Crater Lake is a
calderaA caldera is a cauldron-like volcanic feature usually formed by the collapse of land following a volcanic eruption, such as the one at Yellowstone National Park in the US. They are sometimes confused with volcanic craters...
lakeA lake is a body of relatively still fresh or salt water of considerable size, localized in a basin, that is surrounded by land. Lakes are inland and not part of the ocean and therefore are distinct from lagoons, and are larger and deeper than ponds. Lakes can be contrasted with rivers or streams,...
located in the south-central region of the
U.S. stateA U.S. state is any one of the 50 federated states of the United States of America that share sovereignty with the federal government. Because of this shared sovereignty, an American is a citizen both of the federal entity and of his or her state of domicile. Four states use the official title of...
of
OregonOregon is a state in the Pacific Northwest region of the United States. It is located on the Pacific coast, with Washington to the north, California to the south, Nevada on the southeast and Idaho to the east. The Columbia and Snake rivers delineate much of Oregon's northern and eastern...
. It is the main feature of
Crater Lake National ParkCrater Lake National Park is a United States National Park located in southern Oregon. Established in 1902, Crater Lake National Park is the sixth oldest national park in the United States and the only one in the state of Oregon...
and famous for its deep blue color and water clarity. The lake partly fills a nearly 2148 feet (654.7 m) deep caldera that was formed around 7,700 (± 150) years ago
by the collapse of the volcano
Mount MazamaMount Mazama is a destroyed stratovolcano in the Oregon part of the Cascade Volcanic Arc and the Cascade Range. The volcano's collapsed caldera holds Crater Lake, and the entire mountain is located within Crater Lake National Park....
. There are no rivers flowing into or out of the lake; the evaporation is compensated for by rain and snowfall at a rate such that the total amount of water is replaced every 250 years.
On June 12, 1853,
John Wesley HillmanJohn Wesley Hillman was an American prospector during the California Gold Rush and explorer who was among the first European Americans to see Crater Lake in the U.S. state of Oregon....
was reportedly the first person of European descent to see what he named "Deep Blue Lake" in Oregon. The lake was renamed at least three times, as Blue Lake, Lake Majesty, and finally Crater Lake.
Crater Lake is known for the "
Old Man of the LakeThe Old Man of the Lake is the name given to a tall tree stump, most likely a hemlock, which has been bobbing vertically in Oregon's Crater Lake since at least 1896....
", a full-sized tree which is now a stump that has been bobbing vertically in the lake for more than a century. Due to the cold water, the tree has been rather well preserved.
While having no indigenous fish population, the lake was stocked from 1888 to 1941 with a variety of fish. Several species have formed self sustaining populations.
Since 2002, one of the state's regular-issue
license plate designsThe U.S. state of Oregon first required its residents to register their motor vehicles and display license plates in 1911.-Passenger baseplates 1956 to present:...
has featured Crater Lake.
The commemorative Oregon State Quarter, which was released by the
United States MintThe United States Mint primarily produces circulating coinage for the United States to conduct its trade and commerce. The Mint was created by Congress with the Coinage Act of 1792, and placed within the Department of State...
in 2005, features an image of Crater Lake on its reverse.
Dimensions and depth
Crater Lake is located in
Klamath County-National protected areas:* Bear Valley National Wildlife Refuge* Crater Lake National Park * Deschutes National Forest * Fremont National Forest * Klamath Marsh National Wildlife Refuge* Lower Klamath National Wildlife Refuge...
, approximately 60 miles (96.6 km) northwest of the county seat of
Klamath FallsKlamath Falls is a city in Klamath County, Oregon, United States. Originally called Linkville when George Nurse founded the town in 1867, after the Link River on whose falls this city sat, although no falls currently exist; the name was changed to Klamath Falls in 1892...
, and about 80 miles (128.7 km) northeast of the city of
MedfordMedford is a city in Jackson County, Oregon, United States. As of the 2010 US Census, the city had a total population of 74,907 and a metropolitan area population of 207,010, making the Medford MSA the 4th largest metro area in Oregon...
.
The lake is 5 by across with an average depth of 1148 feet (349.9 m). Its maximum depth has been measured at 1949 feet (594.1 m), which fluctuates slightly as the weather changes. On the basis of maximum depth, Crater Lake is the deepest lake in the
United StatesThe United States of America is a federal constitutional republic comprising fifty states and a federal district...
