QuakeScout
Magnitude3.3

Reviewed by USGSAlaska14y ago

M3.3 earthquake 83 km WSW of Atka, Alaska

Thursday, May 17, 2012, 03:57:47 UTC · 52.026°N, 175.390°W

A magnitude 3.3 earthquake struck 83 km WSW of Atka, Alaska on Thursday, May 17, 2012, 03:57:47 UTC, at a depth of 12.2 km (shallow).

Magnitude
3.3
Minor · ml
Depth
12 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

1 tons of TNT

That is about 1/11,203 of the Hiroshima bomb. A magnitude 5.0 releases about 355 times more energy.

Tectonic setting

136 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

12 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 1 M2.5+ earthquake within 50 km in the following 30 days; the largest was M2.7 on May 22, 2012. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.

M31h6h1d3d7d14d30dMainshock M3.3
Time after the mainshock on a logarithmic scale (first hours stretched), magnitude on the vertical axis. M2.5+ events from USGS.
  1. 2.786 km ESE of Adak, Alaska14y ago · 49 km S of this epicenter

Regional history

Past M5+ earthquakes within 300 km

USGS lists 1,030 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:

  1. 8.61957 Atka, Alaska EarthquakeMarch 9, 1957 · 61 km S of this epicenter
  2. 8.01986 Atka, Alaska EarthquakeMay 7, 1986 · 70 km SE of this epicenter
  3. 7.977 km WSW of Adak, AlaskaJune 10, 1996 · 163 km W of this epicenter
  4. 7.65 km WNW of Adak, AlaskaFebruary 14, 1905 · 91 km W of this epicenter
  5. 7.388 km WSW of Adak, AlaskaJuly 7, 1929 · 173 km W of this epicenter
  6. 7.346 km SSW of Adak, AlaskaJune 10, 1996 · 117 km SW of this epicenter
  7. 7.3Fox Islands, Aleutian Islands, AlaskaJune 24, 2011 · 243 km E of this epicenter
  8. 7.2207 km WSW of Adak, AlaskaDecember 19, 2007 · 293 km W 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, which together caused about 2 recorded deaths. The most severe:

  1. 1957M8.6

    Alaska

    9 Mar 1957 · 61 km away

    2 deathsSevere damage ($5–24M)tsunami

  2. 1986M8.0

    Aleutian Islands: Adak

    7 May 1986 · 70 km away · intensity VI

    Moderate damage ($1–5M)tsunami

  3. 1905M7.9

    Andreanof Islands

    14 Feb 1905 · 262 km away

  4. 1996M7.9

    Andreanof Islands

    10 Jun 1996 · 163 km away · intensity VI

    tsunami

  5. 1996M7.3

    Andreanof Islands

    10 Jun 1996 · 117 km away

    tsunami

  6. 2011M7.3

    Aleutian Islands: Fox Islands

    24 Jun 2011 · 243 km away

    tsunami

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

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