Ice Loss in Antarctica

The European Space Agency’s CryoSat has recently detected an acceleration of ice loss in the Southern Antarctica Peninsula. The news is concerning scientists around the globe because this region has previously been stable. Before 2009, the Southern Antarctica Peninsula displayed no signs of change in terms of its ice mass.

In the last six years, however, this 750 kilometer (466 mile) strip of Antarctica has been shedding ice into the ocean at a rate of about 60 cubic km each year. This change was detected by CryoSat, the European Space Agency’s satellite mission that is responsible for measuring and monitoring changes in ice that blanket both Antarctica and Greenland.

Ice coverage is important because ice helps to regulate climate and sea levels. Ice loss is a symptom of global warming.

This particular decrease of ice in the Southern Antarctica Peninsula is alarming because of the rate of loss. While this region has added about 300 cubic kilometers of water in the past six years, other glaciers along the coast are only shedding ice at a rate of four meters each year. Moreover, the Southern Antarctica Peninsula started shedding ice with apparently no warning. In 2009, the ice shelf started to thin, and melting of the glacier beneath the surface reached a critical threshold.

The ice loss is ironic because the Southern Antarctica Peninsula has not shown any changes in the past. This is a region that is largely understudied, however.

The ESA’s CryoSat only detected the ice loss after five years of measurements. CryoSat uses an advanced radar altimeter that is able to measure the surface height variation of ice in detail. This allows scientists to monitor changes in its volume with incredible accuracy.

Many scientists were stunned by the findings of the study. It demonstrates how quickly ice sheets can respond to shifting conditions. Scientists attribute the rapid loss of ice in the Southern Antarctica Peninsula to warming oceans, not changes in snowfall or air temperature.

Scientists believe that climate warming and ozone depletion have caused the winds that encircle the continent to become more vigorous. This, in turn, pushes warmer water towards the poles where it eats away at the glaciers and ice shelves.

This trend is disturbing because ice shelves in the Antarctic region have lost almost one fifth of their thickness just in the last two decades alone. Scientists are especially concerned about more ice loss in the Southern Antarctic Peninsula because much of its ice is grounded on bedrock beneath sea level. The warm water could melt it even more as it chases it inland.

Overall, more research is desperately needed. Data on ice sheet thickness, glacier flow speeds, and ocean floor topography will all go a long way to help scientists predict if and how long the thinning will continue.

References

“CryoSat Detects Sudden Ice Loss in Southern Antarctic Pennisula.” http://www.esa.int/Our_Activities/Observing_the_Earth/CryoSat/CryoSat_detects_sudden_ice_loss_in_Southern_Antarctic_Peninsula

“Introducing CryoSat” http://www.esa.int/Our_Activities/Observing_the_Earth/CryoSat/Introducing_CryoSat

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