Earthquake · reviewed by a seismologist
M 4.2mw
118 km WNW of Petrolia, CA
- When
- Magnitude
- M 4.2 (mw)
- Depth
- 10 km below the surface
- Felt
- 3 reports · strongest reported intensity III
- Measured shaking
- intensity II (ShakeMap)
- USGS impact alert
- green
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 278 days ago
This was a light earthquake. It is usually felt clearly nearby and can rattle windows and dishes, but damage is uncommon. 3 people have reported feeling it to USGS.
How big was it?
This earthquake released about 25 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 6,700× the energy of this one
- Mineral, Virginia 2011 M 5.8 300× the energy of this one
- Magna, Utah 2020 M 5.7 210× the energy of this one
- This earthquake M 4.2 about 25 tons of TNT
- Around the size people start to feel M 3.0 this one released 53× 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 40.3715, -125.6760. Map © OpenStreetMap contributors.
Aftershocks so far
60 earthquakes have been recorded within 50 km since this one.
- 2.9 86 km WNW of Petrolia, CA
- 2.5 135 km W of Ferndale, California
- 3.0 77 km WNW of Petrolia, CA
- 3.0 130 km WNW of Petrolia, CA
- 3.2 155 km W of Ferndale, California
- 2.7 156 km W of Ferndale, California
- 2.7 154 km W of Ferndale, California
- 2.5 152 km WSW of Ferndale, California
- 2.8 163 km W of Ferndale, California
- 2.5 140 km W of Ferndale, California
- 2.7 135 km WNW of Petrolia, CA
- 3.0 86 km WNW of Petrolia, CA
- 2.7 125 km WNW of Petrolia, CA
- 2.7 161 km W of Ferndale, California
- 3.7 77 km WNW of Petrolia, CA
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 6.6 on 2016-12-08 — it released about 4,700 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.