QuakeScout
Magnitude6.9

Reviewed by USGSJapan111y ago

M6.9 earthquake 148 km E of Yamada, Japan

Thursday, March 15, 1917, 00:14:17 UTC · 39.482°N, 143.674°E

A magnitude 6.9 earthquake struck 148 km E of Yamada, Japan on Thursday, March 15, 1917, 00:14:17 UTC, at a depth of 15.0 km (shallow). It is the strongest earthquake within 300 km since an M7.6 on November 1, 1915.

Magnitude
6.9
Strong · mw
Depth
15 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

362 kilotons of TNT

That is about 24 times the Hiroshima bomb. It released about 759 times the energy of a magnitude 5.0.

Tectonic setting

47 km

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

Depth: shallow

15 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 25 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:

  1. 7.7217 km ESE of Kamaishi, JapanJuly 6, 1905 · 125 km S of this epicenter
  2. 7.6119 km SE of Kamaishi, JapanNovember 1, 1915 · 108 km SW of this epicenter
  3. 7.5Near the east coast of Honshu, JapanAugust 9, 1901 · 171 km NW of this epicenter
  4. 7.2Near the east coast of Honshu, JapanAugust 9, 1901 · 151 km NW of this epicenter
  5. 7.013 km ESE of Yokote, JapanMarch 14, 1914 · 257 km W of this epicenter
  6. 7.0Near the east coast of Honshu, JapanJune 15, 1901 · 79 km SW of this epicenter
  7. 7.0Off the east coast of Honshu, JapanMay 2, 1902 · 61 km SE of this epicenter
  8. 7.0Northern Honshu, JapanMay 11, 1900 · 239 km W of this epicenter

History · NOAA

Deadliest earthquakes in this area

NOAA’s significant-earthquake database lists 26 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 29,874 recorded deaths. The most severe:

  1. 1896M8.3

    Sanriku

    15 Jun 1896 · 28 km away

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

  2. 1766M6.9

    Hirosaki

    8 Mar 1766 · 298 km away

    1,700 deathsSevere damage ($5–24M)tsunami

  3. 1793M8.3

    Sanriku,Rikuzen,Rikuchu

    17 Feb 1793 · 113 km away

    745 deathsSevere damage ($5–24M)tsunami

  4. 1896

    Senhoku, Ugo

    31 Aug 1896 · 236 km away

    206 deathsExtreme damage ($25M+)

  5. 1905M7.0

    Off Fukushima

    6 Jul 1905 · 250 km away

    57 deathstsunami

  6. 1856M8.0

    Oshima

    23 Aug 1856 · 114 km away · intensity V

    26 deathsModerate damage ($1–5M)tsunami

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

Nearby trackers

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