Earthquake · reviewed by a seismologist
M 1.5ml
28 km N of Beluga, Alaska
Yes. A magnitude 1.5 earthquake was recorded 28 km N of Beluga, Alaska, 70 km (43 mi) WNW of Anchorage, AK, at 12:39 pm AKDT on 2 September 2018 (20:39 UTC), 5.8 km deep.
70 km (43 mi) WNW of Anchorage, AK
- When
- Magnitude
- M 1.5 (ml)
- Depth
- 5.8 km below the surface
- Felt
- no reports yet
- Nearest
- Anchorage Municipality, 103 km ESE
- Nearest mapped fault
- Castle Mountain fault, 9 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 1185 days ago
Earthquake alerts for Willow, 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 8 km (5 mi) from the epicentre. 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 5.4 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.5 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 2,800,000× the energy of this one
- Magna, Utah 2020 M 5.7 2,000,000× the energy of this one
- Around the size people start to feel M 3.0 180× the energy of this one
- This earthquake M 1.5 about 5.4 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 2016-02-28 — about 16,000 times the energy of this one.
Before 2016, the USGS record lists 21 earthquakes of M5 or more within 50 km; the five largest:
- 6.9 27 km SE of Skwentna, Alaska · 47 km N of this epicentre
- 6.8 Southern Alaska · 33 km S of this epicentre
- 6.8 4 km NE of Beluga, Alaska · 25 km SSE of this epicentre
- 6.0 Southern Alaska · 34 km SW of this epicentre
- 5.8 17 km NW of Beluga, Alaska · 21 km SSW 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 61.3901, -151.1554. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Anchorage Municipality, AK | 103 km (64 mi) | ESE | earthquakes near Anchorage Municipality |
| Kenai Peninsula Borough, AK | 130 km (81 mi) | SSW | earthquakes near Kenai Peninsula Borough |
| Matanuska-Susitna Borough, AK | 130 km (81 mi) | NE | earthquakes near Matanuska-Susitna Borough |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
55 earthquakes have been recorded within 50 km since this one.
- 1.9 30 km WSW of Susitna, Alaska
- 1.7 23 km W of Susitna, Alaska
- 1.5 22 km WNW of Susitna, Alaska
- 2.2 22 km WNW of Susitna, Alaska
- 1.5 29 km SSE of Skwentna, Alaska
- 1.7 33 km NNW of Beluga, Alaska
- 1.9 14 km NE of Beluga, Alaska
- 2.0 Southern Alaska
- 1.8 42 km S of Skwentna, Alaska
- 1.5 22 km NNE of Beluga, Alaska
- 1.7 22 km NNW of Susitna, Alaska
- 1.7 12 km SE of Tyonek, Alaska
- 1.6 21 km NW of Susitna, Alaska
- 1.7 21 km SSE of Skwentna, Alaska
- 1.8 33 km W of Susitna, 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.