Earthquake · reviewed by a seismologist
M 1.9md
Earthquake near Rio Vista, CA
No earthquake was likely felt in Rio Vista in the 24 hours to 8:48 pm PST (04:48 UTC). The last one was M 3.1, 35 km (22 mi) SSW, at 12:25 am PDT on 12 September 2026, estimated intensity II (weak) in town; 257 felt reports to USGS. Every earthquake near Rio Vista
This page: a magnitude 1.9 earthquake was recorded 13 km (8 mi) west of Rio Vista, CA, at 4:53 pm PDT on 22 April 2020 (23:53 UTC), 21 km deep.
USGS: 14km W of Rio Vista, CA
66 km (41 mi) NE of San Francisco, CA · 17 km (10 mi) NNE of Pittsburg, CA
- When
- 4:53 pm PDT on 22 April 2020 ()
- Where
- 13 km (8 mi) west of Rio Vista, CA · earthquakes near Rio Vista
- Magnitude
- M 1.9 (md)
- Depth
- 21 km below the surface
- Felt
- no reports yet
- Nearest
- Solano County, 14 km NW
- Nearest mapped fault
- Great Valley thrust fault system, 17 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 2311 days ago
Earthquake alerts for Rio Vista, CA
Get a notification in this browser when USGS records an earthquake near Rio Vista, 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 it was probably too small to be felt, even directly above it. In Rio Vista, 13 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.
Earthquakes near other towns within 30 km: Pittsburg, Antioch, Bay Point, Suisun, Fairfield, Oakley.
How big was it?
This earthquake released about 24 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.9 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 640,000× the energy of this one
- Magna, Utah 2020 M 5.7 450,000× the energy of this one
- Around the size people start to feel M 3.0 40× the energy of this one
- This earthquake M 1.9 about 24 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 6,200 times the energy of this one.
Before 2016, the USGS record lists 5 earthquakes of M5 or more within 50 km:
- 6.0 The 2014 South Napa, California Earthquake · 41 km W of this epicentre
- 5.8 The 1980 Livermore, California Earthquake · 36 km S of this epicentre
- 5.4 South of Elmira, California · 16 km NNW of this epicentre
- 5.4 9 km NE of Livermore, California · 48 km SSE of this epicentre
- 5.1 11 km E of Blackhawk, California · 39 km S 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 38.1615, -121.8468. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Solano County, CA | 14 km (9 mi) | NW | earthquakes near Solano County |
| Contra Costa County, CA | 28 km (18 mi) | SSW | earthquakes near Contra Costa County |
| Sacramento County, CA | 54 km (34 mi) | NE | earthquakes near Sacramento County |
| San Joaquin County, CA | 56 km (35 mi) | ESE | earthquakes near San Joaquin County |
| Napa County, CA | 57 km (35 mi) | NW | earthquakes near Napa County |
| Alameda County, CA | 57 km (36 mi) | S | earthquakes near Alameda County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
54 earthquakes have been recorded within 50 km since this one.
- 1.6 3km ENE of Oakland, CA
- 1.6 8km WSW of Mountain House, CA
- 2.2 3km ENE of Walnut Creek, CA
- 2.0 8km WSW of Mountain House, CA
- 1.8 2km N of Danville, CA
- 2.7 2km SSE of Crockett, CA
- 1.7 9km WSW of Mountain House, CA
- 2.3 2km NE of El Cerrito, CA
- 1.7 9km WSW of Mountain House, CA
- 1.5 9km WSW of Mountain House, CA
- 1.6 8km WSW of Mountain House, CA
- 1.6 15km ENE of Yountville, CA
- 1.9 13km ENE of Yountville, CA
- 2.6 6km SW of Clayton, CA
- 2.5 6km NE of Alamo, 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.