QuakeIndex

Earthquake · reviewed by a seismologist

M 4.0ml

Earthquake near Sterling, AK

No earthquake was likely felt in Sterling in the 24 hours to 6:17 am AKST (15:17 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 4.0 earthquake was recorded 40 km (25 mi) northeast of Sterling, AK, at 1:27 pm AKST on 21 November 2016 (22:27 UTC), 50 km deep. 22 people have reported feeling it to USGS.

USGS: 31 km ESE of Point Possession, Alaska

52 km (32 mi) SSW of Anchorage, AK

1:27 pm AKST, Nov 21, 2016 · · 50 km deep · released about 15 tons of TNT

Every earthquake near Sterling Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Anchorage Municipality 67 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
1:27 pm AKST on 21 November 2016 ()
Where
40 km (25 mi) northeast of Sterling, AK · earthquakes near Sterling
Magnitude
M 4.0 (ml)
Depth
50 km below the surface
Felt
22 reports · strongest reported intensity IV
Measured shaking
intensity III (ShakeMap)
USGS impact alert
green
Tsunami
USGS flagged this event for tsunami evaluation. Follow tsunami.gov for official messages.
Nearest
Anchorage Municipality, 67 km NE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1198 days ago

This was a light earthquake. It is usually felt clearly nearby and can rattle windows and dishes, but damage is uncommon.

At this magnitude and depth, people at rest would likely notice it out to about 83 km (52 mi) from the epicentre. In Sterling, 40 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: Sterling 40 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 15 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 5.0 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 11,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 500× the energy of this one
  3. Magna, Utah 2020 M 5.7 350× the energy of this one
  4. This earthquake M 4.0 about 15 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 32× 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 4.2 on 2016-02-15 — about 2 times the energy of this one.

Before 2016, the USGS record lists 7 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.8 24 km ENE of Sterling, Alaska · 17 km SW of this epicentre
  2. 6.4 19 km SSE of Tyonek, Alaska · 48 km WNW of this epicentre
  3. 5.5 26 km SSW of Anchorage, Alaska · 27 km N of this epicentre
  4. 5.4 19 km NE of Nikiski, Alaska · 45 km W of this epicentre
  5. 5.2 19 km E of Point Possession, Alaska · 22 km NNW 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 60.7706, -150.1984. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Anchorage Municipality, AK 67 km (41 mi) NE earthquakes near Anchorage Municipality
Kenai Peninsula Borough, AK 124 km (77 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. 2.2 16 km WSW of Anchorage, Alaska
  2. 1.6 19 km ESE of Point Possession, Alaska
  3. 1.5 32 km SE of Point Possession, Alaska
  4. 1.5 9 km ESE of Point Possession, Alaska
  5. 1.5 20 km SE of Funny River, Alaska
  6. 1.5 17 km ENE of Point Possession, Alaska
  7. 1.7 18 km WSW of Anchorage, Alaska
  8. 2.8 13 km WSW of Hope, Alaska
  9. 1.5 23 km ENE of Point Possession, Alaska
  10. 1.5 24 km SW of Hope, Alaska
  11. 1.9 18 km N of Cooper Landing, Alaska
  12. 1.8 12 km E of Sterling, Alaska
  13. 1.8 28 km ENE of Point Possession, Alaska
  14. 1.5 9 km ESE of Point Possession, Alaska
  15. 1.6 11 km NE of Sterling, 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.