QuakeIndex

Earthquake · reviewed by a seismologist

M 2.8ml

116 km SSE of Sand Point, Alaska

· 23 km deep · released about 480 lb 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 2.8 (ml)
Depth
23 km below the surface
Felt
no reports yet
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2087 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 480 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.8 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 32,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 22,000× the energy of this one
  3. Around the size people start to feel M 3.0 2× the energy of this one
  4. This earthquake M 2.8 about 480 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.

Where

Epicentre 54.4046, -159.6565. Map © OpenStreetMap contributors.

Aftershocks so far

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

  1. 2.7 148 km SSE of Sand Point, Alaska
  2. 2.3 86 km SSE of Sand Point, Alaska
  3. 2.9 108 km SSE of Sand Point, Alaska
  4. 4.3 146 km SSE of Sand Point, Alaska
  5. 2.6 127 km SSE of Sand Point, Alaska
  6. 3.0 149 km SSE of Sand Point, Alaska
  7. 2.8 88 km SE of Sand Point, Alaska
  8. 2.7 125 km SSE of Sand Point, Alaska
  9. 2.6 122 km SSE of Sand Point, Alaska
  10. 2.9 105 km SSE of Sand Point, AK
  11. 2.7 108 km SSE of Sand Point, Alaska
  12. 3.6 134 km SSE of Sand Point, Alaska
  13. 2.7 96 km SE of Sand Point, Alaska
  14. 3.7 152 km SSE of Sand Point, Alaska
  15. 3.2 102 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 7.6 on 2020-10-19 — it released about 16,000,000 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.