Magnitude5.6

Reviewed by USGSRussia57y ago

M5.6 earthquake 97 km E of Shikotan, Russia

Saturday, October 25, 1969, 12:03:49 UTC · 43.923°N, 147.919°E

A magnitude 5.6 earthquake struck 97 km E of Shikotan, Russia on Saturday, October 25, 1969, 12:03:49 UTC, at a depth of 45.0 km (shallow). It is the strongest earthquake within 300 km since an M5.8 on September 29, 1969.

Magnitude
5.6
Moderate · mw
Depth
45 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: 75 km aftershock search area

In context

How big was it, and why here?

Energy released

4 kilotons of TNT

That is about 1/4 of the Hiroshima bomb. It released about 9 times the energy of a magnitude 5.0.

Tectonic setting

84 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

45 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 75 km

USGS lists 3 M2.5+ earthquakes within 75 km in the following 30 days; the largest was M5.8 on November 21, 1969. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.

M3M4M5M61h6h1d3d7d14d30dMainshock M5.6
Time after the mainshock on a logarithmic scale (first hours stretched), magnitude on the vertical axis. M2.5+ events from USGS.
  1. 5.897 km ESE of Shikotan, Russia57y ago · 42 km S of this epicenter
  2. 5.7117 km ESE of Shikotan, Russia57y ago · 74 km S of this epicenter
  3. 5.5115 km ESE of Shikotan, Russia57y ago · 53 km S of this epicenter

Regional history

Past M5+ earthquakes within 300 km

USGS lists 392 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 29 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 47 recorded deaths. The most severe:

  1. 1843M8.4

    Hokkaido: Yezo, Kushiro, Nemuro

    25 Apr 1843 · 265 km away

    45 deathsModerate damage ($1–5M)tsunami

  2. 1894M7.9

    Off Coast Of Honshu

    22 Mar 1894 · 222 km away · intensity IX

    1 deathModerate damage ($1–5M)tsunami

  3. 1938M6.1

    E. Hokkaido Island, Japan

    28 May 1938 · 293 km away

    1 deathLimited damage (under $1M)tsunami

  4. 1958M8.3

    Kuril Islands

    6 Nov 1958 · 84 km away · intensity X

    Moderate damage ($1–5M)tsunami

  5. 1969M8.2

    Shikotan Island, Kurilskiye

    11 Aug 1969 · 36 km away · intensity IX

    Moderate damage ($1–5M)tsunami

  6. 1963M8.5

    Kuril Islands

    13 Oct 1963 · 177 km away · intensity IX

    Limited damage (under $1M)tsunami

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

Nearby trackers

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