, the second deepest in
North AmericaNorth America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
, after
Great Slave LakeGreat Slave Lake is the second-largest lake in the Northwest Territories of Canada , the deepest lake in North America at , and the ninth-largest lake in the world. It is long and wide. It covers an area of in the southern part of the territory. Its given volume ranges from to and up to ...
in Canada, and the
ninth deepest lake in the world (
Lake BaikalLake Baikal is the world's oldest at 30 million years old and deepest lake with an average depth of 744.4 metres.Located in the south of the Russian region of Siberia, between Irkutsk Oblast to the northwest and the Buryat Republic to the southeast, it is the most voluminous freshwater lake in the...
is the deepest). Crater Lake is often cited as the seventh deepest lake in the world, but this ranking excludes
Lake VostokLake Vostok is the largest of more than 140 subglacial lakes found under the surface of Antarctica. The overlying ice provides a continuous paleoclimatic record of 400,000 years, although the lake water itself may have been isolated for 15 to 25 million years. The lake is named after the...
, which is situated under nearly 13000 feet (3,962.4 m) of Antarctic ice, and the recent soundings of San Martín Lake, which is located on the border of Chile and Argentina.
However, on the basis of comparing average depths among the world's deepest lakes, Crater Lake becomes the deepest lake in the Western Hemisphere and the third deepest in the world. Comparing average depths among the world's lakes whose basins are entirely above sea level, Crater Lake is the deepest.
The caldera rim of Crater Lake ranges in elevation from 7000 to 8000 ft (2,133.6 to 2,438.4 ).
Geology
Mount Mazama, part of the
Cascade RangeThe Cascade Range is a major mountain range of western North America, extending from southern British Columbia through Washington and Oregon to Northern California. It includes both non-volcanic mountains, such as the North Cascades, and the notable volcanoes known as the High Cascades...
volcanic arcA volcanic arc is a chain of volcanoes positioned in an arc shape as seen from above. Offshore volcanoes form islands, resulting in a volcanic island arc. Generally they result from the subduction of an oceanic tectonic plate under another tectonic plate, and often parallel an oceanic trench...
, was built up mostly of
andesiteAndesite is an extrusive igneous, volcanic rock, of intermediate composition, with aphanitic to porphyritic texture. In a general sense, it is the intermediate type between basalt and dacite. The mineral assemblage is typically dominated by plagioclase plus pyroxene and/or hornblende. Magnetite,...
,
daciteDacite is an igneous, volcanic rock. It has an aphanitic to porphyritic texture and is intermediate in composition between andesite and rhyolite. The relative proportions of feldspars and quartz in dacite, and in many other volcanic rocks, are illustrated in the QAPF diagram...
, and
rhyodaciteRhyodacite is an extrusive volcanic rock intermediate in composition between dacite and rhyolite. It is the extrusive equivalent of granodiorite. Phenocrysts of sodium rich plagioclase, sanidine, quartz, and biotite or hornblende are typically set in an aphanitic to glassy light to intermediate...
over a period of at least 400,000 years. The caldera was created in a massive volcanic eruption that led to the subsidence of Mount Mazama around
5700 BCDuring the 6th millennium BC, agriculture spread from the Balkans to Italy and Eastern Europe, and also from Mesopotamia to Egypt. World population was essentially stable at approximately 5 million, though some speculate up to 7 million.-Events:...
: about 50 cubic kilometers (12 cubic miles) of rhyodacite was erupted in this event. Since that time, all eruptions on Mazama have been confined to the caldera.
Lava eruptions later created a central platform,
Wizard IslandWizard Island is a volcanic cinder cone which forms an island at the west end of Crater Lake in Crater Lake National Park, Oregon. The top of the island reaches above sea level, about above the average surface of the lake. The cone is capped by a volcanic crater about wide and deep. The...
, Merriam Cone, and other, smaller volcanic features, including a
rhyodaciteRhyodacite is an extrusive volcanic rock intermediate in composition between dacite and rhyolite. It is the extrusive equivalent of granodiorite. Phenocrysts of sodium rich plagioclase, sanidine, quartz, and biotite or hornblende are typically set in an aphanitic to glassy light to intermediate...
dome that was eventually created atop the central platform. Sediments and
landslideA landslide or landslip is a geological phenomenon which includes a wide range of ground movement, such as rockfalls, deep failure of slopes and shallow debris flows, which can occur in offshore, coastal and onshore environments...
debris also covered the caldera floor.
Eventually, the caldera cooled, allowing
rainRain is liquid precipitation, as opposed to non-liquid kinds of precipitation such as snow, hail and sleet. Rain requires the presence of a thick layer of the atmosphere to have temperatures above the melting point of water near and above the Earth's surface...
and
snowSnow is a form of precipitation within the Earth's atmosphere in the form of crystalline water ice, consisting of a multitude of snowflakes that fall from clouds. Since snow is composed of small ice particles, it is a granular material. It has an open and therefore soft structure, unless packed by...
to accumulate and eventually form a lake.
Landslides from the caldera rim thereafter formed debris fans and
turbiditeTurbidite geological formations have their origins in turbidity current deposits, which are deposits from a form of underwater avalanche that are responsible for distributing vast amounts of clastic sediment into the deep ocean.-The ideal turbidite sequence:...
sediments on the lake bed.
