QuakeScout
Magnitude2.5

Reviewed by USGSAlaska26y ago

M2.5 earthquake 22 km NNW of Akhiok, Alaska

Saturday, April 29, 2000, 23:14:50 UTC · 57.139°N, 154.256°W

A magnitude 2.5 earthquake struck 22 km NNW of Akhiok, Alaska on Saturday, April 29, 2000, 23:14:50 UTC, at a depth of 65.7 km (shallow).

Magnitude
2.5
Minor · ml
Depth
66 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: 50 km aftershock search area

In context

How big was it, and why here?

Energy released

85 kg of TNT

That is about 1/177,558 of the Hiroshima bomb. A magnitude 5.0 releases about 5,623 times more energy.

Tectonic setting

170 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

66 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 lists 3 M2.5+ earthquakes within 50 km in the following 30 days; the largest was M5.0 on May 8, 2000. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.

M3M4M51h6h1d3d7d14d30dMainshock M2.5
Time after the mainshock on a logarithmic scale (first hours stretched), magnitude on the vertical axis. M2.5+ events from USGS.
  1. 2.831 km SSE of Karluk, Alaska26y ago · 18 km N of this epicenter
  2. 4.223 km SW of Larsen Bay, Alaska26y ago · 26 km N of this epicenter
  3. 5.029 km SSE of Karluk, Alaska26y ago · 20 km N of this epicenter

Regional history

Past M5+ earthquakes within 300 km

USGS lists 316 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:

  1. 7.9Kodiak Island region, AlaskaOctober 9, 1900 · 198 km E of this epicenter
  2. 7.14 km ENE of Karluk, AlaskaNovember 7, 1912 · 51 km N of this epicenter
  3. 7.0113 km ESE of Chignik, AlaskaMay 4, 1923 · 211 km SW of this epicenter
  4. 7.026 km SSE of Karluk, AlaskaDecember 6, 1999 · 23 km N of this epicenter
  5. 7.0164 km SE of Chignik, AlaskaSeptember 4, 1989 · 243 km SW of this epicenter
  6. 6.9105 km ESE of Perryville, AlaskaNovember 17, 1938 · 288 km SW of this epicenter
  7. 6.9143 km ESE of Chignik, AlaskaFebruary 13, 1951 · 194 km SW of this epicenter

History · NOAA

Deadliest earthquakes in this area

NOAA’s significant-earthquake database lists 10 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 · 47 km away · intensity VIII

    Limited damage (under $1M)

  2. 1788M8.0

    Unga Island

    21 Jul 1788 · 77 km away · intensity VII

    Limited damage (under $1M)tsunami

  3. 1970M6.0

    Andreanof Islands

    11 Mar 1970 · 46 km away · intensity V

    Limited damage (under $1M)tsunami

  4. 1792

    Kodiak Island

    1792 · 137 km away · intensity VII

    Limited damage (under $1M)tsunami

  5. 1906M7.6

    Aleutian Islands

    23 Dec 1906 · 39 km away

  6. 1912M7.5

    Alaska Peninsula

    7 Nov 1912 · 60 km away · intensity V

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

Nearby trackers

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