Reviewed by USGSRussia53y ago
M4.8 earthquake 56 km SW of Shikotan, Russia
Thursday, August 9, 1973, 10:54:44 UTC · 43.402°N, 146.291°E
A magnitude 4.8 earthquake struck 56 km SW of Shikotan, Russia on Thursday, August 9, 1973, 10:54:44 UTC, at a depth of 33.0 km (shallow). It is the strongest earthquake within 300 km since an M6.0 on August 9, 1973.
- Magnitude
- 4.8
- Light · mb
- Depth
- 33 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
239 tons of TNT
That is about 1/63 of the Hiroshima bomb. A magnitude 5.0 releases about 2 times more energy.
Tectonic setting
113 km
from the nearest mapped plate boundary, between the Okhotsk and Pacific plates. Earthquakes this far from a boundary happen on faults inside a plate, often less frequently but sometimes strongly.
Depth: shallow
33 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 2 M2.5+ earthquakes within 50 km in the following 30 days; the largest was M5.0 on August 25, 1973. 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 454 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 8.31958 Kuril Islands EarthquakeNovember 6, 1958 · 213 km NE of this epicenter
- 8.21969 Hokkaido Toho-oki EarthquakeAugust 11, 1969 · 121 km E of this epicenter
- 8.11952 Tokachi-Oki EarthquakeMarch 4, 1952 · 244 km SW of this epicenter
- 7.719 km ESE of Nemuro, JapanJune 17, 1973 · 45 km SW of this epicenter
- 7.542 km SSW of Shikotan, RussiaSeptember 11, 1935 · 27 km E of this epicenter
- 7.4170 km ESE of Kuril’sk, RussiaFebruary 21, 1937 · 299 km NE of this epicenter
- 7.426 km S of Shikotan, RussiaJanuary 29, 1968 · 37 km NE of this epicenter
- 7.3Kuril IslandsApril 5, 1901 · 249 km NE of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 31 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 107 recorded deaths. The most severe:
- 1843M8.4
Hokkaido: Yezo, Kushiro, Nemuro
25 Apr 1843 · 158 km away
45 deathsModerate damage ($1–5M)tsunami
- 1952M8.1
Hokkaido
4 Mar 1952 · 243 km away · intensity IX
33 deathsSevere damage ($5–24M)tsunami
- 1973M7.7
Hokkaido Island
17 Jun 1973 · 46 km away · intensity VIII
27 deaths$5 million damagetsunami
- 1894M7.9
Off Coast Of Honshu
22 Mar 1894 · 103 km away · intensity IX
1 deathModerate damage ($1–5M)tsunami
- 1938M6.1
E. Hokkaido Island, Japan
28 May 1938 · 162 km away
1 deathLimited damage (under $1M)tsunami
- 1958M8.3
Kuril Islands
6 Nov 1958 · 219 km away · intensity X
Moderate damage ($1–5M)tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.