Magnitude7.3

Reviewed by USGSJapan94y ago

M7.3 earthquake 110 km ESE of Ishinomaki, Japan

Sunday, June 18, 1933, 21:37:36 UTC · 38.083°N, 142.484°E

A magnitude 7.3 earthquake struck 110 km ESE of Ishinomaki, Japan on Sunday, June 18, 1933, 21:37:36 UTC, at a depth of 30.0 km (shallow). It is the strongest earthquake within 300 km since an M8.4 on March 2, 1933.

Magnitude
7.3
Major · mw
Depth
30 km
Shallow
Felt reports
0
Did You Feel It?
Est. shaking
V
Moderate (ShakeMap)
PAGER alert
None
Not issued
Tsunami
No flag
USGS feed

Outlined circle: this earthquakeColoured lines: estimated shaking intensity (USGS ShakeMap)

In context

How big was it, and why here?

Energy released

1.1 megatons of TNT

That is about 75 times the Hiroshima bomb. It released about 2,371 times the energy of a magnitude 5.0.

Tectonic setting

124 km

from the nearest mapped plate boundary, between the Pacific and Okhotsk plates. Earthquakes this far from a boundary happen on faults inside a plate, often less frequently but sometimes strongly.

Depth: shallow

30 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 has not published any M2.5+ earthquake within 200 km in the 30 days after this event.

Regional history

Past M5+ earthquakes within 300 km

USGS lists 137 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 36 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 33,909 recorded deaths. The most severe:

  1. 1896M8.3

    Sanriku

    15 Jun 1896 · 205 km away

    27,122 deathsExtreme damage ($25M+)tsunami

  2. 1933M8.4

    Sanriku

    2 Mar 1933 · 222 km away

    3,022 deathsExtreme damage ($25M+)tsunami

  3. 1828

    Sandyo In Etigo

    18 Dec 1828 · 270 km away

    1,443 deathsExtreme damage ($25M+)tsunami

  4. 1793M8.3

    Sanriku,Rikuzen,Rikuchu

    17 Feb 1793 · 140 km away

    745 deathsSevere damage ($5–24M)tsunami

  5. 1894M7.0

    Syonai

    22 Oct 1894 · 251 km away

    726 deathsSevere damage ($5–24M)tsunami

  6. 1804M7.3

    Kisakata

    10 Jul 1804 · 245 km away

    450 deathsExtreme damage ($25M+)tsunami

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

Nearby trackers

Closest city pages