Reviewed by USGSJapan54y ago
M4.3 earthquake 232 km SSE of Katsuura, Japan
Monday, January 29, 1973, 08:26:41 UTC · 33.154°N, 141.101°E
A magnitude 4.3 earthquake struck 232 km SSE of Katsuura, Japan on Monday, January 29, 1973, 08:26:41 UTC, at a depth of 23.0 km (shallow).
- Magnitude
- 4.3
- Light · mb
- Depth
- 23 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 earthquakeDashed circle: 50 km aftershock search area
In context
How big was it, and why here?
Energy released
43 tons of TNT
That is about 1/354 of the Hiroshima bomb. A magnitude 5.0 releases about 11 times more energy.
Tectonic setting
61 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
23 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 50 km
USGS lists 7 M2.5+ earthquakes within 50 km in the following 30 days; the largest was M5.3 on February 10, 1973. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.
- 4.1206 km SSE of Tateyama, Japan54y ago · 26 km NW of this epicenter
- 4.1218 km SSE of Tateyama, Japan54y ago · 39 km W of this epicenter
- 5.3211 km SSE of Tateyama, Japan54y ago · 42 km W of this epicenter
- 4.0208 km SSE of Tateyama, Japan54y ago · 44 km W of this epicenter
- 3.6226 km SSE of Katsuura, Japan54y ago · 16 km NE of this epicenter
- 4.5224 km SSE of Tateyama, Japan54y ago · 8 km NW of this epicenter
- 4.1212 km SSE of Tateyama, Japan54y ago · 38 km W of this epicenter
Regional history
Past M5+ earthquakes within 300 km
USGS lists 230 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 · 286 km NW of this epicenter
- 7.9174 km SE of Katsuura, JapanNovember 25, 1953 · 106 km NE of this epicenter
- 7.85 km E of Tateyama, JapanSeptember 2, 1923 · 230 km NW of this epicenter
- 7.3206 km SSE of Wada, JapanDecember 4, 1972 · 29 km NW of this epicenter
- 7.3190 km SE of Hasaki, JapanSeptember 7, 1906 · 221 km NE of this epicenter
- 7.238 km SSW of Shimoda, JapanOctober 24, 1905 · 247 km NW of this epicenter
- 7.2193 km SSE of Wada, JapanFebruary 29, 1972 · 38 km NW of this epicenter
- 7.1150 km ESE of Hasaki, JapanMarch 13, 1909 · 263 km NE of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 20 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 110,974 recorded deaths. The most severe:
- 1923M7.9
Tokyo, Yokohama
1 Sep 1923 · 262 km away
105,385 deaths$600 million damagetsunami
- 1703M8.2
Off Sw Boso Peninsula
30 Dec 1703 · 229 km away
5,233 deathsExtreme damage ($25M+)tsunami
- 1930M7.1
Honshu: Idu
25 Nov 1930 · 282 km away
259 deathsExtreme damage ($25M+)
- 1853
Odawara
11 Mar 1853 · 299 km away
79 deathsSevere damage ($5–24M)
- 1924
Sagami
15 Jan 1924 · 299 km away
14 deathsSevere damage ($5–24M)
- 1936
Nii Jima
27 Dec 1936 · 224 km away
3 deathsLimited damage (under $1M)
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.