Death Valley

Death Valley

From Wikipedia, the free encyclopedia  (Redirected from Death valley)Jump to navigationJump to searchThis article is about the valley. For the park, see Death Valley National Park. For other uses, see Death Valley (disambiguation).

Death Valley
Death Valley
Death ValleyDeath ValleyCalifornia
Floor elevation−86 m (−282 ft)[1]
Area3,000 square miles (7,800 km2)
Geography
Coordinates36°14′49″N 116°49′01″WCoordinates36°14′49″N 116°49′01″W[2]
RiversFurnace Creek
Amargosa River

Death Valley is a desert valley located in Eastern California, in the northern Mojave Desert bordering the Great Basin Desert. It is one of the hottest places in the world along with deserts in the Middle East and the Sahara.[3]

Death Valley’s Badwater Basin is the point of the lowest elevation in North America, at 282 feet (86 m) below sea level.[1] This point is 84.6 miles (136.2 km) east-southeast of Mount Whitney, the highest point in the contiguous United States, with an elevation of 14,505 feet (4,421 m).[4] On the afternoon of July 10, 1913, the United States Weather Bureau recorded a high temperature of 134 °F (56.7 °C) at Furnace Creek in Death Valley.[5] This temperature stands as the highest ambient air temperature ever recorded at the surface of the Earth.[6]

Located near the border of California and Nevada, in the Great Basin, east of the Sierra Nevada mountains, Death Valley constitutes much of Death Valley National Park and is the principal feature of the Mojave and Colorado Deserts Biosphere Reserve. It is located mostly in Inyo County, California. It runs from north to south between the Amargosa Range on the east and the Panamint Range on the west; the Grapevine Mountains and the Owlshead Mountains form its northern and southern boundaries, respectively.[7] It has an area of about 3,000 sq mi (7,800 km2).[8] The highest point in Death Valley itself is Telescope Peak in the Panamint Range, which has an elevation of 11,043 feet (3,366 m).[9]

Contents

Geology[edit]

Main article: Geology of the Death Valley areaMap showing the system of once-interconnected Pleistocene lakes in eastern California (USGS)

Death Valley is an example of a graben, or a downdropped block of land between two mountain ranges.[10] It lies at the southern end of a geological trough known as Walker Lane, which runs north to Oregon. The valley is bisected by a right lateral strike slip fault system, represented by the Death Valley Fault and the Furnace Creek Fault. The eastern end of the left lateral Garlock Fault intersects the Death Valley Fault. Furnace Creek and the Amargosa River flow through the valley but eventually disappear into the sands of the valley floor.Death Valley, California, July 3, 2017, Sentinel-2 true color satellite image, scale 1:250,000.

Death Valley also contains salt pans. According to current geological consensus, at various times during the middle of the Pleistocene era, which ended roughly 10,000–12,000 years ago, an inland lake referred to as Lake Manly formed in Death Valley. Lake Manly was nearly 100 miles (160 km) long and 600 feet (180 m) deep, the end-basin in a chain of lakes that began with Mono Lake in the north and continued through multiple basins down the Owens River Valley through Searles and China Lakes and the Panamint Valley to the immediate west.[11]

As the area turned to desert, the water evaporated, leaving the abundance of evaporitic salts such as common sodium salts and borax, which were later exploited during the modern history of the region, primarily 1883 to 1907.[12]

Climate[edit]

Death Valley has a subtropicalhot desert climate (KöppenBWh), with long, extremely hot summers and short, mild winters, as well as little rainfall.

Death Valley is extremely dry because it sits in the rain shadow of four major mountain ranges (including the Sierra Nevada and Panamint Range). Moisture moving inland from the Pacific Ocean must pass eastward over multiple mountains to reach Death Valley; as air masses are forced upwards by each range, the air cools and moisture condenses to fall as rain or snow on the western slopes. When the air masses ultimately reach Death Valley, most of the moisture has already been “squeezed out” and there is little left to fall as precipitation.[13]

The extreme heat of Death Valley is attributable to a confluence of geographic and topographic factors. Scientists have identified a number of key contributors [13] to Death Valley’s famously hot conditions:

  • Solar heating: The valley’s surface (consisting of soil, rocks, sand, etc.) undergoes intense solar heating due to clear, dry air and dark, sparsely vegetated land. This is especially noticeable in summer when the sun is nearly directly overhead.
  • Air sinking and warming: Any air mass that sinks into lower elevations (e.g. 282 feet below sea level at Badwater Basin) gets compressed and warmed—due to the higher atmospheric pressure found at lower elevations. This is an example of adiabatic warming.
  • Trapping of warm air: Warm air naturally rises and cools,[14] but in Death Valley this air is subject to continual reheating as it is trapped by high, steep valley walls and recycled back to the valley floor.[15] Another factor that traps warm air is the valley’s north-south orientation, which runs perpendicular to prevailing west-to-east winds.
  • Migration of warm air from other areas (advection): Warm desert regions surrounding Death Valley, especially to the south and east, often heat air before it arrives in Death Valley.
  • Warm mountain winds: As winds are forced up and over mountains (e.g. the numerous ranges west of Death Valley), the winds can become progressively warmer due to several factors. The resulting dry, warm winds are known as foehn winds. Their warmth can in part be caused by the release of latent heat, which occurs when water vapor condenses into clouds.

