Altai Mountains

The Altai Mountains in Central Asia span 2000 km (1200 miles) from southeast to northwest, that is, from Gobi (desert) to West Siberia. The name of the mountain comes from the Turkic Mongolian word Altan, which means "gold". The uneven mountains separate the water of big rivers such as the Ob River (flowing northward into the Arctic Ocean) and its main tributary, the Irtysh River, from the water flowing into the vast central Asian basin. It is one of the magnificent mountain systems in Asia, with a NW-SE trend, slanting across the borders of China, Kazakhstan, Russia and Mongolia, stretching for more than 2000 km. The Altay Mountain in China is located on the south slope of the middle section, with a mountain body of more than 500 km long and adjacent to the Junggar Basin in the south. The height of the main ridge is more than 3000 meters, and the highest peak in the north is Youyi peak, with an altitude of 4374 meters; the mountains in the West are the widest, narrower to the southeast, and the height is gradually lower; from the northeast border line, southwestward, it gradually drops to the Irtysh Valley, showing four steps, and the mountain outline is massive and layered; only in the high mountain areas, there are ice erosion terrain and modern glaciers; except along the NW fault line, there are glaciers Altai mountain is a typical fault block mountain.

Altay Mountains

synonym

Altai Mountain generally refers to the Altai Mountains

Altay Mountains, with a northwest southeast trend, straddle China, Kazakhstan, Russia and Mongolia obliquely, stretching for more than 2000 kilometers. Altay Mountains in China belong to the south slope of the middle section, with a mountain body of more than 500 kilometers and an altitude of 1000-3000 meters. The height of the main ridge is more than 3000 meters, and the highest peak in the north is Youyi peak, with an altitude of 4374 meters.

The forest line is generally at the height of 1800-1900 meters, covering an area of 1611457 hectares, of which 1002000 hectares belong to the special protection area, rich in forest and mineral resources. The annual average temperature is 0 ℃. In July, the average temperature below the snow line is 15-17 ℃. In winter, the lowest temperature reaches minus 62 ℃. The average annual precipitation is 500-700 mm.

"Altay" means "six months" in Kazakh. From the Han Dynasty to the Qing Dynasty, there were more than 50000 people panning for gold in the mountains. The Altaic language family gets its name from the Altaic mountains.

Geology and geomorphology

The Altai mountains of Central Asia, stretching about 2000 kilometers from Gobi (desert) to West Siberia, straddle parts of China, Mongolia, Russia and Kazakhstan in a northwest southeast direction.

There are modern glaciers; the mountains in the West are the widest, narrower to the southeast, and lower in height; from the northeast of China's border line, the mountains gradually decrease to about 3000-3500 meters from the northwest to the southeast.

In front of the mountain, there is a large fault in the northwest, which gradually descends to the Erqis Valley in the southwest, showing four steps, and the mountain outline is massive and layered; only in the high mountain area, there are ice erosion terrain and modern glaciers, which is the distribution center of modern glaciers in the northernmost part of China; except for the fault basin along the NW trending fault, there is no large longitudinal valley; Altai mountain is a typical fault block mountain.

It forms "three mountains with two basins" with Tianshan Mountains, Kunlun Mountains, Tarim Basin and Junggar basin.

The jagged mountains separate the water of large rivers such as the Ob River (which flows northward into the Arctic Ocean) and its main tributary, the Irtysh River, from those flowing into the vast central Asian basin. The river originated in mountainous area is controlled by the fault and flows into the Irtysh River to the northwest. It becomes the upper reaches of the EBI River and is the only river flowing into the Arctic Ocean in China. The vertical distribution of mountain vegetation is obvious. The steppe belt is below 1100 meters; the forest belt is between 1100 and 2300 meters, where Siberian pine, Siberian fir and spruce grow; the mountain meadow belt and subalpine meadow belt are above 2300 meters, which are good pastures in summer. There is a small amount of agriculture in the low mountain basin. The mountain area is rich in nonferrous metals (including gold deposits).

geology

It belongs to the Altay geosynclinal fold belt in geological structure. The mountain first appeared in the Caledonian movement, formed a basic outline at the end of Variscan movement, and then the mountain was basically flattened into a peneplain; the Himalayan movement made the mountain follow the NW trending fault, and the fault block displacement rose, which formed the present appearance of Altay Mountain. An earthquake of magnitude 8 occurred in 1931. It is accompanied by a nearly north-south fault, extending 40-60 km.

