QuakeIndex

Earthquake · reviewed by a seismologist

M 3.4ml

Alaska Peninsula

Yes. A magnitude 3.4 earthquake was recorded in the Alaska Peninsula, at 8:42 pm AKDT on 19 July 2023 (04:42 UTC), 35 km deep.

· 35 km deep · released about 1.9 tons of TNT

10 km30 km60 km120 km N Aleutians East Borough 79 km
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 3.4 (ml)
Depth
35 km below the surface
Felt
no reports yet
Nearest
Aleutians East Borough, 79 km NW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1142 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage.

At this magnitude and depth, people at rest would likely notice it out to about 46 km (29 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 1.9 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.4 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 89,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 4,000× the energy of this one
  3. Magna, Utah 2020 M 5.7 2,800× the energy of this one
  4. This earthquake M 3.4 about 1.9 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 4× more

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 in our catalogue was M 7.2 on 2023-07-16 — about 500,000 times the energy of this one.

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 54.7280, -161.1376. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Aleutians East Borough, AK 79 km (49 mi) NW earthquakes near Aleutians East Borough

Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.

Aftershocks so far

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

  1. 2.3 87 km SE of King Cove, Alaska
  2. 2.5 96 km SSW of Sand Point, Alaska
  3. 1.7 78 km SE of King Cove, Alaska
  4. 1.6 93 km SSW of Sand Point, Alaska
  5. 1.8 Alaska Peninsula
  6. 1.6 81 km ESE of King Cove, Alaska
  7. 1.9 79 km SSE of King Cove, Alaska
  8. 4.7 87 km SSW of Sand Point, Alaska
  9. 1.7 63 km SE of King Cove, Alaska
  10. 2.6 112 km SSW of Sand Point, Alaska
  11. 2.6 86 km SSW of Sand Point, Alaska
  12. 1.5 88 km SE of King Cove, Alaska
  13. 2.0 80 km SE of King Cove, Alaska
  14. 1.8 Alaska Peninsula
  15. 1.5 87 km SSW 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.