Shoreline bluffs between Barrow and Prudhoe Bay are tumbling into the Beaufort Sea about twice as fast as they were just 25 years ago, according to a new study by the U.S. Geological Survey.
That could eventually pose problems for coastal villages and oil-drilling ventures, said USGS geographer Benjamin Jones, lead author of a paper published this week by the American Geophysical Union.
The research by Anchorage-based USGS scientists and others focused on a 40-mile-long swath of coastline near Teshekpuk Lake -- a fossil fuel and wildlife-rich area highly valued by oil companies and Native subsistence hunters. It lies within the National Petroleum Reserve-Alaska, about 90 miles southeast of Barrow.
In the 1960s and 1970s, about 20 feet of shoreline there eroded into the sea each year, the study found. The loss of land increased to about 28 feet a year during the 1980s and 1990s.
From 2002 through 2007, however, the rate of erosion at the site jumped to 45 feet per year.
That might just represent a temporary period of heightened erosion in a region that seems to erode faster than just about anywhere else in the circumpolar Arctic, Jones said.
Or it might be a dramatic manifestation of climate change.
The authors note that the fastest erosion occurred during a period of rapid decline in summer sea ice, which -- when present -- protects the coastal bluffs from summer storms.
During 2007, the year Arctic sea ice fell to its lowest level on record, the authors documented some sections of coastline that lost 80 feet to erosion.
Other contributors to the trend may be warmer summer sea temperatures, a slightly higher sea level and increases in storm power and wave action, the study said.
"Taken together these factors may be leading to a new era of ocean-land interactions that seem to be repositioning and reshaping the Arctic coastline," the paper said.
The consequences are already visible, Jones said. Recent erosion in the area studied has gnawed away at a 1970s-era test well for potential oil extraction and sent a cabin and a beached whaling vessel tumbling into the sea.
The vessel had rested on a bluff near the Lonely Short Range Radar Site for nearly a century, Jones said. He snapped a picture of it when he was examining the area in the summer of 2007. The following spring, the boat was gone -- and the bluff it rested on was gone too.
The study measured the rate of erosion by using archived aerial photographs taken by the U.S. Army, as well as USGS and BLM studies, Jones said.
Problems with erosion aren't new to the area -- a turn-of-the-century trading post in the region slipped into the Beaufort Sea in the 1980s -- but the loss of cultural sites in the vicinity might accelerate, the study noted. The abandoned Inupiat village of Kolovik could be the next to go.
Also in the path of change is the rich wildlife habitat surrounding Teshekpuk Lake, calving ground for an estimated 45,000 caribou as well as an important goose-molting habitat.
Audubon Alaska calls it "one of the most ecologically important wetlands in the entire Arctic."
Three years ago the Bush administration opened the area to oil and gas leasing. Joined by Alaska Native subsistence hunters, Audubon fought the decision in court. Last summer the BLM announced it would postpone oil and gas leasing in the Teshekpuk wetlands for at least 10 years.
The study was published in the current issue of "Geophysical Research Letters." Jones and some of his study co-authors are based at the Alaska Science Center in Anchorage.
Find George Bryson online at adn.com/contact/gbryson or call 257-4318.