Earthquake · reviewed by a seismologist
M 2.8ml
Earthquake near Girdwood, AK
No earthquake was likely felt in Girdwood in the 24 hours to 7:12 am AKST (16:12 UTC). The last one was M 1.8, 8 km (5 mi) SE, at 10:01 am AKDT on 19 October 2026, estimated intensity II (weak) in town. Every earthquake near Girdwood
This page: a magnitude 2.8 earthquake was recorded 42 km (26 mi) south-southeast of Girdwood, AK, at 8:54 pm AKST on 24 February 2021 (05:54 UTC), 34 km deep.
USGS: 16 km S of Whittier, Alaska
91 km (56 mi) SE of Anchorage, AK
- When
- 8:54 pm AKST on 24 February 2021 ()
- Where
- 42 km (26 mi) south-southeast of Girdwood, AK · earthquakes near Girdwood
- Magnitude
- M 2.8 (ml)
- Depth
- 34 km below the surface
- Felt
- no reports yet
- Nearest
- Anchorage Municipality, 68 km NNW
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 2019 days ago
Earthquake alerts for Girdwood, 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 it was probably too small to be felt, even directly above it. In Girdwood, 42 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 480 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.8 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 32,000× the energy of this one
- Magna, Utah 2020 M 5.7 22,000× the energy of this one
- Around the size people start to feel M 3.0 2× the energy of this one
- This earthquake M 2.8 about 480 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 4.2 on 2020-06-18 — about 130 times the energy of this one.
Before 2016, the USGS record lists 7 earthquakes of M5 or more within 50 km; the five largest:
- 6.4 22 km ENE of Whittier, Alaska · 35 km NE of this epicentre
- 6.3 27 km ENE of Whittier, Alaska · 40 km NE of this epicentre
- 6.0 21 km N of Whittier, Alaska · 39 km N of this epicentre
- 5.8 29 km NW of Chenega, Alaska · 46 km SSE of this epicentre
- 5.7 13 km S of Girdwood, Alaska · 32 km NW 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 60.6257, -148.7424. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Anchorage Municipality, AK | 68 km (42 mi) | NNW | earthquakes near Anchorage Municipality |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
50 earthquakes have been recorded within 50 km since this one.
- 1.7 4 km SSW of Girdwood, Alaska
- 1.6 19 km SSW of Whittier, Alaska
- 1.5 10 km SSW of Girdwood, Alaska
- 1.5 37 km NNW of Chenega, Alaska
- 1.5 26 km SSE of Whittier, Alaska
- 1.6 14 km ENE of Girdwood, Alaska
- 1.6 35 km ESE of Primrose, Alaska
- 1.6 17 km SW of Whittier, Alaska
- 1.7 7 km NE of Girdwood, Alaska
- 1.5 7 km ESE of Sunrise, Alaska
- 2.4 25 km SSE of Whittier, Alaska
- 2.2 24 km SSE of Whittier, Alaska
- 1.5 41 km NW of Chenega, Alaska
- 2.5 22 km SSE of Whittier, Alaska
- 1.5 Kenai Peninsula, 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.