Alexia Amann

Hebgen Lake

Manmade Retained by earth-filled dam Near Yellowstone

Cause and Damages Earthqake August 17, 1959 – Magnitude 7.5 Destroyed trees, soil, roads The slide fell 1,000 feet into the Madison River

Generated 30 ft waves to travel up and downstream, destroying campgrounds - 28 casualties

Created natural dam – Madison River backed up creating Earthquake Lake

Fault Setting Normal Fault

Basin and Range Tectonics Caused major scarp displacement

Surrounding Rock

Schist Slid along plane of foliation’s

weakness Steep slope angle

References

http://www.earthmagazine.org/earth/article/24c-7d9-8-12

http://www.nvcc.edu/home/cbentley/geoblog/2008/10/madison-river-landslide-montana.html

http://libraryphoto.cr.usgs.gov/cgi-bin/search.cgi?search_mode=exact;selection=Hebgen%20Lake%20Earthquake%201959|Hebgen%20Lake|Earthquake|1959;start=0

http://www.westyellowstonenet.com/attractions/hebgen_lake.php