2016-01-04. West Antarctic Ice Shelf Breaking Up from the Inside Out.

posted Jan 6, 2017, 4:24 PM by Alan Gould

By Lauren Lipuma, EoS - Earth & Space Science News, AGU. For GSS Climate Change chapter 8. Excerpt: Pine Island Glacier and its nearby twin, Thwaites Glacier, sit at the outer edge of the West Antarctic Ice Sheet. Like corks in a bottle, the two glaciers block ice flow and keep nearly 10% of the ice sheet from draining into the sea. Studies have suggested that the West Antarctic Ice Sheet is particularly unstable and could collapse within the next 100 years. The collapse could lead to a sea level rise of nearly 10 feet (3 meters), which would engulf major U.S. cities such as New York and Miami and displace 150 million people living on coasts worldwide. A nearly 225-square-mile (588-square-kilometer) iceberg—nearly the size of Chicago—broke off from Pine Island Glacier in 2015, but it wasn’t until researchers were testing some new image-processing software that they noticed something strange in Landsat 8 satellite images taken before the event. In the images, Jeong et al. saw a rift open in the surface of the ice shelf nearly 20 miles (32 kilometers) inland in 2013. ...this particular rift originated in the center of Pine Island Glacier’s ice shelf and propagated out to the margins. This implies that something weakened the center of the ice shelf. The most likely explanation is that a crevasse melted out at the bedrock level, driven by a warming ocean, according to the researchers....  https://eos.org/research-spotlights/west-antarctic-ice-shelf-breaking-up-from-the-inside-out