The March 15, 1934 earthquake
M5.1near Thatcher, Utah
A magnitude 5.1 earthquake, centred in Box Elder County. The 18th strongest in Utah’s record since 1900, and the strongest within 50 miles since a magnitude 5.9 on March 12, 1934. 1 aftershock of magnitude 2.5 or more followed within 30 days.
The earthquake
- Magnitude
- 5.1
- local magnitude (ml)
- Depth
- —
- Not recorded
- Local time
- Thursday, March 15, 1934
- 05:01 MST; 12:01 UTC
- In Utah’s record
- 18th
- strongest of 2,224 since 1900
USGS ANSS Comprehensive Earthquake Catalog, event ushis1046 (“27 km SW of Thatcher, Utah”). The USGS event page carries the ShakeMap, felt reports and the official summary.
Aftershocks
Earthquakes of magnitude 2.5 or more within 20 miles of the epicentre in the 30 days after.
1
Aftershocks in 30 days
4.8
Largest aftershock, Mar 15, 1934
1
On the first day
4
In the 7 days before
- The search radius is the surface rupture length expected for an earthquake of this magnitude (Wells and Coppersmith, 1994), at least 20 and at most 600 miles, so a great earthquake's sequence is counted along its whole fault.
- Before the modern seismic networks of the 1970s many small aftershocks went unrecorded, so early sequences read short.
Counties and cities within 50 miles
Distance from the epicentre to each county boundary (zero when inside) and to each city centre.
Counties
- Box Elder CountyUT · inside
- Weber CountyUT · 17.7 mi
- Cache CountyUT · 26.8 mi
- Davis CountyUT · 29.0 mi
- Tooele CountyUT · 29.2 mi
- Morgan CountyUT · 39.3 mi
- Franklin CountyID · 39.9 mi
- Oneida CountyID · 39.9 mi
- Cassia CountyID · 43.0 mi
- Salt Lake CountyUT · 47.5 mi
Cities, largest first
- OgdenUT · 33.4 mi
- LaytonUT · 40.5 mi
- LoganUT · 37.8 mi
- SyracuseUT · 36.3 mi
- RoyUT · 32.6 mi
- ClearfieldUT · 37.4 mi
- KaysvilleUT · 43.5 mi
- FarmingtonUT · 47.1 mi
- West HavenUT · 30.7 mi
- ClintonUT · 33.6 mi
- North OgdenUT · 30.8 mi
- Brigham CityUT · 23.2 mi
Earthquakes around the epicentre
131 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
- March 12, 1934M6.6
- March 12, 1934M5.9
- October 5, 1909M5.6
- March 12, 1934M5.1
USGS ANSS Comprehensive Earthquake Catalog. Local time is the time zone of the county nearest the epicentre. Magnitudes are as the catalogue reports them.