Underwater probes measure ecological impact of giant melting icebergs

BBC : After detaching from the Antarctic in 2004, the giant iceberg A-38 followed an ocean current to the South Atlantic island of South Georgia, where it broke up in the shallow seas around the island. When it melted, A-38 dumped 100 billion tons of fresh water into the ocean. Thanks to sensors that he and his colleagues had installed, Mark Brandon of the UK’s Open University could measure changes in the seawater’s salinity, density, and nutrient content. The impact of A-38 on the South Georgian ecosystem was mixed. On the one hand, the iceberg brought trace elements and other nutrients in the form of ground-up rock. On the other, the melting iceberg diverted krill—whale food—away from the island. Brandon reported his results this week in San Francisco at the American Geophysical Union’s fall meeting.