QuakeScout
Magnitude4.8

Reviewed by USGSRussia54y ago

M4.8 earthquake 85 km SE of Severo-Kuril’sk, Russia

Saturday, March 31, 1973, 20:45:31 UTC · 50.179°N, 157.053°E

A magnitude 4.8 earthquake struck 85 km SE of Severo-Kuril’sk, Russia on Saturday, March 31, 1973, 20:45:31 UTC, at a depth of 44.0 km (shallow). It is the strongest earthquake within 300 km since an M5.4 on March 25, 1973.

Magnitude
4.8
Light · mb
Depth
44 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

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

103 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

44 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 has not published any M2.5+ earthquake within 50 km in the 30 days after this event.

Regional history

Past M5+ earthquakes within 300 km

USGS lists 261 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:

  1. 7.8266 km SSW of Severo-Kuril’sk, RussiaMay 1, 1915 · 248 km SW of this epicenter
  2. 7.5253 km SE of Vilyuchinsk, RussiaJune 30, 1936 · 288 km NE of this epicenter
  3. 7.495 km NNE of Ozernovskiy, RussiaMay 4, 1911 · 228 km N of this epicenter
  4. 7.4156 km SE of Severo-Kuril’sk, RussiaOctober 31, 1916 · 71 km SE of this epicenter
  5. 7.297 km NNE of Ozernovskiy, RussiaAugust 17, 1907 · 243 km N of this epicenter
  6. 7.238 km ESE of Severo-Kuril’sk, RussiaFebruary 28, 1973 · 48 km NW of this epicenter
  7. 7.0285 km S of Severo-Kuril’sk, RussiaAugust 1, 1913 · 241 km S of this epicenter
  8. 6.9251 km SSW of Severo-Kuril’sk, RussiaMay 22, 1963 · 245 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 100 recorded deaths. The most severe:

  1. 1737

    Kamchatka

    16 Oct 1737 · 122 km away

    100 deathstsunami

  2. 1841M8.4

    Off Kamchatka

    17 May 1841 · 213 km away · intensity XI

    Moderate damage ($1–5M)tsunami

  3. 1973M7.2

    Kuril Islands, Hiroo, Urakawa

    28 Feb 1973 · 48 km away · intensity VIII

    Moderate damage ($1–5M)tsunami

  4. 1904M8.3

    Off Kamchatka

    25 Jun 1904 · 244 km away · intensity X

    Limited damage (under $1M)tsunami

  5. 1904M8.1

    Off Kamchatka

    25 Jun 1904 · 244 km away · intensity X

    Limited damage (under $1M)tsunami

  6. 1904M7.9

    Off Kamchatka

    27 Jun 1904 · 244 km away · intensity IX

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

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