QuakeIndex

Earthquake · reviewed by a seismologist

M 1.6ml

Earthquake near Fishhook, AK

No earthquake was likely felt in Fishhook in the 24 hours to 5:32 am AKST (14:32 UTC). The last one was M 4.4, 118 km (73 mi) E, at 11:11 am AKDT on 30 October 2026, estimated intensity II (weak) in town; 54 felt reports to USGS. Every earthquake near Fishhook

This page: a magnitude 1.6 earthquake was recorded 16 km (10 mi) north-northwest of Fishhook, AK, at 5:43 am AKDT on 21 March 2023 (13:43 UTC), 7.0 km deep.

USGS: 15 km NNW of Fishhook, Alaska

80 km (50 mi) NNE of Anchorage, AK

5:43 am AKDT, Mar 21, 2023 · · 7.0 km deep · released about 7.6 lb of TNT

Every earthquake near Fishhook Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Matanuska-Susitna Borough 44 kmAnchorage Municipality 79 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
5:43 am AKDT on 21 March 2023 ()
Where
16 km (10 mi) north-northwest of Fishhook, AK · earthquakes near Fishhook
Magnitude
M 1.6 (ml)
Depth
7.0 km below the surface
Felt
no reports yet
Nearest
Matanuska-Susitna Borough, 44 km NNW
Nearest mapped fault
Castle Mountain fault, 18 km from its surface trace — near is not the same as on
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1327 days ago

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

At this magnitude and depth, people at rest would likely notice it out to about 9 km (6 mi) from the epicentre. In Fishhook, 16 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.

Earthquakes near other towns within 30 km: Farm Loop, Sutton-Alpine, Tanaina.

How big was it?

This earthquake released about 7.6 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.6 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 2,000,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,400,000× the energy of this one
  3. Around the size people start to feel M 3.0 130× the energy of this one
  4. This earthquake M 1.6 about 7.6 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 4.5 on 2023-01-16 — about 22,000 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. 5.9 23 km NE of Willow, Alaska · 23 km W of this epicentre
  2. 5.8 37 km ENE of Susitna North, Alaska · 46 km N of this epicentre
  3. 5.8 14 km NNE of Fishhook, Alaska · 11 km ESE of this epicentre
  4. 5.4 25 km NNW of Willow, Alaska · 45 km WNW of this epicentre
  5. 5.3 3 km NNE of Houston, Alaska · 35 km SW 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 61.8818, -149.2991. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Matanuska-Susitna Borough, AK 44 km (27 mi) NNW earthquakes near Matanuska-Susitna Borough
Anchorage Municipality, AK 79 km (49 mi) S earthquakes near Anchorage Municipality

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. 3.7 Central Alaska
  2. 1.6 13 km NNW of Fishhook, Alaska
  3. 1.9 18 km ESE of Susitna North, Alaska
  4. 1.5 47 km E of Susitna North, Alaska
  5. 1.7 7 km SSE of Houston, Alaska
  6. 2.4 14 km NNE of Susitna North, Alaska
  7. 2.1 26 km SSE of Susitna North, Alaska
  8. 1.5 13 km NNE of Susitna North, Alaska
  9. 1.5 8 km NNW of Meadow Lakes, Alaska
  10. 1.8 Central Alaska
  11. 1.7 14 km N of Meadow Lakes, Alaska
  12. 2.4 3 km N of Knik, Alaska
  13. 1.7 10 km NNW of Fishhook, Alaska
  14. 1.7 9 km E of Lazy Mountain, Alaska
  15. 1.7 13 km SSE 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.