Information about the melting of glaciers

Glaciers are huge rivers made of ice, also known as glaciers. In perennial frozen mountains or polar regions, perennial snow is squeezed into ice under the action of gravity and slides down the hillside to form glaciers. Polar glaciers, also known as continental glaciers, cover a wide range and are left over from the ice age. Glacier is the largest fresh water resource on the earth and the largest natural reservoir on the earth after the ocean. There are glaciers on seven continents. Because glaciers were formed in areas frozen for many years, the study of glaciers can help us find ancient geological information. Because the greenhouse effect is particularly obvious in high latitudes and high altitudes, glaciers on the earth are disappearing at an alarming rate. For glaciers that flow directly into the sea, this means the increase of giant icebergs, the rise of sea level and the possible inundation of coastal areas; For glaciers on high mountains, this means that the river flow at the foot of the mountain is unstable, that is, when a large amount of snow melts, it causes floods and the rest of the time causes droughts. As the glacier moves forward, it will cut the rocks on both sides of the valley and take them far downstream. When the glacier retreated, these boulders were left on the river course of the original glacier, including the slopes on both sides. The valley where glaciers flow will change from the original V-shaped cross section to the U-shaped cross section. Iceland's glaciers produce all kinds of debris, called ice deposits. Ice water and ice deposits are debris deposited after the melting of ice called glacial meltwater. Some ice deposits contain stones and boulders similar to boulders. Ice deposits may also be mixed with fine gravel deposits called ice gravel mud by glacial meltwater. The accumulated moraine soil is the debris falling from the top when the glacier melts. The total distribution area is about 16227500 square kilometers, accounting for 1 1% of the earth's land area and 69% of the earth's total fresh water. 97% of modern glacier area and 99% of ice volume are occupied by Antarctic continent and Greenland. In particular, the Antarctic continental ice sheet covers an area of 6.5438+0.398 million square kilometers (including ice shelves), and the maximum ice thickness exceeds 4,000 meters. Ice flows around from the center of the ice sheet and finally collapses into the ocean. Understanding of Glaciers Glacier Scratches Human beings have known about glaciers for a long time. In the Tang Dynasty, China described Muzhaerte Glacier in Tianshan Mountain as ice and snow piled up into ice, which was difficult to understand at the turn of spring and summer ... to the effect that ice and snow piled up into ice and would not melt in spring and summer. But the Alps in Europe are the birthplace of modern glacier research. The First Systematic Study of Alpine Glaciers by Humans 19 Agassi and Jean-Louis Rudolph Agassiz established the world's first glacier research station in 1930s and 1940s, which laid the foundation of glaciology. 19 1 1 year, J.P. Koch and A.L. Wegener initiated the study of continental ice sheets. Since 1950s, some large-scale international cooperation projects and the application of oxygen isotope, radar measurement, satellite remote sensing and telemetry technology have effectively promoted the understanding and classification of glaciers. Glaciers are divided into two types according to their position on the earth. Many geographers believe that their strength, terrain and reasons are significantly different. Although glaciers and glaciers are traditionally synonymous, there are no synonyms for glaciers in the following two classifications, that is to say, mountain glaciers and continental glaciers are relatively rare or not commonly used in geographical research. Schematic diagram of the influence of mountain glacier melting on the surrounding landform The glacier is tongue-shaped and moves under the action of gravity. For example, the glaciers on the Qinghai-Tibet Plateau in China are the largest alpine glaciers in the world. Continental glacier is the largest kind of glacier, which is shield-shaped. This kind of glacier covers a huge ground, and in many cases, its thickness is enough to bury all mountain systems except the highest peak. The area exceeds 14.

000

000 square kilometers of Antarctica, almost all of which are nearly 1 on average.

Glaciers with a thickness of 980 meters cover it, and the thickness of ice in the east can reach 4267 meters. Greenland ice sheet area exceeds 1.

Eight hundred

000 square kilometers, the measured maximum thickness is about 3.

350 meters. Smaller continental ice sheets are often called ice sheets or ice sheets. There are two ice sheets on the earth, the Antarctic ice sheet and the Greenland ice sheet, accounting for 99% of the total volume of global glaciers, of which the Antarctic ice sheet accounts for 90%. About 83% of Greenland is covered by glaciers.

