Reviewed by USGSJapan118y ago
M6.6 earthquake 24 km S of Shizunai-furukawachō, Japan
Thursday, September 16, 1909, 19:38:51 UTC · 42.113°N, 142.362°E
A magnitude 6.6 earthquake struck 24 km S of Shizunai-furukawachō, Japan on Thursday, September 16, 1909, 19:38:51 UTC, at a depth of 35.0 km (shallow). It is the strongest earthquake within 300 km since an M6.6 on July 5, 1907.
- Magnitude
- 6.6
- Strong · mw
- Depth
- 35 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
108 kilotons of TNT
That is about 7 times the Hiroshima bomb. It released about 226 times the energy of a magnitude 5.0.
Tectonic setting
222 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
35 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:
- 7.5Near the east coast of Honshu, JapanAugust 9, 1901 · 168 km S of this epicenter
- 7.2Near the east coast of Honshu, JapanAugust 9, 1901 · 180 km S of this epicenter
- 6.67 km SW of Kitami, JapanJuly 5, 1907 · 219 km NE of this epicenter
- 6.0151 km NE of Miyako, JapanDecember 2, 1907 · 198 km SE of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 19 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 2,020 recorded deaths. The most severe:
- 1766M6.9
Hirosaki
8 Mar 1766 · 193 km away
1,700 deathsSevere damage ($5–24M)tsunami
- 1896
Senhoku, Ugo
31 Aug 1896 · 261 km away
206 deathsExtreme damage ($25M+)
- 1704
N Of Nosiro
27 May 1704 · 268 km away
58 deathsSevere damage ($5–24M)
- 1856M8.0
Oshima
23 Aug 1856 · 203 km away · intensity V
26 deathsModerate damage ($1–5M)tsunami
- 1901M8.2
Off Northeast Coast Honshu
9 Aug 1901 · 168 km away
18 deathsModerate damage ($1–5M)tsunami
- 1793M6.9
Aomori
8 Feb 1793 · 245 km away
12 deathsModerate damage ($1–5M)tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.