Many years of satellite tv for pc observations have now supplied the most detailed view yet of how Antarctica regularly sheds ice gathered from snowfall into the ocean.
The new map is based mostly on an ice-tracking approach that is 10 instances as exact as strategies used for earlier Antarctic surveys, researchers report on-line July 29 in Geophysical Analysis Letters. That supplied the first complete view of how ice strikes throughout all of Antarctica, together with slow-moving ice in the center of the continent relatively than simply quickly melting ice at the coasts.
Charting Antarctic ice move so precisely might reveal the topography of the floor beneath, in addition to enhance forecasts for how a lot ice Antarctica stands to lose to the ocean in the future. Ice melting off the continent is already identified to be a driver of international sea degree rise (SN: 7/7/18, p. 6).
Glaciologists at the College of California, Irvine, uncovered refined actions of Antarctic ice with a form of measurement known as synthetic-aperture radar interferometric part information. Through the use of a satellite tv for pc to bounce radar indicators off a patch of ice, researchers can decide how shortly that ice is shifting towards or away from the satellite tv for pc. Combining observations of the similar spot from totally different angles reveals the pace and route of the ice’s movement alongside the floor.
A new map based mostly on satellite tv for pc radar information reveals the velocity of ice move throughout Antarctica from areas of excessive elevation (thick black strains) to the coasts. Inland ice strikes extremely slowly — a lot of it plods alongside at fewer than 10 meters per yr. Nearer to the ocean, ice can journey tons of to hundreds of meters per yr.
Velocity of ice flowing throughout Antarctica varies by location
To get a number of vantage factors of the similar swathes of ice, researchers needed to cobble collectively information from about half a dozen satellites launched by Canada, Europe and Japan since the early 1990s. “Every introduced a bit piece of the puzzle,” says examine coauthor Eric Rignot.
The ensuing map reveals how ice flows from factors of excessive elevation, often known as basin boundaries towards the coast. For 80 % of Antarctica, the map reveals common ice velocity right down to about 20 centimeters per yr. That’s a significant improve from earlier maps, which relied on ice-tracking methods with uncertainties of just a few meters per yr.
In 2021, NASA and the Indian House Analysis Group plan to launch a satellite tv for pc that can collect sufficient information to replace this map each few months — permitting scientists to higher monitor how ice move throughout Antarctica adjustments as the local weather adjustments.
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Edwin Santos was born and raised in Puerto Rico. He has contributed to Discovery Magazine, Details and the Huffington Post. Edwin has also served as a commentator for NPR and MSNBC. As a journalist for Nosy Media, Edwin mostly covers national news. Aside from earning a living as a freelance journalist, Edwin also works as photographer.