The glaciers in Antarctica are possibly melting faster than once believed. It is believed they did the same thing nearly 15,000 years ago and that the ocean levels went up almost seven feet in only 100 years because of it reports a new research study. These results are the first direct evidence that show intense melting in Antarctica’s past is cause to believe the same will happen in the future.
Peter Clark, who is a climate scientist at Oregon State University, stated that the Antarctic Ice Sheet had been basically stable and even boring in how it had retreated. However it has changed and the ice sheet is beginning to melt again.
Natural climate heating has created large ice sheet breakdowns in Antarctica nearly 10 times in the past 20,000 years, stated the research study. It was printed up in the newest edition of the science journal Nature. There have been measurements taken at Antarctica’s largest glaciers and they seem to show that the ice sheet is on the edge of a similar colossal retreat.
Antarctica’s glaciers have been dwindling since the last great ice age ended around 22,000 years ago. The heating up of the Earth was activated by quivers in its orbit, combined with warming enhancements from both the atmosphere and ocean. There have also been temperature surges from carbon dioxide being released.
The last giant iceberg release was almost 10,000 years ago, and the rate of glacial retreat started to slow down in Antarctica until the 20th century. This was when the melting began again, this time with man-made global warming. Recent models show that climate change has tipped the Antarctic Ice Sheet into a rapid, sudden shrinking once more.
In order to see how the ice sheet stood up to natural climate change, scientists drilled deep down into the seafloor between South America and Antarctica. They found debris from the nearly 10 iceberg surges which had occurred in the last 20,000 years. Icebergs transport sand that gets trapped in ice out to the ocean, and the residue drops to the seabed floor as the icy chunks thaw.
When glaciers withdraw, they send out icebergs that melt and cause the ocean level to rise. The ice that thaws from coming in contact with warm seawater also adds to the rise in sea waters. The major question scientists are asking is where has this ice come from? The melting of the ice sheet is actually the first clear evidence Antarctica contributed to the rise of the oceans.
These findings propose that Antarctica’s huge glaciers respond to global warming with pulses of fast withdrawal, instead of a steady slow retreat. However the finding fails to answer one of Antarctica’s greatest mysteries, what has caused the melting to begin again and why have the glaciers stopped their retreat. Researchers also do not understand what regions of the ice sheet were responsible for the icebergs, though they think it was mainly the Antarctic Peninsula.
It is believed that the gigantic melting produces various ocean flow changes that cause a feedback loop, allowing warmer sea water to reach the ice. Because the melting glaciers in Antarctica hurled so many icebergs into the sea nearly 15,000 years ago, the ocean levels went up almost seven feet in only 100 years. These results are the first direct evidence that show intense melting in Antarctica’s past is cause to believe the same will happen in the future.
By Kimberly Ruble