Reviewed by USGSJapan110y ago
M7.1 earthquake 123 km SE of Honchō, Japan
Sunday, July 29, 1917, 14:32:23 UTC · 41.208°N, 143.747°E
A magnitude 7.1 earthquake struck 123 km SE of Honchō, Japan on Sunday, July 29, 1917, 14:32:23 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
- 7.1
- Major · 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
697 kilotons of TNT
That is about 46 times the Hiroshima bomb. It released about 1,462 times the energy of a magnitude 5.0.
Tectonic setting
71 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 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 27 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.6119 km SE of Kamaishi, JapanNovember 1, 1915 · 290 km S of this epicenter
- 7.5Near the east coast of Honshu, JapanAugust 9, 1901 · 139 km SW of this epicenter
- 7.2Near the east coast of Honshu, JapanAugust 9, 1901 · 131 km SW of this epicenter
- 7.1Off the coast of Hokkaido, JapanDecember 25, 1900 · 272 km NE of this epicenter
- 7.0Near the east coast of Honshu, JapanJune 15, 1901 · 254 km S of this epicenter
- 7.0Off the east coast of Honshu, JapanMay 2, 1902 · 246 km S of this epicenter
- 7.0114 km E of Miyako, JapanOctober 11, 1913 · 156 km S of this epicenter
- 6.9148 km E of Yamada, JapanMarch 15, 1917 · 192 km S of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 24 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 29,118 recorded deaths. The most severe:
- 1896M8.3
Sanriku
15 Jun 1896 · 191 km away
27,122 deathsExtreme damage ($25M+)tsunami
- 1766M6.9
Hirosaki
8 Mar 1766 · 258 km away
1,700 deathsSevere damage ($5–24M)tsunami
- 1896
Senhoku, Ugo
31 Aug 1896 · 268 km away
206 deathsExtreme damage ($25M+)
- 1843M8.4
Hokkaido: Yezo, Kushiro, Nemuro
25 Apr 1843 · 207 km away
45 deathsModerate damage ($1–5M)tsunami
- 1856M8.0
Oshima
23 Aug 1856 · 81 km away · intensity V
26 deathsModerate damage ($1–5M)tsunami
- 1901M8.2
Off Northeast Coast Honshu
9 Aug 1901 · 139 km away
18 deathsModerate damage ($1–5M)tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.