ice quake · reviewed by a seismologist
M 1.6ml
Earthquake near Girdwood, AK
No earthquake was likely felt in Girdwood in the 24 hours to 10:28 am AKST (19:28 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
No: USGS classifies this as a ice quake, not an earthquake. A magnitude 1.6 ice quake was recorded 41 km (26 mi) east-northeast of Girdwood, AK, at 1:01 pm AKDT on 9 October 2020 (21:01 UTC), less than 1 km deep.
USGS: 32 km NNE of Whittier, Alaska
81 km (51 mi) ESE of Anchorage, AK
- When
- 1:01 pm AKDT on 9 October 2020 ()
- Where
- 41 km (26 mi) east-northeast of Girdwood, AK · earthquakes near Girdwood
- Magnitude
- M 1.6 (ml)
- Depth
- 0.0 km below the surface
- Felt
- no reports yet
- Nearest
- Anchorage Municipality, 48 km WNW
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 2221 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 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 11 km (7 mi) from the epicentre. In Girdwood, 41 km away, the estimate is intensity I (not felt). 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.
USGS catalogues this as ice quake, not an earthquake.
How big was it?
This earthquake released about 7.6 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.6 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 2,000,000× the energy of this one
- Magna, Utah 2020 M 5.7 1,400,000× the energy of this one
- Around the size people start to feel M 3.0 130× the energy of this one
- This earthquake M 1.6 about 7.6 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
No earthquake of M4 or more has been recorded within 50 km since our catalogue begins in 2016.
Before 2016, the USGS record lists 13 earthquakes of M5 or more within 50 km; the five largest:
- 6.6 57 km ENE of Whittier, Alaska · 36 km E of this epicentre
- 6.4 22 km ENE of Whittier, Alaska · 21 km SSE of this epicentre
- 6.3 27 km ENE of Whittier, Alaska · 19 km SSE of this epicentre
- 6.1 54 km WNW of Tatitlek, Alaska · 46 km E of this epicentre
- 6.0 21 km N of Whittier, Alaska · 16 km WSW 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 61.0365, -148.4292. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Anchorage Municipality, AK | 48 km (30 mi) | WNW | earthquakes near Anchorage Municipality |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
56 earthquakes have been recorded within 50 km since this one.
- 2.1 40 km NE of Whittier, Alaska
- 1.6 20 km ENE of Girdwood, Alaska
- 2.7 40 km NE of Whittier, Alaska
- 2.5 26 km SE of Whittier, Alaska
- 2.7 37 km ESE of Whittier, Alaska
- 2.3 34 km NNE of Whittier, Alaska
- 1.6 39 km ENE of Whittier, Alaska
- 1.9 36 km NE of Girdwood, Alaska
- 1.9 32 km NNE of Whittier, Alaska
- 2.1 40 km SSE of Knik River, Alaska
- 1.5 35 km NNE of Whittier, Alaska
- 1.9 16 km SSW of Whittier, Alaska
- 1.5 34 km NNE of Whittier, Alaska
- 1.8 37 km NNE of Whittier, Alaska
- 1.6 40 km NNE of Whittier, 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.