QuakeIndex

Earthquake · reviewed by a seismologist

M 4.7mb

151 km S of False Pass, Alaska

· 17 km deep · released about 170 tons of TNT

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 4.7 (mb)
Depth
17 km below the surface
Felt
no reports yet
Measured shaking
intensity II (ShakeMap)
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1142 days ago

This was a light earthquake. It is usually felt clearly nearby and can rattle windows and dishes, but damage is uncommon.

How big was it?

This earthquake released about 170 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 5.7 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 1,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 45× the energy of this one
  3. Magna, Utah 2020 M 5.7 32× the energy of this one
  4. This earthquake M 4.7 about 170 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 350× 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.

Where

Epicentre 53.5032, -163.1656. Map © OpenStreetMap contributors.

Aftershocks so far

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

  1. 4.5 154 km S of False Pass, Alaska
  2. 2.9 157 km S of False Pass, Alaska
  3. 2.5 133 km S of False Pass, Alaska
  4. 3.3 116 km S of False Pass, Alaska
  5. 3.1 166 km S of False Pass, Alaska
  6. 2.6 157 km S of False Pass, Alaska
  7. 2.5 153 km S of False Pass, Alaska
  8. 2.6 140 km S of False Pass, Alaska
  9. 2.6 111 km S of False Pass, Alaska
  10. 2.8 122 km SSE of False Pass, Alaska
  11. 2.8 159 km S of False Pass, Alaska
  12. 1.9 115 km S of False Pass, Alaska
  13. 3.0 161 km S of False Pass, Alaska
  14. 1.7 103 km S of False Pass, Alaska
  15. 2.7 142 km S 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.

For this area

The largest earthquake within 50 km in our catalogue was M 5.9 on 2016-10-27 — it released about 63 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.