QuakeScout
Magnitude5.2

Reviewed by USGSRussia54y ago

M5.2 earthquake 77 km S of Severo-Kuril’sk, Russia

Thursday, April 12, 1973, 12:17:15 UTC · 49.982°N, 155.992°E

A magnitude 5.2 earthquake struck 77 km S of Severo-Kuril’sk, Russia on Thursday, April 12, 1973, 12:17:15 UTC, at a depth of 55.0 km (shallow). It is the strongest earthquake within 300 km since an M5.4 on March 25, 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 earthquake

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

148 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 has not published any M2.5+ earthquake within 75 km in the 30 days after this event.

Regional history

Past M5+ earthquakes within 300 km

USGS lists 235 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 · 191 km SW of this epicenter
  2. 7.495 km NNE of Ozernovskiy, RussiaMay 4, 1911 · 264 km N of this epicenter
  3. 7.4156 km SE of Severo-Kuril’sk, RussiaOctober 31, 1916 · 137 km E of this epicenter
  4. 7.2Kuril IslandsJanuary 18, 1925 · 282 km SW of this epicenter
  5. 7.297 km NNE of Ozernovskiy, RussiaAugust 17, 1907 · 270 km N of this epicenter
  6. 7.238 km ESE of Severo-Kuril’sk, RussiaFebruary 28, 1973 · 70 km NE of this epicenter
  7. 7.0285 km S of Severo-Kuril’sk, RussiaAugust 1, 1913 · 208 km S of this epicenter
  8. 6.9251 km SSW of Severo-Kuril’sk, RussiaMay 22, 1963 · 179 km SW of this epicenter

History · NOAA

Deadliest earthquakes in this area

NOAA’s significant-earthquake database lists 11 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 · 189 km away

    100 deathstsunami

  2. 1841M8.4

    Off Kamchatka

    17 May 1841 · 265 km away · intensity XI

    Moderate damage ($1–5M)tsunami

  3. 1973M7.2

    Kuril Islands, Hiroo, Urakawa

    28 Feb 1973 · 72 km away · intensity VIII

    Moderate damage ($1–5M)tsunami

  4. 1913M7.7

    Kuril Islands

    1 Aug 1913 · 278 km away

  5. 1929M7.7

    Kuril Islands

    13 Jan 1929 · 88 km away · intensity VII

  6. 1911M7.6

    Near Kamchatka

    4 May 1911 · 202 km away · intensity VII

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

Nearby trackers

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