Berg on the Move...Or Not
by Terri Gregory
The mammoth tabular iceberg B-15 broke free from the Ross Ice Shelf in March 2000. Since then, this Antarctic ice shelf and the Ronne Ice Shelf have calved other large icebergs, but B-15 has maintained its hold on public interest. It was the largest tabular iceberg ever observed by satellite.
Since 2000, B-15 has broken into many large pieces, each capable of wreaking havoc in shipping lanes, holding penguins captive, or keeping sea ice from melting in normal course. In the austral summer of 2004, B-15A, the largest piece of the fabled berg at about 300 km by 37 km (180 mi. by 22 mi.), began to move along Antarctica’s Scott Coast from the place it had held since 2000 close to Lewis Bay. On 14 December, B-15A was 24 km from the Drygalski Ice Tongue, the end of the David Glacier on Mt. Joyce that floats onto the Ross Sea.
By March, B-15A had run aground off the Drygalski and remained there, shifting back and forth. By 26 April, it had moved in front of the ice tongue. On 5 May, it looked to be moving slowly away from the ice tongue, possibly out to sea. By 19 May, it had continued to move slowly along the coast, and on 22 May, it was pressed against the Aviator Ice Tongue, stopped in its easterly movement along the coast. B-15A is not expected to move out to sea, but to move along the Antarctic coast until it reaches the Adelie Coast’s “Iceberg Graveyard,” probably doing damage along the way.
SSEC’s Antarctic Meteorological Research Center (AMRC) and Douglas MacAyeal’s University of Chicago group have continuously monitored this iceberg and all the other tabular iceberg calvings since 2001. UW–Madison’s Automatic Weather Station team and MacAyeal placed iceberg tracking equipment on B-15A in January 2001 to closely track its movement and weather conditions on it.
Archived iceberg images are found at the bottom of the AMRC iceberg
page, so you can track all the big bergs over time. http://amrc.ssec.wisc.edu/iceberg.html