Magnitude7.5

Reviewed by USGSRussia92y ago

M7.5 earthquake 42 km SSW of Shikotan, Russia

Wednesday, September 11, 1935, 14:04:03 UTC · 43.424°N, 146.618°E

A magnitude 7.5 earthquake struck 42 km SSW of Shikotan, Russia on Wednesday, September 11, 1935, 14:04:03 UTC, at a depth of 35.0 km (shallow). No earthquake of this size or larger appears within 300 km in the USGS catalog since 1900.

Magnitude
7.5
Major · mw
Depth
35 km
Shallow
Felt reports
0
Did You Feel It?
Est. shaking
VI
Strong (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

2.3 megatons of TNT

That is about 155 times the Hiroshima bomb. It released about 4,898 times the energy of a magnitude 5.0.

Tectonic setting

100 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 200 km

USGS lists 1 M2.5+ earthquake within 200 km in the following 30 days; the largest was M6.5 on October 2, 1935. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.

M3M4M5M6M71h6h1d3d7d14d30dMainshock M7.5
Time after the mainshock on a logarithmic scale (first hours stretched), magnitude on the vertical axis. M2.5+ events from USGS.
  1. 6.565 km S of Shikotan, Russia92y ago · 29 km SE of this epicenter

Regional history

Past M5+ earthquakes within 300 km

USGS lists 63 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 13 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 · 166 km away

    45 deathsModerate damage ($1–5M)tsunami

  2. 1894M7.9

    Off Coast Of Honshu

    22 Mar 1894 · 114 km away · intensity IX

    1 deathModerate damage ($1–5M)tsunami

  3. 1904M7.6

    Hokkaido

    18 Mar 1904 · 122 km away · intensity X

    Limited damage (under $1M)

  4. 1839M7.3

    Se. Hokkaido Island, Japan

    1 May 1839 · 167 km away

    Limited damage (under $1M)tsunami

  5. 1900M7.9

    Kuril Islands

    25 Dec 1900 · 69 km away · intensity IX

  6. 1896M7.6

    Kuril Islands

    18 Nov 1896 · 51 km away · intensity IX

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

Nearby trackers

Closest city pages