Ice-penetrating radar technology inserted aboard Nasa survey flights has discovered frozen forms of ice blocks at the very bottom of the Greenland ice sheet which are as tall as city skyscrapers and as wide as the island of Manhattan.
The Thwaites Glacier in Antarctica is seen in this undated NASA image. Vast glaciers in West Antarctica seem to be locked in an irreversible thaw linked to global warming that may push up sea levels for centuries, scientists said on May 12, 2014. Six glaciers including the Thwaites Glacier, eaten away from below by a warming of sea waters around the frozen continent, were flowing fast into the Amundsen Sea, according to the report based partly