Greenland ice sheet melting at a very fast rate, says study

MIAMI: The speed at which the Greenland ice sheet is melting is likely to increase in the upcoming years despite a recent slowdown, said researchers yesterday after making a new discovery about how the glaciers move.

Greenland contains enough ice to make the sea level mount 23 feet (seven meters) if it were to melt completely.

The findings in the journal Science Advances show that ice in Greenland moves more quickly over sediment than hard rock.

That means that as the world warms due to climate change, ice flow will likely speed up because the sediment beneath Greenland will become weaker, wetter, and more slippery.

"Greenland's margin has many outlet glaciers that act as fast conveyor belts of ice. Thousands of surface lakes act as taps that deliver meltwater to the ice base, turning it into a slippery bathtub," said lead researcher Bernd Kulessa of the College of Science at Swansea University.

"This discovery leaves us concerned because we have so far accepted the exact opposite – that Greenland's icy conveyor would slow down."

Researchers based their findings on seismic surveys that send acoustic waves through the ice to gain insights on the sediment underneath.

A previous theory held that glacier melt would slow down at the end of the summer "because large networks of channels drain water away at the base, increasing frictional resistance to ice flow," said the report.

But the seismic surveys showed that sediment played the key role in controlling ice sheet flow, and weakened sub glacial sediment "leads to accelerated ice flow".

Ice is melting across the Arctic, as the polar region warms about twice as fast as the rest of the planet.

ePaper - Nawaiwaqt