evidence: When ice shelves shrink or collapse, they no longer hold the massive ice sheet’s glaciers in place. Without these stoppers holding back glacial flow, the ice flows more freely into the ocean, raising sea levels. A study published in 2020 analyzed satellite data from 1994 to 2018, finding that Antarctica’s ice shelves have lost nearly 4 trillion metric tons of ice since the mid-1990s. From 1979 to 2017, the mass balance in Antarctica shows a decline for the entire period, with a ramping up in the 2000s for coasts most exposed to the warm circumpolar deep water. The Amundsen and Ross Seas appear to have the strongest impact in terms of higher temperatures as these warmer ocean waters move in, but there is evidence of subglacial melt from warming ocean waters in both East and West Antarctica.