Earthquake · reviewed by a seismologist
M 4.0mw
19 km N of Girdwood, Alaska
- When
- Magnitude
- M 4.0 (mw)
- Depth
- 38 km below the surface
- Felt
- 305 reports · strongest reported intensity IV
- Tsunami
- USGS flagged this event for tsunami evaluation. Follow tsunami.gov for official messages.
- Nearest
- Anchorage Municipality, 10 km NW
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 1152 days ago
This was a light earthquake. It is usually felt clearly nearby and can rattle windows and dishes, but damage is uncommon. 305 people have reported feeling it to USGS.
How big was it?
This earthquake released about 15 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 5.0 would have released about 32 times as much.
- Northridge, California 1994 M 6.7 11,000× the energy of this one
- Mineral, Virginia 2011 M 5.8 500× the energy of this one
- Magna, Utah 2020 M 5.7 350× the energy of this one
- This earthquake M 4.0 about 15 tons of TNT
- Around the size people start to feel M 3.0 this one released 32× more
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.
Where
Epicentre 61.1186, -149.1495. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction | |
|---|---|---|---|
| Anchorage Municipality, AK | 10 km (6 mi) | SE of here | earthquakes near Anchorage Municipality |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
59 earthquakes have been recorded within 50 km since this one.
- 2.4 7 km NNE of Hope, Alaska
- 2.0 8 km NW of Eagle River, Alaska
- 1.5 1 km N of Eagle River, Alaska
- 1.6 3 km NNE of Girdwood, Alaska
- 1.5 13 km S of Hope, Alaska
- 1.6 6 km ESE of Knik River, Alaska
- 1.6 34 km NE of Girdwood, Alaska
- 1.6 9 km W of Whittier, Alaska
- 1.8 12 km SW of Whittier, Alaska
- 1.6 16 km ESE of Elmendorf Air Force Base, Alaska
- 2.0 2 km SE of Elmendorf Air Force Base, Alaska
- 1.6 4 km NE of Hope, Alaska
- 1.7 Southern Alaska
- 1.6 5 km SSW of Hope, Alaska
- 1.8 22 km NNE of Girdwood, 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.