The hills in the northern part of the Altay Mountains separate them from the West Siberian plain, and the northeast part of the Altay Mountains connects with the West Sayan mountains. Altai Mountain in Mongolia rises to become nayramdalin peak (4374m), then extends to the southeast and then to the East. The Altai mountain of Gobi starts about 483km southwest of Ulan Bator, the capital of Mongolia, occupying the south of the country and towering over the Gobi sea.

landforms

The Altai mountains are round, with moraines widely distributed on the hillsides. The U-shaped valleys cover the U-shaped valleys. The ancient ice buckets are arranged in layers, and the yangbeishi, lateral moraines, middle moraines, and final moraines are clearly visible. Altai Mountain has multi-level planation surface, which is generally recognized as grade 4. According to statistics in 2010, the altitudes were 2900-3000m, 2600-2700m, 1800-2000m and 1400-1600m respectively. The geomorphic vertical zoning is obvious, from high to low: Modern ice and snow action zone, above 3200m above sea level, with Youyi peak and Kuitun peak as the center, developing valley glacier, iceberg glacier and suspended glacier. In addition, there are modern glaciers in the upper source of akturgun and akuligun rivers around akekuli Lake; frost action zone, 2400-3200m (Statistics in 2010), clear ancient ice erosion terrain, snow up to 8 months, mainly cold weathering; erosion zone, 1500-2400m, mainly water cutting; dry denudation zone, below 1500m. Kanas comprehensive natural landscape reserve is located at the edge of the belt.

From high to low, the soil is mainly composed of ice marsh soil, alpine meadow soil, subalpine meadow soil, grass ash soil, gray forest soil, chernozem, chestnut soil, brown calcareous soil, etc.

Climatic characteristics

The regional climate is very continental. Due to the influence of Asian anticyclone, i.e. high pressure region, winter is long and cold. In January, the temperature ranges from - 14 ℃ in the hills to - 32 ℃ in the sheltered valleys in the East, while in the Chuhe grassland, the temperature can drop sharply to - 60 ℃. Occasionally there are one or two permafrost zones, which cover a vast area of northern Siberia. In July, the temperature is warm and even hot - 24 ℃ during the day, sometimes as high as 40 ℃ on low slopes - but in most parts of the Highlands, summer is short and cool. In the west, especially in the Highlands between 1524-1981 meters, the precipitation is high, about 20-40 inches, and the annual precipitation can reach 80 ml. If we continue to move eastward, the total precipitation will be reduced to 1 / 3, and there will be no snow at all in some areas. Glaciers cover the flanks of the highest peak. There are about 1500 glaciers, covering an area of about 648 square kilometers.

Climate Altay Mountains towering over the arid desert and arid semi desert areas in the hinterland of Asia. The westerly circulation brings the Atlantic water vapor, driving straight into the Irtysh Valley and Kazakhstan Zhaisang Valley, and encountering Altay Mountains to the north, forcing the uplift of precipitation. The precipitation is rich, increasing with altitude and decreasing from west to East, more in winter and summer, less in spring and autumn. The annual precipitation of low mountains is 200-300 mm, and the high mountains can reach more than 600 mm. The snowfall is more than rainfall, and the time of snow cover increases with altitude. The snow cover of middle and high mountains lasts for 6-8 months, and that of low mountains is only 5-6 months. The snow line is as low as 2800 meters above sea level, which is the lowest snow line in China With the increase of height, the degree of soil erosion decreases. The climate in Altai mountain area has obvious vertical gradient change, which is characterized by long winter and short summer, but not spring and autumn.

The whole region has a continental climate, warm and rainy in summer, cold in winter, little snow in the valley and heavy snow in the high mountains. The annual average temperature here is 0 degrees, and the average temperature below the snow line in July is 15 ~ 17 degrees. The lowest temperature in winter is - 62 degrees, and the average annual precipitation is 500 ~ 700 mm.

Water system

Altai mountain is rich in runoff, and developed the Ertis River and Wulungu river. Both rivers form a typical asymmetric comb like water system. Irtysh River is the only outflow River in Xinjiang. According to the statistics in 2010, the drainage area in China is 50000 square kilometers, with a total length of 546 kilometers. The main sources of water supply are precipitation, snow melt water and glaciers. The annual average runoff is more than 10 billion cubic meters, accounting for 89% of the total runoff in Altay region, which flows into zhaisangpo and finally into the Arctic Ocean. Wulungu River, a tributary in mountainous area, is a lost area in front of the mountain, with a total length of 573 km, and finally belongs to Wulungu Lake (brento sea and Fuhai). It is above ertai station, with a drainage area of 22000 square kilometers. Its recharge source is mainly snow in winter, with an average annual runoff of 1.1 billion cubic meters. There are many canyons and fault basins in the upper reaches of the two rivers, with large drop, clear water flow, less sediment and hydraulic reserves of about 500000 kW.

Chinese PinYin : A Er Tai Shan