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ElwoodBlues Most of the Earth's ice is in Antarctica and Greenland; are those glaciers and ice sheets shrinking?
A recent study of Greenland’s ice sheet found that glaciers are retreating in nearly every sector of the island, while also undergoing other physical changes. Some of those changes are causing the rerouting of freshwater rivers beneath the ice.
In a study led by Twila Moon of the National Snow and Ice Data Center, researchers took a detailed look at physical changes to 225 of Greenland’s ocean-terminating glaciers—narrow fingers of ice that flow from the ice sheet interior to the ocean. They found that none of those glaciers has substantially advanced since the year 2000, and 200 of them have retreated.
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“The coastal environment in Greenland is undergoing a major transformation,” said Alex Gardner, a snow and ice scientist at NASA’s Jet Propulsion Laboratory and co-author of the study. “We are already seeing new sections of the ocean and fjords opening up as the ice sheet retreats, and now we have evidence of changes to these freshwater flows. So losing ice is not just about changing sea level, it’s also about reshaping Greenland’s coastline and altering the coastal ecology.”
https://earthobservatory.nasa.gov/images/147728/shrinking-margins-of-greenland
Antarctica
[media=https://youtu.be/AmSovbt5Bho]
April 1, 2021. The Antarctic ice sheet's mass has changed over the last decades. Research based on satellite data indicates that between 2002 and 2020, Antarctica shed an average of 149 billion metric tons of ice per year, adding to global sea level rise.Apr 1, 2021
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Areas in East Antarctica experienced modest amounts of mass gain due to increased snow accumulation. However, this gain is more than offset by significant ice mass loss on the West Antarctic Ice Sheet (dark red) over the 19-year period. Floating ice shelves whose mass change GRACE and GRACE-FO do not measure are colored gray.
https://climate.nasa.gov/climate_resources/265/video-antarctic-ice-mass-loss-2002-2020/
For Antarctica, BEDMAP2 and Bedmachine provides the most complete and up-to-date estimate of ice volume, and it is derived by combining thousands of radar and seismic measurements of ice thickness [2,3].
In fact, BEDMAP 2 is derived from 25 million measurements. Fretwell et al. 2013 estimated that the Antarctic Ice Sheet comprised 27 million km3 of ice, with a sea level equivalent of ~58 m. BedMachine estimates the sea level equivalent of Antarctica to be 57.9±0.9m
https://www.antarcticglaciers.org/glaciers-and-climate/estimating-glacier-contribution-to-sea-level-rise/
