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The Swift Creek Landslide is an active, slow moving landslide located in western Washington, USA, due east of Everson on Sumas Mountain. Asbestos laden sediment originating from the landslide has recently generated much interest in this area. Asbestos is a known carcinogen. EPA sampling has documented asbestos in sediments in Swift Creek and in downstream Sumas River. Average asbestos levels in Swift Creek dredged material exceed the level that, in construction materials, triggers worker safety requirements and material handling and disposal regulations. Swift Creek Landslide side view from west side (WWU Landscape Observatory ) == Cause == Landslides in the Pacific Northwest have a number of causes. One is the geology of the area; layers of loosely consolidated sediments, such as sand, overlay strongly consolidated (less permeable) layers of sediments such as clays.〔Department of Ecology: Puget Sound Landslides. Retrieved March 1, 2008 from http://www.ecy.wa.gov/programs/sea/landslides/info/info.html〕 That, in addition to the large amount of precipitation received in Washington state each year, makes for prime landsliding conditions. Earthquakes are thought to help trigger landslides in the Puget Sound, as well as things such as logging and wave erosion.〔 The Swift Creek Landslide is thought to be a smaller reactivation of an older and larger landslide in that area; perhaps an earthquake set the older, then static landslide into motion. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Swift Creek Landslide」の詳細全文を読む スポンサード リンク
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