Giant Iceberg from Mertz Glacier in Antarctica could Affect Ocean Conveyor Belt
26.02.2010 - Water & Oceans, Ice & Snow, Antarctic
A 2,550 square-kilometer iceberg knocked loose from the Mertz Glacier Tongue in East Antarctica earlier this month could disrupt the ocean currents driving weather patterns around the globe, researchers found. The iceberg, which was dislodged by an older one, could disturb the area's exceptionally rich biodiversity.
Responsible for the calving are natural cycles and manmade climate change, as well as tide and ocean currents that constantly beat against exposed areas, while longer summers and rising temperatures weaken the ice tongues.
The Mertz Glacier Tongue, which is equipped with GPS beacons and several measurement instruments, might provide the first ever complete record of the full cycle of a major calving event. After breaking off, the two icebergs moved into a polynya, a patch of dense, cold and very salty water that sinks to the bottom of the sea and drives the conveyor-belt-like ocean circulation around the globe.
The icebergs are now likely to impede on the production of this dense water, shutting down the particularly strong Mertz Glacier Polynya, which accounts for 20 percent of the "bottom water" in the world.
Although the icebergs are expected to eventually disappear, their lifespan will depend on where they move.
