M7.4 earthquake 170 km ESE of Kuril’sk, Russia

Sunday, February 21, 1937, 07:02:42 UTC · 44.447°N, 149.733°E

A magnitude 7.4 earthquake struck 170 km ESE of Kuril’sk, Russia on Sunday, February 21, 1937, 07:02:42 UTC, at a depth of 30.0 km (shallow). It is the strongest earthquake within 300 km since an M7.5 on September 11, 1935.

Magnitude: 7.4; Major · mw
Depth: 30 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 earthquakeDashed circle: 200 km aftershock search areaColoured lines: estimated shaking intensity (USGS ShakeMap)

In context

How big was it, and why here?

Energy released

2.2 megatons of TNT

That is about 145 times the Hiroshima bomb. It released about 4,571 times the energy of a magnitude 5.0.

Tectonic setting

50 km

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

Depth: shallow

30 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 200 km

USGS lists 11 M2.5+ earthquakes within 200 km in the following 30 days; the largest was M6.4 on February 23, 1937. 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 90 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 11 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 35 recorded deaths. The most severe:

1918M8.3
Kuril Islands
7 Sep 1918 · 182 km away
23 deathsModerate damage ($1–5M)tsunami
1780M7.5
Kuril Islands
29 Jun 1780 · 150 km away
12 deathsLimited damage (under $1M)tsunami
1937M7.6
Kuril Islands
21 Feb 1937 · 27 km away
Limited damage (under $1M)
1913M7.5
Kuril Islands
19 Jan 1913 · 248 km away
Limited damage (under $1M)
1918M7.8
Kuril Islands
8 Nov 1918 · 140 km away
tsunami
1908M7.6
Kuril Islands
6 Nov 1908 · 65 km away

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

Nearby trackers