QuakeIndex

Earthquake · reviewed by a seismologist

M 5.9mww

144 km SSE of Sand Point, Alaska

· 31 km deep · released about 11 kilotons 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 5.9 (mww)
Depth
31 km below the surface
Felt
no reports yet
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1241 days ago

This was a moderate earthquake. Shaking at this size can damage poorly built structures close to the epicentre.

How big was it?

This earthquake released about 11 kilotons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 6.9 would have released about 32 times as much.

  1. Ridgecrest, California 2019 M 7.1 63× the energy of this one
  2. Loma Prieta, California 1989 M 6.9 32× the energy of this one
  3. Northridge, California 1994 M 6.7 16× the energy of this one
  4. This earthquake M 5.9 about 11 kilotons of TNT
  5. Mineral, Virginia 2011 M 5.8 this one released 1.4× more
  6. Magna, Utah 2020 M 5.7 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.

Where

Epicentre 54.1535, -159.5619. Map © OpenStreetMap contributors.

Aftershocks so far

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

  1. 4.8 114 km SSE of Sand Point, Alaska
  2. 3.5 107 km SSE of Sand Point, Alaska
  3. 3.5 112 km SSE of Sand Point, Alaska
  4. 4.8 139 km SSE of Sand Point, Alaska
  5. 4.1 113 km SSE of Sand Point, Alaska
  6. 3.2 109 km SSE of Sand Point, Alaska
  7. 4.0 114 km SSE of Sand Point, Alaska
  8. 4.2 103 km SSE of Sand Point, Alaska
  9. 3.3 108 km SSE of Sand Point, Alaska
  10. 3.4 120 km SSE of Sand Point, Alaska
  11. 3.2 100 km SSE of Sand Point, Alaska
  12. 3.5 98 km SSE of Sand Point, Alaska
  13. 3.2 105 km SE of Sand Point, Alaska
  14. 4.0 127 km SSE of Sand Point, Alaska
  15. 3.1 112 km SSE of Sand Point, 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 5.7 on 2020-10-19.

From the QuakeIndex catalogue, built from the USGS FDSN event service.

On USGS

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.