QuakeIndex

Earthquake · reviewed by a seismologist

M 3.0ml

217 km SSW of Adak, Alaska

· 10 km deep · released about 950 lb of TNT

Felt it? Tell USGS Check my area
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 3.0 (ml)
Depth
10 km below the surface
Felt
no reports yet
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1608 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 950 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.0 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 350,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 16,000× the energy of this one
  3. Magna, Utah 2020 M 5.7 11,000× the energy of this one
  4. This earthquake M 3.0 about 950 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 49.9707, -177.3193. Map © OpenStreetMap contributors.

Aftershocks so far

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

  1. 2.6 200 km S of Adak, Alaska
  2. 3.5 215 km SSW of Adak, Alaska
  3. 2.9 191 km S of Adak, Alaska
  4. 3.1 256 km SSW of Adak, Alaska
  5. 2.6 171 km S of Adak, Alaska
  6. 2.7 220 km SSW of Adak, Alaska
  7. 2.7 172 km SSW of Adak, Alaska
  8. 2.7 184 km SSW of Adak, Alaska
  9. 2.3 191 km SSW of Adak, Alaska
  10. 2.8 189 km S of Adak, Alaska
  11. 3.4 208 km S of Adak, Alaska
  12. 3.1 178 km SSW of Adak, Alaska
  13. 2.8 174 km S of Adak, Alaska
  14. 2.2 195 km SSW of Adak, Alaska
  15. 2.0 187 km SSW of Adak, 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 4.3 on 2019-06-30 — it released about 89 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.