is typical. Water from the Colorado River is diverted near Yuma, Arizona , into the 82-mile (132 km) All-American Canal . The canal runs west along

15904-465: The present time. The Pleistocene has been dated from 2.580 million (±0.005) to 11,700 years BP with the end date expressed in radiocarbon years as 10,000 carbon-14 years BP. It covers most of the latest period of repeated glaciation , up to and including the Younger Dryas cold spell. The end of the Younger Dryas has been dated to about 9700 BCE (11,700 calendar years BP). The end of

16046-413: The primary sources that feed the lake. The Salton Sea is the largest lake in California by surface area. The average annual inflow is less than 1.2 million  acre⋅ft (1.5 km), which is enough to maintain a maximum depth of 43 feet (13 m) and a total volume of about 6 million  acre⋅ft (7.4 km). Due to changes in water apportionments agreed upon for the Colorado River under

16188-608: The problems. His wife and some politicians took up the cause as a form of tribute to Bono after his death in a 1998 skiing accident. Congress passed and President Bill Clinton signed into law the Salton Sea Reclamation Act of 1998 (Public Law 105-372). In 1999, the lake began to recede dramatically. The dropping water level stranded many of the remaining boat docks, residences, and businesses. Water-management priorities were changing including diverting water from agricultural areas to cities. The U.S. Department of

16330-603: The project. In October 2024, expanding the SCH project by 750 acres (300 ha) was announced with the allocation of $ 70 million in federal funding for improving drought infrastructure. Many concepts have been proposed on how to deal with the problems. The idea of importing seawater from the Pacific Ocean or the Sea of Cortez in Mexico has been around for a long time. The area's plentiful geothermal power could be used to desalinate

16472-598: The properties of seawater called the thermodynamic equation of seawater 2010 ( TEOS-10 ) was introduced, advocating absolute salinity as a replacement for practical salinity, and conservative temperature as a replacement for potential temperature . This standard includes a new scale called the reference composition salinity scale . Absolute salinities on this scale are expressed as a mass fraction, in grams per kilogram of solution. Salinities on this scale are determined by combining electrical conductivity measurements with other information that can account for regional changes in

16614-419: The proposal mandated by the legislature. The state released an $ 8.9-billion proposal in 2007 that involved building a horseshoe-shaped outer lake, a berm crossing the center of the lake and an extensive system of dikes, channels and pumps. Due to their concerns about the impact on the lake, the district only approved the water transfer agreement after Governor Gray Davis had signed the 2003 legislation known as

16756-417: The ratio of O to O (two isotopes of oxygen ) by mass (measured by a mass spectrometer ) present in the calcite of oceanic core samples is used as a diagnostic of ancient ocean temperature change and therefore of climate change. Cold oceans are richer in O , which is included in the tests of the microorganisms ( foraminifera ) contributing the calcite. A more recent version of

16898-570: The revised definition of the Quaternary , by pushing back the start date of the Pleistocene to 2.58 Ma, results in the inclusion of all the recent repeated glaciations within the Pleistocene. Radiocarbon dating is considered to be inaccurate beyond around 50,000 years ago. Marine isotope stages (MIS) derived from Oxygen isotopes are often used for giving approximate dates. Pleistocene non-marine sediments are found primarily in fluvial deposits , lakebeds, slope and loess deposits as well as in

17040-650: The right, modified from Por (1972), follows the "Venice system" (1959). In contrast to homoiohaline environments are certain poikilohaline environments (which may also be thalassic ) in which the salinity variation is biologically significant. Poikilohaline water salinities may range anywhere from 0.5 to greater than 300 ‰. The important characteristic is that these waters tend to vary in salinity over some biologically meaningful range seasonally or on some other roughly comparable time scale. Put simply, these are bodies of water with quite variable salinity. Highly saline water, from which salts crystallize (or are about to),

