Alaska Science Forum
January 25, 2012
Eroding islands, disappearing glaciers, lots of greenhouse gases
by Ned Rozell
Kasatochi Island, pictured here one year after its 2008 eruption, is experiencing some of the fastest erosion on the planet, with about 3 feet of its muddy shoreline eaten away each day.
Photo by Ned Rozell.
The latest meeting of the American Geophysical Union in San Francisco in December 2011 featured hundreds of talks about Earth science, some of those relating to Alaska (and some of those comprehensible to a non-scientist). Here are a few items from the notebook I carried around the Moscone Center:
An Aleutian Island morphs at high speed: Chris Waythomas of the Alaska Volcano Observatory in Anchorage spoke of how Kasatochi Island in the Aleutians has changed in diameter since its explosive 2008 eruption. “Erosion by wave action has eaten away the coast at about (1,000 feet) per year. This may be a world record,” he said. That’s about three feet of shoreline disappearing every day.
Waythomas also noted that the northern part of the island has lost about 70 percent of the ash and mud deposited by the eruption four years ago, but that the ocean deposited much of it to the south end of the island. “It should be three or four more years until Kasatochi gets to its original size.”
Canada ice on the wane: Glaciologist Garry Clarke of the University of British Columbia said that the portion of the St. Elias Range in Canada will lose half its volume of ice by the year 2100, and almost all the ice in the north and central Rocky Mountains in Canada will be gone by then. “We’re going to be witness during the next century to the disappearance of glaciers in western North America,” Clarke said.
Double the midges on northern river: A second generation of midges hatched last summer along a