QuakeIndex

Earthquake · reviewed by a seismologist

M 3.2ml

218 km SSE of False Pass, Alaska

Yes. A magnitude 3.2 earthquake was recorded 218 km SSE of False Pass, Alaska at 18:29 UTC on 2017-04-08, 10 km deep.

· 10 km deep · released about 1,900 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 3.2 (ml)
Depth
10 km below the surface
Felt
no reports yet
Nearest mapped fault
Alaska-Aleutian subduction zone, 24 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 1194 days ago

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

At this magnitude and depth, people at rest would likely notice it out to about 45 km (28 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.

How big was it?

This earthquake released about 1,900 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.2 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 180,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 7,900× the energy of this one
  3. Magna, Utah 2020 M 5.7 5,600× the energy of this one
  4. This earthquake M 3.2 about 1,900 lb of TNT
  5. Around the size people start to feel M 3.0 this one released 2× more

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

The largest earthquake within 50 km since 2016 was M 5.0 on 2016-10-01 — about 500 times the energy of this one.

Before 2016, the USGS record lists 9 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.3 226 km SSE of False Pass, Alaska · 37 km E of this epicentre
  2. 6.2 172 km SSE of False Pass, Alaska · 47 km NNW of this epicentre
  3. 6.0 195 km S of False Pass, Alaska · 46 km WNW of this epicentre
  4. 5.9 228 km S of False Pass, Alaska · 38 km WSW of this epicentre
  5. 5.7 187 km SSE of False Pass, Alaska · 41 km NNE 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 52.9530, -162.5647. Map © OpenStreetMap contributors.

Aftershocks so far

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

  1. 2.2 191 km S of False Pass, Alaska
  2. 2.1 206 km S of False Pass, Alaska
  3. 2.2 224 km S of False Pass, Alaska
  4. 2.3 254 km S of False Pass, Alaska
  5. 2.7 200 km SSE of False Pass, Alaska
  6. 3.1 251 km SSE of False Pass, Alaska
  7. 2.9 201 km S of False Pass, Alaska
  8. 2.7 224 km S of False Pass, Alaska
  9. 3.6 224 km S of False Pass, Alaska
  10. 2.9 227 km SSE of False Pass, Alaska
  11. 2.7 198 km SSE of False Pass, Alaska
  12. 3.8 209 km SSE of False Pass, Alaska
  13. 2.8 227 km SSE of False Pass, Alaska
  14. 2.4 240 km S of False Pass, Alaska
  15. 2.9 240 km SSE of False Pass, 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.