17182-415: The river alternately flowed into the valley or diverted around it, creating either a salt lake called Lake Cahuilla or a dry desert basin , respectively. When the river diverted around the valley, the lake dried completely, as it did around 1580. Hundreds of archaeological sites have been found in this region, indicating possibly long-term Native American villages and temporary camps. The modern lake

17324-410: The river's delta expanded until it cut off the northern part of the gulf. Since then, the Colorado River has alternated between emptying into the basin, creating a freshwater lake, and emptying into the gulf, leaving the lake to dry and turn to desert. Wave-cut shorelines at various elevations record a repeated cycle of filling and drying over hundreds of thousands of years. The most recent freshwater lake

17466-467: The rivers and canals that fed the Salton Sea, including redbelly tilapia , threadfin shad , carp , red shiner , channel catfish , white catfish , largemouth bass , mosquitofish , and sailfin molly . Tilapia populations have reached such low volumes such that the fish-eating birds in the area cannot be sustained anymore. Scientists have approximated that if the sea's salinity reaches levels of 70 parts per thousand (more likely to occur than not due to

17608-407: The sampling process makes use of modern glacial ice cores. Although less rich in O than seawater, the snow that fell on the glacier year by year nevertheless contained O and O in a ratio that depended on the mean annual temperature. Temperature and climate change are cyclical when plotted on a graph of temperature versus time. Temperature coordinates are given in the form of

17750-424: The sea include mosquito production, which is usually abundant in high salinity salt marshes but have been low because of the presence of fish. There have been worries about this potential outcome as mosquitoes in warm regions have been known to "act as vectors of West Nile virus , Western equine encephalitis and St. Louis encephalitis ". The California Office of Environmental Health Hazard Assessment developed

17892-487: The secretary of the California Resources Agency to prepare a restoration plan for the Salton Sea ecosystem , and an Environmental Impact Report. The Salton Sea Authority had a consultant study the alternatives and in 2004 issued their preferred alternative. After receiving comments from other agencies, they approved a new report in 2006. They hoped the reports would influence the state as it prepared

18034-418: The signing of the 2003 agreement to send more water to coastal cities. Local, state and federal bodies all had found minimal success dealing with the dust, dying wildlife, and other problems for which warnings had been issued decades before. In 2017, the Salton Sea Management Program was developed by the state. The Torres Martinez Desert Cahuilla Indians partnered with the state to restore shallow wetlands along

18176-649: The sole factor responsible for the variations in climate since they explain neither the long-term cooling trend over the Plio-Pleistocene nor the millennial variations in the Greenland Ice Cores known as Dansgaard-Oeschger events and Heinrich events. Milankovitch pacing seems to best explain glaciation events with periodicity of 100,000, 40,000, and 20,000 years. Such a pattern seems to fit the information on climate change found in oxygen isotope cores. In oxygen isotope ratio analysis, variations in

18318-421: The study of cyclical climate changes. The glacials in the following tables show historical usages, are a simplification of a much more complex cycle of variation in climate and terrain, and are generally no longer used. These names have been abandoned in favour of numeric data because many of the correlations were found to be either inexact or incorrect and more than four major glacials have been recognised since

18460-485: The summer. The desert pupfish is the only native fish species in the sea and is a federally listed endangered species . The desert pupfish, notable for its ability to withstand the rising salinity of the Salton Sea, can survive salinities ranging from freshwater to twice as salty as seawater. The pupfish have adapted to the Imperial Irrigation District’s drains, which funnel water runoff from farms into

18602-541: The town of Salton, a Southern Pacific Railroad siding, the New Liverpool Salt Company facility and miniature railroad, and Torres Martinez Desert Cahuilla Indian Reservation were submerged. Established in 1876, nearly half of the reservation was eventually flooded as the Indigenous people packed their belongings and headed into the mountains. The influx of water and the lack of any drainage from

18744-399: The vaporized dust from the lake regularly hangs over the communities in the valley. With a dense blend of ozone and particulate matter , Imperial County became known for some of the worst air quality in the country. Eastern Coachella communities have disproportionately higher rates of asthma and respiratory complications because of high concentrations of contaminants in the air. Over 20% of

