Magnitude6.5

Reviewed by USGSRussia105y ago

M6.5 earthquake 192 km SE of Atlasovo, Russia

Monday, February 12, 1923, 01:58:39 UTC · 54.333°N, 161.677°E

A magnitude 6.5 earthquake struck 192 km SE of Atlasovo, Russia on Monday, February 12, 1923, 01:58:39 UTC, at a depth of 20.0 km (shallow). It is the strongest earthquake within 300 km since an M7.3 on February 3, 1923.

Magnitude
6.5
Strong · mw
Depth
20 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 earthquakeDashed circle: 100 km aftershock search area

In context

How big was it, and why here?

Energy released

97 kilotons of TNT

That is about 6 times the Hiroshima bomb. It released about 204 times the energy of a magnitude 5.0.

Tectonic setting

96 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

20 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 2 M2.5+ earthquakes within 100 km in the following 30 days; the largest was M5.9 on February 18, 1923. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.

M3M4M5M61h6h1d3d7d14d30dMainshock M6.5
Time after the mainshock on a logarithmic scale (first hours stretched), magnitude on the vertical axis. M2.5+ events from USGS.
  1. 5.8213 km S of Ust’-Kamchatsk Staryy, Russia105y ago · 46 km E of this epicenter
  2. 5.9228 km ENE of Petropavlovsk-Kamchatsky, Russia105y ago · 57 km S of this epicenter

Regional history

Past M5+ earthquakes within 300 km

USGS lists 23 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:

  1. 1923M7.2

    Near Kamchatka

    13 Apr 1923 · 246 km away · intensity X

    18 deathsSevere damage ($5–24M)tsunami

  2. 1923M8.4

    Kamchatka

    3 Feb 1923 · 80 km away · intensity XI

    3 deaths$2 million damagetsunami

  3. 1923M7.7

    Kamchatka Peninsula

    24 Feb 1923 · 88 km away

    Limited damage (under $1M)

  4. 1827

    Kamchatka

    9 Aug 1827 · 256 km away

    Limited damage (under $1M)tsunami

  5. 1849

    Kamchatka

    28 Sep 1849 · 288 km away

    Limited damage (under $1M)tsunami

  6. 1792M8.4

    Near Kamchatka

    22 Aug 1792 · 43 km away · intensity XI

    tsunami

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

Nearby trackers

Closest city pages