M8.5 earthquake 1963 Kuril Islands Earthquake

Sunday, October 13, 1963, 05:17:59 UTC · 44.872°N, 149.483°E

A magnitude 8.5 earthquake struck 1963 Kuril Islands Earthquake on Sunday, October 13, 1963, 05:17:59 UTC, at a depth of 35.0 km (shallow). No earthquake of this size or larger appears within 300 km in the USGS catalog since 1900.

Magnitude: 8.5; Great · mw
Depth: 35 km; Shallow
Felt reports: 0; Did You Feel It?
Est. shaking: VII; Very strong (ShakeMap)
PAGER alert: None; Not issued
Tsunami: No flag; USGS feed

Outlined circle: this earthquakeDashed circle: 400 km aftershock search areaColoured lines: estimated shaking intensity (USGS ShakeMap)

In context

How big was it, and why here?

Energy released

85 megatons of TNT

That is about 5,632 times the Hiroshima bomb. It released about 177,828 times the energy of a magnitude 5.0.

Tectonic setting

100 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

35 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 400 km

USGS lists 21 M2.5+ earthquakes within 400 km in the following 30 days; the largest was M7.8 on October 20, 1963. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.

Time after the mainshock on a logarithmic scale (first hours stretched), magnitude on the vertical axis. M2.5+ events from USGS.

Regional history

Past M5+ earthquakes within 300 km

USGS lists 213 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:

History · NOAA

Deadliest earthquakes in this area

NOAA’s significant-earthquake database lists 22 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 · 173 km away
23 deathsModerate damage ($1–5M)tsunami
1780M7.5
Kuril Islands
29 Jun 1780 · 143 km away
12 deathsLimited damage (under $1M)tsunami
1958M8.3
Kuril Islands
6 Nov 1958 · 84 km away · intensity X
Moderate damage ($1–5M)tsunami
1963M8.5
Kuril Islands
13 Oct 1963 · 27 km away · intensity IX
Limited damage (under $1M)tsunami
1937M7.6
Kuril Islands
21 Feb 1937 · 42 km away
Limited damage (under $1M)
1913M7.5
Kuril Islands
19 Jan 1913 · 233 km away
Limited damage (under $1M)

NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.

Nearby trackers