Reviewed by USGSJapan53y ago
M5.6 earthquake 196 km SSE of Tateyama, Japan
Wednesday, December 26, 1973, 20:30:06 UTC · 33.402°N, 140.826°E
A magnitude 5.6 earthquake struck 196 km SSE of Tateyama, Japan on Wednesday, December 26, 1973, 20:30:06 UTC, at a depth of 63.0 km (shallow). It is the strongest earthquake within 300 km since an M5.6 on October 1, 1973.
- Magnitude
- 5.6
- Moderate · mb
- Depth
- 63 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: 75 km aftershock search area
In context
How big was it, and why here?
Energy released
4 kilotons of TNT
That is about 1/4 of the Hiroshima bomb. It released about 8 times the energy of a magnitude 5.0.
Tectonic setting
33 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
63 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 lists 5 M2.5+ earthquakes within 75 km in the following 30 days; the largest was M4.4 on January 20, 1974. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.
- 4.4241 km SSE of Tateyama, Japan53y ago · 46 km SE of this epicenter
- 4.1185 km SSE of Katsuura, Japan53y ago · 30 km NE of this epicenter
- 4.1202 km SSE of Tateyama, Japan53y ago · 7 km SE of this epicenter
- 3.8219 km SSE of Tateyama, Japan53y ago · 29 km S of this epicenter
- 4.0230 km SSE of Tateyama, Japan53y ago · 35 km S of this epicenter
Regional history
Past M5+ earthquakes within 300 km
USGS lists 252 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 · 249 km NW of this epicenter
- 7.9174 km SE of Katsuura, JapanNovember 25, 1953 · 100 km NE of this epicenter
- 7.85 km E of Tateyama, JapanSeptember 2, 1923 · 194 km NW of this epicenter
- 7.450 km SSW of Ōyama, JapanJanuary 21, 1906 · 273 km W of this epicenter
- 7.3206 km SSE of Wada, JapanDecember 4, 1972 · 10 km S of this epicenter
- 7.3190 km SE of Hasaki, JapanSeptember 7, 1906 · 217 km NE of this epicenter
- 7.264 km ENE of Hasaki, JapanJune 1, 1923 · 288 km N of this epicenter
- 7.238 km SSW of Shimoda, JapanOctober 24, 1905 · 210 km NW of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 26 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 · 225 km away
105,385 deaths$600 million damagetsunami
- 1855M7.0
Tokyo
11 Nov 1855 · 267 km away
6,757 deathsExtreme damage ($25M+)tsunami
- 1703M8.2
Off Sw Boso Peninsula
30 Dec 1703 · 193 km away
5,233 deathsExtreme damage ($25M+)tsunami
- 1707M8.4
Enshunada
28 Oct 1707 · 290 km away
2,000 deathsSevere damage ($5–24M)tsunami
- 1854M8.3
Enshunada Sea
23 Dec 1854 · 279 km away
1,000 deathsExtreme damage ($25M+)tsunami
- 1930M7.1
Honshu: Idu
25 Nov 1930 · 244 km away
259 deathsExtreme damage ($25M+)
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.