18886-533: The water level caused by variations in agricultural runoff, the ancient salt deposits in the lake bed, and the relatively high salinity of the inflow feeding the sea are all causing increasing salinity. The concentration has been increasing at a rate of about 3% per year. About 3.6 million tonnes of salt are deposited in the valley each year. An undated report on the University of California: Imperial County website provides these specifics: "Salton Sea salinity

19028-407: The water. Around 2004, Aqua Genesis Ltd proposed such a project that would sell the nonsaline water. Their proposal involved the construction of over 20 miles (32 km) of pipes and tunneling that would have provided 1,000,000 acre-feet (1.2 km) of water to Southern California coastal cities each year. Berkshire Hathaway Energy has a subsidiary that already operates 10 geothermal plants in

19170-549: The wind-borne dust travel all the way into Southern California and Arizona. Residents in the Los Angeles Basin , some 150 miles (240 km) away, complained about the odor that drifted their way in 2012, after the biomass on the sea bottom was churned by a storm. During the first 15 years after the sale of the Imperial water to San Diego County , the Imperial Irrigation District has been required to put water into

19312-676: Was Lake Cahuilla , also known as the Blake Sea after American professor and geologist William Phipps Blake . It covered over 2,000 square miles (5,200 km), six times the area of the Salton Sea. Archaeological sites and radiocarbon dates indicate that the lake was filled three or four times over the last 1,300 years. When full, the lake would attract Native Americans to its shores. Hundreds of sites have been found, some possibly long-term villages and others temporary camps. The occupants ate at least four species of fish (two of which were razorback sucker and bonytail chub ), birds (particularly

19454-543: Was a series of glacials and interglacials, stadials and interstadials, mirroring periodic climate changes. The main factor at work in climate cycling is now believed to be Milankovitch cycles . These are periodic variations in regional and planetary solar radiation reaching the Earth caused by several repeating changes in the Earth's motion. The effects of Milankovitch cycles were enhanced by various positive feedbacks related to increases in atmospheric carbon dioxide concentrations and Earth's albedo. Milankovitch cycles cannot be

19596-426: Was declared because of the "heavily polluted New River, which empties into the Salton Sea". The Imperial County Board of Supervisors were hoping that this would accelerate the restoration projects by enabling the state to obtain federal funding. Nearly all the state's funding comes from bond measures for the Salton Sea projects. Since 2000, California voters have approved five bond measures as of 2020. In February 2020,

19738-462: Was formed from an inflow of water from the Colorado River in 1905. Beginning in 1900, an irrigation canal was dug from the Colorado River to provide water to the Imperial Valley for farming. Water from spring floods broke through a canal head-gate, diverting a portion of the river flow into the Salton Basin for two years before repairs were completed. The water in the formerly dry lake bed created

19880-456: Was occupied by the Colorado. This waterfall was initially 15 feet (4.6 m) high but grew to 80 feet (20 m) high before the flow through the breach was stopped. Originally, the waterfall was feared to recede upstream to the true main path of the Colorado, becoming up to 100 to 300 feet (30 to 90 m) high, when it would be practically impossible to stop the flow. As the basin filled,

20022-407: Was temporarily fallowed to meet the reductions in the water transfer agreement. Since the most recent creation of the lake, local farms in the Imperial Valley have produced alfalfa , wheat , and vegetables such as carrots and Brussels sprouts . As of 2015, the most widely planted crop was alfalfa, followed by bermuda grass and sudan grass . A third of the hay produced here was exported to China,

20164-408: Was warning that the lack of replenishment water was leading to a "period of very rapid deterioration." The rapidly shrinking sea was a "looming environmental and public health crisis". With the increased shrinkage, dust storms would increase and the rotten-egg smell would reach the coastal cities more frequently. About 36,000 acres (15,000 ha), or about 10%, of Imperial Valley's arable farmland

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