Earthquake · reviewed by a seismologist
M 2.4ml
Earthquake near Valdez, AK
No earthquake was likely felt in Valdez in the 24 hours to 9:32 am AKST (18:32 UTC). The last one was M 4.4, 85 km (53 mi) NNW, at 11:11 am AKDT on 30 October 2026, estimated intensity II (weak) in town; 54 felt reports to USGS. Every earthquake near Valdez
This page: a magnitude 2.4 earthquake was recorded 31 km (19 mi) northwest of Valdez, AK, at 2:28 am AKDT on 21 September 2020 (10:28 UTC), 20 km deep.
USGS: 30 km NW of Valdez, Alaska
- When
- 2:28 am AKDT on 21 September 2020 ()
- Where
- 31 km (19 mi) northwest of Valdez, AK · earthquakes near Valdez
- Magnitude
- M 2.4 (ml)
- Depth
- 20 km below the surface
- Felt
- no reports yet
- Nearest
- Chugach Census Area, 96 km SSE
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 2176 days ago
Earthquake alerts for Valdez, AK
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Alerts are on for .
Not a warning. An alert comes after USGS publishes a quake, usually minutes after the shaking. For early warning use ShakeAlert, through your phone's Wireless Emergency Alerts or the MyShake app.
This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.
At this magnitude and depth, people at rest would likely notice it out to about 7 km (4 mi) from the epicentre. In Valdez, 31 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 120 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.4 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 130,000× the energy of this one
- Magna, Utah 2020 M 5.7 89,000× the energy of this one
- Around the size people start to feel M 3.0 7.9× the energy of this one
- This earthquake M 2.4 about 120 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 4.3 on 2018-10-16 — about 710 times the energy of this one.
Before 2016, the USGS record lists 16 earthquakes of M5 or more within 50 km; the five largest:
- 6.6 37 km WNW of Tatitlek, Alaska · 39 km SW of this epicentre
- 6.4 37 km SSE of Glacier View, Alaska · 39 km NW of this epicentre
- 6.1 54 km WNW of Tatitlek, Alaska · 48 km WSW of this epicentre
- 6.0 Near Valdez, Alaska · 44 km SE of this epicentre
- 5.9 42 km S of Glacier View, Alaska · 44 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 61.2964, -146.8051. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Chugach Census Area, AK | 96 km (59 mi) | SSE | earthquakes near Chugach Census Area |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
60 earthquakes have been recorded within 50 km since this one.
- 1.5 44 km N of Valdez, Alaska
- 1.6 43 km NNW of Valdez, Alaska
- 1.7 39 km SSE of Nelchina, Alaska
- 2.2 50 km SSE of Glacier View, Alaska
- 2.3 24 km WNW of Tatitlek, Alaska
- 1.9 48 km SSE of Nelchina, Alaska
- 2.3 43 km NNW of Valdez, Alaska
- 3.1 44 km SSE of Nelchina, Alaska
- 1.6 46 km N of Valdez, Alaska
- 1.6 44 km N of Valdez, Alaska
- 1.6 42 km SSE of Nelchina, Alaska
- 1.5 47 km WNW of Valdez, Alaska
- 2.0 11 km W of Tatitlek, Alaska
- 2.3 25 km NW of Valdez, Alaska
- 1.6 47 km NNW of Valdez, 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
- The official USGS event page — the source of record for every value above
- Did you feel it? Report it to USGS — reports go to USGS, not to us
- ShakeMap for this event, when USGS has produced one
QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.