QuakeIndex

Earthquake · reviewed by a seismologist

M 3.0ml

Gulf of Alaska

Yes. A magnitude 3.0 earthquake was recorded in the Gulf of Alaska at 06:33 UTC on 2023-05-04, 10 km deep.

· 10 km deep · released about 950 lb of TNT

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10 km30 km60 km120 km N
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 3.0 (ml)
Depth
10 km below the surface
Felt
no reports yet
Nearest mapped fault
Gulf of Alaska shear zone, 15 km from its surface trace — near is not the same as on
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1217 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 35 km (22 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 950 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.0 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 350,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 16,000× the energy of this one
  3. Magna, Utah 2020 M 5.7 11,000× the energy of this one
  4. This earthquake M 3.0 about 950 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 4.2 on 2016-02-15 — about 63 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. 7.8 Gulf of Alaska · 40 km S of this epicentre
  2. 6.9 283 km SW of Yakutat, Alaska · 35 km NNE of this epicentre
  3. 6.2 290 km SW of Yakutat, Alaska · 29 km NE of this epicentre
  4. 5.8 296 km SW of Yakutat, Alaska · 25 km N of this epicentre
  5. 5.3 290 km SW of Yakutat, Alaska · 28 km NE 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 57.3062, -143.1195. Map © OpenStreetMap contributors.

Aftershocks so far

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

  1. 3.1 286 km SW of Yakutat, Alaska
  2. 2.4 Gulf of Alaska
  3. 2.8 287 km SW of Yakutat, Alaska
  4. 4.2 285 km SW of Yakutat, Alaska
  5. 2.7 Gulf of Alaska
  6. 2.5 292 km SW of Yakutat, Alaska
  7. 3.1 Gulf of Alaska
  8. 2.7 Gulf of Alaska
  9. 2.4 270 km SW of Yakutat, Alaska
  10. 3.4 282 km SW of Yakutat, Alaska
  11. 2.6 284 km SW of Yakutat, Alaska
  12. 2.7 Gulf of Alaska
  13. 2.4 274 km SW of Yakutat, Alaska
  14. 2.3 283 km SW of Yakutat, Alaska
  15. 2.7 277 km SW of Yakutat, 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.