Reviewed by USGSJapan55y ago
M7.2 earthquake 193 km SSE of Wada, Japan
Tuesday, February 29, 1972, 09:23:00 UTC · 33.446°N, 140.890°E
A magnitude 7.2 earthquake struck 193 km SSE of Wada, Japan on Tuesday, February 29, 1972, 09:23:00 UTC, at a depth of 46.4 km (shallow). It is the strongest earthquake within 300 km since an M7.9 on November 25, 1953.
- Magnitude
- 7.2
- Major · mw
- Depth
- 46 km
- Shallow
- Felt reports
- 0
- Did You Feel It?
- Est. shaking
- VI
- Strong (ShakeMap)
- PAGER alert
- None
- Not issued
- Tsunami
- No flag
- USGS feed
Outlined circle: this earthquakeDashed circle: 200 km aftershock search areaColoured lines: estimated shaking intensity (USGS ShakeMap)
In context
How big was it, and why here?
Energy released
801 kilotons of TNT
That is about 53 times the Hiroshima bomb. It released about 1,679 times the energy of a magnitude 5.0.
Tectonic setting
29 km
from the nearest mapped plate boundary, between the North American and African plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.
Depth: shallow
46 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 lists 4 M2.5+ earthquakes within 200 km in the following 30 days; the largest was M6.0 on February 29, 1972. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.
Regional history
Past M5+ earthquakes within 300 km
USGS lists 226 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 8.05 km SSE of Ōiso, JapanSeptember 1, 1923 · 248 km NW of this epicenter
- 7.9174 km SE of Katsuura, JapanNovember 25, 1953 · 92 km NE of this epicenter
- 7.85 km E of Tateyama, JapanSeptember 2, 1923 · 193 km NW of this epicenter
- 7.450 km SSW of Ōyama, JapanJanuary 21, 1906 · 277 km W of this epicenter
- 7.3190 km SE of Hasaki, JapanSeptember 7, 1906 · 210 km NE of this epicenter
- 7.264 km ENE of Hasaki, JapanJune 1, 1923 · 282 km N of this epicenter
- 7.238 km SSW of Shimoda, JapanOctober 24, 1905 · 213 km NW of this epicenter
- 7.1150 km ESE of Hasaki, JapanMarch 13, 1909 · 245 km NE of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 27 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 120,755 recorded deaths. The most severe:
- 1923M7.9
Tokyo, Yokohama
1 Sep 1923 · 224 km away
105,385 deaths$600 million damagetsunami
- 1855M7.0
Tokyo
11 Nov 1855 · 265 km away
6,757 deathsExtreme damage ($25M+)tsunami
- 1703M8.2
Off Sw Boso Peninsula
30 Dec 1703 · 191 km away
5,233 deathsExtreme damage ($25M+)tsunami
- 1707M8.4
Enshunada
28 Oct 1707 · 295 km away
2,000 deathsSevere damage ($5–24M)tsunami
- 1854M8.3
Enshunada Sea
23 Dec 1854 · 283 km away
1,000 deathsExtreme damage ($25M+)tsunami
- 1930M7.1
Honshu: Idu
25 Nov 1930 · 245 km away
259 deathsExtreme damage ($25M+)
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.