QuakeIndex

Earthquake · reviewed by a seismologist

M 1.7ml

Earthquake near Fishhook, AK

No earthquake was likely felt in Fishhook in the 24 hours to 10:55 am AKST (19:55 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 1.7 earthquake was recorded 24 km (15 mi) northwest of Fishhook, AK, at 5:19 am AKDT on 20 July 2021 (13:19 UTC), 28 km deep.

USGS: 24 km NW of Fishhook, Alaska

77 km (48 mi) NNE of Anchorage, AK

5:19 am AKDT, Jul 20, 2021 · · 28 km deep · released about 11 lb of TNT

Every earthquake near Fishhook Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Matanuska-Susitna Borough 42 kmAnchorage Municipality 81 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
5:19 am AKDT on 20 July 2021 ()
Where
24 km (15 mi) northwest of Fishhook, AK · earthquakes near Fishhook
Magnitude
M 1.7 (ml)
Depth
28 km below the surface
Felt
no reports yet
Nearest
Matanuska-Susitna Borough, 42 km N
Nearest mapped fault
Castle Mountain fault, 22 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 1831 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 Fishhook, 24 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: Willow, Meadow Lakes.

How big was it?

This earthquake released about 11 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.7 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,400,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,000,000× the energy of this one
  3. Around the size people start to feel M 3.0 89× the energy of this one
  4. This earthquake M 1.7 about 11 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 5.1 on 2020-11-07 — about 130,000 times the energy of this one.

Before 2016, the USGS record lists 11 earthquakes of M5 or more within 50 km; the five largest:

  1. 5.9 23 km NE of Willow, Alaska · 9 km WNW of this epicentre
  2. 5.8 37 km ENE of Susitna North, Alaska · 49 km NNE of this epicentre
  3. 5.8 14 km NNE of Fishhook, Alaska · 25 km E of this epicentre
  4. 5.6 11 km NW of Big Lake, Alaska · 45 km SW of this epicentre
  5. 5.4 25 km NNW of Willow, Alaska · 31 km WNW 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 61.8935, -149.5736. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Matanuska-Susitna Borough, AK 42 km (26 mi) N earthquakes near Matanuska-Susitna Borough
Anchorage Municipality, AK 81 km (51 mi) S earthquakes near Anchorage Municipality

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

Aftershocks so far

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

  1. 1.5 15 km S of Susitna North, Alaska
  2. 1.6 11 km NE of Willow, Alaska
  3. 2.1 5 km WNW of Fishhook, Alaska
  4. 1.6 17 km ENE of Willow, Alaska
  5. 2.7 6 km WSW of Meadow Lakes, Alaska
  6. 2.3 22 km ESE of Susitna North, Alaska
  7. 1.8 9 km NNW of Big Lake, Alaska
  8. 1.5 11 km S of Willow, Alaska
  9. 1.8 6 km SSW of Willow, Alaska
  10. 1.6 12 km N of Fishhook, Alaska
  11. 1.8 15 km WNW of Fishhook, Alaska
  12. 1.9 11 km NNE of Meadow Lakes, Alaska
  13. 1.5 14 km ESE of Susitna North, Alaska
  14. 2.9 11 km SSE of Susitna North, Alaska
  15. 1.6 Southern 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.