Information Page: ArcticErosion2009
Bluff Erosion in the Arctic, 2009
|Keywords:||coastal bluff erosion|
|Model name:||Animation model name|
|Where:||Beaufort Coast, Alaska|
|When:||July 13th-August 22nd|
Grade level: Under graduate (13-16)
Statement: Time-lapse series of coastal bluff erosion along the Arctic Coast at Drew Point, Beaufort Sea, Alaska.
Abstract: Time-lapse series of coastal bluff erosion along the Arctic Coast at Drew Point, Beaufort Sea, Alaska. Coastal erosion rates exceeding 20 meters per year are being observed along the Arctic Coast, and they are especially high along Alaska’s Beaufort Sea coastline. Comparison of aerial photos and LANDSAT imagery suggest accelerating erosion rates over the last 50 years. Arctic sea ice coverage has been declining dramatically over the last few decades and record September minima were observed in 2007. These observations suggest a causal relationship between sea ice decline and coastal change. The timelapse movies presented here show that the relative roles of thermal and wave energy may be significant. The bluffs consist of silt and have high ice-content. The thawing of the ice-rich bluffs by relatively warm seawater undermines coastal bluffs, leading to topple failures of discrete blocks defined by ice-wedge polygons. The fine-grained nature of these materials does not function as a protective barrier for incoming waves, so there is not a strong negative feedback on erosion rates, so that coastal erosion rates in this setting are likely to increase with continued Arctic warming.
This movie was captured during the summer of 2009 looks from the sea towards the 4-5m high bluffs. A USGS research team rigged a camera on top of a pipe wedged into the seafloor about 5 to 6 meters offshore. The camera was set to photograph the coast several times every day between July 13th and August 22nd. The movie shows the sea forming a hollow niche at the base of the bluff. Then a large chunk of the bluff fell into the sea and was washed away within 5 days, the water continued to hollow out the niche and more chunks of land toppled off the bluff.
The part "]]" of the query was not understood.</br>Results might not be as expected.