The Sierra Nevada
Nevada is U.S.A
Block mountain, Cordillera
Part of the west edge of the mountain. North of Lassen peak, South to the Tehachapi pass, 640 km long, wide 80 to 130 km, with roughly north-south stretch in the eastern part of California. The mountain was formed in the Jurassic Period
To the end of Cretaceous
At the beginning of the Nevada orogeny, the general elevation of 1800 to 3000 meters, the mountain from west to East tilt: Dongpo cliff steep, out in the East The Great Basin
Above the height of 1500 to 3000 meters, the vegetation is sparse and mostly shrub grass; West Slope gentle tendency California
The Central Valley, deep valleys, rivers cut into the dense forests, moist air and abundant rain and snow at Pacific Ocean, rivers, lakes, abundant water resources, the Central Valley has become rich An agricultural region
The Sierra Nevada
The Sierra Nevada Geology and geomorphology The Sierra Nevada
Pulse (Nevada, Sierra) or Sierra Nevada. Is the North
The Sierra Nevada
Part of the West hilly mountains. Stateside The state of California
East。 North South extension of 640 km. The peak Whitney
At an altitude of 4418 meters, the highest peak in the United states. Dongpo steep, dry forest; the west slope of the dense forest. Rich water resources and gold. The peak of modern glacier. Unique natural landscape, has created a national park.
Nevada is North America
The main Miangen mountains, the eastern margin of California in the United states. A large, large area west of the Central Valley depression, east of the basin and the mountain area.
since Mojave Desert
Northern Oregon and north to the California Cascade Range stretches more than and 400 kilometers (more than and 250 miles), Lake Tahoe
(Lake Tahoe) wide area about 129 kilometers (80 miles), South 80 kilometers (50 miles). The magnificent ridge and spectacular landscape, as one of the most magnificent American natural scenic area.
For recreation center, its facilities to attract California city four area residents. It is a very important source of electricity and water. The famous California" The gold rush
"We focus on this area.
Due to mining, logging and tourism, the changes caused by changes in many areas of the scene of mountains and rivers than several thousand years glaciers and water caused by the larger.
The Sierra Nevada mountains on both sides of the ridge and the obvious asymmetry, East peak. Peak elevation of 3350 to 4270 meters (11000 to 14000 feet), the Whitney peak elevation of 4418 meters (14494 feet), the highest peak in the United states. North peak is much lower, Lake Tahoe to the north of the peak altitude of only 7000 to 9000 feet.
Rock mostly granite granite or similar. There are bad (change due to heat and pressure and the occurrence of sedimentary rocks (interlayer) remnants are sedimentary basin once the huge area) and some large areas of extrusive rocks, Especially the Lake Tahoe area to the north; the northern end of the Sierra Nevada, the fusion of rock and cascades volcano facies.
The Sierra Nevada Climatic characteristics
In the mid latitude zone, and the Pacific and the temperate mountain climate is abnormal. Although the valley winter temperatures often drop to -18 degrees C (0 degrees F), but in the hillside area so little at low temperature. The mountains of Northwest - southeast direction exactly with the central North America winter storm paths intersect, results in the wet season (November to April) windward slope (West Slope) abundant rainfall, leeward (East) appeared obvious rain shadow effect.
The western foothills of the average rainfall of 760 mm (30 inches), the northern half mountain elevation 4500 to 6500 feet. The 70 ~ 80 inches. Leeward slope rainfall is much less, only 20 to 40 inches. Snowfall increases with altitude and latitude, the northern mountain snowfall from 10 to 12 meters (33 to 38 feet). Echo peak (Echo Summit) had one day snow 1.7 meters (55 feet) of, at an altitude of 2160 meters (7085 feet). Tang Na P.
(Donner Pass) was measured over 20 meters (67 feet) of snow. The snow area 7000 feet above 3 to 4.6 meters (10 to 15 feet) are not uncommon.
Type of wind over the Sierra Nevada to the Pacific Subtropical Anticyclone in summer, the most powerful, dry air blowing through the mountains to the sea. If the pressure brought to the power in winter is not weakened, there will be several consecutive years of drought, mid 1930s, mid 70s and mid 80s to early 90s has occurred in this case, the jet stream at mid latitude storm path will diminish, split or pushed north.
The Sierra Nevada Water situation
The west slope is gentle as a series of river cut by rivers, much longer than the su. Youba (Yuba) River, America River, Mo Kay Remis River (Mokelumne), Stanislaus (Stanislaus), Merced River (Merced), Kern River (Kern) cutting River and other rivers have been dominated by granite and some volcano rock valley. In addition to the rest of Kern River, North River respectively into the Central Valley and south of the Sacramento River The San Joaquin River
The two tributaries in the Gulf of San Francisco, merged into the Delta, and finally into the Pacific ocean. For the Kern River inland river, into the San Joaquin River south of the lake basin, bouet naweisi tower.
