Earthquake · reviewed by a seismologist
M 2.1ml
Earthquake near Anchorage, AK
No earthquake was likely felt in Anchorage in the 24 hours to 5:50 am AKST (14:50 UTC). The last one was M 3.5, 39 km (24 mi) SSW, at 4:48 pm AKDT on 27 October 2026, estimated intensity II (weak) in town; 98 felt reports to USGS. Every earthquake near Anchorage
This page: a magnitude 2.1 earthquake was recorded 27 km (17 mi) west-northwest of Anchorage, AK, at 10:11 am AKDT on 10 August 2017 (18:11 UTC), 43 km deep. 1 person has reported feeling it to USGS.
USGS: 23 km WSW of Point MacKenzie, Alaska
27 km (17 mi) WNW of Anchorage, AK
- When
- 10:11 am AKDT on 10 August 2017 ()
- Where
- 27 km (17 mi) west-northwest of Anchorage, AK · earthquakes near Anchorage
- Magnitude
- M 2.1 (ml)
- Depth
- 43 km below the surface
- Felt
- 1 report · strongest reported intensity I
- Nearest
- Anchorage Municipality, 60 km ESE
- Nearest mapped fault
- Castle Mountain fault, 21 km from its surface trace — near is not the same as on
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 1192 days ago
Earthquake alerts for Anchorage, AK
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This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.
At this magnitude and depth it was probably too small to be felt, even directly above it. In Anchorage, 27 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 43 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.1 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 350,000× the energy of this one
- Magna, Utah 2020 M 5.7 250,000× the energy of this one
- Around the size people start to feel M 3.0 22× the energy of this one
- This earthquake M 2.1 about 43 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 2016-02-15 — about 1,400 times the energy of this one.
Before 2016, the USGS record lists 26 earthquakes of M5 or more within 50 km; the five largest:
- 6.8 Southern Alaska · 45 km WSW of this epicentre
- 6.8 4 km NE of Beluga, Alaska · 36 km WSW of this epicentre
- 5.8 27 km N of Beluga, Alaska · 37 km WNW of this epicentre
- 5.8 20 km ENE of Beluga, Alaska · 21 km WSW of this epicentre
- 5.6 11 km NW of Big Lake, Alaska · 36 km NNE 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 61.2844, -150.3819. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Anchorage Municipality, AK | 60 km (37 mi) | ESE | earthquakes near Anchorage Municipality |
| Matanuska-Susitna Borough, AK | 118 km (74 mi) | NNE | earthquakes near Matanuska-Susitna Borough |
| Kenai Peninsula Borough, AK | 147 km (91 mi) | SW | earthquakes near Kenai Peninsula Borough |
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.
- 2.0 15 km ESE of Susitna, Alaska
- 1.6 7 km NNE of Point MacKenzie, Alaska
- 1.5 27 km E of Point Possession, Alaska
- 2.4 22 km N of Point Possession, Alaska
- 2.2 21 km SSW of Susitna, Alaska
- 1.7 12 km SE of Point Possession, Alaska
- 2.1 12 km NNE of Point Possession, Alaska
- 1.6 Southern Alaska
- 1.5 14 km SSW of Anchorage, Alaska
- 1.8 12 km WSW of Susitna, Alaska
- 2.3 6 km WSW of Point Possession, Alaska
- 1.7 10 km SW of Point MacKenzie, Alaska
- 2.3 12 km SE of Point Possession, Alaska
- 2.7 21 km SSE of Susitna, Alaska
- 1.5 5 km S of Big Lake, 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.