Antarctic Pack Ice

January 08, 2012

Antarctic Pack Ice final

Photographer: Edmund Stump; Edmund's Web site  
Summary Author: Edmund Stump; Jim Foster

The photo above showing pack ice in the Ross Sea off Antarctica was snapped from an altitude of about 20,000 ft (6,096 m). We were flying to McMurdo Station, located on Ross Island. At the time the picture was taken, we were approximately 500 mi (805 km) north of McMurdo Station, off the coast of Victoria Land. The area covered on the photo is about a square kilometer (a little less than half a square mile). Every winter the Southern Ocean surrounding Antarctica freezes over with seasonal ice, and every summer this ice breaks up, drifts northward and melts. Pack ice is the name given to the broken pieces of seasonal ice, distinct from the much thicker icebergs, which form by the calving of ice from glacier tongues or ice shelves. Depending on storms and currents, the ice pack may be loose or tight, the individual ice floes large or small, sharp-edged or blunted. While Arctic sea ice has been continuing to decrease in recent decades, the total Antarctic sea ice has increased by 158,302 sq mi (about 410,000 sq km) during the same period (from 1979 - 2011). Some of this gain is attributed to increased precipitation in the Southern Ocean during the past 30 years, which acts to cool the ocean surface. Photo taken in January of 2004.

Photo details: Pentax MX camera; Tamron 28-200 mm zoom lens.