Since its launch in April 2010, ESA’s CryoSat spacecraft has been flying over the North and South Poles of our planet. Its mission is to observe changes in the thickness of the ice that covers these regions.
After three years of observations, CryoSat has confirmed that the volume of Arctic ice (North Pole) is decreasing. CryoSat has also shown that the West Antarctic Ice Sheet (South Pole) is losing more than 150 cubic kilometres of ice each year. That is equal to a slab of ice 1 km wide, 1 km deep and 150 km long!
The massive blankets of ice that cover Earth’s polar regions are not permanent. They grow during colder periods, known as ice ages, and they shrink when temperatures increase or local conditions change. Even the Antarctic ice sheet, which is almost 3 km thick, can be affected.
West Antarctica is currently experiencing rapid ice loss. CryoSat has shown that most of this occurs in the glaciers that flow into the Amundsen Sea. The rate of ice thinning soars to 4-8 m per year where the Pine Island, Thwaites and Smith Glaciers leave the land and begin to float out over the ocean.
Melting in West Antarctica was thought to have caused a global rise in sea level of 0.28 mm each year between 2005 and 2010. However, new results from CryoSat suggest that the region’s contribution to sea level rise is even greater! This could either be because the ice is thinning faster than scientists previously thought, or CryoSat provides a more accurate picture than other satellites!
