Massive Antarctic iceberg breaks in two

In what could be a boom or a bust for some Antarctic shipping, a massive, 100-mile long iceberg known as B-15A has split in two, satellite photos have confirmed.

Monitoring the Antarctic ice using NASA’s Terra satellite, scientists at the UW–Madison’s Space Science and Engineering Center were among the first to notice the fracture creating two giant icebergs in the Ross Sea, due south of New Zealand.

Since B-15A first broke off the Antarctic’s Ross Ice Shelf in 2000, the enormous iceberg has been trapping sea ice near Ross Island, home to McMurdo Station, one of the main U.S. scientific outposts in the Antarctic. The trapped ice has made shipping and the delivery of fuel and supplies to McMurdo increasingly difficult.

The splitting of B-15A, according to Matthew Lazzara, a meteorologist at SSEC’s Antarctic Meteorological Research Center, could help clear the trapped ice near McMurdo, or it could compound the problem, making it even more difficult for ships to traverse the Ross Sea.

“It’s been kind of stuck in this location for almost two years and the sea ice behind it has been growing thicker instead of dispersing as it usually does,” Lazzara says. “It will be interesting to see if it goes away and creates fewer problems or if it makes it even harder to get ships to McMurdo.”

With support from the National Science Foundation, scientists from UW–Madison and the University of Chicago have together been studying the massive iceberg. Three remotely operated weather stations have been placed on the iceberg by UW–Madison scientists and a Wisconsin team is now in the Antarctic preparing to deploy seismic equipment to the iceberg and perform routine maintenance and repair on the automated weather stations.

“The data we’re collecting, we hope, will give us some clues about why these things behave as they do,” explains Lazzara. “Using the data we collect, and the models developed at the University of Chicago, we hope to get a better understanding of the life cycle of these very large icebergs.”

The intact B-15A iceberg was an estimated 90 to 100 miles long. The now-split iceberg has divided into two, with one berg about 75 miles long, and the other an estimated 20-25 miles in length.