The March 11, 1977 earthquake
M5.2near Hebgen Lake Estates, Montana
A magnitude 5.2 earthquake 3.1 miles deep, centred in Madison County. The 19th strongest in Montana’s record since 1900, and the strongest within 50 miles since a magnitude 5.5 on December 8, 1976.
The earthquake
- Magnitude
- 5.2
- body-wave magnitude (mb)
- Depth
- 3.1 mi
- 5.0 km below the surface
- Local time
- Friday, March 11, 1977
- 05:17 MST; 12:17 UTC
- In Montana’s record
- 19th
- strongest of 1,459 since 1900
USGS ANSS Comprehensive Earthquake Catalog, event usp0000mvt (“26 km WNW of Hebgen Lake Estates, Montana”). The USGS event page carries the ShakeMap, felt reports and the official summary.
Counties and cities within 50 miles
Distance from the epicentre to each county boundary (zero when inside) and to each city centre.
Counties
- Madison CountyMT · inside
- Fremont CountyID · 8.5 mi
- Gallatin CountyMT · 9.0 mi
- Beaverhead CountyMT · 9.7 mi
- Clark CountyID · 21.4 mi
- Park CountyWY · 24.2 mi
- Park CountyMT · 24.6 mi
- Teton CountyWY · 25.2 mi
Earthquakes around the epicentre
389 earthquakes of magnitude 3 or more within 50 miles of this epicentre since 1973.
Earlier earthquakes of magnitude 5 or more within 50 miles, strongest first
- August 17, 1959M7.2
- August 18, 1959M6.5
- August 18, 1959M6.3
- November 23, 1947M6.1
- August 18, 1959M6.0
- August 18, 1959M6.0
- June 30, 1975M5.9
- August 18, 1959M5.7
- December 8, 1976M5.5
- October 19, 1976M5.3
USGS ANSS Comprehensive Earthquake Catalog. Local time is the time zone of the county nearest the epicentre. Magnitudes are as the catalogue reports them.