Earthquake · reviewed by a seismologist
M 1.8md
Earthquake near Discovery Bay, CA
No earthquake was likely felt in Discovery Bay in the 24 hours to 11:24 am PST (19:24 UTC). The last one was M 3.5, 56 km (35 mi) SSE, at 7:21 am PDT on 27 September 2026, estimated intensity II (weak) in town; 8 felt reports to USGS. Every earthquake near Discovery Bay
This page: a magnitude 1.8 earthquake was recorded 2 km (1 mi) east-southeast of Discovery Bay, CA, at 1:44 am PDT on 22 June 2018 (08:44 UTC), 7.4 km deep.
USGS: 2km ESE of Discovery Bay, CA
13 km (8 mi) ESE of Brentwood, CA · 70 km (44 mi) NNE of San Jose, CA
- When
- 1:44 am PDT on 22 June 2018 ()
- Where
- 2 km (1 mi) east-southeast of Discovery Bay, CA · earthquakes near Discovery Bay
- Magnitude
- M 1.8 (md)
- Depth
- 7.4 km below the surface
- Felt
- no reports yet
- Nearest
- San Joaquin County, 27 km E
- Nearest mapped fault
- Greenville fault, 22 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 3054 days ago
Earthquake alerts for Discovery Bay, 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 11 km (7 mi) from the epicentre. In Discovery Bay, 2 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: Discovery Bay 2 km, intensity II · Brentwood 11 km, intensity II. Estimated for each town centre; each link is that town's own record.
How big was it?
This earthquake released about 14 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.8 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 1,100,000× the energy of this one
- Magna, Utah 2020 M 5.7 790,000× the energy of this one
- Around the size people start to feel M 3.0 70× the energy of this one
- This earthquake M 1.8 about 14 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
No earthquake of M4 or more has been recorded within 50 km since our catalogue begins in 2016.
Before 2016, the USGS record lists 4 earthquakes of M5 or more within 50 km:
- 5.8 The 1980 Livermore, California Earthquake · 18 km WSW of this epicentre
- 5.7 15 km NE of East Foothills, California · 48 km SSW of this epicentre
- 5.4 9 km NE of Livermore, California · 20 km SSW of this epicentre
- 5.1 11 km E of Blackhawk, California · 20 km WSW 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 37.8995, -121.5803. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| San Joaquin County, CA | 27 km (17 mi) | E | earthquakes near San Joaquin County |
| Contra Costa County, CA | 33 km (20 mi) | W | earthquakes near Contra Costa County |
| Alameda County, CA | 40 km (25 mi) | SW | earthquakes near Alameda County |
| Solano County, CA | 52 km (32 mi) | NW | earthquakes near Solano County |
| Stanislaus County, CA | 63 km (39 mi) | SE | earthquakes near Stanislaus County |
| Sacramento County, CA | 65 km (40 mi) | NNE | earthquakes near Sacramento County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
49 earthquakes have been recorded within 50 km since this one.
- 1.6 5km E of Fremont, CA
- 2.6 8km SE of Sunol, CA
- 2.3 3km E of Pacheco, CA
- 1.6 2km ESE of Pleasanton, CA
- 1.7 6km NE of Blackhawk, CA
- 1.6 6km WNW of Mountain House, CA
- 2.8 6km WNW of Mountain House, CA
- 1.5 16km SSE of Livermore, CA
- 1.6 2km W of Diablo, CA
- 1.8 2km NE of San Ramon, CA
- 2.0 14km N of Pittsburg, CA
- 2.2 1km NNW of Alamo, CA
- 1.6 2km SW of Diablo, CA
- 1.7 3km NW of Diablo, CA
- 2.3 16km SSE of Livermore, 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.