Earthquake · automatic estimate, may change
M 3.0ml
63 km SE of Port Graham, Alaska
- When
- Magnitude
- M 3.0 (ml)
- Depth
- 55 km below the surface
- Felt
- no reports yet
- Status
- Automatic — a machine’s first estimate, which may change
USGS · last changed by USGS · we first saw it 2 hours ago
This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage.
How big was it?
This earthquake released about 950 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.0 would have released about 32 times as much.
- Northridge, California 1994 M 6.7 350,000× the energy of this one
- Mineral, Virginia 2011 M 5.8 16,000× the energy of this one
- Magna, Utah 2020 M 5.7 11,000× the energy of this one
- This earthquake M 3.0 about 950 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 4.7 on 2023-02-24 — about 350 times the energy of this one.
Before 2016, the USGS record lists 4 earthquakes of M5 or more within 50 km:
- 5.7 78 km SSE of Port Graham, Alaska · 25 km SSW of this epicentre
- 5.7 30 km ESE of Port Graham, Alaska · 35 km NW of this epicentre
- 5.4 22 km ESE of Port Graham, Alaska · 42 km NW of this epicentre
- 5.0 49 km SE of Port Graham, Alaska · 18 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 58.9770, -150.9940. Map © OpenStreetMap contributors.
Aftershocks so far
No further earthquakes have been recorded within 50 km since this one.
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.
Revisions
USGS refines a solution as more stations report. Every change we have seen is listed here.
| What changed | From | To | When |
|---|---|---|---|
| magnitude | 2.9 | 3 | |
| location | 61 km SE of Port Graham, Alaska | 63 km SE of Port Graham, Alaska | |
| longitude | -151.01 | -150.99 | |
| latitude | 58.99 | 58.98 | |
| depth | 56.6 | 54.5 |
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.