It measures 70 miles long, 300 feet wide and nearly a third of a mile deep. Last month, NASA’s IceBridge mission snapped a breathtaking photo of a massive rift in the Antarctic Peninsula’s Larsen C ice shelf.
The rift cuts completely to the bottom of the ice shelf, but not all the way across it. Once it does, though, it will produce an iceberg about the size of Delaware.
Scientists have been keeping a close eye on the Larsen C ice shelf for a while. Back in August, UK-based Project MIDAS reported a large crack in the ice shelf grew another 13 miles over a six-month period. The crack it was monitoring stretched more than 80 miles long.
Computer modeling performed by Project MIDAS at the time predicted the crack will only keep growing. Eventually, a decent sized chunk of the ice shelf will collapse. The UK-based group estimates about 9-12% of the ice shelf will break away. It might not sound like much, but that percentage equals about 2,300 square miles of ice.
Here’s how Larsen C looked from NASA’s Terra satellite when it flew over on August 22.
The Multiangle Imaging SpectroRadiometer (MISR) instrument gives a couple of different looks at the ice shelf. On the left, we see the ice shelf as it appears in natural color. We can see several cracks stretching vertically on the lower left portion of the image.
On the right is a composite image made by combining data from three other cameras aboard the MISR. Smooth surfaces show up as blue-purple, while rougher surfaces shine orange. Cracks pop from the surrounding ice. The crack marked by the arrow is the actively growing one being monitored by Project MIDAS.
Operation IceBridge has been conducting airborne surveys over Antarctica for years.
“We are probing the most remote corners of Spaceship Earth to learn more about changes that affect all of us locally, such as how ice sheets are contributing to sea level rise,” said NASA Deputy Administrator Dava Newman recently.
John Sonntag, an IceBridge mission scientist, said this year’s batch of flights led to “possibly the best Antarctic campaign IceBridge has ever had.”
The number of flights matched IceBridge’s best years. And each flight returned more science than previous campaigns. How? IceBridge scientists are continuously improving the instrumentation aboard its plain. Great weather in the Weddell Sea also helped their sea ice flights big time says Sonntag.
Every 2016 flight began in Chile, but that’s changing next year. Operation IceBridge’s home base in 2017 will be McMurdo Station on the south tip of Ross Island. The shift in the base of operations will help IceBridge hit important new science targets and continue its close monitoring of Antarctica’s changing icescape.
Image credits: NASA