Glacier Retreat in Greenland Not Completely Irreversible, According to Study
31.01.2012 - Ice & Snow, Arctic
Climate warming and short-term climate variability have pushed a number of massive glaciers in Greenland towards retreat, which has some scientists concerned that the retreat may be irreversible once it has begun. However research published in Geophysical Research Letters suggests that Greenland glaciers’ rapid ice loss may not be an entirely irreversible phenomenon.
A team from the University at Buffalo and other institutions studied two moraines in the Jakobshavn Isbræ (Glacier) in western Greenland. A moraine is an accumulation of unconsolidated glacial debris, which forms at the furthest extent a glacier reaches before retreating. Suspecting the moraines were tied to two periods of abrupt cooling Greenland experienced 9,300 and 8,200 years ago, the researchers used radiocarbon and beryllium isotope analyses of the area around the moraines in order to determine how long the rock has been ice-free (Beryllium-10 forms when cosmic radiation strikes the Earth’s surface, and its concentration indicates how long rock has been exposed to the sun’s rays).
Their research indicates that the moraines were laid down 9,200 and 8,200 years ago respectively, which corresponds to the abrupt cooling periods Greenland experienced around those times. Each time the Jakobshavn Glacier began to grow, it deposited a moraine at its furthest extent before retreating again.