QuakeIndex

Earthquake · reviewed by a seismologist

M 5.0mww

242 km WSW of Adak, Alaska

· 38 km deep · released about 480 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 5.0 (mww)
Depth
38 km below the surface
Felt
no reports yet
Measured shaking
intensity IV (ShakeMap)
Tsunami
USGS flagged this event for tsunami evaluation. Follow tsunami.gov for official messages.
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1004 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 480 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 6.0 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 350× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 16× the energy of this one
  3. Magna, Utah 2020 M 5.7 11× the energy of this one
  4. This earthquake M 5.0 about 480 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 1,000× 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 51.1400, -179.9169. Map © OpenStreetMap contributors.

Aftershocks so far

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

  1. 3.0 213 km WSW of Adak, Alaska
  2. 2.6 241 km WSW of Adak, Alaska
  3. 1.6 197 km WSW of Adak, Alaska
  4. 1.5 233 km WSW of Adak, Alaska
  5. 3.9 229 km W of Adak, Alaska
  6. 1.5 210 km WSW of Adak, Alaska
  7. 1.7 238 km WSW of Adak, Alaska
  8. 1.6 240 km WSW of Adak, Alaska
  9. 3.1 226 km WSW of Adak, Alaska
  10. 2.0 222 km WSW of Adak, Alaska
  11. 1.5 212 km WSW of Adak, Alaska
  12. 2.9 245 km WSW of Adak, Alaska
  13. 1.5 249 km WSW of Adak, Alaska
  14. 1.8 217 km WSW of Adak, Alaska
  15. 2.8 227 km WSW 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 6.1 on 2020-01-26 — it released about 45 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.