QuakeIndex

Earthquake · reviewed by a seismologist

M 2.8ml

Earthquake near Susitna North, AK

No earthquake was likely felt in Susitna North in the 24 hours to 10:43 am AKST (19:43 UTC). The last one was M 3.6, 19 km (12 mi) E, at 9:16 am AKDT on 27 October 2026, estimated intensity II (weak) in town; 17 felt reports to USGS. Every earthquake near Susitna North

This page: a magnitude 2.8 earthquake was recorded 42 km (26 mi) northeast of Susitna North, AK, at 6:30 am AKDT on 18 September 2019 (14:30 UTC), 52 km deep.

USGS: 38 km E of Chase, Alaska

6:30 am AKDT, Sep 18, 2019 · · 52 km deep · released about 480 lb of TNT

10 km30 km60 km120 km N Matanuska-Susitna Borough 22 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
6:30 am AKDT on 18 September 2019 ()
Where
42 km (26 mi) northeast of Susitna North, AK · earthquakes near Susitna North
Magnitude
M 2.8 (ml)
Depth
52 km below the surface
Felt
no reports yet
Nearest
Matanuska-Susitna Borough, 22 km SSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2529 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. In Susitna North, 42 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.

How big was it?

This earthquake released about 480 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.8 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 32,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 22,000× the energy of this one
  3. Around the size people start to feel M 3.0 2× the energy of this one
  4. This earthquake M 2.8 about 480 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 4.6 on 2016-04-26 — about 500 times the energy of this one.

Before 2016, the USGS record lists 5 earthquakes of M5 or more within 50 km:

  1. 5.8 37 km ENE of Susitna North, Alaska · 20 km SSE of this epicentre
  2. 5.4 54 km NE of Chase, Alaska · 45 km N of this epicentre
  3. 5.1 25 km ENE of Susitna North, Alaska · 23 km S of this epicentre
  4. 5.1 49 km NE of Chase, Alaska · 40 km NNW of this epicentre
  5. 5.0 70 km ENE of Chase, Alaska · 38 km NE 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 62.4554, -149.3529. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Matanuska-Susitna Borough, AK 22 km (14 mi) SSW earthquakes near Matanuska-Susitna Borough

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

Aftershocks so far

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

  1. 1.5 40 km NNE of Chase, Alaska
  2. 2.2 53 km NE of Susitna North, Alaska
  3. 1.5 55 km ENE of Susitna North, Alaska
  4. 1.8 22 km ESE of Susitna North, Alaska
  5. 1.6 29 km NE of Chase, Alaska
  6. 1.5 29 km ESE of Susitna North, Alaska
  7. 1.7 33 km NNE of Chase, Alaska
  8. 2.9 39 km NNE of Chase, Alaska
  9. 1.5 5 km ENE of Susitna North, Alaska
  10. 1.5 60 km NE of Chase, Alaska
  11. 1.7 65 km S of Cantwell, Alaska
  12. 1.6 42 km NNE of Chase, Alaska
  13. 1.9 64 km NE of Chase, Alaska
  14. 1.7 44 km N of Sutton-Alpine, Alaska
  15. 2.5 30 km NE of Susitna North, 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.