QuakeIndex

Earthquake · reviewed by a seismologist

M 3.1ml

Earthquake near Willow, AK

No earthquake was likely felt in Willow in the 24 hours to 1:48 am AKST (10:48 UTC). The last one was M 2.8, 20 km (12 mi) S, at 6:17 am AKST on 6 November 2026, estimated intensity II (weak) in town; 3 felt reports to USGS. Every earthquake near Willow

This page: a magnitude 3.1 earthquake was recorded 12 km (7 mi) east of Willow, AK, at 5:16 pm AKDT on 1 November 2017 (01:16 UTC), 45 km deep. 5 people have reported feeling it to USGS.

USGS: 11 km E of Willow, Alaska

59 km (37 mi) N of Anchorage, AK

5:16 pm AKDT, Nov 1, 2017 · · 45 km deep · released about 1,300 lb of TNT

Every earthquake near Willow Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Matanuska-Susitna Borough 60 kmAnchorage Municipality 70 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
5:16 pm AKDT on 1 November 2017 ()
Where
12 km (7 mi) east of Willow, AK · earthquakes near Willow
Magnitude
M 3.1 (ml)
Depth
45 km below the surface
Felt
5 reports · strongest reported intensity III
Nearest
Matanuska-Susitna Borough, 60 km NNE
Nearest mapped fault
Castle Mountain fault, 10 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 1191 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 Willow, 12 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: Houston, Meadow Lakes, Tanaina, Big Lake, Wasilla, Knik-Fairview.

How big was it?

This earthquake released about 1,300 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.1 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 250,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 11,000× the energy of this one
  3. Magna, Utah 2020 M 5.7 7,900× the energy of this one
  4. This earthquake M 3.1 about 1,300 lb of TNT
  5. Around the size people start to feel M 3.0 this one released 1.4× 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 4.3 on 2017-08-21 — about 63 times the energy of this one.

Before 2016, the USGS record lists 16 earthquakes of M5 or more within 50 km; the five largest:

  1. 5.9 23 km NE of Willow, Alaska · 18 km NNE of this epicentre
  2. 5.8 14 km NNE of Fishhook, Alaska · 39 km ENE of this epicentre
  3. 5.6 11 km NW of Big Lake, Alaska · 25 km SW of this epicentre
  4. 5.6 5 km N of Susitna, Alaska · 40 km WSW of this epicentre
  5. 5.5 2 km ENE of Eagle River, Alaska · 49 km SSE 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 61.7473, -149.8139. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Matanuska-Susitna Borough, AK 60 km (37 mi) NNE earthquakes near Matanuska-Susitna Borough
Anchorage Municipality, AK 70 km (43 mi) SSE 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. 1.5 11 km W of Houston, Alaska
  2. 2.0 5 km W of Big Lake, Alaska
  3. 1.8 5 km SSE of Big Lake, Alaska
  4. 1.5 5 km SSW of Point MacKenzie, Alaska
  5. 1.9 20 km N of Meadow Lakes, Alaska
  6. 1.8 16 km NNE of Willow, Alaska
  7. 2.0 21 km SSW of Susitna North, Alaska
  8. 2.3 4 km S of Houston, Alaska
  9. 1.5 7 km SSE of Willow, Alaska
  10. 1.5 4 km NW of Tanaina, Alaska
  11. 3.1 5 km SSW of Houston, Alaska
  12. 2.4 5 km WSW of Big Lake, Alaska
  13. 1.9 3 km SSE of Houston, Alaska
  14. 1.7 20 km WNW of Fishhook, Alaska
  15. 1.9 16 km NW of Fishhook, 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.