Where did these "broken ice", "circle circle" and "crushing stone" from the ground came from?

Frozen soil, a special soil below zero degrees Celsius and ice, is distributed in high latitudes and high -altitude areas, such as Xing'an Ridge and Qinghai -Tibet Plateau in my country.

Frozen soil has extremely special properties, so it can form a variety of strange frozen landforms. These "black magic" mentioned in this article are caused by frozen soil.

01

The groundwater is going out

An important condition for forming frozen soil is that the soil contains water. When these water is constantly frozen and melted, many interesting landforms will be formed.

Underground ice, as the name suggests, is the ice formed in frozen soil for many years, including condensation, buried ice, pulse ice, etc. Underground ice is an extremely important water resources in frozen soil areas for many years, and the existence of underground ice has a great impact on frozen earth engineering and climate change.

Underground ice. Picture source: Wikipedia Encyclopedia

Frozen swelling hills refer to landforms that expand the soil upward due to the increase of ice under the increase of ice. Specifically, the melting layer of the winter season is frozen from top to bottom, from bottom to bottom, and the overwhelite surface is reduced. With the development of the frozen surface, when the pressure of the upper water of the frozen layer is greater than the intensity of the upper soil layer, the surface is raised, and the frozen swelling hug is formed.

Frozen and swelling hills are a kind of frozen land appearance that can often be seen in frozen soil areas in my country for many years. The diameter at the bottom of the frozen and swelling hug is from a few meters to tens of meters, 1 to 2 meters high, and some can reach 3 to 5 meters. The surface of the frozen and swelling hug often has a criss -crossed crack. The largest frozen and swelling dance in my country is in 62 classes in Qinghai -Tibet Highway. Its bottom diameter is 40-50 meters, up to 20 meters.

Frozen swelling hill section. Picture source: Wikipedia Encyclopedia

In many years of frozen soil area, sometimes you can see the glittering ice body of the silver light. This is the ice cone. The melting layer is frozen in the winter, the pressure of the groundwater increases, the overflow of the soil overflowing layer overflows the surface, and the overflowing ice body gradually increases and is cone -shaped. Frozen by the flow of the overflow and extending along the ground underground water flow, the ice cone is formed.

The shape and size of the ice cone varies a lot, some of which are 2 to 3 meters, and some extend dozens of meters or even hundreds of meters in the ice slope. Sometimes there are several overflows. Ice vertebra is very common in frozen soil.

The ice cone in melting. Picture source: China Science Popularization Expo

02

Frozen soil also likes to enclosure

Have you ever seen a circle of gravel? The effect of freezing and fusion unique to frozen soil will separate different substances, so this "enclosure" phenomenon is more likely to appear in the frozen soil area. Circle "landform.

In the flat and thick surface layer, through the effects of frozen melting, soil and small rock crumbs are concentrated in the middle, and the rocks will be crowded to the surrounding area, which is polygon or nearly circular. Circle, this frozen land appearance is called stone ring.

Stone ring. Picture source: Wikipedia Encyclopedia

The area where the stone rings are formed must be mixed with the thickness of the soil, and it also requires sufficient water. The duration of the temperature fluctuating up and down the zero -degree Celsius is longer. Only in this way, the stones mixed in the soil will be squeezed out.

The stone rings are common in flat or rivers not far from the river beach, because there are conditions for the formation of stone rings.

The frozen bloating grass rings form the polygon or nearly round on the ground surface, and it is exposed to the rock crumbs. This is a relatively rare type of ice and landforms in the frozen soil area. At present, scientists are not very clear about its formation mechanism and process.

Frozen bloating grass rings. Picture source: reference [1]

03

"Broken Stone" in frozen soil

Due to the cracks, when the water frozen expansion, the rock rupture into many small pieces, or due to temperature changes, the minerals that form a rock are unevenly swollen and contracted, causing rock rupture. In this case, a large number of angular rocks and rock crumbs of varying sizes will be generated. Under the conditions of gentle terrain, most of the rock crumbs remain in place to form crushed rock covering the ground. This is the stone sea.

Shihai. Picture source: Wikipedia Encyclopedia

Shi Hai is distributed in the frozen soil areas of the Qinghai -Tibet Plateau in my country, the western mountains, and the northern frozen soil area of ​​Daxing'an Ridge. Developed stone sea must not only be crispy and many cracks, but also have certain water and heat conditions. That is, the rock must have a certain amount of moisture, and at the same time, the temperature of the moisture should be large, and the temperature continues to fluctuate for a long time from 0 ° C.

The material source of the stone slope is generally similar to the stone sea, but the landforms that appear in the two are different. Shi Hai is more common in the gentle mountain items, while the stone slope appears on the hillside.

The rocks and debris of the stone slope, in addition to the frozen weathering in the slope, also rolled down from the mountain by gravity. In this way, the composition of the stone slope is thin and thick, and the top slope is mostly small rock chips, and the bottom of the slope is mainly large rocks.

Stone slope. Picture source: Wikipedia Encyclopedia

The stone flow slope is a common type of ice and landforms in frozen soil areas for many years. It is widely distributed in Daxinganling and the high mountains and plateau frozen soil areas in western my country, and can be seen almost everywhere.

Under natural conditions, surface substances are often mixed. Due to the different thermal conductivity of stones and soil, the freezing speed is different. The crushed thermal heating rate will be frozen first, and the water will migrate near the stone and form ice near it. After the water forms ice, the volume will swell, so that the crushed gravel can be moved. In this way, thick matter and fine substances will There will be separation. This phenomenon scientist calls the effect of freezing fusion, because it is like a sieve to separate different substances. The stone strip is caused by the repeated freezing and frozen sorting of the gravel on the stone flow slope to bring the gravel at a low place, and extend down the slopes down the slope through gravity. Therefore, stone strips often exist at the same time as the stone slope, and the gravel and fine particles are arranged in the shape of the slope.

Stone bar, "brother" of stone slope. Picture source: Wikipedia Encyclopedia

The rocks and rock crumbs generated by the cold weather are gathered in the groove under the slope under the action of gravity. The gravel moves slowly down the groove to form a small river filled with stones, so it is named stone river.

Shi Hai, Shi slope, and Shihe are brothers of the same family. There are organic connections with each other. They often appear at the same time in the same mountain. Often, boulders on the mountains are paved with boulder, the hillside crushed rocks are spread, and the foothills are flowing.

Shihe. Picture source: Wikipedia Encyclopedia

The "broken stone" of nature can be formed by the rock in a special frozen earth environment. Although its form is peculiar, only human beings take care of the fragile frozen soil environment can it cause continuous shock to humans.

references:

[1] hjort, jan. (2006). Environmental factorS Affecting the Occurrence of PerigLacial Landforms in Finnish Lapland: A NUMERICAL APPROACH.

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Production ｜ Earth Story Team

Produced ｜ China Science Popularization Expo

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