Earthquake · reviewed by a seismologist
M 2.1md
Earthquake near Union City, CA
No earthquake was likely felt in Union City in the 24 hours to 2:19 pm PST (22:19 UTC). The last one was M 1.9, 9 km (6 mi) NNE, at 10:32 am PST on 2 November 2026, estimated intensity II (weak) in town. Every earthquake near Union City
This page: a magnitude 2.1 earthquake was recorded 4 km (2 mi) east-southeast of Union City, CA, at 1:27 pm PDT on 7 June 2026 (20:27 UTC), 8.1 km deep. 1 person has reported feeling it to USGS.
USGS: 4 km ESE of Union City, CA
in Union City, CA · 35 km (22 mi) NNW of San Jose, CA
- When
- 1:27 pm PDT on 7 June 2026 ()
- Where
- 4 km (2 mi) east-southeast of Union City, CA · earthquakes near Union City
- Magnitude
- M 2.1 (md)
- Depth
- 8.1 km below the surface
- Felt
- 1 report · strongest reported intensity I
- Nearest
- Alameda County, 9 km NE
- Nearest mapped fault
- Hayward fault, 2 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 150 days ago
Earthquake alerts for Union City, CA
Get a notification in this browser when USGS records an earthquake near Union City, 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 15 km (9 mi) from the epicentre. In Union City, 4 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: Fremont 4 km, intensity II · Union City 4 km, intensity II · Newark 8 km, intensity II · Pleasanton 13 km, intensity II · Hayward 13 km, intensity II · Dublin 14 km, intensity II. Estimated for each town centre; each link is that town's own record.
How big was it?
This earthquake released about 38 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.1 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 390,000× the energy of this one
- Magna, Utah 2020 M 5.7 280,000× the energy of this one
- Around the size people start to feel M 3.0 25× the energy of this one
- This earthquake M 2.1 about 38 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 5.1 on 2022-10-25 — about 31,000 times the energy of this one.
Before 2016, the USGS record lists 15 earthquakes of M5 or more within 50 km; the five largest:
- 6.2 Near San Jose, California · 35 km SSE of this epicentre
- 6.2 The 1984 Morgan Hill, California Earthquake · 40 km SE of this epicentre
- 6.1 Near San Jose, California · 45 km SSE of this epicentre
- 5.8 7 km NNW of Boulder Creek, California · 46 km SSW of this epicentre
- 5.8 The 1980 Livermore, California Earthquake · 34 km NNE 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 37.5802, -121.9783. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Alameda County, CA | 9 km (6 mi) | NE | earthquakes near Alameda County |
| Contra Costa County, CA | 38 km (23 mi) | N | earthquakes near Contra Costa County |
| San Mateo County, CA | 39 km (24 mi) | WSW | earthquakes near San Mateo County |
| Santa Clara County, CA | 47 km (29 mi) | SSE | earthquakes near Santa Clara County |
| Santa Cruz County, CA | 63 km (39 mi) | S | earthquakes near Santa Cruz County |
| San Joaquin County, CA | 74 km (46 mi) | ENE | earthquakes near San Joaquin County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
57 earthquakes have been recorded within 50 km since this one.
- 1.8 3 km NNE of Portola Valley, CA
- 1.7 6 km SSE of Portola Valley, CA
- 1.9 3 km NNE of Portola Valley, CA
- 2.5 2 km SE of Concord, CA
- 1.8 15 km E of Seven Trees, CA
- 1.6 1 km ENE of Hayward, CA
- 1.6 2 km WNW of Concord, CA
- 2.2 3 km NNE of San Leandro, CA
- 1.6 4 km NNE of San Leandro, CA
- 2.8 4 km N of San Leandro, CA
- 3.8 3 km N of San Leandro, CA
- 1.7 8 km WSW of Byron, CA
- 2.1 3 km NNE of San Leandro, CA
- 1.8 3 km SW of Clayton, CA
- 1.9 0 km SSW of Pleasant Hill, 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.