Glaciers in West Antarctica have lost hundreds of metres of solid ice since the early 2000s, an amount one expert is calling "truly astonishing".
The glaciers are located in the Amundsen Sea and are melting due to warm ocean waters running beneath them.
Between 2002 and 2009, Smith Glacier lost almost 500m of ice thickness.
A new study, published in journal Nature Communications on Wednesday, says the warm waters have grown over the last 15 years and that's made the ice erode faster.
And it could lead to further loss.
"Rapid thinning will hence result if the glacier cannot adjust quickly enough to compensate mass lost to the ocean at the newly exposed bottom surface," the authors wrote.
The study also examined the Pope and Kohler Glaciers, looking into data gathered by NASA's IceBridge surveys.
For the Pope Glacier, it lost between 200-250m over the 2002 to 2009 period, while the Kohler Glacier lost around 100m-200m in the same period.
The Antarctic Research Centre's Andrew Mackintosh, who is an associate professor at Victoria University of Wellington, says the amount of ice lost in the melts is surprising.
"The authors show that a truly astonishing amount of ice (around 300-490m) has been lost in less than a decade in this region," he says.
It confirms the Amundsen Sea region is a "hot spot" for rapid changes, he says.
"The authors show that extremely rapid ice sheet changes can be driven by increases in ocean heat," Assoc Prof Mackintosh says.
"Future ocean warming will undoubtedly lead to similar or increased levels of melt, but over a wider region."
He says it's still difficult to predict the effect the melt would have on the world's sea level, but overall this study proves ice sheets can change rapidly.