QuakeIndex

ice quake · reviewed by a seismologist

M 2.2ml

143 km ESE of Cordova, Alaska

No: USGS classifies this as a ice quake, not an earthquake. A magnitude 2.2 ice quake was recorded 143 km ESE of Cordova, Alaska at 19:14 UTC on 2019-10-31, less than 1 km deep.

· 0.0 km deep · released about 60 lb of TNT

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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
0.0 km below the surface
Felt
no reports yet
Nearest mapped fault
Hope Creek fault (Chugach-St. Elias fold and thrust belt), 12 km from its surface trace — near is not the same as on
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2548 days ago

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

At this magnitude and depth, people at rest would likely notice it out to about 18 km (11 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.

USGS catalogues this as ice quake, not an earthquake.

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.

For this area

No earthquake of M4 or more has been recorded within 50 km since our catalogue begins in 2016.

Before 2016, the USGS record lists 2 earthquakes of M5 or more within 50 km:

  1. 5.8 162 km WNW of Yakutat, Alaska · 48 km ESE of this epicentre
  2. 5.5 164 km S of McCarthy, Alaska · 45 km ESE 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 60.1477, -143.2835. Map © OpenStreetMap contributors.

Aftershocks so far

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

  1. 2.6 103 km S of McCarthy, Alaska
  2. 1.6 104 km S of McCarthy, Alaska
  3. 2.1 109 km S of McCarthy, Alaska
  4. 2.1 107 km S of McCarthy, Alaska
  5. 2.0 122 km S of McCarthy, Alaska
  6. 1.9 124 km SSW of McCarthy, Alaska
  7. 2.5 123 km SSW of McCarthy, Alaska
  8. 2.0 122 km S of McCarthy, Alaska
  9. 1.6 103 km S of McCarthy, Alaska
  10. 1.6 101 km S of McCarthy, Alaska
  11. 2.6 125 km SSW of McCarthy, Alaska
  12. 1.7 103 km S of McCarthy, Alaska
  13. 2.3 107 km SSW of McCarthy, Alaska
  14. 1.6 131 km S of McCarthy, Alaska
  15. 1.8 129 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.