QuakeIndex

Earthquake · automatic estimate, may change

M 3.4ml

23 km NW of Nanwalek, Alaska

· 78 km deep · released about 1.9 tons of TNT

10 km30 km60 km120 km N Kenai Peninsula Borough 95 km
Distance rings around the epicentre, with the nearest towns at their true direction. Not a shaking map — see the USGS ShakeMap for that.
When
Magnitude
M 3.4 (ml)
Depth
78 km below the surface
Felt
no reports yet
Nearest
Kenai Peninsula Borough, 95 km N
Status
Automatic — a machine’s first estimate, which may change

USGS · last changed by USGS · we first saw it 2 hours ago

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

How big was it?

This earthquake released about 1.9 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.4 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 89,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 4,000× the energy of this one
  3. Magna, Utah 2020 M 5.7 2,800× the energy of this one
  4. This earthquake M 3.4 about 1.9 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 4× 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 2,000 times the energy of this one.

Before 2016, the USGS record lists 9 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.4 25 km NW of Nanwalek, Alaska · 5 km WSW of this epicentre
  2. 6.0 53 km W of Anchor Point, Alaska · 46 km NW of this epicentre
  3. 5.9 Southern Alaska · 40 km WSW of this epicentre
  4. 5.5 6 km WNW of Nanwalek, Alaska · 19 km SSE of this epicentre
  5. 5.4 22 km ESE of Port Graham, Alaska · 50 km ESE 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 59.5140, -152.2020. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Kenai Peninsula Borough, AK 95 km (59 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

No further earthquakes have been recorded within 50 km since this one.

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.

Revisions

USGS refines a solution as more stations report. Every change we have seen is listed here.

What changedFromToWhen
location26 km NW of Nanwalek, Alaska23 km NW of Nanwalek, Alaska
longitude-152.25-152.2
latitude59.5359.51
depth79.177.9
magnitude3.33.4

On USGS

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