Earthquake · reviewed by a seismologist
M 2.7md
96km W of Petrolia, CA
Yes. A magnitude 2.7 earthquake was recorded 96km W of Petrolia, CA, at 1:07 am PDT on 24 July 2018 (08:07 UTC), 24 km deep. 1 person has reported feeling it to USGS.
- When
- Magnitude
- M 2.7 (md)
- Depth
- 24 km below the surface
- Felt
- 1 report · strongest reported intensity III
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 3032 days ago
Earthquake alerts for Ferndale, CA
Get a notification in this browser when USGS records an earthquake near Ferndale, CA. No account or email needed.
Alerts are on for .
Not a warning. An alert comes after USGS publishes a quake, usually minutes after the shaking. For early warning use ShakeAlert, through your phone's Wireless Emergency Alerts or the MyShake app.
This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage.
At this magnitude and depth, people at rest would likely notice it out to about 9 km (6 mi) from the epicentre. Estimated from magnitude, depth and distance with the intensity equation USGS Did You Feel It? uses; felt reports, where there are any, are the measurement.
How big was it?
This earthquake released about 380 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.7 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 40,000× the energy of this one
- Magna, Utah 2020 M 5.7 29,000× the energy of this one
- Around the size people start to feel M 3.0 2.5× the energy of this one
- This earthquake M 2.7 about 380 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 5.6 on 2016-09-03 — about 23,000 times the energy of this one.
Before 2016, the USGS record lists 5 earthquakes of M5 or more within 50 km:
- 5.9 61 km WSW of Ferndale, California · 38 km E of this epicentre
- 5.5 54 km WSW of Ferndale, California · 50 km E of this epicentre
- 5.5 60 km WSW of Ferndale, California · 41 km E of this epicentre
- 5.3 62 km WSW of Ferndale, California · 45 km ESE of this epicentre
- 5.0 65 km WSW of Ferndale, California · 35 km E 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 40.4012, -125.4082. Map © OpenStreetMap contributors.
Aftershocks so far
56 earthquakes have been recorded within 50 km since this one.
- 2.6 72km W of Petrolia, CA
- 2.5 65km W of Petrolia, CA
- 2.5 63km W of Petrolia, CA
- 2.4 54km W of Petrolia, CA
- 3.3 115km W of Petrolia, CA
- 2.9 51km W of Ferndale, CA
- 2.5 55km W of Petrolia, CA
- 2.7 83km W of Petrolia, CA
- 3.1 63km W of Petrolia, CA
- 2.5 65km W of Petrolia, CA
- 2.5 56km W of Petrolia, CA
- 2.7 68km W of Petrolia, CA
- 2.6 76km WSW of Petrolia, CA
- 2.9 78km W of Petrolia, CA
- 2.9 112km W 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.
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.