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Great Salt Lake

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Great Salt Lake
Coordinates41°0′N 112°0′W / 41.000°N 112.000°W / 41.000; -112.000
TypeEndorheic
hypersaline
Primary inflowsBear
Jordan
Weber
Catchment area21,500 square miles (34,601 km²)
Basin countriesUSA
Max. length75 miles (120 km)
Max. width28 miles (45 km)
Surface area~1,700 square miles (~4,400 km²)
Max. depth35 feet (10.6 m)
Surface elevation4,200 feet (1,283 m)
Islands8-13 (variable, see Islands)
SettlementsSalt Lake and Ogden metropolitan areas.

Great Salt Lake, located in the northern part of the U.S. State of Utah, is the fourth largest terminal lake in the world[1] and the largest salt lake in the Western Hemisphere.[2] It is also the 33rd largest lake in the world by area.[3] In an average year the lake covers an area of around 1,700 square miles[1] (4,400 km²), but the lake's size fluctuates substantially due to its shallowness. For instance, in 1963 it reached its lowest recorded level at 950 square miles (1,529 km²), but in 1987 the surface area was at the historic high of 3,300 square miles[1](5,311 km²). Like the much larger Great Lakes of North America, Great Salt Lake is large enough to produce lake effect snow.[4]

The lake is the largest remnant of Lake Bonneville, a prehistoric lake which was roughly ten times the size of Great Salt Lake,[1] more than 1,000 feet (305 m) deep,[5] and covered much of present-day Utah and small portions of Idaho and Nevada. Great Salt Lake is endorheic (has no outlet besides evaporation), and therefore has very high salinity, far saltier than the ocean. The three major feeder rivers deposit around 1.1 million tons of minerals in the lake each year,[2] and the balance of evaporated water is mineral-free, concentrating the lake further. Because of its unusually high salt concentration, most people can easily float in the lake as a result of the higher density of the water, particularly in the saltier north arm (Gunnison Bay) of the lake.[6]

Although sometimes referred to as "America's Dead Sea" (or Utah's[7]), the lake provides habitat for millions of shorebirds and waterfowl, including the largest staging population of Wilson's Phalarope in the world.[8] In addition to birds and brine shrimp, the lake is also home, oddly enough, to a Chilean flamingo named Pink Floyd (see below).

Geography

File:09-19-04a.jpg
Great Salt Lake from airspace over Salt Lake City

Salt Lake City and its suburbs are located to the southeast and east of the lake, between the lake and the Wasatch Mountains, but land around the north and west shores is almost uninhabited. The Bonneville Salt Flats lie to the west, and the Oquirrh Mountains rise to the south.

The Great Salt Lake is fed by three major rivers and several minor streams. The three major rivers are each fed directly or indirectly from the Uinta Mountain range in northeastern utah. The Bear River starts in the north slope of the Uintas and flows north past Bear Lake, into which some of Bear River's waters have been diverted[9] via a man-made canal into the lake, but later empty back into the river by means of the Bear Lake outlet which drains Bear Lake; The river then turns south in southern Idaho and eventually flows into the northeast arm of Great Salt Lake. The Weber River also starts in the north slope of the Uinta Mountains and flows into the east edge of the lake. The Jordan River does not receive its water directly from the Uintas, but it drains freshwater Utah Lake, which itself is fed primarily by the Provo River which begins in the south slope of the Uintas and flows into the east part of Utah Lake. The Jordan flows from the north part of Utah Lake into the southeast corner of Great Salt Lake. A railroad line—the Lucin Cutoff—runs across the lake, crossing the southern end of Promontory Peninsula. The mostly-solid causeway supporting the railway divides the lake into three portions: northeast arm, northwest arm and southern. This causeway prevents the normal mixing of the waters of the lake due to its lack of water passages, and since there are no rivers, with the exception of a few minor streams, flowing directly into the northwest arm (also called "Gunnison Bay"), it is now noticeably saltier than the rest of the lake.

Islands

Depending on the source and the water level, there are eight[10] to thirteen islands[11] in the Great Salt Lake, seven in the southern arm and four in the northwest. Whether or not they are counted as islands depends mostly on the level of the lake which can vary greatly from year to year. From largest to smallest, they are Antelope, Stansbury, Fremont, Carrington, Dolphin, Cub, Badger, Strongs Knob, Gunnison, Hat (Bird), Egg Island, Black Rock and White Rock. Dolphin, Gunnison, Cub, and Strongs Knob are in the northwest arm, and the rest are in the southern portion. There are also a number of small, unnamed islands whose size and number greatly depends on the level of the lake.

