January 27, 2011 - Icebergs B15J (right) and C26 (left) in the Southern Ocean

Icebergs B15J (right) and C26 (left) in the Southern Ocean

On January 23, 2011 the clouds over the Southern Ocean parted, allowing the Moderate Resolution Imaging Spectroradiometer (MODIS) aboard the Terra satellite to capture this true-color image of icebergs B15J (right) and C26 (left) afloat on the cold, dark ocean waters.

The B15 iceberg, one of the world’s largest recorded icebergs, with a surface area of over 11,000 square kilometers (4.250 square miles), was calved from the eastern side of the Ross Ice Shelf in March of 2000. Over the next several years it was carried by currents in the Ross Sea, colliding into the ice shelf and other icebergs, and breaking apart into smaller pieces. Some of these smaller icebergs have drifted out to open ocean, but B15J remains circulating in the Ross Sea.

Since James Cook’s second voyage of discovery (1772-1775), when south-polar icebergs were first observed and documented, icebergs have been a focus of scientific inquiry. Because of their erratic drift, unpredictable calving habits, and powerful movements, direct observation - scientists working on or near the iceberg – is both risky and often impractical. While field campaigns are held, despite the risks – for example, a GPS location station was installed on B15J to track its movement - satellite instruments provide a rich source of data for study of sea ice and icebergs.

Image Facts
Satellite: Terra
Date Acquired: 1/23/2011
Resolutions: 1km ( B), 500m ( B), 250m ( B)
Bands Used: 1,4,3
Image Credit: Jeff Schmaltz, MODIS Land Rapid Response Team, NASA GSFC