Reviewed by USGSRussia103y ago
M6.6 earthquake 56 km E of Shikotan, Russia
Sunday, February 1, 1925, 05:24:03 UTC · 43.830°N, 147.428°E
A magnitude 6.6 earthquake struck 56 km E of Shikotan, Russia on Sunday, February 1, 1925, 05:24:03 UTC, at a depth of 30.0 km (shallow). It is the strongest earthquake within 300 km since an M6.8 on January 28, 1925.
- Magnitude
- 6.6
- Strong · mw
- Depth
- 30 km
- Shallow
- Felt reports
- 0
- Did You Feel It?
- Est. shaking
- V
- Moderate (ShakeMap)
- PAGER alert
- None
- Not issued
- Tsunami
- No flag
- USGS feed
Outlined circle: this earthquakeDashed circle: 100 km aftershock search areaColoured lines: estimated shaking intensity (USGS ShakeMap)
In context
How big was it, and why here?
Energy released
120 kilotons of TNT
That is about 8 times the Hiroshima bomb. It released about 251 times the energy of a magnitude 5.0.
Tectonic setting
98 km
from the nearest mapped plate boundary, between the Okhotsk and Pacific plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.
Depth: shallow
30 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 100 km
USGS lists 3 M2.5+ earthquakes within 100 km in the following 30 days; the largest was M6.8 on February 2, 1925. 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 22 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.3Kuril IslandsApril 5, 1901 · 146 km NE of this epicenter
- 7.2159 km ENE of Kuril’sk, RussiaNovember 6, 1908 · 274 km NE of this epicenter
- 7.2268 km SE of Kuril’sk, RussiaMay 22, 1910 · 221 km E of this epicenter
- 7.1Off the coast of Hokkaido, JapanDecember 25, 1900 · 148 km SW of this epicenter
- 7.1147 km E of Kuril’sk, RussiaOctober 18, 1920 · 252 km NE of this epicenter
- 7.0Kuril IslandsNovember 24, 1900 · 59 km SE of this epicenter
- 6.948 km SW of Shikotan, RussiaDecember 28, 1924 · 99 km W of this epicenter
- 6.949 km E of Nemuro, JapanOctober 13, 1911 · 112 km SW of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 13 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 46 recorded deaths. The most severe:
- 1843M8.4
Hokkaido: Yezo, Kushiro, Nemuro
25 Apr 1843 · 234 km away
45 deathsModerate damage ($1–5M)tsunami
- 1894M7.9
Off Coast Of Honshu
22 Mar 1894 · 188 km away · intensity IX
1 deathModerate damage ($1–5M)tsunami
- 1904M7.6
Hokkaido
18 Mar 1904 · 198 km away · intensity X
Limited damage (under $1M)
- 1839M7.3
Se. Hokkaido Island, Japan
1 May 1839 · 246 km away
Limited damage (under $1M)tsunami
- 1900M7.9
Kuril Islands
25 Dec 1900 · 148 km away · intensity IX
- 1896M7.6
Kuril Islands
18 Nov 1896 · 121 km away · intensity IX
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.