QuakeIndex

Earthquake · reviewed by a seismologist

M 3.8ml

Earthquake near Knik-Fairview, AK

No earthquake was likely felt in Knik-Fairview in the 24 hours to 5:13 am AKST (14:13 UTC). The last one was M 2.1, 7 km (4 mi) NW, at 8:17 am AKST on 11 November 2026, estimated intensity II (weak) in town; 1 felt report to USGS. Every earthquake near Knik-Fairview

This page: a magnitude 3.8 earthquake was recorded 9 km (5 mi) east-southeast of Knik-Fairview, AK, at 8:24 am AKST on 8 March 2023 (17:24 UTC), 45 km deep. 252 people have reported feeling it to USGS.

USGS: 8 km ESE of Knik-Fairview, Alaska

38 km (24 mi) NE of Anchorage, AK

8:24 am AKST, Mar 8, 2023 · · 45 km deep · released about 7.6 tons of TNT

Every earthquake near Knik-Fairview Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Anchorage Municipality 36 kmMatanuska-Susitna Borough 87 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
8:24 am AKST on 8 March 2023 ()
Where
9 km (5 mi) east-southeast of Knik-Fairview, AK · earthquakes near Knik-Fairview
Magnitude
M 3.8 (ml)
Depth
45 km below the surface
Felt
252 reports · strongest reported intensity III
Measured shaking
intensity III (ShakeMap)
USGS impact alert
green
Nearest
Anchorage Municipality, 36 km SSE
Nearest mapped fault
Castle Mountain fault, 20 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 1278 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, people at rest would likely notice it out to about 69 km (43 mi) from the epicentre. In Knik-Fairview, 9 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.

Likely felt in: Knik-Fairview 9 km, intensity II · Tanaina 16 km, intensity II · Eagle River 19 km, intensity II · Palmer 22 km, intensity II · Butte 23 km, intensity II · Big Lake 27 km, intensity II · Fishhook 31 km, intensity II · Lazy Mountain 31 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 7.6 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.8 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 22,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 1,000× the energy of this one
  3. Magna, Utah 2020 M 5.7 710× the energy of this one
  4. This earthquake M 3.8 about 7.6 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 16× 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 7.1 on 2018-11-30 — about 89,000 times the energy of this one.

Before 2016, the USGS record lists 15 earthquakes of M5 or more within 50 km; the five largest:

  1. 5.9 23 km NE of Willow, Alaska · 50 km NNW of this epicentre
  2. 5.8 14 km NNE of Fishhook, Alaska · 45 km NNE of this epicentre
  3. 5.6 11 km NW of Big Lake, Alaska · 37 km WNW of this epicentre
  4. 5.5 2 km ENE of Eagle River, Alaska · 18 km SSW of this epicentre
  5. 5.5 9 km E of Susitna, Alaska · 48 km W 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 61.4849, -149.4493. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Anchorage Municipality, AK 36 km (22 mi) SSE earthquakes near Anchorage Municipality
Matanuska-Susitna Borough, AK 87 km (54 mi) N earthquakes near Matanuska-Susitna Borough

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

Aftershocks so far

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

  1. 2.2 Southern Alaska
  2. 1.5 Southern Alaska
  3. 1.7 10 km NNW of Fishhook, Alaska
  4. 2.5 7 km N of Houston, Alaska
  5. 1.6 14 km NW of Fishhook, Alaska
  6. 1.8 15 km N of Meadow Lakes, Alaska
  7. 1.5 Southern Alaska
  8. 1.8 Southern Alaska
  9. 1.6 3 km SE of Big Lake, Alaska
  10. 1.9 Southern Alaska
  11. 2.1 18 km N of Hope, Alaska
  12. 1.9 6 km SSW of Meadow Lakes, Alaska
  13. 3.3 4 km S of Lazy Mountain, Alaska
  14. 1.9 2 km SSW of Big Lake, Alaska
  15. 1.5 4 km ESE of Big Lake, 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.