Reviewed by USGSJapan112y ago
M7.0 earthquake 208 km SE of Katsuura, Japan
Friday, April 21, 1916, 11:31:20 UTC · 33.700°N, 141.759°E
A magnitude 7.0 earthquake struck 208 km SE of Katsuura, Japan on Friday, April 21, 1916, 11:31:20 UTC, at a depth of 15.0 km (shallow). It is the strongest earthquake within 300 km since an M7.1 on March 13, 1909.
- Magnitude
- 7.0
- 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
494 kilotons of TNT
That is about 33 times the Hiroshima bomb. It released about 1,035 times the energy of a magnitude 5.0.
Tectonic setting
9 km
from the nearest mapped plate boundary, between the Philippine Sea and Pacific 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 10 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.3190 km SE of Hasaki, JapanSeptember 7, 1906 · 137 km NE of this epicenter
- 7.238 km SSW of Shimoda, JapanOctober 24, 1905 · 278 km W of this epicenter
- 7.1150 km ESE of Hasaki, JapanMarch 13, 1909 · 184 km N of this epicenter
- 7.082 km ENE of Hasaki, JapanMarch 12, 1909 · 244 km N of this epicenter
- 6.553 km ESE of Hasaki, JapanNovember 8, 1911 · 208 km N of this epicenter
- 6.473 km S of Shimoda, JapanSeptember 17, 1906 · 272 km W of this epicenter
- 6.3116 km ESE of Katsuura, JapanFebruary 24, 1906 · 108 km N of this epicenter
- 6.1154 km ESE of Hasaki, JapanApril 24, 1915 · 189 km N of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 11 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 12,093 recorded deaths. The most severe:
- 1855M7.0
Tokyo
11 Nov 1855 · 281 km away
6,757 deathsExtreme damage ($25M+)tsunami
- 1703M8.2
Off Sw Boso Peninsula
30 Dec 1703 · 217 km away
5,233 deathsExtreme damage ($25M+)tsunami
- 1853
Odawara
11 Mar 1853 · 288 km away
79 deathsSevere damage ($5–24M)
- 1894M7.5
Tokyo
20 Jun 1894 · 280 km away
24 deathsLimited damage (under $1M)
- 1782M7.3
Tokaido, Japan
22 Aug 1782 · 245 km away
Severe damage ($5–24M)tsunami
- 1909M7.5
Yokohama
13 Mar 1909 · 92 km away
Limited damage (under $1M)tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.