QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1ml

116 km SE of Perryville, Alaska

· 39 km deep · released about 43 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 2.1 (ml)
Depth
39 km below the surface
Felt
no reports yet
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2207 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 43 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.1 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 350,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 250,000× the energy of this one
  3. Around the size people start to feel M 3.0 22× the energy of this one
  4. This earthquake M 2.1 about 43 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 55.0532, -158.0938. Map © OpenStreetMap contributors.

Aftershocks so far

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

  1. 2.4 107 km SE of Perryville, Alaska
  2. 2.3 84 km SSE of Perryville, Alaska
  3. 2.9 119 km SE of Perryville, Alaska
  4. 3.7 124 km SE of Perryville, Alaska
  5. 2.5 128 km SE of Perryville, Alaska
  6. 2.5 74 km SE of Perryville, AK
  7. 3.0 161 km SSE of Perryville, Alaska
  8. 4.2 75 km SE of Perryville, Alaska
  9. 2.6 68 km SE of Perryville, AK
  10. 2.0 66 km SSE of Perryville, Alaska
  11. 2.3 97 km SE of Perryville, Alaska
  12. 2.2 122 km SE of Perryville, Alaska
  13. 3.1 158 km SSE of Perryville, Alaska
  14. 2.6 150 km SSE of Perryville, Alaska
  15. 2.6 127 km SSE of Perryville, 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 7.8 on 2020-07-22 — it released about 350,000,000 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.