File:100 0297.jpg
The Great Salt Lake as seen looking north towards Antelope Island from Sunset Beach

Antelope and Fremont Islands are extensions of the Oquirrh mountain range. Stansbury Island and other smaller islands are extensions of the Stansbury mountain range. The lake is deepest in the area between these island chains, about 35 feet (10.7 m) deep at the 4,200 foot (1,280 m) level. The lake averages 13 feet (4 m) deep at the same level. When the water levels are low (as they were in late 2004 averaging under 4,195 feet (1279 m), Antelope island becomes connected to the shore as a peninsula, as do some of the other islands. In fact, Stansbury Island and Strongs Knob remain peninsulas unless the water level rises above average. At high levels, some of the smaller islands become completely submerged.

Antelope,[12] Gunnison,[13] and Hat[14] islands each have weather monitoring stations operated by various state and federal agencies.

Hydrology

Water levels have been recorded since 1875,[1] averaging about 4,200 feet (1,280 m) above sea level. Since the Great Salt Lake is a shallow lake with gently sloping shores around all edges except on the south side, small variations in the water level can greatly affect the extent of the shoreline. During low levels, the lake is difficult to approach because it is fringed by long and sometimes quite odorous mud flats.

Because the water level is variable, it can rise dramatically in wet years and fall during drought years. The water level is also affected by the amount of water flow diverted for agricultural and urban uses. The Jordan and Weber rivers are particularly diverted for other uses. In the 1880s Grove Karl Gilbert predicted that the lake — then in the middle of many years of recession — would virtually disappear except for a small remnant between the islands.[15] Record high levels in the 1980s caused massive property damage for owners on the eastern side, and started to erode the base of Interstate 80. In response, the state built pumps on the western side of the lake to pump dangerously high water out into the west desert, but as of 2004 these pumps are dry and miles away from the lake's shore. They are, however, maintained in the event the lake rises to those levels again.

Salinity

Most of the salts dissolved in the lake and deposited in the desert flats around it reflect the concentration of solutes by evaporation; Lake Bonneville itself was fresh enough to support populations of fish.[16][17] More salt is added yearly via rivers and streams, though the amount is much less than the relict salt from Bonneville.[16]

The salinity of Great Salt Lake is highly variable, and depends on the lake's level; it ranges from 5 to 27% (or 50-270 ppt).[6] The ionic composition is similar to seawater, much more so than the Dead Sea's; compared to the ocean, Great Salt Lake's waters are slightly enriched in potassium, and depleted in calcium.[6]

Ecosystem

The high salinity of the lake makes it uninhabitable for all but a few species, including brine shrimp, brine flies, and several forms of algae. The brine flies serve as the main source of food for many of the birds which migrate to the lake, and have an estimated population of over one hundred billion.[18] However, the fresh- and salt-water wetlands along the eastern and northern edges of the Great Salt Lake provide critical habitat for millions of migratory shorebirds and waterfowl in western North America. These marshes account for approximately 75 percent of the wetlands in Utah.[19] Some of the birds that depend on these marshes include:[20] Wilson's phalarope, red-necked phalarope, American avocet, black-necked stilt, marbled godwit, snowy plover, western sandpiper, long-billed dowitcher, tundra swan, American white pelican, white-faced ibis, California gull, eared grebe, peregrine falcon, bald eagle, plus large populations of various ducks and geese.

American avocets at Bear River Migratory Bird Refuge

Great Salt Lake wetland/wildlife management areas include the Bear River Migratory Bird Refuge; Gillmor Sanctuary; Great Salt Lake Shorelands Preserve; Salt Creek, Public Shooting Grounds, Harold Crane, Locomotive Springs, Ogden Bay, Timpie Springs and Farmington Bay Waterfowl Management Areas.[citation needed]

Several small islands in the lake provide critical nesting areas for various birds. Access to Hat, Gunnison and Cub islands is strictly limited by the State of Utah in an effort to protect nesting colonies of American white pelican (Pelecanus erythrorhynchos).[citation needed]

The only aquatic animals able to live in the lake are tiny brine shrimp (Artemia franciscana). Their tiny, hard-walled eggs or cysts (diameter of about 200 micrometers) are harvested in quantity during the fall and early winter. They are fed to prawns in Asia,[18] sold as novelty "Sea-Monkeys," and used in testing of toxins, drugs, and other chemicals.[8] There are also two species of salt flies[citation needed] and some bacteria and algae.

