Do glaciers also have a butterfly effect? ​​From "violent transportation" to "gentle nourishment"

This is a story about "Sumeru" and "mustard seed". In our daily lives, we are "watched" by those extremely grand beings, just like we observe busy ants under the shade of trees in summer. On the Pamir Plateau, you can see them directly. The Muztagh Ata Peak, which is over 7,500 meters above sea level, is high in the clouds. Looking up at the foot of the mountain, the faintly blue glaciers are like super tentacles thousands of meters long, rushing towards you, which is daunting.

Kanas Glacier in the Altai Mountains. Photo by Hao Pei, quoted from the Planetary Research Institute WeChat account

The final contact was extremely gentle. The huge glacier's tongue slowly extended into the gravel belt in front of the mountain, and the meltwater flowed into a gurgling stream, which flowed over the grassland and formed the Karakul Lake, which reflected the blue sky like a mirror, and then flowed out from the other end, all the way down. The glaciers of Muztagh Ata Peak extended from all sides to the foot of the mountain, and the meltwater flowed into many rivers such as the Tiznapu River, Taxkorgan River, and Yarkand River. Glaciers have become the most important condition for maintaining many lives in Xinjiang.

The glaciers represented by the Muztagh Ata area are not ancient. They are the product of the Quaternary (about 2.5 million years ago to the present) Earth's glacial age and are called "modern glaciers". There are 12,664 glaciers in the Tarim River Basin, covering an area of ​​nearly 17,650 square kilometers and with an ice reserve of more than 1,841 cubic kilometers, both of which are the largest among China's secondary basin glaciers. The formation and energy conversion of modern glaciers eventually led to the birth of the Tahe River system, and this area is where the glaciers in Xinjiang are most concentrated.

In the Altai Mountains further north, the meltwater from glaciers forms the Irtysh River, which flows northwards and ends up in the Arctic Ocean. Under the action of the sun, the huge glaciers in the Altai Mountains, Tianshan Mountains, Kunlun Mountains and Karakoram Mountains continuously precipitate crystal clear water droplets, which eventually nourish the vast ocean of life in the heart of Asia. Xia Jianxin, a professor at the School of Life and Environmental Sciences of Minzu University of China, and others pointed out that glaciers regulate the flow of rivers in the basin under different climates, so that there is no shortage of water in dry years and no serious floods in rainy years, and they have an important function of buffering drought and flood disasters.

When it rains in mountainous areas, the temperature drops and the melting rate of glaciers slows down, resulting in a runoff dominated by rainwater. Xinjiang, which is far away from the ocean, has little rainfall compared with the eastern coastal areas, so floods are relatively weak. When the temperature is hot and the sky is cloudless, the melting rate of glaciers and snow intensifies, and the scale is large and long-lasting, with abundant water, becoming the main source of floods in Xinjiang rivers during the flood season. When the sun is high in the sky on the top of the mountain and the mountainside is covered with clouds and rain, the two streams of water merge, and the surging flood peak rushes down. If it breaks through the silted up lake embankments on the mountains, the lake water will flow into the river, and the most destructive top flood peak will be formed.

Regardless of the type of flood, another key factor that produces the world's shocking power is the drop in water level. The longest of Xinjiang's major rivers, from the source of glaciers and snow to the exit of the mountain, is no more than 200 to 300 kilometers. In this extremely short distance, the highest drop in the river can reach thousands of meters. "Flying down three thousand feet" is not an exaggeration here, but an extremely conservative description.

Amid the violent "march" of thousands of rivers and streams, the great transport began.

Over millions of years, the huge temperature difference between day and night caused the rocks to expand and contract repeatedly, gradually breaking them apart. This allowed water to penetrate into the cracks in the rocks and expand in volume after freezing, causing the rocks to further break apart.

This cycle repeats itself, and the mountain rocks break down into gravel and sand, which are carried down by the water and become a continuous source of "nourishment" for all things below the mountain.

Alluvial fan plains were formed first, and rich nutrients were deposited here. Grass, trees, animals, birds, and of course humans gathered there over a long period of time. Dotted oases became the habitat of civilization. Some of the rivers formed by glaciers evaporated back to the sky, and most of them seeped deep into the ground. However, in the higher sky, atmospheric circulation drives the energy cycle of the earth, often causing water vapor in the distance to condense into snow on the top of the ice peaks visible to our naked eyes and fall down. A cycle within the scale of the earth repeats itself over and over again.

Nothing is more amazing than this: the vast glaciers glittering in the sky, after thousands of journeys, eventually become vital water in the tiny bodies of living things, giving life on this land in the heart of Asia a myriad of forms. This is the butterfly effect of glaciers, and it is closely related to everything about us.