Antarctica Revealed at High Resolution
Eighty Eight percent (88%) of the world’s ice is in Antarctica. If the Antarctic glaciers and ice sheet were to melt entirely, global sea level would be about 187 feet (57 meters) higher than at present. Fortunately that cannot happen anytime soon.
Antarctica is changing very quickly however. Each year brings new surprises. With the ice sheet several miles deep moving around hidden mountains, with enormous caverns hidden from view, we need better information to monitor the changes. In particular, there are a few “mega glaciers” with the potential to change the world.
Fortunately the technology has arrived to monitor those changes. The Ice Sat 2 satellite launched in 2018 has markedly improved our ability to measure and track changes all over the massive continent. As can be seen on the composite NASA image above (with added labels for major glaciers), there is finally great detail across all of Antarctica. (Last week a paper was published in the journal Science, with some additional and similar images.) From the dark red showing a loss of 6 meters in thickness a year (~20 feet) to the dark blue showing an increase of a meter (~3 feet) we can finally track and visualize what is happening. This is the first full year of this high resolution information. Tracking this year by year will yield valuable comparisons. In addition to learning more about Antarctica, that should greatly improve our information about rates of sea level rise. As glaciers move from land to sea, or as the meltwater finds its way to the ocean, global sea level increases.
I might point out the two large ice shelves colored blue, the Ronne abutting the Weddell Sea and the Ross shelf by the sea of the same name are floating ice. Thus they do not directly affect sea level since their mass is already supported by water, much like an iceberg. It is the glaciers on land that are of primary concern.
In particular, there are four glaciers shown in dark red that I would bring to your attention. Imagining a clock face, the Pine Island Glacier group, including the dominant Thwaites are at about the 8-9 o’clock position. At the 3-4 o’clock position are Denman and Totten Glaciers. As a group, the six “Pine Island glaciers” hold about ten feet (3 meters) of global sea level rise. Denman holds about five feet and Totten more than ten feet. This new high resolution data confirms dozens of other studies showing the accelerating melting and movement in these glaciers, indicated here by dark red.
Antarctica has always been the most mysterious place on the planet’s surface. It’s ironic since what happens there will change sea level, coastlines, and real estate all over the world. Thankfully, technology now allows us to monitor this critical but previously inaccessible region.