Began 1 million 600 thousand years ago ended during the Pleistocene glaciation 10 thousand years ago, by the river valley has been a large area of etching glaciers. Glacial climate there are at least 4 times development and disappear, every time there is an excess of snow ice and snow fields and glaciers built deep.
The west slope of V valley glaciers will be etched into U Valley, at an altitude of about 5000 feet deep. The icing results very much, the glacier merged to form a cap. The ice caps from the north near Hunan to Tahoe Whitney peak mountain stretches nearly 322 kilometers (200 miles).
The ice cap extends downward many finger like valley glaciers, glacier west slope is relatively flat and steep uplift on slope is relatively short. The glacier erosion caused very spectacular: a huge cirque (amphitheater shaped basin, steep rock), a moraine (rock deposits), there are tens of thousands of lakes dotted on the mountain and semi mountain landscape. This exciting magnificent terrain is Jose Miti (Yosemite) the main landscape Basin National Park and lake tahoe. Lake Tahoe is the world's largest and deepest lake, the water area of nearly 518 square kilometers (200 square miles), northwest of the deepest depth of about 500 meters (1640 feet).
The Sierra Nevada natural resources
The western slope of the Sierra Nevada mountains have 5 distinct vegetation zones. The lower foothills mostly deciduous trees and shrubs, evergreen and interior live oak (Quercus wislizenii). At the higher the foothills are black oak, pine and cypress, North america. Mountain forest is the main business district of wood, there are Douglas fir
Red fir, Jeffrey Song (Jeffrey Pine) and Sequoia
(public protection area of Sequoia National Park is specially established for this purpose).
In the subalpine forest in the mountains, mountain hemlock, black pine, western white pine and cypress. Above the timberline is widely distributed with moss, lichen and low Alpine flowering plants. Dry mountains, Dongpo sagebrush bitterbrush, cypress, pine and poplar. In addition to the mountain area outside the mountains on both sides of the growth with chaparral, mainly dwarf oak, bear fruit and California evergreen shrub.
Since twentieth Century the most recognizable in the Sierra Nevada mountains of large mammals are not so rich, partly because more and more people come here. The black bear habitat area than in the big grizzly.
Stone goat now only in the south of it. Mule deer and mountain lions live at the foot of the mountain. In the middle and low altitude mountains, small mammals have Huan America, Canada star weasel, Red cat
The beaver, and the northern flying squirrel. Fishers and Gulo Gulo are rare. In the upper limit of dwelling trees and vegetation with hyraxes, rabbits and marmot.
There is low at the blue headed blackbird, California horned lark and pheasant rich birds in the Sierra Nevada mountains; the bushes and at the foot of the Pearl neck Ling area, canyon wren and Roadrunner; forest belt tits, spotted owl and spotted tail pigeon; and the higher the forest eagle and Hammond (Hammond flycatcher); sub flycatcher Alpine birds are Sparrowhawk and white toed woodpecker.
Some mountain streams in Nevada trout is the local varieties, the other is introduced from outside. Because the dam and other natural ecological change, the fish in the mountainous region is quite common. Salmon and steelhead trout will be traced back to the mountain rivers in the spawning season.
The Sierra Nevada Human history
The Sierra Nevada living American Indians lived in hunter gatherer life. In addition to capture prey and set fire to cause local impact, the economic landscape of the mountains did not cause long-term effects. The first Europeans came to the area of the Spanish explorers and missionaries, they in early eighteenth Century have been to California, impact on Sierra Nevada also not worth mentioning.
In January 1848 America River (near the present-day state of California, Prather or Placerville) found a gold nugget, set off an international gold rush, not only to California but also to the United States the historical evolution of influence.
For the first time found that after two years, there are about 50 thousand miners in the Sierra Nevada mountains. Require banks, retail business, transportation facilities, logging, agriculture and industry to meet the rapid growth of the population, such as the start and prosper like bamboo shoots after a spring rain. The economic development of California to join the union, contributed to the construction of the central area of the first famous, such as San Francisco and sacramento. To the 1880 golden age reached its peak, although there are still some mining activity continues.
The Sierra Nevada tourist resources
After the initial crude Mine Road, from 1860s to 70s built area of railway and transcontinental railway. Built in 1920s the first through the Sierra Nevada several paved road. But the central mountains still did not pass the highway or railway throughout the year. The rapid development of the economy has been endangering the environment. For example, the Lake Tahoe Basin is one of the most beautiful places in mountainous area, it is a tourist resort, often encountered in air and water pollution, traffic congestion, sewage treatment, and the decline of aesthetic value.
For water and power (and after the Second World War to the needs of amusement) has changed the face of the Sierra nevada. Through the length of the western slope of the river 3/4 is under control. At the beginning of twentieth Century, the first large-scale water conservancy projects for water in San Francisco Yosemite National Park
Beh Zich Chi river reservoir built (Hetch Hetchy Reservoir), flooded comparable near Yosemite Valley natural scenery scenery. The latest and most magnificent river water conservancy development Fischer (Feather River, state water conservancy) project started in 1950s to early 90s, still under construction.