Salinity differences between the sections of the lake separated by the railroad causeway result in significantly different biota. A phytoplankton community dominated by blue-green or green algae tint the water south of the causeway a greenish color. North of the causeway, the lake is dominated by halophilic bacteria which gives the water an unusual reddish or purplish color.[citation needed] These color differences are especially noticeable in satellite photographs. Although brine shrimp can be found in the arm of the lake north of the causeway, studies conducted by the Utah Division of Wildlife Resources seem to indicate that these animals are likely transient.[citation needed] Populations of brine shrimp are mostly restricted to the lake's south arm.

Pink Floyd the flamingo

As of 2005, a solitary Chilean flamingo named Pink Floyd winters at the Great Salt Lake. It escaped from Salt Lake City's Tracy Aviary in 1987 and now lives in the wild, eating brine shrimp and socializing with gulls and swans. Utah residents have suggested petitioning the state to release more flamingos in an effort to keep Floyd company and as a possible tourist attraction. Wildlife biologists have resisted these efforts, saying that deliberate introduction of a non-native species would be ecologically unsound and might have detrimental consequences.[21]

Commerce

Saltair Resort, once hailed as the "Coney Island of the West", before it burned down.

Shallow artificial ponds at the edge of the lake are used to produce salt magnesium and other minerals for commercial sale.

The harvest of brine shrimp cysts during fall and early winter has developed into a significant local industry.

There is a problem with pollution of the lake by industrial and urban effluent. Also, especially when the waters are low, decay of insects and other wildlife give the shore of the lake a distinctive odor, which may keep some tourists from coming near the lake.

A large resort called Saltair has been operated on the southern shore of the lake. Rising and lowering water levels have affected Saltair, and it has burned twice.[22] The new resort built in 1981 after large fires completely destroyed the second and largest in the 1960s, is a but a skeleton of the resort's former grandeur.

Dramatically fluctuating lake levels have inhibited the creation and success of tourist-related developments. Despite this, the lake remains one of Utah's largest tourist attractions[citation needed]. Antelope Island State Park is a popular tourist destination that offers panoramic views of the lake, hiking and biking trails, wildife viewing and access to beaches.

The northwest arm of the lake, near Rozel Point, is the location for Robert Smithson's significant work of land art, Spiral Jetty (1970).

Superstitions

In mid-1877, J.H. McNeil was with many other Barnes and Co. Salt Works employees on the lake’s north shore in the evening. They claimed to have seen a large monster with a body like a crocodile and a horse’s head in the lake. They claimed this monster attacked the men, who quickly ran away and hid until morning. This creature is regarded by some to have simply been a buffalo in the lake. 30 years prior, "Brother Bainbridge " claimed to have sighted a creature that looked like a dolphin in the lake near Antelope Island. This monster is called by some the "North Shore Monster"[23]

See also

Footnotes

  1. ^ a b c d e Great Salt Lake, Utah. U.S. Geological Survey.
  2. ^ a b Great Salt Lake. Encyclopedia Britannica Online
  3. ^ Large Lakes of the World. Factmonster.com.
  4. ^ Warm water helps create Great Lakes snowstorms. USATODAY.com
  5. ^ Where was Lake Bonneville, how large was it, and when did it exist?. Utah Geological Survey.
  6. ^ a b c Can I float in Great Salt Lake?. Utah Geological Survey.
  7. ^ Great Salt Lake: More than meets the nose. CNN Travel.
  8. ^ a b Birds and Great Salt Lake. U.S. Geological Survey.
  9. ^ Bear Lake by the Utah Division of Water Quality (PDF format)
  10. ^ Overview of the Great Salt Lake. Utah Museum of Fine Arts.
  11. ^ Commonly Asked Questions About Utah's Great Salt Lake and Ancient Lake Bonneville, pg 05. Utah Geological Survey.
  12. ^ Weather Conditions for SNX
  13. ^ Weather Conditions for GNI
  14. ^ Weather Conditions for HATUT
  15. ^ Morgan (1947)
  16. ^ a b Commonly Asked Questions About Utah's Great Salt Lake and Ancient Lake Bonneville, pg 03
  17. ^ Commonly Asked Questions About Utah's Great Salt Lake and Ancient Lake Bonneville, pg 02
  18. ^ a b Great Salt Lake Facts. Utah.com.
  19. ^ Utah Wetlands Interpretive Network.
  20. ^ Great Salt Lake, UT - What Shorebird Species Use This Site?. Manomet Center for Conservation Sciences.
  21. ^ A Flamingo Flies the Coop to Fame. The Christian Science Monitor.
  22. ^ Saltair Resort. Utah City Guide.
  23. ^ Great tales surrounding the Great Salt Lake. Lynn Arave, Deseret News.

References

Wikimedia Commons has media related to Great Salt Lake.
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