QuakeIndex

Earthquake · reviewed by a seismologist

M 5.6mw

50 km ENE of Pedro Bay, Alaska

· 143 km deep · released about 3.8 kilotons of TNT

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10 km30 km60 km120 km N Kenai Peninsula Borough 69 km
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 5.6 (mw)
Depth
143 km below the surface
Felt
599 reports · strongest reported intensity IV
Measured shaking
intensity IV (ShakeMap)
USGS impact alert
green
Tsunami
USGS flagged this event for tsunami evaluation. Follow tsunami.gov for official messages.
Nearest
Kenai Peninsula Borough, 69 km NE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1137 days ago

This was a moderate earthquake. Shaking at this size can damage poorly built structures close to the epicentre. 599 people have reported feeling it to USGS.

How big was it?

This earthquake released about 3.8 kilotons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 6.6 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 45× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 2× the energy of this one
  3. Magna, Utah 2020 M 5.7 1.4× the energy of this one
  4. This earthquake M 5.6 about 3.8 kilotons of TNT
  5. Around the size people start to feel M 3.0 this one released 7,900× 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 59.9550, -153.2658. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Kenai Peninsula Borough, AK 69 km (43 mi) SW of here earthquakes near Kenai Peninsula Borough

Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.

Aftershocks so far

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

  1. 1.9 52 km E of Pedro Bay, Alaska
  2. 2.4 53 km ENE of Pedro Bay, Alaska
  3. 2.7 53 km WSW of Anchor Point, Alaska
  4. 2.1 70 km WNW of Happy Valley, Alaska
  5. 1.9 39 km ENE of Pedro Bay, Alaska
  6. 1.8 55 km E of Pedro Bay, Alaska
  7. 2.0 35 km E of Pedro Bay, Alaska
  8. 1.8 62 km W of Anchor Point, Alaska
  9. 2.7 Southern Alaska
  10. 1.9 67 km E of Port Alsworth, Alaska
  11. 1.8 58 km WNW of Happy Valley, Alaska
  12. 2.0 68 km E of Port Alsworth, Alaska
  13. 2.2 50 km ESE of Port Alsworth, Alaska
  14. 1.9 66 km W of Happy Valley, Alaska
  15. 2.0 56 km ENE of Pedro Bay, 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 7.1 on 2016-01-24 — it released about 180 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.