Earthquake · reviewed by a seismologist
M 1.5md
Earthquake near Larkfield-Wikiup, CA
No earthquake was likely felt in Larkfield-Wikiup in the 24 hours to 1:29 am PST (09:29 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 1.5 earthquake was recorded 3 km (2 mi) north-northwest of Larkfield-Wikiup, CA, at 3:50 pm PDT on 22 July 2018 (22:50 UTC), 5.2 km deep.
USGS: 2km NNW of Larkfield-Wikiup, CA
11 km (7 mi) NNW of Santa Rosa, CA
- When
- 3:50 pm PDT on 22 July 2018 ()
- Where
- 3 km (2 mi) north-northwest of Larkfield-Wikiup, CA · earthquakes near Larkfield-Wikiup
- Magnitude
- M 1.5 (md)
- Depth
- 5.2 km below the surface
- Felt
- no reports yet
- 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 3033 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 minor earthquake. Quakes this small are rarely felt and do not cause damage.
At this magnitude and depth, people at rest would likely notice it out to about 9 km (6 mi) from the epicentre. In Larkfield-Wikiup, 3 km away, the estimate is intensity II (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 II. Estimated for each town centre; each link is that town's own record.
How big was it?
This earthquake released about 5.7 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.5 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 2,600,000× the energy of this one
- Magna, Utah 2020 M 5.7 1,900,000× the energy of this one
- Around the size people start to feel M 3.0 170× the energy of this one
- This earthquake M 1.5 about 5.7 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 170,000 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 · 24 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 38.5347, -122.7608. 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 (33 mi) | S | earthquakes near Marin County |
| Lake County, CA | 64 km (40 mi) | N | earthquakes near Lake County |
| Yolo County, CA | 76 km (47 mi) | ENE | earthquakes near Yolo County |
| Solano County, CA | 77 km (48 mi) | ESE | earthquakes near Solano County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
58 earthquakes have been recorded within 50 km since this one.
- 2.8 4km SSW of Anderson Springs, CA
- 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
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.