QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1ml

139 km ESE of Akutan, Alaska

· 17 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
17 km below the surface
Felt
no reports yet
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2634 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 53.5799, -163.8774. Map © OpenStreetMap contributors.

Aftershocks so far

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

  1. 2.1 125 km SSW of False Pass, Alaska
  2. 2.8 Unimak Island region, Alaska
  3. 2.2 111 km S of False Pass, Alaska
  4. 2.2 108 km S of False Pass, Alaska
  5. 2.7 166 km SE of Akutan, Alaska
  6. 2.5 110 km SSW of False Pass, Alaska
  7. 3.3 112 km SSW of False Pass, Alaska
  8. 2.5 162 km S of False Pass, Alaska
  9. 2.3 153 km S of False Pass, Alaska
  10. 2.2 114 km SSW of False Pass, Alaska
  11. 3.0 155 km SE of Akutan, Alaska
  12. 2.6 117 km SSW of False Pass, Alaska
  13. 3.8 121 km ESE of Akutan, Alaska
  14. 2.6 167 km S of False Pass, Alaska
  15. 2.3 104 km ESE of Akutan, 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 5.5 on 2018-05-27 — it released about 130,000 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.