24% of West Antarctic ice is now unstable

By combining 25 years of European Space Agency satellite altimeter measurements and a model of the regional climate, the UK Centre for Polar Observation and Modelling (CPOM) have tracked changes in snow and ice cover across the continent.

A team of researchers, led by Professor Andy Shepherd from the University of Leeds, found that Antarctica’s ice sheet has thinned by up to 122 metres in places, with the most rapid changes occurring in West Antarctica where ocean melting has triggered glacier imbalance.

This means that the affected glaciers are unstable as they are losing more mass through melting and iceberg calving than they are gaining through snowfall.

The team found that the pattern of glacier thinning has not been static. Since 1992, the thinning has spread across 24% of West Antarctica and over the majority of its largest ice streams – the Pine Island and Thwaites Glaciers – which are now losing ice five times faster than they were at the start of the survey.

The study, published today in Geophysical Research Letters, used over 800 million measurements of the Antarctic ice sheet height recorded by the ERS-1, ERS-2, Envisat, and CryoSat-2 satellite altimeter missions between 1992 and 2017 and simulations of snowfall over the same period produced by the RACMO regional climate model.

Together, these measurements allow changes in the ice sheet height to be separated into those due to weather patterns, such as less snowfall, and those due to longer term changes in climate, such as increasing ocean temperatures that eat away ice.

Lead author and CPOM Director Professor Andy Shepherd explained: “In parts of Antarctica the ice sheet has thinned by extraordinary amounts, and so we set out to show how much was due to changes in climate and how much was due to weather.”

To do this, the team compared the measured surface height change to the simulated changes in snowfall, and where the discrepancy was greater they attributed its origin to glacier imbalance.

They found that fluctuations in snowfall tend to drive small changes in height over large areas for a few years at a time, but the most pronounced changes in ice thickness are signals of glacier imbalance that have persisted for decades.

Professor Shepherd added: “Knowing how much snow has fallen has really helped us to detect the underlying change in glacier ice within the satellite record. We can see clearly now that a wave of thinning has spread rapidly across some of Antarctica’s most vulnerable glaciers, and their losses are driving up sea levels around the planet.

“Altogether, ice losses from East and West Antarctica have contributed 4.6 mm to global sea level rise since 1992.”

Dr Marcus Engdahl of the European Space Agency, a co-author of the study, added: “This is an important demonstration of how satellite missions can help us to understand how our planet is changing. The polar regions are hostile environments and are extremely difficult to access from the ground. Because of this, the view from space is an essential tool for tracking the effects of climate change.”

Related Articles

Exercise sweat can charge your electronics

  When you workout, people say you burn a lot of energy. What if some of that could be harvested to power, say, your iPhone? A team of engineers from UC San Diego say they’ve developed stretchable fuel cells that can pull energy from sweat and can charge electronics. These aren’t the first so-called biofuel […]
Read more
Sea otters have low genetic diversity like endangered species, biologists report

Sea otters have low genetic diversity like endangered species, biologists report

Sea otters have low genetic diversity, which could endanger their health as a species, a UCLA-led team of life scientists has discovered. The findings have implications for the conservation of rare and endangered species, in which low genetic diversity could increase the odds of extinction. Genetic diversity is a measure of how many differences exist […]
Read more

Ancestral people of Chaco Canyon likely grew their own food

Researchers think they have a better understanding for how ancient North Americans thrived for centuries in northwestern New Mexico’s arid desert. A multidisciplinary team of experts from the University of Cincinnati determined that the sandy soils of Chaco Canyon were not too salty to grow crops such as maize, beans and squash for the more […]
Read more

Leave a Reply

Your email address will not be published. Required fields are marked *

Shopping Cart Items

Empty cart

No products in the cart.

Return to Shop
Search for: