By Sid Perkins
An area of Antarctic seafloor that until recently was covered by thick, floating ice is host to a several-millennia-old ecosystem apparently based on chemical nourishment, not sunshine, according to a recent underwater survey of the area.
More than 60 percent of the Larsen B ice shelf disintegrated and drifted away early in 2002 (SN: 3/30/02, p. 197: Available to subscribers at All Cracked Up from the Heat? Major hunk of an Antarctic ice shelf shatters and drifts away). That ice mass had been floating, although attached to shore, for 10,000 to 12,000 years, says Scott E. Ishman, a marine geologist at Southern Illinois University in Carbondale. Before that time, during the last ice age, the ice reached all the way to the seafloor and scraped the bottom clear of sediments.