M8.4 earthquake 1923 Kamchatka, Russia Earthquake

Saturday, February 3, 1923, 16:01:50 UTC · 54.486°N, 160.472°E

A magnitude 8.4 earthquake struck 1923 Kamchatka, Russia Earthquake on Saturday, February 3, 1923, 16:01:50 UTC, at a depth of 15.0 km (shallow). No earthquake of this size or larger appears within 300 km in the USGS catalog since 1900.

Magnitude: 8.4; Great · mw
Depth: 15 km; Shallow
Felt reports: 0; Did You Feel It?
Est. shaking: VII; Very strong (ShakeMap)
PAGER alert: None; Not issued
Tsunami: No flag; USGS feed

Outlined circle: this earthquakeDashed circle: 400 km aftershock search areaColoured lines: estimated shaking intensity (USGS ShakeMap)

In context

How big was it, and why here?

Energy released

60 megatons of TNT

That is about 3,987 times the Hiroshima bomb. It released about 125,893 times the energy of a magnitude 5.0.

Tectonic setting

175 km

from the nearest mapped plate boundary, between the Okhotsk and Pacific plates. Earthquakes this far from a boundary happen on faults inside a plate, often less frequently but sometimes strongly.

Depth: shallow

15 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 400 km

USGS lists 6 M2.5+ earthquakes within 400 km in the following 30 days; the largest was M7.4 on February 24, 1923. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.

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 20 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 15 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 21 recorded deaths. The most severe:

1923M7.2
Near Kamchatka
13 Apr 1923 · 258 km away · intensity X
18 deathsSevere damage ($5–24M)tsunami
1923M8.4
Kamchatka
3 Feb 1923 · 0 km away · intensity XI
3 deaths$2 million damagetsunami
1904M8.3
Off Kamchatka
25 Jun 1904 · 293 km away · intensity X
Limited damage (under $1M)tsunami
1904M8.1
Off Kamchatka
25 Jun 1904 · 293 km away · intensity X
Limited damage (under $1M)tsunami
1923M7.7
Kamchatka Peninsula
24 Feb 1923 · 136 km away
Limited damage (under $1M)
1827
Kamchatka
9 Aug 1827 · 210 km away
Limited damage (under $1M)tsunami

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

Nearby trackers