QuakeIndex

Earthquake · reviewed by a seismologist

M 1.5ml

132 km W of Adak, Alaska

· 6.6 km deep · released about 5.6 lb 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 1.5 (ml)
Depth
6.6 km below the surface
Felt
no reports yet
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 201 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

How big was it?

This earthquake released about 5.6 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.5 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 2,700,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,900,000× the energy of this one
  3. Around the size people start to feel M 3.0 170× the energy of this one
  4. This earthquake M 1.5 about 5.6 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 51.6957, -178.5355. Map © OpenStreetMap contributors.

Aftershocks so far

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

  1. 3.0 162 km WSW of Adak, Alaska
  2. 1.6 153 km W of Adak, Alaska
  3. 3.4 109 km WSW of Adak, Alaska
  4. 1.8 163 km WSW of Adak, Alaska
  5. 2.3 112 km WSW of Adak, Alaska
  6. 3.6 114 km WSW of Adak, Alaska
  7. 2.3 101 km W of Adak, Alaska
  8. 1.9 125 km WSW of Adak, Alaska
  9. 2.6 133 km W of Adak, Alaska
  10. 2.6 176 km WSW of Adak, Alaska
  11. 2.1 123 km WSW of Adak, Alaska
  12. 2.3 127 km WSW of Adak, Alaska
  13. 2.3 135 km WSW of Adak, Alaska
  14. 2.2 126 km WSW of Adak, Alaska
  15. 2.1 168 km W 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 6.5 on 2018-08-15 — it released about 31,000,000 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.