QuakeIndex

Earthquake · reviewed by a seismologist

M 3.0ml

203 km SE of Chignik, Alaska

Yes. A magnitude 3.0 earthquake was recorded 203 km SE of Chignik, Alaska at 17:22 UTC on 2025-06-18, 11 km deep.

· 11 km deep · released about 950 lb of TNT

Felt it? Tell USGS Check my area
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
11 km below the surface
Felt
no reports yet
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 436 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 5.6 on 2021-09-16 — about 7,900 times the energy of this one.

Before 2016, the USGS record lists 11 earthquakes of M5 or more within 50 km; the five largest:

  1. 7.0 164 km SE of Chignik, Alaska · 46 km NNW of this epicentre
  2. 6.2 189 km SE of Chignik, Alaska · 17 km WNW of this epicentre
  3. 6.1 210 km SE of Chignik, Alaska · 46 km NE of this epicentre
  4. 6.0 223 km SSW of Akhiok, Alaska · 50 km ENE of this epicentre
  5. 6.0 168 km SE of Chignik, Alaska · 39 km NNW 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 54.9199, -156.2757. Map © OpenStreetMap contributors.

Aftershocks so far

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

  1. 3.1 243 km SE of Chignik, Alaska
  2. 3.2 202 km SE of Perryville, Alaska
  3. 3.1 194 km SE of Perryville, Alaska
  4. 3.1 202 km SE of Perryville, Alaska
  5. 3.9 197 km SE of Perryville, Alaska
  6. 2.8 199 km SE of Perryville, Alaska
  7. 2.9 200 km SE of Perryville, Alaska
  8. 3.0 195 km SE of Chignik, Alaska
  9. 3.3 190 km SE of Chignik, Alaska
  10. 2.8 190 km SE of Chignik, Alaska
  11. 3.2 187 km SE of Chignik, Alaska
  12. 2.8 226 km SE of Chignik, Alaska
  13. 3.7 197 km SE of Chignik, Alaska
  14. 3.1 194 km SE of Perryville, Alaska
  15. 3.7 212 km SE of Chignik, 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.