Magnitude6.9

Reviewed by USGSRussia103y ago

M6.9 earthquake 48 km SW of Shikotan, Russia

Sunday, December 28, 1924, 22:55:12 UTC · 43.494°N, 146.285°E

A magnitude 6.9 earthquake struck 48 km SW of Shikotan, Russia on Sunday, December 28, 1924, 22:55:12 UTC, at a depth of 75.0 km (intermediate). It is the strongest earthquake within 300 km since an M7.3 on April 5, 1901.

Magnitude
6.9
Strong · mw
Depth
75 km
Intermediate
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

388 kilotons of TNT

That is about 26 times the Hiroshima bomb. It released about 813 times the energy of a magnitude 5.0.

Tectonic setting

122 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: intermediate

75 km

Intermediate-depth earthquakes usually break inside a plate that is sinking into the mantle. Shaking spreads over a wide area but is gentler at the epicenter than a shallow quake of the same size.

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; the largest was M6.1 on January 3, 1925. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.

M3M4M5M6M71h6h1d3d7d14d30dMainshock M6.9
Time after the mainshock on a logarithmic scale (first hours stretched), magnitude on the vertical axis. M2.5+ events from USGS.
  1. 6.1101 km SE of Nemuro, Japan103y ago · 82 km S of this epicenter

Regional history

Past M5+ earthquakes within 300 km

USGS lists 16 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 12 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 46 recorded deaths. The most severe:

  1. 1843M8.4

    Hokkaido: Yezo, Kushiro, Nemuro

    25 Apr 1843 · 168 km away

    45 deathsModerate damage ($1–5M)tsunami

  2. 1894M7.9

    Off Coast Of Honshu

    22 Mar 1894 · 113 km away · intensity IX

    1 deathModerate damage ($1–5M)tsunami

  3. 1904M7.6

    Hokkaido

    18 Mar 1904 · 117 km away · intensity X

    Limited damage (under $1M)

  4. 1839M7.3

    Se. Hokkaido Island, Japan

    1 May 1839 · 152 km away

    Limited damage (under $1M)tsunami

  5. 1900M7.9

    Kuril Islands

    25 Dec 1900 · 60 km away · intensity IX

  6. 1896M7.6

    Kuril Islands

    18 Nov 1896 · 23 km away · intensity IX

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

Nearby trackers

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