QuakeIndex

Earthquake · reviewed by a seismologist

M 2.2ml

136 km S of Sand Point, Alaska

Yes. A magnitude 2.2 earthquake was recorded 136 km S of Sand Point, Alaska, at 4:01 pm AKDT on 22 October 2023 (00:01 UTC), 12 km deep.

· 12 km deep · released about 60 lb of TNT

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Distance rings around the epicentre, with the nearest towns at their true direction and later quakes as coloured dots. Not a shaking map — see the USGS ShakeMap for that.
When
Magnitude
M 2.2 (ml)
Depth
12 km below the surface
Felt
no reports yet
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1100 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

At this magnitude and depth, people at rest would likely notice it out to about 14 km (9 mi) from the epicentre. Estimated from magnitude, depth and distance with the intensity equation USGS Did You Feel It? uses; felt reports, where there are any, are the measurement.

How big was it?

This earthquake released about 60 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.2 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 250,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 180,000× the energy of this one
  3. Around the size people start to feel M 3.0 16× the energy of this one
  4. This earthquake M 2.2 about 60 lb of TNT

Energy from the Gutenberg–Richter relation (log10E = 1.5M + 4.8), rounded to two figures; bar length is magnitude, which is already a logarithm of energy. Magnitudes of past earthquakes from the USGS catalogue.

For this area

The largest earthquake within 50 km since 2016 was M 7.2 on 2023-07-16 — about 32,000,000 times the energy of this one.

Before 2016, the USGS record lists 9 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.4 159 km SSE of King Cove, Alaska · 46 km SW of this epicentre
  2. 6.2 141 km SSE of King Cove, Alaska · 36 km WSW of this epicentre
  3. 5.9 131 km S of Sand Point, Alaska · 16 km ENE of this epicentre
  4. 5.7 100 km SSW of Sand Point, Alaska · 49 km NNW of this epicentre
  5. 5.5 137 km S of Sand Point, Alaska · 17 km W of this epicentre

Since 2016: the QuakeIndex catalogue (US, M1.5+), built from the USGS FDSN event service. Before 2016: USGS ComCat, M5+ from 1900. Distances are between epicentres. This is the record, not a forecast.

Where

Epicentre 54.1153, -160.6326. Map © OpenStreetMap contributors.

Aftershocks so far

56 earthquakes have been recorded within 50 km since this one.

  1. 3.6 111 km S of Sand Point, Alaska
  2. 2.4 148 km SSE of King Cove, Alaska
  3. 1.9 133 km SE of King Cove, Alaska
  4. 1.9 111 km S of Sand Point, Alaska
  5. 2.1 126 km SE of King Cove, Alaska
  6. 3.1 111 km SSW of Sand Point, Alaska
  7. 1.8 106 km S of Sand Point, Alaska
  8. 2.2 112 km S of Sand Point, Alaska
  9. 1.7 109 km S of Sand Point, Alaska
  10. 2.0 93 km SSW of Sand Point, Alaska
  11. 2.1 108 km SSW of Sand Point, Alaska
  12. 2.0 111 km S of Sand Point, Alaska
  13. 2.6 91 km SSW of Sand Point, Alaska
  14. 2.2 129 km SE of King Cove, Alaska
  15. 1.6 124 km S of Sand Point, Alaska

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of . QuakeIndex does not forecast aftershocks. When USGS issues an operational aftershock forecast it appears on the USGS event page.

On USGS

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.