Reviewed by USGSJapan59y ago
M6.0 earthquake 113 km E of Miyako, Japan
Friday, July 12, 1968, 03:56:28 UTC · 39.614°N, 143.261°E
A magnitude 6.0 earthquake struck 113 km E of Miyako, Japan on Friday, July 12, 1968, 03:56:28 UTC, at a depth of 20.2 km (shallow). It is the strongest earthquake within 300 km since an M6.0 on July 12, 1968.
- Magnitude
- 6.0
- 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 earthquakeDashed circle: 75 km aftershock search area
In context
How big was it, and why here?
Energy released
14 kilotons of TNT
That is about the energy of the Hiroshima bomb. It released about 30 times the energy of a magnitude 5.0.
Tectonic setting
83 km
from the nearest mapped plate boundary, between the Pacific and Okhotsk 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 lists 1 M2.5+ earthquake within 75 km in the following 30 days; the largest was M5.7 on July 23, 1968. 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 421 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 8.41933 Sanriku (Sanriku-oki) Earthquake, JapanMarch 2, 1933 · 123 km E of this epicenter
- 8.21968 Tokachi-Oki EarthquakeMay 16, 1968 · 142 km N of this epicenter
- 8.11952 Tokachi-Oki EarthquakeMarch 4, 1952 · 280 km N of this epicenter
- 8.0113 km ENE of Miyako, JapanMarch 20, 1960 · 28 km N of this epicenter
- 7.978 km E of Hachinohe, JapanMarch 9, 1931 · 130 km NW of this epicenter
- 7.970 km S of Honchō, JapanMay 16, 1968 · 212 km N of this epicenter
- 7.7277 km SSE of Kushiro, JapanMay 3, 1919 · 232 km NE of this epicenter
- 7.7116 km E of Namie, JapanNovember 6, 1938 · 262 km S of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 58 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 33,491 recorded deaths. The most severe:
- 1896M8.3
Sanriku
15 Jun 1896 · 65 km away
27,122 deathsExtreme damage ($25M+)tsunami
- 1933M8.4
Sanriku
2 Mar 1933 · 123 km away
3,022 deathsExtreme damage ($25M+)tsunami
- 1766M6.9
Hirosaki
8 Mar 1766 · 260 km away
1,700 deathsSevere damage ($5–24M)tsunami
- 1793M8.3
Sanriku,Rikuzen,Rikuchu
17 Feb 1793 · 139 km away
745 deathsSevere damage ($5–24M)tsunami
- 1804M7.3
Kisakata
10 Jul 1804 · 292 km away
450 deathsExtreme damage ($25M+)tsunami
- 1896
Senhoku, Ugo
31 Aug 1896 · 198 km away
206 deathsExtreme damage ($25M+)
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.