Effects of the 1959 Hebgen Lake,
Montana earthquake
This Mw 7.5 earthquake triggered an enormous
landslide that buried a campground, causing 28
deaths and dammed the Madison River, forming
Quake Lake. The earthquake, together with the
nearby 1983 Ms 7.3 Borah Peak, Idaho, earthquake,
illustrate the large earthquakes that occur in the
intermountain seismic belt, part of the North
America - Pacific plate boundary zone. The
regional tectonics appear to reflect a complex
interaction between the Yellowstone volcanic
system and Basin and Range extension. About 6
m of normal fault motion on a NW-SE striking
fault lowered the valley floor, dropping the
houses shown into the lake. These dramatic
effects are still visible today and make the site well worth visiting.
A visitor center and parking lot are built on the slide.
Contributed by Seth Stein, Northwestern University |
