Earthquake · reviewed by a seismologist
M 4.2ml
109 km SE of Perryville, Alaska
- When
- Magnitude
- M 4.2 (ml)
- Depth
- 29 km below the surface
- Felt
- no reports yet
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 2017 days ago
This was a light earthquake. It is usually felt clearly nearby and can rattle windows and dishes, but damage is uncommon.
How big was it?
This earthquake released about 30 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 5.2 would have released about 32 times as much.
- Northridge, California 1994 M 6.7 5,600× the energy of this one
- Mineral, Virginia 2011 M 5.8 250× the energy of this one
- Magna, Utah 2020 M 5.7 180× the energy of this one
- This earthquake M 4.2 about 30 tons of TNT
- Around the size people start to feel M 3.0 this one released 63× 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 55.2222, -157.8975. Map © OpenStreetMap contributors.
Aftershocks so far
59 earthquakes have been recorded within 50 km since this one.
- 3.2 Alaska Peninsula
- 3.8 122 km SSE of Perryville, Alaska
- 2.8 157 km SE of Perryville, Alaska
- 3.0 119 km SSE of Perryville, Alaska
- 4.5 154 km SE of Perryville, Alaska
- 3.2 106 km SSE of Perryville, Alaska
- 3.4 116 km SSE of Perryville, Alaska
- 3.2 94 km SSE of Perryville, Alaska
- 3.7 113 km SSE of Perryville, Alaska
- 2.5 62 km SE of Perryville, Alaska
- 4.8 135 km SE of Perryville, Alaska
- 4.5 142 km SE of Perryville, Alaska
- 4.5 136 km SE of Perryville, Alaska
- 4.2 91 km SSE of Chignik, Alaska
- 3.9 118 km SE of Perryville, 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.
For this area
The largest earthquake within 50 km in our catalogue was M 5.7 on 2016-05-31 — it released about 180 times the energy of this one.
From the QuakeIndex catalogue, built from the USGS FDSN event service.
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.