Magnitude6.8

Reviewed by USGSCalifornia72y ago

M6.8 earthquake 123 km W of Ferndale, California

Thursday, November 25, 1954, 11:16:40 UTC · 40.447°N, 125.711°W

A magnitude 6.8 earthquake struck 123 km W of Ferndale, California on Thursday, November 25, 1954, 11:16:40 UTC, at a depth of 10.0 km (shallow). It is the strongest earthquake within 300 km since an M7.1 on January 22, 1923.

Magnitude
6.8
Strong · mw
Depth
10 km
Shallow
Felt reports
0
Did You Feel It?
Est. shaking
V
Moderate (ShakeMap)
PAGER alert
None
Not issued
Tsunami
No flag
USGS feed

Outlined circle: this earthquakeColoured lines: estimated shaking intensity (USGS ShakeMap)

In context

How big was it, and why here?

Energy released

284 kilotons of TNT

That is about 19 times the Hiroshima bomb. It released about 596 times the energy of a magnitude 5.0.

Tectonic setting

9 km

from the nearest mapped plate boundary, between the Pacific and Juan de Fuca plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.

Depth: shallow

10 km

Shallow earthquakes (under 70 km) produce the strongest surface shaking for their size, so they are the ones most likely to cause damage near the epicenter.

Did You Feel It?

Where it was felt

No “Did You Feel It?” reports have been published for this event yet. If you felt it, you can add your report on the USGS website.

I felt it — report to USGS ↗

USGS PAGER estimate

Who was exposed to shaking

USGS publishes PAGER impact estimates for significant earthquakes, usually within an hour. No PAGER estimate is available for this event.

After the main event

Aftershocks within 100 km

USGS lists 1 M2.5+ earthquake within 100 km in the following 30 days. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.

M3M4M5M6M71h6h1d3d7d14d30dMainshock M6.8
Time after the mainshock on a logarithmic scale (first hours stretched), magnitude on the vertical axis. M2.5+ events from USGS.

    Regional history

    Past M5+ earthquakes within 300 km

    USGS lists 63 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:

    History · NOAA

    Deadliest earthquakes in this area

    NOAA’s significant-earthquake database lists 10 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 2 recorded deaths. The most severe:

    1. 1954M6.6

      Humboldt County

      21 Dec 1954 · 160 km away

      1 death$2 million damage

    2. 1932M6.5

      Eureka

      6 Jun 1932 · 124 km away · intensity VIII

      1 deathModerate damage ($1–5M)

    3. 1865

      Fort Humboldt, Eureka

      1 Oct 1865 · 119 km away · intensity IX

      Moderate damage ($1–5M)

    4. 1922M7.6

      Northern

      31 Jan 1922 · 64 km away

      Limited damage (under $1M)

    5. 1923M7.1

      Northern

      22 Jan 1923 · 57 km away · intensity VIII

      Limited damage (under $1M)tsunami

    6. 1873M6.7

      Northern

      23 Nov 1873 · 224 km away · intensity VIII

      Limited damage (under $1M)tsunami

    NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.

    Nearby trackers

    Closest city pages