For the past five months, NASA scientists have been tracking a rather large iceberg that separated from the front of Antarctica's Pine Island Glacier. Measuring some 20 miles (33 km) long and 12 miles (20 km) wide, the so-called "ice island" has now drifted out to sea.
Called B31, the massive object came loose in early November 2013. NASA scientists have since tracked its journey using the Moderate Resolution Imaging Spectroradiometer (MODIS), an instrument on NASA's Terra and Aqua satellites.
A view of B31 when it first separated (up at top).
"Iceberg calving is a very normal process," noted NASA glaciologist Kelly Brunt in a statement. "However, the detachment rift, or crack, that created this iceberg was well upstream of the 30-year average calving front of Pine Island Glacier (PIG), so this a region that warrants monitoring."
A glimpse of B31 during the early stages of its journey.
Indeed, PIG has been a particularly important region of study on account of the rapid melting that's experienced there. In fact, it's considered the largest single contributor to sea level rise. What's more, the slew of icebergs generated by the region needs to be tracked owing to the danger posed to passing ships.
"It has been very interesting how little sea ice there has been in the area," said the University of Sheffield's Grant Bigg. "In the video, you can certainly see clouds suggesting strong katabatic wind flow off the glacier in the first month or two, which would have kept the Bay ice-free and helped guide the iceberg out."
Here's the timelapse video that Bigg is referring to:
B31, which could be as much as 1,640 feet (500 meters) thick, is now well out of Pine Island Bay and will soon join the more general flow in the Southern Ocean, which could be east or west in this region. The scientists are concerned that B31 will be hard to track over the coming months on account of the dark Antarctic winter that's settling in.
All images: Jeff Schmaltz, LANCE/EOSDIS Rapid Response.