Magnitude3.7

Reviewed by USGSJapan54y ago

M3.7 earthquake 225 km SSE of Tateyama, Japan

Saturday, July 7, 1973, 10:03:53 UTC · 33.126°N, 140.848°E

A magnitude 3.7 earthquake struck 225 km SSE of Tateyama, Japan on Saturday, July 7, 1973, 10:03:53 UTC, at a depth of 57.0 km (shallow).

Magnitude
3.7
Minor · mb
Depth
57 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: 50 km aftershock search area

In context

How big was it, and why here?

Energy released

5 tons of TNT

That is about 1/2,814 of the Hiroshima bomb. A magnitude 5.0 releases about 89 times more energy.

Tectonic setting

64 km

from the nearest mapped plate boundary, between the North American and African plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.

Depth: shallow

57 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 50 km

USGS lists 3 M2.5+ earthquakes within 50 km in the following 30 days; the largest was M4.0 on July 30, 1973. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.

M3M41h6h1d3d7d14d30dMainshock M3.7
Time after the mainshock on a logarithmic scale (first hours stretched), magnitude on the vertical axis. M2.5+ events from USGS.
  1. 3.6226 km SSE of Tateyama, Japan53y ago · 3 km S of this epicenter
  2. 4.0207 km SSE of Katsuura, Japan53y ago · 41 km NE of this epicenter
  3. 3.9207 km SSE of Tateyama, Japan53y ago · 18 km N of this epicenter

Regional history

Past M5+ earthquakes within 300 km

USGS lists 239 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 25 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 118,755 recorded deaths. The most severe:

  1. 1923M7.9

    Tokyo, Yokohama

    1 Sep 1923 · 252 km away

    105,385 deaths$600 million damagetsunami

  2. 1855M7.0

    Tokyo

    11 Nov 1855 · 297 km away

    6,757 deathsExtreme damage ($25M+)tsunami

  3. 1703M8.2

    Off Sw Boso Peninsula

    30 Dec 1703 · 223 km away

    5,233 deathsExtreme damage ($25M+)tsunami

  4. 1854M8.3

    Enshunada Sea

    23 Dec 1854 · 290 km away

    1,000 deathsExtreme damage ($25M+)tsunami

  5. 1930M7.1

    Honshu: Idu

    25 Nov 1930 · 269 km away

    259 deathsExtreme damage ($25M+)

  6. 1853

    Odawara

    11 Mar 1853 · 292 km away

    79 deathsSevere damage ($5–24M)

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

Nearby trackers

Closest city pages