QuakeIndex

Earthquake · reviewed by a seismologist

M 5.2mww

187 km SE of Akutan, Alaska

· 10 km deep · released about 950 tons 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 5.2 (mww)
Depth
10 km below the surface
Felt
3 reports · strongest reported intensity III
Measured shaking
intensity III (ShakeMap)
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 160 days ago

This was a moderate earthquake. Shaking at this size can damage poorly built structures close to the epicentre. 3 people have reported feeling it to USGS.

How big was it?

This earthquake released about 950 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 6.2 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 180× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 7.9× the energy of this one
  3. Magna, Utah 2020 M 5.7 5.6× the energy of this one
  4. This earthquake M 5.2 about 950 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 2,000× 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 52.9219, -163.8153. Map © OpenStreetMap contributors.

Aftershocks so far

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

  1. 3.0 219 km SE of Akutan, Alaska
  2. 3.3 231 km SE of Akutan, Alaska
  3. 3.9 213 km SE of Akutan, Alaska
  4. 2.6 231 km SE of Akutan, Alaska
  5. 2.9 198 km SE of Akutan, Alaska
  6. 2.9 213 km SE of Akutan, Alaska
  7. 2.8 220 km SE of Akutan, Alaska
  8. 3.2 233 km SE of Akutan, Alaska
  9. 3.1 223 km SE of Akutan, Alaska
  10. 3.2 201 km SE of Akutan, Alaska
  11. 2.7 142 km SE of Akutan, Alaska
  12. 2.9 211 km SE of Akutan, Alaska
  13. 3.0 221 km SE of Akutan, Alaska
  14. 2.9 225 km SE of Akutan, Alaska
  15. 2.9 211 km SE of Akutan, 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 4.6 on 2018-04-19.

From the QuakeIndex catalogue, built from the USGS FDSN event service.

On USGS

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