Reviewed by USGSRussia54y ago
M5.2 earthquake 75 km ENE of Severo-Kuril’sk, Russia
Wednesday, March 21, 1973, 02:24:21 UTC · 50.821°N, 157.165°E
A magnitude 5.2 earthquake struck 75 km ENE of Severo-Kuril’sk, Russia on Wednesday, March 21, 1973, 02:24:21 UTC, at a depth of 55.0 km (shallow). It is the strongest earthquake within 300 km since an M6.1 on March 12, 1973.
- Magnitude
- 5.2
- Moderate · mb
- Depth
- 55 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
951 tons of TNT
That is about 1/16 of the Hiroshima bomb. It released about 2 times the energy of a magnitude 5.0.
Tectonic setting
149 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
55 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 4 M2.5+ earthquakes within 75 km in the following 30 days; the largest was M6.1 on April 12, 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 294 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 9.089 km ESE of Petropavlovsk-Kamchatsky, RussiaNovember 4, 1952 · 269 km NE of this epicenter
- 7.5253 km SE of Vilyuchinsk, RussiaJune 30, 1936 · 258 km E of this epicenter
- 7.495 km NNE of Ozernovskiy, RussiaMay 4, 1911 · 156 km N of this epicenter
- 7.4156 km SE of Severo-Kuril’sk, RussiaOctober 31, 1916 · 121 km SE of this epicenter
- 7.351 km SE of Petropavlovsk-Kamchatsky, RussiaNovember 24, 1971 · 258 km NE of this epicenter
- 7.297 km NNE of Ozernovskiy, RussiaAugust 17, 1907 · 173 km N of this epicenter
- 7.238 km ESE of Severo-Kuril’sk, RussiaFebruary 28, 1973 · 55 km SW of this epicenter
- 6.9119 km E of Ozernovskiy, RussiaMarch 24, 1921 · 97 km NE of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 18 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 10,101 recorded deaths. The most severe:
- 1952M9.0
Kamchatka Peninsula
4 Nov 1952 · 293 km away · intensity VII
10,000 deaths$1 million damagetsunami
- 1737
Kamchatka
16 Oct 1737 · 66 km away
100 deathstsunami
- 1959M8.2
Near East Coast Of Kamchatka
4 May 1959 · 247 km away · intensity X
1 deathModerate damage ($1–5M)tsunami
- 1841M8.4
Off Kamchatka
17 May 1841 · 143 km away · intensity XI
Moderate damage ($1–5M)tsunami
- 1973M7.2
Kuril Islands, Hiroo, Urakawa
28 Feb 1973 · 53 km away · intensity VIII
Moderate damage ($1–5M)tsunami
- 1904M8.3
Off Kamchatka
25 Jun 1904 · 183 km away · intensity X
Limited damage (under $1M)tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.