Reviewed by USGS107y ago
M6.5 earthquake east of the Kuril Islands
Tuesday, September 21, 1920, 17:42:12 UTC · 44.854°N, 153.472°E
A magnitude 6.5 earthquake struck east of the Kuril Islands on Tuesday, September 21, 1920, 17:42:12 UTC, at a depth of 15.0 km (shallow). It is the strongest earthquake within 300 km since an M7.8 on November 8, 1918.
- Magnitude
- 6.5
- Strong · mw
- Depth
- 15 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 earthquake
In context
How big was it, and why here?
Energy released
71 kilotons of TNT
That is about 5 times the Hiroshima bomb. It released about 150 times the energy of a magnitude 5.0.
Tectonic setting
87 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
15 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 has not published any M2.5+ earthquake within 100 km in the 30 days after this event.
Regional history
Past M5+ earthquakes within 300 km
USGS lists 17 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 8.11918 Kuril Islands EarthquakeSeptember 7, 1918 · 92 km W of this epicenter
- 7.8east of the Kuril IslandsNovember 8, 1918 · 117 km W of this epicenter
- 7.2159 km ENE of Kuril’sk, RussiaNovember 6, 1908 · 296 km W of this epicenter
- 6.5Kuril IslandsJanuary 19, 1913 · 292 km NW of this epicenter
- 6.5east of the Kuril IslandsFebruary 23, 1906 · 137 km SW of this epicenter
- 6.5254 km E of Kuril’sk, RussiaSeptember 14, 1918 · 189 km W of this epicenter
- 6.5252 km E of Kuril’sk, RussiaMay 3, 1908 · 209 km NW of this epicenter
- 6.3192 km E of Kuril’sk, RussiaJune 7, 1915 · 253 km W of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 8 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 35 recorded deaths. The most severe:
- 1918M8.3
Kuril Islands
7 Sep 1918 · 170 km away
23 deathsModerate damage ($1–5M)tsunami
- 1780M7.5
Kuril Islands
29 Jun 1780 · 185 km away
12 deathsLimited damage (under $1M)tsunami
- 1913M7.5
Kuril Islands
19 Jan 1913 · 172 km away
Limited damage (under $1M)
- 1915M8.1
Kuril Islands
1 May 1915 · 266 km away
- 1918M7.8
Kuril Islands
8 Nov 1918 · 161 km away
tsunami
- 1908M7.6
Kuril Islands
6 Nov 1908 · 274 km away
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.