Just as no-slip strips on floors prevent people from slipping on a wet floor, "tiger stripes", named after Princeton's tiger mascot, do the same. Tiger stripes are narrow stripes of dirt and rock underneath glaciers in the Antarctic , these stripes create areas of friction that reduce the speed of the flow of ice toward the sea. Researchers at Princeton University and the British Antarctic Survey have worked to understand how these stripes form; this information could also aid researchers in understanding how the flow of these glaciers reacts to a warming climate.
Researchers want to understand what helps to determine the flow of glaciers, to do this they studied two glaciers, the Pine Island Glacier and the Thwaites Glacier in West Antarctica. These two glaciers together contribute to about 10% of the recorded sea-level rise in the past 20 years, according to the researchers the Pine Island Glacier moves at a velocity of about 1.5 miles per year.
Researchers run into a problem when trying to study these tiger stripes, studying the bottom of these glaciers is almost impossible because the ice is too thick to see through; the glaciers are over a mile-and-a-half thick. Instead, the researchers use satellite to measure the ices velocity and they use ground-penetrating radar to detect bedrock and surface topography. Using the data collected, the researchers created a mathematical model that calculated what happens inside the glacier as it flows along the bedrock, this model actually predicted the tiger stripes.
The friction is a major factor in the speed of a glacier, when friction is high, the glacier moves slowly and when friction is low, the glacier moves more quickly. The tiger stripes, lie at 30-degree angles along with the direction of the glacier's movement. These stripes form and decay due to a natural processes that occurs over 50 to 100 years, the process is strongly affected by how water, goes through the space between the ice sheet and the bedrock. "The ribs may play an important role in buffering the effects of a warming climate, since they slow the movement of ice that reaches the ocean and contributes to sea-level rise… These changes can happen independently of climate change," said by one of the researchers. Although more investigations are needed to verify models of rib formation, they guess that the tiger stripes are related to landforms that exist in the areas of North America and Europe.
Sources:
http://images.sciencedaily.com/2013/11/131108091341-large.jpg
No comments:
Post a Comment