(CNN) - A startling new study finds that nearly a quarter of the West Antarctic ice sheet is affected by ice thinning.
Scientists at the University of Leeds in England found in their research that the ice sheet has thinned at much as 122 meters, or approximately 400 feet.
The thinning is causing instability in the glaciers.
Melting and calving - the breaking off of ice chunks - is reducing the mass of the glaciers faster than can be replenished by snowfall.
The largest ice streams in the region - the Pine Island and Thwaites glaciers - are losing ice five times faster than they were when the measurements began.
A team of researchers at the university used 25 years of satellite observations and climate models to track the evolution of snow and ice cover in the area.
The measurements they study aim to distinguish between short-term changes due to weather patterns and long-term trends.
The ice losses are indeed driving up sea levels across the globe, with lead study author and director of the UK’s Center for Polar Observation and Modeling noting, “Altogether, ice losses from East and West Antarctica have contributed 4.6mm to global sea level rise since 1992.”