FumaroleA fumarole is an opening in a planet's crust, often in the neighborhood of volcanoes, which emits steam and gases such as carbon dioxide, sulfur dioxide, hydrochloric acid, and hydrogen sulfide. The steam is created when superheated water turns to steam as its pressure drops when it emerges from...
s and
hot springA hot spring is a spring that is produced by the emergence of geothermally heated groundwater from the Earth's crust. There are geothermal hot springs in many locations all over the crust of the earth.-Definitions:...
s remained common and active during this period. Also after some time, the slopes of the lake's caldera rim more or less stabilized,
streamA stream is a body of water with a current, confined within a bed and stream banks. Depending on its locale or certain characteristics, a stream may be referred to as a branch, brook, beck, burn, creek, "crick", gill , kill, lick, rill, river, syke, bayou, rivulet, streamage, wash, run or...
s restored a radial drainage pattern on the
mountainImage:Himalaya_annotated.jpg|thumb|right|The Himalayan mountain range with Mount Everestrect 58 14 160 49 Chomo Lonzorect 200 28 335 52 Makalurect 378 24 566 45 Mount Everestrect 188 581 920 656 Tibetan Plateaurect 250 406 340 427 Rong River...
, and dense
forestA forest, also referred to as a wood or the woods, is an area with a high density of trees. As with cities, depending where you are in the world, what is considered a forest may vary significantly in size and have various classification according to how and what of the forest is composed...
s began to revegetate the barren landscape. It is estimated that about 720 years was required to fill the lake to its present depth of 594 m. Much of this occurred during a period when the prevailing climate was less moist than at present.
Some hydrothermal activity remains along the lake floor, suggesting that at some time in the future Mazama may erupt once again.
Water quality
Due to several unique factors, most prominently that it has no inlets or tributaries, the waters of Crater Lake are some of the purest in terms of the absence of pollutants in North America.
Secchi diskThe Secchi disk, created in 1865 by Pietro Angelo Secchi SJ, is a circular disk used to measure water transparency in oceans and lakes. The disc is mounted on a pole or line, and lowered slowly down in the water. The depth at which the pattern on the disk is no longer visible is taken as a measure...
clarity readings have consistently been in the high-20 meter to mid-30 meter (80–115 ft) range, which is very clear for any natural body of water. In 1997, scientists recorded a record clarity of 43.3 meters (142 ft).
The lake has relatively high levels of dissolved salts, total
alkalinityAlkalinity or AT measures the ability of a solution to neutralize acids to the equivalence point of carbonate or bicarbonate. The alkalinity is equal to the stoichiometric sum of the bases in solution...
, and conductivity. The average
pHIn chemistry, pH is a measure of the acidity or basicity of an aqueous solution. Pure water is said to be neutral, with a pH close to 7.0 at . Solutions with a pH less than 7 are said to be acidic and solutions with a pH greater than 7 are basic or alkaline...
has generally ranged between 7 and 8.
Sacred significance
The Klamath tribe of
Native AmericansNative Americans in the United States are the indigenous peoples in North America within the boundaries of the present-day continental United States, parts of Alaska, and the island state of Hawaii. They are composed of numerous, distinct tribes, states, and ethnic groups, many of which survive as...
, who may have witnessed the collapse of Mount Mazama and the formation of Crater Lake, have long regarded the lake as a sacred site. Their legends tell of a battle between the sky god Skell and
LlaoLlao is the god of the underworld in the mythology of the Klamath Native American tribe. Llao fought a great battle with the sky god, Skell, which caused the eruption of Mount Mazama, creating Crater Lake.-Llao and Skell:...
, the god of the underworld. Mount Mazama was destroyed in the battle, creating Crater Lake. The Klamath people used Crater Lake in
vision questA vision quest is a rite of passage in some Native American cultures.In many Native American groups, the vision quest is a turning point in life taken before puberty to find oneself and the intended spiritual and life direction. When an older child is ready, he or she will go on a personal,...
s, which often involved climbing the caldera walls and other dangerous tasks. Those who were successful in such quests were often regarded as having more spiritual powers. The tribe still holds Crater Lake in high regard as a spiritual site.
See also
- List of lakes in Oregon
- Volcanic Legacy Scenic Byway
The Volcanic Legacy Scenic Byway is an All-American Road in the U.S. states of California and Oregon. It is roughly 500 miles long and travels through the Cascade Range past numerous volcanoes. It is composed of two separate National Scenic Byways, the Volcanic Legacy Scenic Byway - Oregon and...
- Old Man of the Lake
The Old Man of the Lake is the name given to a tall tree stump, most likely a hemlock, which has been bobbing vertically in Oregon's Crater Lake since at least 1896....
External links