Sea level the warmer water expands. For at least the last 100 years, sea level has been rising at an average rate of about per year. Most of this rise can be attributed to the increase in temperature of the sea and the resulting slight thermal expansion of the upper of sea water. Additional contributions, as much as one-quarter of the total, come from water sources on land, such as melting snow and glaciers and extraction of groundwater for irrigation and other agricultural and human uses. Pilots can estimate height above sea level with an altimeter set to a defined barometric pressure.
Sea level rise A rapid collapse of West Antarctic Ice Sheet could raise sea level by at an unknown rate. The Thwaites and Pine Island glaciers have been identified to be potentially prone to these processes, since both glaciers bedrock topography gets deeper farther inland, exposing them to more warm water intrusion at the grounding line, and with the continued melt, retreat, eventually raising global sea levels. Most ice on Greenland is part of the Greenland ice sheet which rises to an average of . The rest of the ice on Greenland is part of isolated glaciers and ice caps. The sources contributing