QuakeScout
Magnitude6.4

Reviewed by USGSJapan121y ago

M6.4 earthquake 73 km S of Shimoda, Japan

Monday, September 17, 1906, 04:16:38 UTC · 34.021°N, 138.834°E

A magnitude 6.4 earthquake struck 73 km S of Shimoda, Japan on Monday, September 17, 1906, 04:16:38 UTC, at a depth of 20.0 km (shallow). It is the strongest earthquake within 300 km since an M7.4 on January 21, 1906.

Magnitude
6.4
Strong · mw
Depth
20 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 earthquake

In context

How big was it, and why here?

Energy released

56 kilotons of TNT

That is about 4 times the Hiroshima bomb. It released about 117 times the energy of a magnitude 5.0.

Tectonic setting

42 km

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

Depth: shallow

20 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 100 km

USGS has not published any M2.5+ earthquake within 100 km in the 30 days after this event.

Regional history

Past M5+ earthquakes within 300 km

USGS lists 4 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:

  1. 7.450 km SSW of Ōyama, JapanJanuary 21, 1906 · 76 km W of this epicenter
  2. 7.238 km SSW of Shimoda, JapanOctober 24, 1905 · 35 km N of this epicenter
  3. 6.3116 km ESE of Katsuura, JapanFebruary 24, 1906 · 247 km E of this epicenter
  4. 5.812 km NE of Gujō, JapanApril 20, 1906 · 256 km NW of this epicenter

History · NOAA

Deadliest earthquakes in this area

NOAA’s significant-earthquake database lists 18 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 24,257 recorded deaths. The most severe:

  1. 1891M8.4

    Mino-Owari

    27 Oct 1891 · 235 km away

    7,273 deathsExtreme damage ($25M+)

  2. 1855M7.0

    Tokyo

    11 Nov 1855 · 201 km away

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

  3. 1703M8.2

    Off Sw Boso Peninsula

    30 Dec 1703 · 153 km away

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

  4. 1707M8.4

    Enshunada

    28 Oct 1707 · 96 km away

    2,000 deathsSevere damage ($5–24M)tsunami

  5. 1854

    Iga, Ise, Yamato

    9 Jul 1854 · 282 km away

    1,352 deathsSevere damage ($5–24M)

  6. 1854M8.3

    Enshunada Sea

    23 Dec 1854 · 86 km away

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

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

Nearby trackers

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