Reference: zh. *** /w/index？ Title =% E5% 86% B0% E5% B7% 9d&; Variant = =zh-#.E5.88.86.E5.B8.83

Partial melting situation Arctic Ocean-Arctic sea ice has lost 65,438+0.8-3.65,438+0 meters of ice in the past 35 years. It is predicted that it will not snow in the summer of 2050. Since 1993, the ice layer of Greenland-Greenland ice sheet has been thinned by about 1m every year, and the number of glaciers in American Rocky Mountains-Glacier National Park has been reduced to 50 since 1850, and the rest will disappear within 30 years. The Antarctic Peninsula-Larsen Ice Shelf collapsed in 1998, losing 300 km2, and lost 1 in 98-99.

7 14km2, still losing. The Russian-Caucasus Mountains lost 50% of their glacier area in the past century, and the Alps in Europe lost 50% from 1850. Only a few scholars predict that glaciers will no longer be seen in Alps and Switzerland by the end of this century. The ice in the Grand Canyon of Malaya will melt completely. Some scientists used laser rangefinder to compare the height of *** 67 glacier in Jalas and other places in Canada with the topographic map made in 1950s and 1960s. It is found that glaciers in this area are losing at a rate of 50 square kilometers per year, which is equivalent to 8 kilometers long. According to the global loss figures, the global glaciers lose about 92 square kilometers of ice every year, and the ice surface rises. Tuvalu is the first country in the world to be submerged. Tuvalu has a total area of only 26 square kilometers and consists of 9 atolls with a total population of 1. 1 10,000. On February 8, 2000, Tuvalu was almost submerged in the sea. On that day, the airport and some houses in the capital were immersed in the sea of Wang Yang. On February 19, the sea level in the country rose to 3.2 meters around 5 pm, and the tide slowly receded at 5: 44 pm on February 20. The highest altitude in Tuvalu is only 4.5 meters, so houses in low-lying areas have no roofs. ■ In the past decade, seawater has eroded 65,438+0% of Tuvalu's land. Experts predict that if the earth's environment continues to deteriorate, within 50 years, all nine small islands in Tuvalu will not go into the sea and disappear on the world map forever. ■ Tuvalu once considered buying land in a neighboring country, but it was too poor to afford much land. The best way is to immigrate to the whole country. ■ Australian Immigration Minister Philip Ruddock said: "In fact, we have been talking about this issue for the past twenty years. If Tuvalu is really swallowed up by the sea in the future, then Australia will never die. But now it seems that they are not facing real danger. " ■ Pusinili Rayafa, Tuvalu's Deputy Foreign Minister, has another view: "Tuvalu's population is getting denser and denser, and more and more land is being swallowed up by seawater, which is really worrying." He also revealed that he never imagined that Australia, with its vast territory and sparse population, was so indifferent to the demands of the people of Tuvalu. ■ Who's next for island countries: It is reported that Kiribati, Cook Islands, Nauru, Western Samoa and other low-lying island countries are also facing the same threat as Tuvalu. In viti levu, Fiji, the water on the seashore is extremely shallow, and fishermen can't walk waist-deep for hundreds of meters. It turns out that these shallow waters used to be part of the land. It is predicted that more than 80,000 Kiribati residents will face the fate of losing their homes in the next 40 years. ■ If the situation does not improve, Tuvalu is destined to be the first country to be forced to leave their homes due to rising sea levels. Unfortunately, it will never be the last one. Who's next? Beijing Youth Daily 20065438+0165438+2310 Other examples of global warming leading to sea level rise in the Baltic Sea. Polish scholars predict that the sea level in the Baltic Sea may rise by 30 cm to 100 cm in the future 1983. The coastline retreats to land on average10m. In some places, seawater encroaches on the coast up to 450 meters, and in some places, the coastline even recedes by 1700 meters, from 1985 to 1995, and the sea level in the eastern Baltic Sea rises by 6 mm. Scientists believe that even if the sea level rises by only 30 cm, it will cause great damage to the Polish coastline with soft soil and soft sand. Xinhua News Agency September 28, 2000 Other examples of sea level rise Global warming has accelerated the melting of glaciers in the Himalayas. Global warming has accelerated the melting of glaciers in the Himalayas, and the water levels of glaciers and lakes have continued to rise, which will eventually lead to the bursting of many lakes. In the past three years, the United Nations Environment Programme has observed 3,252 glaciers and 2,323 glacial lakes in Nepal, 677 glaciers and 2,674 glacial lakes in Bhutan. The results show that the temperature in these areas has increased by a full 1 celsius compared with that in the 1970s, and the water level in glacial lakes has risen sharply. The research shows that the water levels of 20 glacial lakes in Nepal and 24 glacial lakes in Bhutan are rising continuously, and these lakes will burst their banks in 5 to 10 years. There is evidence that many glacial lakes in other parts of the world are also facing the same threat. The mountain is the water tower of the earth. After the glaciers melt, water is injected into all the rivers and lakes on which life depends. If the global glaciers shrink rapidly, many rivers in the world will dry up, and the drinking water supply of human beings and the survival of wild animals will face serious threats. Xinhua News Agency April 18, 2002 Other examples of glacier shrinkage in the Andes According to a survey by Argentine scientists, the glaciers in the central Andes have shrunk severely, resulting in a sharp drop in the water volume of local rivers. Since 1990s, Plomo Glacier has been shrinking, and its ice reserves have also decreased significantly. Glaciologists in Argentina found that Plomo glacier retreated 7 kilometers compared with 19 14, which is equivalent to a decrease of 25 square kilometers, that is, a decrease of one third, and a decrease of120,000 cubic meters of ice storage. Plomo Glacier is the main source of rivers such as Mendoza River and Plomo River in Argentina. According to the hydrological department, the water volume of the Mendoza River has been reduced by half. The reason for the melting of glaciers is the greenhouse effect. The sun shines on the earth.

