2017-04-26

MYSTERIOUS PATTERNS AND SHAPES FOUND IN ANTARCTIC SEA FLOOR


Many thousands of kilometers of the Antarctic and Arctic Sea have now been charted in what is a very ambitious and detailed atlas of the seabed in the Polar Regions, and it has revealed many strange shapes that have been gouged out of the sea floor to reveal more dramatic periods of times of the past of the poles. Many have said that today we know more about Mars` surface than what we know about the ocean floors here on Earth. One thing that is known is that the bed of the sea on Earth is perhaps the scantiest in the remotest Polar Regions.

FIRST ATTEMPT IN 20 YEARS AT MAKING AN ATLAS IN THE REGION 

The atlas of the findings that is being given at a meeting in Vienna of the European Geosciences Union will change this. The map now covers a region of the seabed in the Polar Regions that is bigger than Great Britain, and this happens to be the very first attempt at making an atlas that is in-depth of the region in more than 20 years.

A marine geophysicist at the British Antarctic Survey, Kelly Hogan, worked on producing the atlas along with presenting the results of it. Hogan said that they are the fingerprints of how the ice has shaped the sea floor at high latitudes. Hogan went on to say that ships had been taken across up to high latitudes and then used echo-sounding methods, pinging a sound pulse onto the floor of the sea and then recording the response at the ship. 

3D HIGH-RESOLUTION MAP CREATED BY SENDING DOWN SOUND PULSES 

It was said that it could be used to probe the sea floor surface along with the sediments that lay beneath, therefore creating a map in 3D in high resolution. Hogan pointed out that it was the remote sensing of the floor of the sea in much the same way that satellites move around the globe and take photographs. This is exactly what they did on the ships, but they sent down pulses instead to the seafloor. The photographs show the scarring of the sea floor that was left by the sheets of ice and glaciers when they grew and then retreated over what will have been many thousands of years. A plow mark that twirls was found in the Barents Sea in the Arctic, and it revealed how the tip of an iceberg rotates, with many prongs that dig out a series of trenches that are circular, in the bed of the sea, around 10 meters in depth. Scientists think that it would have been carved out between 12,000 and 15,000 years ago and this would be when the sheet of ice in the area fell apart, and a big number of icebergs were released.


Other plow marks reveal big shallow depressions and loop-the-loops; this is where bigger and heavier icebergs would have ground their way past. Hogan went on to say that the loop-the-loop plow mark would be the youngest and it would have been made by an iceberg that came from a surge of the Brasvellbreen Glacier between 1936 and 1938 on Svalbard, once the glacier had reached over 15km along and 30km long front.

PHOTOS REVEAL POLYGONS MADE BY FROST DURING ICE AGE 

Another of the photos revealed polygons that were said to be made by frost at a time when the region of seabed would have been above the ground, at some time in the last Ice Age. It was found in the Laptev Sea in shallow waters above eastern Siberia. The shapes would have been caused when the ground contracted in what would have been extremely cold conditions. The polygons are thought to have been submerged by the sea around 8,000 years ago at a time when the level of the sea rose, towards the end of the Ice Age. 


It is thought that the new findings along with others from the atlas will inform climate modeling research and allow a much better understanding of just how the sheets of ice might have behaved during the past tens of thousands of years. It may help scientists studying the climate make projections that are more accurate of the climate changes along with the rises in sea level.
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