QuakeIndex

Earthquake · reviewed by a seismologist

M 5.2mww

189 km SSE of Unalaska, Alaska

· 23 km deep · released about 950 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 5.2 (mww)
Depth
23 km below the surface
Felt
1 report · strongest reported intensity II
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 279 days ago

This was a moderate earthquake. Shaking at this size can damage poorly built structures close to the epicentre. 1 person has 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 52.2481, -165.6894. Map © OpenStreetMap contributors.

Aftershocks so far

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

  1. 2.6 185 km SSE of Unalaska, Alaska
  2. 2.9 south of the Aleutian Islands
  3. 2.9 south of the Aleutian Islands
  4. 2.1 198 km SSE of Unalaska, Alaska
  5. 2.6 south of the Aleutian Islands
  6. 1.7 179 km SSE of Unalaska, Alaska
  7. 2.4 195 km SSE of Unalaska, Alaska
  8. 2.3 208 km S of Unalaska, Alaska
  9. 3.1 196 km SSE of Unalaska, Alaska
  10. 2.5 179 km SSE of Unalaska, Alaska
  11. 2.8 192 km SSE of Unalaska, Alaska
  12. 2.9 197 km SSE of Unalaska, Alaska
  13. 2.3 194 km SSE of Unalaska, Alaska
  14. 3.0 199 km S of Unalaska, Alaska
  15. 2.4 189 km S of Unalaska, 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.

On USGS

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