London: In a new research into impact of melting ice on sea level, scientists have found that thinning ice in Antarctica is contributing nearly 10% of sea level rise and Pine Island Glacier is the major source.
Using Autosub, an autonomous underwater vehicle, researchers led by the British Antarctic Survey have captured ocean and sea-floor measurements, which revealed a 300 metre high ridge on the sea floor.
Pine Island Glacier was once sitting atop this underwater ridge, which slowed its flow into the sea. However in recent decades it has thinned and disconnected from the ridge, allowing the glacier to move ice more rapidly from land into sea.
This also permitted deep warm ocean water to flow over the ridge and into a widening cavity that now extends to an area of 1000sqkm under the ice shelf. The warm water, trapped under the ice, is causing the bottom of the ice shelf to thaw, resulting in continuous thinning and acceleration of glacial melt.
Lead author Adrian Jenkins said, "The discovery of the ridge has raised new questions about whether the current loss of ice from Pine Island glacier is caused by recent climate change or is a continuation of a longer-term process that began when the glacier disconnected from the ridge."
First Published: Wednesday, June 23, 2010, 10:56