Tamara Traubman
without any relation to the trend of global warming, which worries many experts
In recent years, American geologists have discovered that the glacier
The western part of the Antarctic continent is disappearing. Geological evidence
Thousands of years old they collected, teachers according to them, because the glacier is huge
The dimensions in the west have been melting for 7,600 years. In their opinion, in the end
Nothing will be left of it, and man has no way to stop it.
The rate of glacier retreat varies from region to region. In one place,
For example, it was discovered that between the years '74-84 it retreated at a rate of 30
meters per year, while in other places it was found that in the thirty years
Recently, it has retreated at a rate of about 450 meters per year.
The size of the glacier of West Antarctica is about 930 thousand square kilometers, as their area
of Texas and Colorado together. According to the researchers, whose research is being published
Today in the scientific journal "Science the complete disappearance of the glacier."
will cause an increase of about five to six meters in sea level,
and flood all the low-lying areas of the world, which lie on the coast line.
Most of the world's inhabitants live in these areas today. One of the suggestions
It is to build huge dams that will protect the cities prone to flooding.
The rocky base on which the West Antarctic ice sheet sits has been found
below sea level, which is actually the main reason for its relative disappearance
fast The sea water "gnaws away" at the ice, and later causes parts
from which to detach from the base and collapse into the sea, in what appears to be a slide of
Huge icefalls.
In the center of the Antarctic continent runs a mountain range, known as the ridge
The Transantarctic, which divides the Antarctic ice cap into two
Separate parts - western and eastern. to the eastern part of Antarctica
There is no danger of a similar collapse. It rests on solid ground that is present
above sea level, so it remains relatively stable over the years.
The researchers recreated the historical changes that took place in Alfie
The last few years in the West Antarctic ice sheet with the help of data
Radar and ice samples, taken from where the glacier meets below
Sea level on solid ground. They determined the age of the ice samples
Through laboratory tests, which allow the age of materials to be determined
created many years ago. Thus they discovered that in the 7,600 years
Recently, the glacier has retreated every year at an average rate of about 120 meters.
"It seems that the collapse is part of a prolonged natural cycle, which most likely is
Caused by sea level rise, which started with the melting of a surface
The ice in the northern hemisphere at the end of the last ice age," he says
Prof. Howard Conway, geophysicist from Univ
Washington, who headed the study. According to him, "the process is easily accelerated
If we continue to contribute to the warming of the atmosphere and the oceans."
The glacier of West Antarctica first formed hundreds of thousands of years ago
years, and in previous studies hints were found that the ice cap of
West Antarctica has melted in the past. "There is no indication of slowing down
The retreat, and it will most likely continue, at least in the near future."
says Conway. He and his colleagues cite other researchers in their study,
who claim that if the melting of the glacier continues at a rate similar to today's,
It will melt completely in about 7,000 years.
{Appeared in Haaretz newspaper, 8/10/1999{
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