Earthquake · reviewed by a seismologist
M 2.5md
Earthquake near Larkfield-Wikiup, CA
No earthquake was likely felt in Larkfield-Wikiup in the 24 hours to 8:47 am PST (16:47 UTC). The last one was M 1.9, 8 km (5 mi) ESE, at 2:01 pm PDT on 23 October 2026, estimated intensity II (weak) in town. Every earthquake near Larkfield-Wikiup
This page: a magnitude 2.5 earthquake was recorded 3 km (2 mi) north-northwest of Larkfield-Wikiup, CA, at 11:12 pm PDT on 21 July 2018 (06:12 UTC), 5.3 km deep. 134 people have reported feeling it to USGS.
USGS: 3km NNW of Larkfield-Wikiup, CA
12 km (7 mi) NNW of Santa Rosa, CA
- When
- 11:12 pm PDT on 21 July 2018 ()
- Where
- 3 km (2 mi) north-northwest of Larkfield-Wikiup, CA · earthquakes near Larkfield-Wikiup
- Magnitude
- M 2.5 (md)
- Depth
- 5.3 km below the surface
- Felt
- 134 reports · strongest reported intensity III
- Nearest
- Sonoma County, 14 km W
- Nearest mapped fault
- Rodgers Creek fault, 1 km from its surface trace — near is not the same as on
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 3031 days ago
Earthquake alerts for Larkfield-Wikiup, CA
Get a notification in this browser when USGS records an earthquake near Larkfield-Wikiup, 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 22 km (14 mi) from the epicentre. In Larkfield-Wikiup, 3 km away, the estimate is intensity III (weak). 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.
Likely felt in: Windsor 5 km, intensity III · Santa Rosa 12 km, intensity II · Healdsburg 12 km, intensity II · Calistoga 17 km, intensity II. Estimated for each town centre; each link is that town's own record.
How big was it?
This earthquake released about 200 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.5 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 75,000× the energy of this one
- Magna, Utah 2020 M 5.7 53,000× the energy of this one
- Around the size people start to feel M 3.0 4.7× the energy of this one
- This earthquake M 2.5 about 200 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 5.0 on 2016-12-14 — about 4,900 times the energy of this one.
Before 2016, the USGS record lists 2 earthquakes of M5 or more within 50 km:
- 5.3 3 km E of Bloomfield, California · 25 km S of this epicentre
- 5.3 Northern California · 25 km SSW 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 38.5387, -122.7657. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Sonoma County, CA | 14 km (9 mi) | W | earthquakes near Sonoma County |
| Napa County, CA | 38 km (24 mi) | E | earthquakes near Napa County |
| Marin County, CA | 54 km (34 mi) | S | earthquakes near Marin County |
| Lake County, CA | 63 km (39 mi) | N | earthquakes near Lake County |
| Yolo County, CA | 77 km (48 mi) | ENE | earthquakes near Yolo County |
| Solano County, CA | 78 km (49 mi) | ESE | earthquakes near Solano County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
60 earthquakes have been recorded within 50 km since this one.
- 1.8 4km S of Anderson Springs, CA
- 1.6 6km NW of The Geysers, CA
- 1.9 11km WNW of The Geysers, CA
- 1.6 3km NNW of The Geysers, CA
- 3.3 3km NW of The Geysers, CA
- 1.9 10km WNW of The Geysers, CA
- 2.6 3km SE of The Geysers, CA
- 1.5 5km W of Cobb, CA
- 1.6 3km SSW of Anderson Springs, CA
- 1.9 7km WNW of The Geysers, CA
- 1.7 9km WNW of The Geysers, CA
- 1.8 4km WNW of The Geysers, CA
- 1.6 8km NW of The Geysers, CA
- 2.0 3km W of Cobb, CA
- 1.7 4km ENE of Graton, 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.