QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8ml

Earthquake near Susitna North, AK

No earthquake was likely felt in Susitna North in the 24 hours to 11:22 am AKST (20:22 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 1.8 earthquake was recorded 29 km (18 mi) southeast of Susitna North, AK, at 4:42 am AKST on 17 February 2020 (13:42 UTC), 39 km deep.

USGS: 29 km SE of Susitna North, Alaska

90 km (56 mi) NNE of Anchorage, AK

4:42 am AKST, Feb 17, 2020 · · 39 km deep · released about 15 lb of TNT

Every earthquake near Susitna North Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Matanuska-Susitna Borough 30 kmAnchorage Municipality 92 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
4:42 am AKST on 17 February 2020 ()
Where
29 km (18 mi) southeast of Susitna North, AK · earthquakes near Susitna North
Magnitude
M 1.8 (ml)
Depth
39 km below the surface
Felt
no reports yet
Nearest
Matanuska-Susitna Borough, 30 km N
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2446 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

At this magnitude and depth it was probably too small to be felt, even directly above it. In Susitna North, 29 km away, the estimate is intensity I (not felt). 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.

Earthquakes near other towns within 30 km: Fishhook.

How big was it?

This earthquake released about 15 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.8 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,000,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 710,000× the energy of this one
  3. Around the size people start to feel M 3.0 63× the energy of this one
  4. This earthquake M 1.8 about 15 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 4.3 on 2017-08-21 — about 5,600 times the energy of this one.

Before 2016, the USGS record lists 8 earthquakes of M5 or more within 50 km; the five largest:

  1. 5.9 23 km NE of Willow, Alaska · 20 km WSW of this epicentre
  2. 5.8 37 km ENE of Susitna North, Alaska · 35 km NNE of this epicentre
  3. 5.8 14 km NNE of Fishhook, Alaska · 22 km SE of this epicentre
  4. 5.4 25 km NNW of Willow, Alaska · 38 km W of this epicentre
  5. 5.3 3 km NNE of Houston, Alaska · 42 km SSW 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 61.9957, -149.4110. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Matanuska-Susitna Borough, AK 30 km (19 mi) N earthquakes near Matanuska-Susitna Borough
Anchorage Municipality, AK 92 km (57 mi) S earthquakes near Anchorage Municipality

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 5 km NW of Houston, Alaska
  2. 1.6 20 km N of Meadow Lakes, Alaska
  3. 1.7 14 km S of Susitna North, Alaska
  4. 1.6 31 km ESE of Susitna North, Alaska
  5. 1.9 3 km N of Lakes, Alaska
  6. 2.4 8 km NW of Houston, Alaska
  7. 1.6 27 km SE of Susitna North, Alaska
  8. 2.3 32 km NNW of Sutton-Alpine, Alaska
  9. 2.2 11 km E of Willow, Alaska
  10. 1.5 22 km N of Fishhook, Alaska
  11. 1.9 15 km W of Fishhook, Alaska
  12. 1.5 2 km SE of Houston, Alaska
  13. 1.7 20 km NW of Fishhook, Alaska
  14. 1.9 3 km WSW of Houston, Alaska
  15. 2.1 3 km NNW of Houston, 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.