Earthquake · reviewed by a seismologist
M 3.3ml
Earthquake near Cordova, AK
No earthquake was likely felt in Cordova in the 24 hours to 5:52 am AKST (14:52 UTC). The last one was M 3.1, 39 km (24 mi) SSW, at 7:37 pm AKDT on 28 June 2026, estimated intensity II (weak) in town; 3 felt reports to USGS. Every earthquake near Cordova
This page: a magnitude 3.3 earthquake was recorded 45 km (28 mi) south-southwest of Cordova, AK, at 3:32 pm AKDT on 28 April 2017 (23:32 UTC), 18 km deep.
USGS: 45 km SSW of Cordova, Alaska
- When
- 3:32 pm AKDT on 28 April 2017 ()
- Where
- 45 km (28 mi) south-southwest of Cordova, AK · earthquakes near Cordova
- Magnitude
- M 3.3 (ml)
- Depth
- 18 km below the surface
- Felt
- no reports yet
- Nearest
- Chugach Census Area, 32 km N
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 1194 days ago
Earthquake alerts for Cordova, 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 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 49 km (30 mi) from the epicentre. In Cordova, 45 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: Cordova 45 km, intensity II. Estimated for each town centre; each link is that town's own record.
How big was it?
This earthquake released about 1.3 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.3 would have released about 32 times as much.
- Northridge, California 1994 M 6.7 130,000× the energy of this one
- Mineral, Virginia 2011 M 5.8 5,600× the energy of this one
- Magna, Utah 2020 M 5.7 4,000× the energy of this one
- This earthquake M 3.3 about 1.3 tons of TNT
- Around the size people start to feel M 3.0 this one released 2.8× 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
No earthquake of M4 or more has been recorded within 50 km since our catalogue begins in 2016.
Before 2016, the USGS record lists 24 earthquakes of M5 or more within 50 km; the five largest:
- 6.3 60 km SW of Cordova, Alaska · 25 km W of this epicentre
- 6.3 56 km WSW of Cordova, Alaska · 31 km WNW of this epicentre
- 6.0 78 km S of Cordova, Alaska · 46 km SSE of this epicentre
- 6.0 67 km E of Chenega, Alaska · 42 km SW of this epicentre
- 5.8 66 km E of Chenega, Alaska · 34 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 60.2012, -146.2119. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Chugach Census Area, AK | 32 km (20 mi) | N | earthquakes near Chugach Census Area |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
52 earthquakes have been recorded within 50 km since this one.
- 2.5 60 km S of Cordova, Alaska
- 1.7 69 km SSW of Cordova, Alaska
- 1.6 69 km SSW of Cordova, Alaska
- 1.8 63 km SSW of Cordova, Alaska
- 1.9 69 km SW of Cordova, Alaska
- 2.3 79 km SSW of Cordova, Alaska
- 1.9 Southern Alaska
- 3.4 84 km SSW of Cordova, Alaska
- 2.5 31 km SSW of Cordova, Alaska
- 1.7 49 km WSW of Cordova, Alaska
- 1.5 35 km SSW of Cordova, Alaska
- 1.5 36 km S of Cordova, Alaska
- 2.1 36 km SSW of Cordova, Alaska
- 1.6 37 km S of Cordova, Alaska
- 4.9 36 km SSW of Cordova, 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.