Magnitude7.1

Reviewed by USGSAlaska115y ago

M7.1 earthquake 4 km ENE of Karluk, Alaska

Thursday, November 7, 1912, 07:40:21 UTC · 57.592°N, 154.389°W

A magnitude 7.1 earthquake struck 4 km ENE of Karluk, Alaska on Thursday, November 7, 1912, 07:40:21 UTC, at a depth of 35.0 km (shallow). It is the strongest earthquake within 300 km since an M7.9 on October 9, 1900.

Magnitude
7.1
Major · mw
Depth
35 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: 200 km aftershock search area

In context

How big was it, and why here?

Energy released

629 kilotons of TNT

That is about 42 times the Hiroshima bomb. It released about 1,318 times the energy of a magnitude 5.0.

Tectonic setting

213 km

from the nearest mapped plate boundary, between the North American 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 200 km

USGS lists 1 M2.5+ earthquake within 200 km in the following 30 days; the largest was M6.1 on December 5, 1912. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.

M3M4M5M6M71h6h1d3d7d14d30dMainshock M7.1
Time after the mainshock on a logarithmic scale (first hours stretched), magnitude on the vertical axis. M2.5+ events from USGS.
  1. 6.113 km S of Akhiok, Alaska115y ago · 86 km S of this epicenter

Regional history

Past M5+ earthquakes within 300 km

USGS lists 49 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 8 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700. The most severe:

  1. 1900M8.3

    Kodiak Island

    9 Oct 1900 · 78 km away · intensity VIII

    Limited damage (under $1M)

  2. 1788M8.0

    Unga Island

    21 Jul 1788 · 106 km away · intensity VII

    Limited damage (under $1M)tsunami

  3. 1792

    Kodiak Island

    1792 · 158 km away · intensity VII

    Limited damage (under $1M)tsunami

  4. 1906M7.6

    Aleutian Islands

    23 Dec 1906 · 88 km away

  5. 1912M7.5

    Alaska Peninsula

    7 Nov 1912 · 38 km away · intensity V

  6. 1854

    Gulf Of Alaska

    27 Jan 1854 · 158 km away · intensity V

    tsunami

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

Nearby trackers

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