A new study has warned that ice glaciers in Antarctica are becoming unstable with a quarter of glaciers now melting in just 25 years.
Ocean melting has caused ice thinning in west Antarctica by up to 122 metres in places. – And the effect is to drive up sea levels affecting coastal communities across the planet.
This has left affected glaciers unstable as they are losing more mass through melting and iceberg calving than they are gaining through snowfall.
Ice is being lost five times more than in 1992, with snowfall failing to restore the Pine Island Glacier and the Thwaites.
While the majority of the ice sheet has remained stable, a quarter of west Antarctica is “now in a state of dynamical imbalance.”
Melt water from east and west Antarctica have contributed to a 4.6mm – 0.16in – in the rise of the sea level, scientists warn.
Professor Andy Shepherd, director of CPOM, said: “In parts of Antarctica, the ice sheet has thinned by extraordinary amounts.
“We set out to show how much was due to changes in climate and how much was due to weather.”
The study found the most pronounced changes in thickness were signals of glacier imbalance that have persisted for decades.
Professor Shepherd explained: “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.”
Co-author Dr Marcus Engdahl, of the European Space Agency said: “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.”
The team compared surface height changes to simulated changes in snowfall and credited it to glacier imbalances.
Researchers found that fluctuations in snowfall tended to drive small changes in height over large areas for years at a time.
Satellite images were analysed at the UK Centre for Polar Observation and Modelling (CPOM) based at the University of Leeds
They combined 25 years of European Space Agency satellite altimeter measurements to track changes in ice and snow.
Researchers compared images to a model of Antarctica’s regional climate and found that melting “triggered imbalances”.
The study used more than 800 million measurements recorded by the ERS-1, ERS-2, Envisat, and CryoSat-2 satellites.
Together, these measurements allowed changes in the height of the ice sheet to be separated from those due to weather patterns.
The study was published in the AGU journal Geophysical Research Letters.
By Ben Gelblum and Daniel Hammond
