Earthquake · reviewed by a seismologist
M 1.5md
Earthquake near Green Valley, CA
No earthquake was likely felt in Green Valley in the 24 hours to 11:02 pm PST (07:02 UTC). The last one was M 1.8, 13 km (8 mi) S, at 11:09 am PST on 4 November 2026, estimated intensity II (weak) in town. Every earthquake near Green Valley
This page: a magnitude 1.5 earthquake was recorded in Green Valley, CA, at 11:21 am PDT on 20 June 2023 (18:21 UTC), 9.7 km deep. 1 person has reported feeling it to USGS.
USGS: 1km S of Green Valley, CA
11 km (7 mi) W of Fairfield, CA · 56 km (35 mi) NNE of San Francisco, CA
- When
- 11:21 am PDT on 20 June 2023 ()
- Where
- in Green Valley, CA · earthquakes near Green Valley
- Magnitude
- M 1.5 (md)
- Depth
- 9.7 km below the surface
- Felt
- 1 report · strongest reported intensity II
- Nearest
- Solano County, 20 km E
- Nearest mapped fault
- Green Valley fault, under 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 1240 days ago
Earthquake alerts for Green Valley, CA
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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 3 km (2 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.
Earthquakes near other towns within 30 km: Fairfield, Suisun, American Canyon, Napa, Vallejo, Vacaville.
How big was it?
This earthquake released about 5.4 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 2,800,000× the energy of this one
- Magna, Utah 2020 M 5.7 2,000,000× the energy of this one
- Around the size people start to feel M 3.0 180× the energy of this one
- This earthquake M 1.5 about 5.4 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 4.5 on 2019-10-15 — about 28,000 times the energy of this one.
Before 2016, the USGS record lists 2 earthquakes of M5 or more within 50 km:
- 6.0 The 2014 South Napa, California Earthquake · 14 km WSW of this epicentre
- 5.4 South of Elmira, California · 24 km ENE 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 38.2452, -122.1620. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Solano County, CA | 20 km (12 mi) | E | earthquakes near Solano County |
| Napa County, CA | 32 km (20 mi) | NNW | earthquakes near Napa County |
| Contra Costa County, CA | 41 km (25 mi) | SSE | earthquakes near Contra Costa County |
| Yolo County, CA | 53 km (33 mi) | NNE | earthquakes near Yolo County |
| Marin County, CA | 55 km (34 mi) | WSW | earthquakes near Marin County |
| Alameda County, CA | 70 km (43 mi) | SSE | earthquakes near Alameda County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
38 earthquakes have been recorded within 50 km since this one.
- 2.5 3 km NNW of Piedmont, CA
- 1.6 11 km ENE of Yountville, CA
- 1.8 6 km ESE of Santa Venetia, CA
- 1.5 6 km NNE of Orinda, CA
- 1.8 11 km E of Yountville, CA
- 2.2 1 km NW of Green Valley, CA
- 2.4 4 km W of Glen Ellen, CA
- 1.6 7 km WNW of Yountville, CA
- 1.8 3 km WNW of Boyes Hot Springs, CA
- 2.3 8 km ENE of Kenwood, CA
- 1.8 6 km NE of Kenwood, CA
- 2.2 2 km NW of Concord, CA
- 1.8 10 km ESE of Black Point-Green Point, CA
- 1.8 1 km ENE of Pittsburg, CA
- 1.8 3 km WNW of Concord, 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.