QuakeScout
Magnitude6.4

Reviewed by USGSRussia107y ago

M6.4 earthquake 39 km WNW of Severo-Kuril’sk, Russia

Sunday, February 6, 1921, 04:27:54 UTC · 50.850°N, 155.640°E

A magnitude 6.4 earthquake struck 39 km WNW of Severo-Kuril’sk, Russia on Sunday, February 6, 1921, 04:27:54 UTC, at a depth of 35.0 km (shallow). It is the strongest earthquake within 300 km since an M7.4 on October 31, 1916.

Magnitude
6.4
Strong · mw
Depth
35 km
Shallow
Felt reports
0
Did You Feel It?
Est. shaking
—
No ShakeMap
PAGER alert
None
Not issued
Tsunami
No flag
USGS feed

Outlined circle: this earthquake

In context

How big was it, and why here?

Energy released

52 kilotons of TNT

That is about 3 times the Hiroshima bomb. It released about 110 times the energy of a magnitude 5.0.

Tectonic setting

226 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

35 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 has not published any M2.5+ earthquake within 100 km in the 30 days after this event.

Regional history

Past M5+ earthquakes within 300 km

USGS lists 14 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:

  1. 7.8266 km SSW of Severo-Kuril’sk, RussiaMay 1, 1915 · 277 km S of this epicenter
  2. 7.495 km NNE of Ozernovskiy, RussiaMay 4, 1911 · 189 km NE of this epicenter
  3. 7.4156 km SE of Severo-Kuril’sk, RussiaOctober 31, 1916 · 196 km SE of this epicenter
  4. 7.297 km NNE of Ozernovskiy, RussiaAugust 17, 1907 · 185 km NE of this epicenter
  5. 6.854 km SSE of Vilyuchinsk, RussiaJanuary 20, 1914 · 277 km NE of this epicenter
  6. 6.7221 km WNW of Ozernovskiy, RussiaOctober 8, 1906 · 233 km NW of this epicenter
  7. 6.6240 km SSW of Severo-Kuril’sk, RussiaMay 3, 1915 · 254 km S of this epicenter
  8. 6.5232 km WSW of Severo-Kuril’sk, RussiaJuly 13, 1909 · 203 km W of this epicenter

History · NOAA

Deadliest earthquakes in this area

NOAA’s significant-earthquake database lists 8 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 100 recorded deaths. The most severe:

  1. 1737

    Kamchatka

    16 Oct 1737 · 168 km away

    100 deathstsunami

  2. 1841M8.4

    Off Kamchatka

    17 May 1841 · 208 km away · intensity XI

    Moderate damage ($1–5M)tsunami

  3. 1904M8.3

    Off Kamchatka

    25 Jun 1904 · 266 km away · intensity X

    Limited damage (under $1M)tsunami

  4. 1904M8.1

    Off Kamchatka

    25 Jun 1904 · 266 km away · intensity X

    Limited damage (under $1M)tsunami

  5. 1904M7.9

    Off Kamchatka

    27 Jun 1904 · 266 km away · intensity IX

  6. 1911M7.6

    Near Kamchatka

    4 May 1911 · 109 km away · intensity VII

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

Nearby trackers

Closest city pages