Earthquake · reviewed by a seismologist
M 4.2mb
197 km SW of Nikolski, Alaska
- When
- Magnitude
- M 4.2 (mb)
- Depth
- 21 km below the surface
- Felt
- no reports yet
- Measured shaking
- intensity III (ShakeMap)
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 88 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 51.8512, -171.1561. Map © OpenStreetMap contributors.
Aftershocks so far
53 earthquakes have been recorded within 50 km since this one.
- 3.5 158 km SW of Nikolski, Alaska
- 3.9 166 km WSW of Nikolski, Alaska
- 3.6 167 km WSW of Nikolski, Alaska
- 2.9 170 km WSW of Nikolski, Alaska
- 3.3 172 km SW of Nikolski, Alaska
- 3.2 169 km WSW of Nikolski, Alaska
- 4.0 166 km SW of Nikolski, Alaska
- 2.8 171 km WSW of Nikolski, Alaska
- 3.8 171 km WSW of Nikolski, Alaska
- 3.1 172 km WSW of Nikolski, Alaska
- 3.0 168 km SW of Nikolski, Alaska
- 3.2 178 km E of Atka, Alaska
- 2.7 168 km SW of Nikolski, Alaska
- 3.2 172 km WSW of Nikolski, Alaska
- 2.6 202 km ESE of Atka, 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 6.0 on 2024-05-19 — it released about 500 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.