Antarctica Ice Shelf Nearing End
A recent study led by NASA's Jet Propulsion Laboratory's Ala Khazendar revealed that the Larsen B Ice Shelf may be gone before the end of this decade.
Warning signs the glacier is further weakening after its 2002 partial collapse include a faster flow, the development of large cracks, and an increasingly fragmented glacier. The study also found faster glacial flows and a rapid thinning on two of its three tributary glaciers, Leppard and Flask.
Coauthor of the paper, JPL glaciologist Eric Rignot, stated that the information gained from studying the Antarctic Peninsula glaciers "provides insights about how ice shelves farther south, which hold much more land ice, will react to a warming climate."
Original data in the few years following the 2002 collapse show few changes in the glaciers, so scientists assumed they remained relatively stable. But more recent study data shows that by 2012, a remarkable 36 percent acceleration of the fastest moving part of the Flask Glacier occurred, while both the tributary glaciers thinned anywhere from 65-72 feet. The smaller Starbuck glacier has remained relatively stable which scientists attribute to its strong bedrock anchoring.
"This study of the Antarctic Peninsula glaciers provides insights about how ice shelves farther south, which hold much more land ice, will react to a warming climate." -- Eric Rignot, JPL glaciologist and paper coauthor
Ice Shelf Loss Will Impact Global Sea Level Rise
Data was gathered by NASA's Operation IceBridge campaign aircraft that had instruments to measure ice surface elevations and bedrock depths, that has provided multiyear, annual recordings of the ice sheets, glaciers, and ice shelves in Antarctica.
NASA noted that the loss of the Larsen Ice Shelf is significant because ice shelves act as gatekeepers -- without these shelves, glacial ice flows toward the ocean at a faster rate, increasing the rate of sea level rise globally.
"Although it’s fascinating scientifically to have a front-row seat to watch the ice shelf becoming unstable and breaking up, it’s bad news for our planet. This ice shelf has existed for at least 10,000 years, and soon it will be gone." -- Ala Khazedar, Scientist, NASA's Jet Propulsion Laboratory, Pasadena, California.
Acceleration of Unchecked Glacial Movement to Sea Likely
According to the NASA report, the Larsen B Ice Shelf has been in existence "for at least 10,000 years, and soon it will be gone." The current remaining life span estimate comes from Khazendar, who indicated that a widening chasm near the grounding line of the ice shelf is going to eventually crack and become free floating. The shattering of the ice shelf into hundreds of icebergs that drift away will leave the door open for the glaciers to move unchecked into the sea.