The March 7, 1992 earthquake

M5.3near Shelter Cove, California

A magnitude 5.3 earthquake 5.9 miles deep, centred in Humboldt County. The 265th strongest in California’s record since 1900, and the strongest within 50 miles since a magnitude 6.0 on August 17, 1991. 7 aftershocks of magnitude 2.5 or more followed within 30 days.

The earthquake

Magnitude
5.3
duration magnitude (md)
Depth
5.9 mi
9.5 km below the surface
Local time
Saturday, March 7, 1992
19:43 PST; 03:43 UTC on Mar 8, 1992
Epicentre
40.23°N, 124.26°W
In Humboldt County
In California’s record
265th
strongest of 97,065 since 1900
Within 50 miles
3
counties; more on this date

USGS ANSS Comprehensive Earthquake Catalog, event nc255182 (“27 km NW of Shelter Cove, California”). 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.

7

Aftershocks in 30 days

4.0

Largest aftershock, Mar 16, 1992

0

On the first day

1

In the 7 days before

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

2,247 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: 5 1974: 26 1975: 43 1976: 45 1977: 47 1978: 62 1979: 47 1980: 66 1981: 90 1982: 45 1983: 68 1984: 47 1985: 39 1986: 66 1987: 77 1988: 47 1989: 53 1990: 46 1991: 76 1992: 291 291 1993: 45 1994: 71 1995: 36 1996: 29 1997: 30 1998: 23 1999: 19 2000: 29 2001: 22 2002: 36 2003: 28 2004: 21 2005: 22 2006: 29 2007: 20 2008: 9 2009: 10 2010: 33 2011: 9 2012: 16 2013: 20 2014: 18 2015: 10 2016: 12 2017: 14 2018: 8 2019: 34 2020: 25 2021: 42 2022: 38 2023: 27 2024: 132 2025: 44 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.