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Satellites track variations in Antarctica's glacial retreat

12 December 2016

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Five satellites spanning two decades have revealed variations in the timing and pace of glacial retreat in West Antarctica. Some glaciers' thinning spreads up to three times faster than on neighbouring tributaries, and was offset by decades.

The glaciers flowing into the Amundsen Sea have been drastically losing ice, likely due to rising sea temperatures recorded around Antarctica in recent decades.

The Pine Island Glacier is known to contribute more to rising sea levels than any other ice stream on the planet, and the neighbouring Thwaites and smaller Pope, Smith and Kohler Glaciers are also losing ice.

But the rate at which these glaciers are melting varies between them, despite their relative vicinity. Possible reasons for this include differences in glacier catchment size, bedrock, topography and hydrology.

What remains clear, however, is that over the past 25 years, all three have seen thinning from the grounding line - where the ice stream lifts up off the land and begins to float out over the ocean - across the glacier surface.

Using data dating back to 1992 from the ERS-1 mission, together with information from ERS-2, Envisat, CryoSat and NASA's IceSat, scientists from the UK's Centre for Polar Observation and Modelling reconstructed surface heights along a series of glacial flowlines to see how thinning at the grounding lines had been passed further inland.

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