QuakeIndex

Earthquake · reviewed by a seismologist

M 2.9ml

60 km W of Anchor Point, Alaska

Yes. A magnitude 2.9 earthquake was recorded 60 km W of Anchor Point, Alaska, at 5:20 am AKDT on 8 August 2017 (13:20 UTC), 100 km deep. 1 person has reported feeling it to USGS.

· 100 km deep · released about 680 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Kenai Peninsula Borough 67 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 2.9 (ml)
Depth
100 km below the surface
Felt
1 report · strongest reported intensity II
Nearest
Kenai Peninsula Borough, 67 km NNE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1192 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage.

At this magnitude and depth it was probably too small to be felt, even directly above it. Estimated from magnitude, depth and distance with the intensity equation USGS Did You Feel It? uses; felt reports, where there are any, are the measurement.

How big was it?

This earthquake released about 680 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.9 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 22,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 16,000× the energy of this one
  3. Around the size people start to feel M 3.0 1.4× the energy of this one
  4. This earthquake M 2.9 about 680 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.

For this area

The largest earthquake within 50 km since 2016 was M 7.1 on 2016-01-24 — about 2,000,000 times the energy of this one.

Before 2016, the USGS record lists 27 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.4 75 km WNW of Ninilchik, Alaska · 49 km N of this epicentre
  2. 6.4 52 km ENE of Pedro Bay, Alaska · 17 km WNW of this epicentre
  3. 6.2 70 km E of Port Alsworth, Alaska · 35 km NNW of this epicentre
  4. 6.0 53 km W of Anchor Point, Alaska · 8 km ESE of this epicentre
  5. 5.9 66 km ENE of Pedro Bay, Alaska · 22 km NNW of this epicentre

Since 2016: the QuakeIndex catalogue (US, M1.5+), built from the USGS FDSN event service. Before 2016: USGS ComCat, M5+ from 1900. Distances are between epicentres. This is the record, not a forecast.

Where

Epicentre 59.8408, -152.9060. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Kenai Peninsula Borough, AK 67 km (42 mi) NNE earthquakes near Kenai Peninsula Borough

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

Aftershocks so far

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

  1. 1.7 53 km SE of Pedro Bay, Alaska
  2. 1.8 61 km WNW of Ninilchik, Alaska
  3. 1.7 45 km ENE of Pedro Bay, Alaska
  4. 1.6 53 km W of Anchor Point, Alaska
  5. 1.9 64 km W of Anchor Point, Alaska
  6. 1.6 67 km WNW of Ninilchik, Alaska
  7. 2.1 48 km W of Anchor Point, Alaska
  8. 1.6 37 km WNW of Nanwalek, Alaska
  9. 1.6 59 km ENE of Pedro Bay, Alaska
  10. 1.5 55 km E of Pedro Bay, Alaska
  11. 1.7 48 km WNW of Anchor Point, Alaska
  12. 1.6 64 km ENE of Pedro Bay, Alaska
  13. 1.7 36 km W of Happy Valley, Alaska
  14. 2.2 58 km W of Anchor Point, Alaska
  15. 1.6 47 km WNW of Nanwalek, 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.