The September 2, 1992 earthquake

M5.9near Washington, Utah

A magnitude 5.9 earthquake 8.6 miles deep, centred in Washington County. The 4th strongest in Utah’s record since 1900, and the strongest within 50 miles since a magnitude 5.9 on August 16, 1966. 1 aftershock of magnitude 2.5 or more followed within 30 days.

The earthquake

Magnitude
5.9
local magnitude (ml)
Depth
8.6 mi
13.9 km below the surface
Local time
Wednesday, September 2, 1992
04:26 MDT; 10:26 UTC
Epicentre
37.10°N, 113.50°W
In Washington County
In Utah’s record
4th
strongest of 2,224 since 1900
Within 50 miles
6
counties; more on this date

USGS ANSS Comprehensive Earthquake Catalog, event uu50067050 (“3 km SSE of Washington, 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

2.6

Largest aftershock, Sep 10, 1992

0

On the first day

0

In the 7 days before

Aftershocks of magnitude 2.5 or more, by day after the earthquake 1: 0 2: 0 3: 0 4: 0 5: 0 6: 0 7: 0 8: 1 1 9: 0 10: 0 11: 0 12: 0 13: 0 14: 0 15: 0 16: 0 17: 0 18: 0 19: 0 20: 0 21: 0 22: 0 23: 0 24: 0 25: 0 26: 0 27: 0 28: 0 29: 0 30: 0 1611162126
  1. 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.

Counties and cities within 50 miles

Distance from the epicentre to each county boundary (zero when inside) and to each city centre.

Counties

Cities, largest first

Earthquakes around the epicentre

108 earthquakes of magnitude 3 or more within 50 miles of this epicentre since 1973.

Earthquakes of magnitude 3 or more within 50 miles of the epicentre, by year 1973: 0 1974: 1 1975: 0 1976: 0 1977: 0 1978: 0 1979: 2 1980: 3 1981: 2 1982: 0 1983: 1 1984: 1 1985: 0 1986: 1 1987: 0 1988: 5 1989: 5 1990: 0 1991: 2 1992: 5 1993: 2 1994: 3 1995: 4 1996: 0 1997: 1 1998: 1 1999: 2 2000: 1 2001: 1 2002: 2 2003: 2 2004: 1 2005: 0 2006: 0 2007: 4 2008: 2 2009: 2 2010: 8 8 2011: 3 2012: 2 2013: 2 2014: 6 2015: 1 2016: 5 2017: 4 2018: 0 2019: 3 2020: 3 2021: 2 2022: 2 2023: 1 2024: 4 2025: 6 19731978198319881993199820032008201320182023

Earlier earthquakes of magnitude 5 or more within 50 miles, strongest first

USGS ANSS Comprehensive Earthquake Catalog. Local time is the time zone of the county nearest the epicentre. Magnitudes are as the catalogue reports them.