Severe heat and dryness contribute to perpetual drought-like conditions in Death Valley and prevent much cloud formation from passing through the confines of the valley, where precipitation is often in the form of a virga.[16]

The depth and shape of Death Valley strongly influence its climate. The valley is a long, narrow basin that reaches down to below sea level, yet is walled by high, steep mountain ranges. The clear, dry air and sparse plant cover allow sunlight to heat the desert surface. Summer nights provide little relief, as overnight lows may only dip into the 82 to 98 °F (28 to 37 °C) range. Moving masses of super-heated air blow through the valley creating extremely high temperatures.[17]Sand dunes at Mesquite Flats

The hottest air temperature ever recorded in Death Valley was 134 °F (56.7 °C) on July 10, 1913, at Greenland Ranch (now Furnace Creek),[6] which is the highest atmospheric temperature ever recorded on earth.[5] A report of a temperature of 58 °C (136.4 °F) recorded in Libya in 1922 was later determined to be inaccurate.[6] During the heat wave that peaked with that record, five consecutive days reached 129 °F (54 °C) or above. Some meteorologists dispute the accuracy of the 1913 temperature measurement.[18]The lowest temperature recorded at Greenland Ranch was 15 °F (−9 °C) in January 1913.[19]

The highest surface temperature ever recorded in Death Valley was 201.0 °F (93.9 °C) on July 15, 1972, at Furnace Creek, which is the highest ground surface temperature ever recorded on earth, as well as the only recorded surface temperature of above 200 °F (93.3 °C).[20]

The greatest number of consecutive days with a maximum temperature of 100 °F (38 °C) or above was 154 days in the summer of 2001. The summer of 1996 had 40 days over 120 °F (49 °C), and 105 days over 110 °F (43 °C). The summer of 1917 had 52 days where the temperature reached 120 °F (49 °C) or above with 43 of them consecutive.View from Badwater Basin

The highest overnight or low temperature recorded in Death Valley is 110 °F (43 °C), recorded on July 5, 1918.[21] However this value is disputed and a record high low of 107 °F (42 °C) on July 12, 2012 is considered reliable.[22] This is one of the highest values ever recorded[23] Also on July 12, 2012, the mean 24-hour temperature recorded at Death Valley was 117.5 °F (47.5 °C), which makes it the world’s warmest 24-hour temperature on record.[24]

Four major mountain ranges lie between Death Valley and the ocean, each one adding to an increasingly drier rain shadow effect, and in 1929, 1953, and 1989, no rain was recorded for the whole year.[17] The period from 1931 to 1934 was the driest stretch on record with only 0.64 inches (16 mm) of rain over a 40-month period.[16] The average annual precipitation in Death Valley is 2.36 inches (60 mm), while the Greenland Ranch station averaged 1.58 in (40 mm).[25] The wettest month on record is January 1995, when 2.59 inches (66 mm) fell on Death Valley.[16] The wettest period on record was mid-2004 to mid-2005, in which nearly 6 inches (150 mm) of rain fell in total, leading to ephemeral lakes in the valley and the region and tremendous wildflower blooms.[26] Snow with accumulation has only been recorded in January 1922, while scattered flakes have been recorded on other occasions.

hideClimate data for Death Valley (Furnace Creek Station)
MonthJanFebMarAprMayJunJulAugSepOctNovDecYear
Record high °F (°C)87
(31)
97
(36)
102
(39)
113
(45)
122
(50)
129
(54)
134
(57)
127
(53)
123
(51)
113
(45)
98
(37)
89
(32)
134
(57)
Mean maximum °F (°C)77.0
(25.0)
83.9
(28.8)
93.4
(34.1)
103.4
(39.7)
112.1
(44.5)
120.4
(49.1)
123.7
(50.9)
121.9
(49.9)
116.0
(46.7)
104.2
(40.1)
88.8
(31.6)
77.0
(25.0)
124.5
(51.4)
Average high °F (°C)66.9
(19.4)
73.3
(22.9)
82.1
(27.8)
90.5
(32.5)
100.5
(38.1)
109.9
(43.3)
116.5
(46.9)
114.7
(45.9)
106.5
(41.4)
92.8
(33.8)
77.1
(25.1)
65.2
(18.4)
91.4
(33.0)
Daily mean °F (°C)53.4
(11.9)
59.8
(15.4)
68.4
(20.2)
76.3
(24.6)
86.6
(30.3)
95.5
(35.3)
102.2
(39.0)
100.2
(37.9)
91.1
(32.8)
77.1
(25.1)
62.6
(17.0)
51.7
(10.9)
77.2
(25.1)
Average low °F (°C)40.0
(4.4)
46.3
(7.9)
Social media & sharing icons powered by UltimatelySocial
error

Enjoy this blog? Please spread the word :)

RSS
Follow by Email
LinkedIn
LinkedIn
Share
Scroll to Top