QuakeIndex

Earthquake · reviewed by a seismologist

M 4.3mw

Earthquake near Anchor Point, AK

No earthquake was likely felt in Anchor Point in the 24 hours to 7:31 am AKST (16:31 UTC). The last one was M 4.3, 69 km (43 mi) NE, at 2:30 am AKST on 1 November 2026, estimated intensity II (weak) in town; 115 felt reports to USGS. Every earthquake near Anchor Point

This page: a magnitude 4.3 earthquake was recorded 29 km (18 mi) southwest of Anchor Point, AK, at 1:15 pm AKDT on 30 September 2017 (21:15 UTC), 84 km deep. 7 people have reported feeling it to USGS.

USGS: 28 km SW of Anchor Point, Alaska

1:15 pm AKDT, Sep 30, 2017 · · 84 km deep · released about 43 tons of TNT

Every earthquake near Anchor Point Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Kenai Peninsula Borough 83 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
1:15 pm AKDT on 30 September 2017 ()
Where
29 km (18 mi) southwest of Anchor Point, AK · earthquakes near Anchor Point
Magnitude
M 4.3 (mw)
Depth
84 km below the surface
Felt
7 reports · strongest reported intensity III
Tsunami
USGS flagged this event for tsunami evaluation. Follow tsunami.gov for official messages.
Nearest
Kenai Peninsula Borough, 83 km N
Status
Reviewed by a seismologist

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

This was a light earthquake. It is usually felt clearly nearby and can rattle windows and dishes, but damage is uncommon.

At this magnitude and depth, people at rest would likely notice it out to about 88 km (55 mi) from the epicentre. In Anchor Point, 29 km away, the estimate is intensity II (weak). 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.

Likely felt in: Anchor Point 29 km, intensity II · Diamond Ridge 39 km, intensity II · Homer 39 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 43 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 5.3 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 4,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 180× the energy of this one
  3. Magna, Utah 2020 M 5.7 130× the energy of this one
  4. This earthquake M 4.3 about 43 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 89× 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.

For this area

The largest earthquake within 50 km since 2016 was M 5.6 on 2017-03-02 — about 89 times the energy of this one.

Before 2016, the USGS record lists 10 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.4 25 km NW of Nanwalek, Alaska · 14 km S of this epicentre
  2. 6.2 16 km WNW of Happy Valley, Alaska · 44 km NNE of this epicentre
  3. 6.0 53 km W of Anchor Point, Alaska · 36 km NW of this epicentre
  4. 5.9 Southern Alaska · 42 km WSW of this epicentre
  5. 5.8 23 km WNW of Happy Valley, Alaska · 44 km N 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 59.6210, -152.2422. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Kenai Peninsula Borough, AK 83 km (52 mi) N earthquakes near Kenai Peninsula Borough

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

Aftershocks so far

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

  1. 1.6 45 km W of Anchor Point, Alaska
  2. 1.6 40 km NW of Nanwalek, Alaska
  3. 1.6 50 km WNW of Anchor Point, Alaska
  4. 2.5 25 km W of Anchor Point, Alaska
  5. 2.1 27 km SW of Anchor Point, Alaska
  6. 1.9 4 km N of Anchor Point, Alaska
  7. 1.8 7 km W of Seldovia, Alaska
  8. 1.5 50 km WNW of Anchor Point, Alaska
  9. 2.0 47 km WNW of Nanwalek, Alaska
  10. 1.7 23 km SSW of Anchor Point, Alaska
  11. 1.5 36 km WNW of Nanwalek, Alaska
  12. 1.6 39 km W of Nanwalek, Alaska
  13. 1.5 22 km WSW of Anchor Point, Alaska
  14. 1.7 24 km WSW of Anchor Point, Alaska
  15. 1.9 47 km WNW of Anchor Point, 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.