QuakeIndex

Earthquake · reviewed by a seismologist

M 2.2ml

168 km ESE of Chignik, Alaska

· 14 km deep · released about 60 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 2.2 (ml)
Depth
14 km below the surface
Felt
no reports yet
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1521 days ago

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

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.

Where

Epicentre 55.5759, -156.0315. Map © OpenStreetMap contributors.

Aftershocks so far

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

  1. 2.6 148 km ESE of Chignik, Alaska
  2. 2.1 170 km SSW of Akhiok, Alaska
  3. 2.6 175 km SW of Akhiok, Alaska
  4. 2.6 168 km ESE of Chignik, Alaska
  5. 2.3 170 km ESE of Chignik, Alaska
  6. 3.2 165 km ESE of Chignik, Alaska
  7. 2.4 154 km SW of Akhiok, Alaska
  8. 3.2 190 km SE of Chignik, Alaska
  9. 2.4 147 km ESE of Chignik, Alaska
  10. 2.5 154 km SE of Chignik, Alaska
  11. 3.2 159 km ESE of Chignik, Alaska
  12. 3.4 157 km ESE of Chignik, Alaska
  13. 2.4 146 km SW of Akhiok, Alaska
  14. 3.7 199 km SE of Chignik, Alaska
  15. 2.8 171 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.

For this area

The largest earthquake within 50 km in our catalogue was M 4.8 on 2021-07-29 — it released about 7,900 times the energy of this one.

From the QuakeIndex catalogue, built from the USGS FDSN event service.

On USGS

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