Reviewed by USGSJapan66y ago
M5.7 earthquake 123 km SE of Nishinoomote, Japan
Friday, July 21, 1961, 22:39:56 UTC · 29.871°N, 131.807°E
A magnitude 5.7 earthquake struck 123 km SE of Nishinoomote, Japan on Friday, July 21, 1961, 22:39:56 UTC, at a depth of 20.0 km (shallow). It is the strongest earthquake within 300 km since an M5.8 on July 21, 1961.
- Magnitude
- 5.7
- Moderate · 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
5 kilotons of TNT
That is about 1/3 of the Hiroshima bomb. It released about 11 times the energy of a magnitude 5.0.
Tectonic setting
24 km
from the nearest mapped plate boundary, between the Okinawa 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 75 km
USGS has not published any M2.5+ earthquake within 75 km in the 30 days after this event.
Regional history
Past M5+ earthquakes within 300 km
USGS lists 97 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 8.01941 Hyuganada EarthquakeNovember 18, 1941 · 251 km N of this epicenter
- 7.958 km ESE of Takanabe, JapanNovember 2, 1931 · 225 km N of this epicenter
- 7.518 km NNE of Nichinan, JapanFebruary 26, 1961 · 210 km N of this epicenter
- 7.518 km SE of Honmachi, JapanNovember 10, 1909 · 299 km N of this epicenter
- 7.4152 km ESE of Koshima, JapanFebruary 1, 1916 · 41 km S of this epicenter
- 7.422 km N of Nishinoomote, JapanJuly 13, 1923 · 139 km NW of this epicenter
- 7.229 km ESE of Takanabe, JapanApril 13, 1913 · 240 km N of this epicenter
- 7.2Ryukyu Islands, JapanJune 24, 1901 · 272 km SW of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 14 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 81 recorded deaths. The most severe:
- 1914M7.1
Sakurijima
12 Jan 1914 · 219 km away
63 deaths$19 million damagetsunami
- 1911M8.0
Ryukyu Islands
15 Jun 1911 · 272 km away
12 deathsSevere damage ($5–24M)tsunami
- 1961M7.3
Miyazaki
26 Feb 1961 · 192 km away
2 deathsModerate damage ($1–5M)tsunami
- 1941M7.4
Shikoku
18 Nov 1941 · 238 km away
2 deathsLimited damage (under $1M)tsunami
- 1939M6.6
Seikaido, Japan
20 Mar 1939 · 271 km away
1 deathLimited damage (under $1M)tsunami
- 1931M7.5
Kyushu
2 Nov 1931 · 239 km away
1 deathtsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.