QuakeIndex

Earthquake · reviewed by a seismologist

M 2.5ml

Earthquake near Sterling, AK

No earthquake was likely felt in Sterling in the 24 hours to 7:48 am AKST (16:48 UTC). The last one was M 2.5, 22 km (13 mi) NNE, at 9:11 pm AKST on 11 November 2026, estimated intensity II (weak) in town; 1 felt report to USGS. Every earthquake near Sterling

This page: a magnitude 2.5 earthquake was recorded 27 km (17 mi) north-northeast of Sterling, AK, at 11:53 pm AKDT on 5 August 2021 (07:53 UTC), 56 km deep.

USGS: 21 km SSE of Point Possession, Alaska

62 km (39 mi) SSW of Anchorage, AK

11:53 pm AKDT, Aug 5, 2021 · · 56 km deep · released about 170 lb of TNT

Every earthquake near Sterling Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Anchorage Municipality 82 kmKenai Peninsula Borough 107 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
11:53 pm AKDT on 5 August 2021 ()
Where
27 km (17 mi) north-northeast of Sterling, AK · earthquakes near Sterling
Magnitude
M 2.5 (ml)
Depth
56 km below the surface
Felt
no reports yet
Nearest
Anchorage Municipality, 82 km NE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1847 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 Sterling, 27 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.

How big was it?

This earthquake released about 170 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.5 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 89,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 63,000× the energy of this one
  3. Around the size people start to feel M 3.0 5.6× the energy of this one
  4. This earthquake M 2.5 about 170 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 4.4 on 2017-11-17 — about 710 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. 6.8 24 km ENE of Sterling, Alaska · 13 km SSE of this epicentre
  2. 6.7 6 km WNW of Nikiski, Alaska · 48 km W of this epicentre
  3. 6.4 19 km SSE of Tyonek, Alaska · 33 km WNW of this epicentre
  4. 5.7 19 km NNW of Nikiski, Alaska · 48 km WNW of this epicentre
  5. 5.5 26 km SSW of Anchorage, Alaska · 36 km NE 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 60.7470, -150.5195. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Anchorage Municipality, AK 82 km (51 mi) NE earthquakes near Anchorage Municipality
Kenai Peninsula Borough, AK 107 km (67 mi) WSW earthquakes near Kenai Peninsula Borough

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

Aftershocks so far

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

  1. 2.0 7 km W of Funny River, Alaska
  2. 1.5 11 km SE of Point Possession, Alaska
  3. 1.8 7 km NNE of Sterling, Alaska
  4. 1.8 3 km ESE of Ridgeway, Alaska
  5. 1.7 25 km SW of Anchorage, Alaska
  6. 2.2 23 km E of Beluga, Alaska
  7. 1.5 6 km SSW of Point Possession, Alaska
  8. 1.5 7 km WNW of Point Possession, Alaska
  9. 1.7 14 km E of Point Possession, Alaska
  10. 1.5 31 km NW of Cooper Landing, Alaska
  11. 2.0 1 km N of Funny River, Alaska
  12. 2.0 19 km ESE of Funny River, Alaska
  13. 2.2 7 km SE of Point Possession, Alaska
  14. 1.5 11 km N of Point Possession, Alaska
  15. 1.5 15 km ESE of Tyonek, 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.