QuakeIndex

Earthquake · reviewed by a seismologist

M 3.8mb

203 km SSE of Sand Point, Alaska

· 18 km deep · released about 7.6 tons 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 3.8 (mb)
Depth
18 km below the surface
Felt
no reports yet
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2108 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 7.6 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.8 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 22,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 1,000× the energy of this one
  3. Magna, Utah 2020 M 5.7 710× the energy of this one
  4. This earthquake M 3.8 about 7.6 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 16× 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 53.5447, -159.8484. Map © OpenStreetMap contributors.

Aftershocks so far

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

  1. 2.9 203 km S of Sand Point, Alaska
  2. 3.0 226 km S of Sand Point, Alaska
  3. 2.6 223 km S of Sand Point, Alaska
  4. 2.7 south of Alaska
  5. 2.5 207 km S of Sand Point, Alaska
  6. 2.7 185 km S of Sand Point, Alaska
  7. 2.8 208 km S of Sand Point, Alaska
  8. 2.5 219 km S of Sand Point, Alaska
  9. 3.1 168 km SSE of Sand Point, Alaska
  10. 3.1 222 km S of Sand Point, Alaska
  11. 3.5 217 km S of Sand Point, Alaska
  12. 3.0 207 km S of Sand Point, Alaska
  13. 2.9 192 km S of Sand Point, Alaska
  14. 3.1 241 km S of Sand Point, Alaska
  15. 2.3 190 km S 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.

On USGS

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