Google Earth Community: Pacific Cooler Than Normal in Oregon Dead Zone

Pacific Cooler Than Normal in Oregon Dead Zone

Off the coast of Oregon, a large dead zone—an area of water where the oxygen concentration is so low that little to no marine life can survive—has been appearing each summer since 2002. The dead zones appear to be linked to an unusually persistent northerly wind that pushes surface waters away from the coast. The cool waters that well up from deeper in the ocean to replace them are rich in nutrients but low in oxygen. These high-nutrient, low-oxygen waters “pack a one-two punch in creating dead zones,” says Francis Chan, an Oregon State University scientist studying the events. The excess nutrients fertilize an overgrowth of algae and other marine phytoplankton. When the plants die, bacterial decomposition sucks more oxygen out of the already oxygen-poor water.

Repeated upwelling of deep water can produce a cool sea surface temperature anomaly, places where temperatures are lower than long-term average conditions. rest of article here

Edited by danescombe (09/03/06 05:05 PM)

Post Extras