Monday, 27 June 2011

Geography Picture of the Day - Ocean currents carving out cavities in glaciers

Whilst doing some research for my EPQ, I came across this picture.......
Pine Island glacier ice shelf in Antarctica
This image shows the impact of stronger ocean currents on glaciers. Increasing winds over the South Pole, over the last few decades, is one possible reason for the increasing strength of the ocean currents. This increase in strength has lead to the chiselling of the ice beneath the ice shelf, provoking the formation of the cavity above. This cavity has allowed for warm water to flow into the glacier; increasing the rate of melt as the warm water upwellings, from the deep sea, melt the glacier from below up. Despite only a 0.2 degree Celcius rise in surface sea temperatures in this region, the melt from beneath the shelf has increased by 50% (both over the last 15 years), and scientists believe that this could be one possible reason. Therefore they are hoping that if they are able to calculate the changes in ocean currents, especially their strength, then they will be in a better position to predict the rate at which Antarctica's glaciers are melting and so what contribution they will provide to rising sea levels.

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