1 / 6

Surface Process Hazards Unit 4 Oso , Washington, Landslide

Surface Process Hazards Unit 4 Oso , Washington, Landslide. Sarah Hall (College of the Atlantic) Becca Walker ( Mt. San Antonio C ollege). Version: June 19, 2017. Oso Landslide Event. S aturday March 22, 2014 , 10:37 a.m . 43 people killed (most in U.S. landslide event )

ntibbits
Download Presentation

Surface Process Hazards Unit 4 Oso , Washington, Landslide

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Surface Process Hazards Unit 4Oso, Washington, Landslide Sarah Hall (College of the Atlantic) Becca Walker (Mt. San Antonio College) Version: June 19, 2017

  2. Oso Landslide Event • Saturday March 22, 2014,10:37 a.m. • 43 people killed (most in U.S.landslide event) • Nearly 50 buildings destroyed • 6 km east of Oso, WA, in Snohomish County, which is about 80 km north of Seattle.

  3. Perfect Storm • Steelhead Haven community on the floodplain across the river from the base of the unstable slope was immediately buried by about 8 million m3 of debris that encompassed an area exceeding 1 km2. • The landslide dam created a lake, hampering search efforts and resulting in the urgent need to drain it to prevent establishment of a new channel along the south margin of the valley, which was the focus of the search efforts • 1.5 km of Highway 530(including access to 35 homes)was blocked for two months by landslide material that locally exceeded 25 m of depth • Damages - $150 million

  4. Perfect Storm • Weak glacio-lacustrine silt & clay • Logging is common in the area • 7.5 acres intruded into a restricted zone;caused excess water infiltration • Wettest March in Seattle History,” recieving more than200% of the normal rain in justfew weeks

  5. Shaded-relief image calculated from the 2013 lidar survey. Colored areas show older landslide deposits, distinguished by their relative age: A, youngest, to D, oldest. The red cross-hatched area marks the approximate extent of deposits from the March 22, 2014, landslide.

  6. Rotational Slump

More Related