In October, 2011, NASA's Operation IceBridge discovered a large crack in the Pine Island Glacier in western Antarctica. It extends at least 18 miles and is 50 meters deep. It could produce an iceberg more than 800 square kilometers in size. IceBridge scientists returned soon after to make the first-ever detailed airborne measurements of a major iceberg calving in progress.
From the
NASA mission page for Icebridge...
NASA's DC-8 airborne science laboratory has completed its Antarctic 2011 Operation IceBridge science flights and arrived home at its base in Palmdale, Calif., Nov. 22. The IceBridge flight and science team flew a record 24 science flights during the six-week campaign, recording data from a suite of sophisticated instruments on the thickness and depth of Antarctic ice sheets and glacial movement.
Please visit an excellent and more comprehensive previous diary on this subject with additional analysis of the Antarctic ice problem by
fishoutofwater in November. Today's diary adds three video clips discussing the situation.
More below the squiggle...
Rationale For the Flights
Why are the scientists conducting Operation Icebridge. Basically, it bridges the gap between coverage by two satellites.
Data collected during IceBridge will help scientists bridge the gap in polar observations between NASA's Ice, Cloud and Land Elevation Satellite (ICESat) -- in orbit since 2003 -- and ICESat-2, planned for late 2015. ICESat stopped collecting science data in 2009, making IceBridge critical for ensuring a continuous series of observations. IceBridge will use airborne instruments to map Arctic and Antarctic areas once a year.
The scientists are concerned about the rapid melting taking place in the Antarctica. So, the mission is designed to gather as much airborne data as possible. What follows with this next video link is a discussion of some of the reasoning and strategies behind this operation. They are measuring sea ice extent, depth of the ice, depth of the bottom, and the topography of the bottom. The information will be useful in modeling the region and predicting what might be in the future for the ice shelf.
http://espo.nasa.gov/...
Digitized Fly Through of the Glacier Crack
On February 23, NASA released a video fly through of the crack using the digital elevation model from the aircraft flights.
The crack in the glacier continues to grow with calving expected soon. Calving is a natural process. But, the frequency of such events is increasing. Each calved iceberg from a glacier with its source over land will add to the rise in sea levels by a small amount.