Melting Ice Shelves

“Together, the Antarctic and Greenland Ice Sheets contain more than 99 percent of freshwater ice on Earth. If they both completely melted, they would raise sea level by an estimated 67.4 meters (223 feet). Long-term satellite data indicate that through most of the twentieth century, the ice sheets made very little contribution to sea level, and were nearly in balance in annual snowfall gain and ice or meltwater loss. However, the stability of the ice sheets has changed considerably in the twenty-first century…” – Ice Sheets Today

Two Studies on Greenland Reveal Ominous Signs for Sea Level Rise – the New York Times

Streams and rivers that form on top of the Greenland ice sheet during spring and summer are the main agent transporting melt runoff from the ice sheet to the ocean (by Maria-José Viñas courtesy of NASA Goddard Space Flight Center CC BY 2.0 DEED via Flickr).

Greenland’s mountain glaciers and floating ice shelves are melting faster than they were just a few decades ago and becoming destabilized, according to two separate studies published this week. The island’s peripheral glaciers, located mostly in coastal mountains and not directly connected to the larger Greenland ice sheet, retreated twice as fast between 2000 and 2021 as they did before the turn of the century, according to a study published on Thursday. “It got a lot harder to be a glacier in Greenland in the 21st century than it had been even in the 1990s,” said Yarrow Axford, a professor of geological sciences at Northwestern University and a co-author of the paper, published in the journal Nature Climate Change…

What the Melting of Antarctic Ice Shelves Means for the Planet – Inside Climate News

Edge of an ice shelf in Adelaide Island, off the Antarctic Peninsula (by Maria-Jose Vinas courtesy of NASA Goddard Space Flight Center CC BY 2.0 DEED via Flickr).

Antarctica’s ice shelves are the gatekeepers between the continent’s glaciers and the open ocean. As the planet warms, these shelves shrink, exposing more and more ice, which leads to more melting. This frozen continent rests under a massive ice sheet averaging more than a mile thick. But a recent study in Science Advances found that Antarctica had 68 ice shelves that shrunk significantly between 1997 and 2021, adding up to about 8.3 trillion tons lost during that time…

Greenland’s ice shelves hold back sea level rise. There are just 5 left – the Washington Post

Ice accelerating as it flows towards the coast creates heavy crevassing near the coast of Melville Bay in west Greenland (by John Sonntag/NASA’s Operation IceBridge courtesy of NASA Earth Observatory, public domain).

And now there are only five large shelves left, stretching out from their fjords toward the Greenland Sea and the Arctic Ocean. That includes three major ones — Petermann, Ryder and Nioghalvfjerdsbrae (often referred to as 79 North for its location in degrees latitude) — whose respective glaciers could ultimately account for 3.6 feet of sea level rise if they were to melt entirely — a process that would take centuries to play out…