QuakeIndex

Earthquake · reviewed by a seismologist

M 3.0ml

138 km ESE of Cordova, Alaska

· 0.9 km deep · released about 950 lb of TNT

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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
0.9 km below the surface
Felt
no reports yet
Measured shaking
intensity IV (ShakeMap)
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 27 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage.

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.

Where

Epicentre 60.2020, -143.3470. Map © OpenStreetMap contributors.

Aftershocks so far

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

  1. 1.9 127 km SSW of McCarthy, Alaska
  2. 2.3 109 km E of Cordova, Alaska
  3. 1.5 124 km E of Cordova, Alaska
  4. 1.7 112 km E of Cordova, Alaska
  5. 1.6 121 km S of McCarthy, Alaska
  6. 1.6 122 km S of McCarthy, Alaska
  7. 2.4 102 km S of McCarthy, Alaska
  8. 1.9 120 km S of McCarthy, Alaska
  9. 1.5 128 km S of McCarthy, Alaska
  10. 2.3 137 km S of McCarthy, Alaska
  11. 3.5 141 km ESE of Cordova, Alaska
  12. 1.8 126 km S of McCarthy, Alaska
  13. 1.5 133 km S of McCarthy, Alaska
  14. 1.5 122 km SSW of McCarthy, Alaska
  15. 1.8 137 km S of McCarthy, 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.