QuakeScout
Magnitude5.8

Reviewed by USGSAlaska70y ago

M5.8 earthquake 75 km SSE of Nikolski, Alaska

Wednesday, April 17, 1957, 13:25:03 UTC · 52.297°N, 168.480°W

A magnitude 5.8 earthquake struck 75 km SSE of Nikolski, Alaska on Wednesday, April 17, 1957, 13:25:03 UTC, at a depth of 25.0 km (shallow). It is the strongest earthquake within 300 km since an M5.9 on April 15, 1957.

Magnitude
5.8
Moderate · mw
Depth
25 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

8 kilotons of TNT

That is about 1/2 of the Hiroshima bomb. It released about 16 times the energy of a magnitude 5.0.

Tectonic setting

43 km

from the nearest mapped plate boundary, between the North American and Pacific plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.

Depth: shallow

25 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 M6.3 on May 2, 1957. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.

M3M4M5M61h6h1d3d7d14d30dMainshock M5.8
Time after the mainshock on a logarithmic scale (first hours stretched), magnitude on the vertical axis. M2.5+ events from USGS.
  1. 6.352 km S of Nikolski, Alaska70y ago · 26 km NW of this epicenter
  2. 6.350 km S of Nikolski, Alaska70y ago · 28 km NW of this epicenter
  3. 5.663 km S of Nikolski, Alaska70y ago · 31 km W of this epicenter
  4. 5.862 km SSE of Nikolski, Alaska70y ago · 13 km NW of this epicenter

Regional history

Past M5+ earthquakes within 300 km

USGS lists 91 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:

  1. 7.8234 km SSW of Nikolski, AlaskaMarch 7, 1929 · 179 km SW of this epicenter
  2. 7.4133 km WNW of Nikolski, AlaskaApril 18, 1916 · 194 km NW of this epicenter
  3. 7.139 km S of Akutan, AlaskaMarch 22, 1957 · 245 km NE of this epicenter
  4. 7.135 km SW of Nikolski, AlaskaMarch 11, 1957 · 65 km NW of this epicenter
  5. 7.0203 km SSE of Unalaska, AlaskaAugust 22, 1940 · 204 km E of this epicenter
  6. 6.980 km SW of Nikolski, AlaskaMarch 9, 1957 · 73 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. The most severe:

  1. 1901M7.8

    Aleutian Islands: Fox Islands

    31 Dec 1901 · 198 km away

    Limited damage (under $1M)tsunami

  2. 1917M7.9

    Alaska Peninsula

    31 May 1917 · 280 km away · intensity V

  3. 1902M7.8

    Aleutian Islands: Fox Islands

    1 Jan 1902 · 68 km away

  4. 1907M7.8

    Aleutian Islands

    2 Sep 1907 · 91 km away

  5. 1929M7.8

    Aleutian Islands: Fox Islands

    7 Mar 1929 · 178 km away · intensity V

    tsunami

  6. 1916M7.5

    Aleutian Islands: Fox Islands

    18 Apr 1916 · 151 km away

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

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