The ground reflects sunlight.

On the way, it was blocked by water vapor, dust and greenhouse gases in the atmosphere.

Heat is thus preserved. This method of storing heat is called the greenhouse effect.

Because the atmosphere is like the roof of a greenhouse, preventing heat loss. Global Warming In the last hundred years, that is, after the industrial revolution, the global average temperature has risen by 0.6~0.7℃. At present, scientists have admitted that global warming in the past century is the result of the enhancement of global greenhouse effect. During the period of 1993- 1997, the global glaciers melted and the snow melted the fastest in the world.

Glacier retreat is about16.5m; However, since 1998, it has shrunk by 20 meters in one year, and the glaciers in the Himalayas of China (Dokayani Bamak Glacier) have shrunk by 33% from 1989 to 2000. Estimated within 10 years.

That is, it completely disappeared before 20 15. Qili Madzar Glacier1978 In 2000, Qori Kalis in Tanzania, Africa decreased by 3m every year, but increased to 30m every year in 1990s, and it is estimated that it will disappear in 2020. The disappearance of glaciers in a week now is equivalent to the disappearance of the previous whole year. Qori Kalis glacier in Peru, South America.

The solution is to reduce global warming ... all places should implement policies and laws to reduce and control greenhouse gas emissions ... in order to alleviate global warming ... and slow down the melting rate of glaciers. The following news is also related to ... The melting of Arctic glaciers has become an important warning signal of global warming. Environment ministers and officials from 23 countries recently held a meeting in the Danish Greenland town of Ilulissat in the Arctic Circle. Ilulisat is the mouth of Sermeq Kujalleq Glacier, located 250 kilometers north of the Arctic Circle. It is famous for its glacier wonders and is listed as a world heritage. However, with the intensification of global warming, local glaciers are melting rapidly and facing a major crisis. Participating countries include China, Japan, Germany, France and even the United States. The United States refused to sign the Kyoto Protocol, but recently put forward another plan to reduce air pollution. After the meeting, representatives of all countries agreed that action must be taken to solve the global warming problem as soon as possible, but there are still great differences in methods.

Reference: yenching.edu/geog/newsindex