Earthquake · reviewed by a seismologist
M 1.5md
Earthquake near Diablo, CA
No earthquake was likely felt in Diablo in the 24 hours to 3:21 am PST (11:21 UTC). The last one was M 2.5, 18 km (11 mi) NNW, at 1:23 am PST on 2 November 2026, estimated intensity II (weak) in town; 39 felt reports to USGS. Every earthquake near Diablo
This page: a magnitude 1.5 earthquake was recorded 2 km (1 mi) south-southwest of Diablo, CA, at 2:20 am PDT on 24 July 2019 (09:20 UTC), 6.9 km deep. 1 person has reported feeling it to USGS.
USGS: 2km SSW of Diablo, CA
7 km (4 mi) NNW of San Ramon, CA · 40 km (25 mi) E of San Francisco, CA
- When
- 2:20 am PDT on 24 July 2019 ()
- Where
- 2 km (1 mi) south-southwest of Diablo, CA · earthquakes near Diablo
- Magnitude
- M 1.5 (md)
- Depth
- 6.9 km below the surface
- Felt
- 1 report · strongest reported intensity III
- Nearest
- Contra Costa County, 11 km N
- Nearest mapped fault
- Pleasanton 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 2667 days ago
Earthquake alerts for Diablo, 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 8 km (5 mi) from the epicentre. In Diablo, 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: Danville 3 km, intensity II · San Ramon 4 km, intensity II · Alamo 6 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 4.4 on 2018-01-04 — about 19,000 times the energy of this one.
Before 2016, the USGS record lists 6 earthquakes of M5 or more within 50 km; the five largest:
- 5.8 The 1980 Livermore, California Earthquake · 18 km E of this epicentre
- 5.7 15 km NE of East Foothills, California · 45 km SE of this epicentre
- 5.5 6 km NNE of East Foothills, California · 46 km SSE of this epicentre
- 5.4 9 km NE of Livermore, California · 25 km ESE of this epicentre
- 5.3 The 1957 San Francisco, California Earthquake · 48 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 37.8175, -121.9718. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Contra Costa County, CA | 11 km (7 mi) | N | earthquakes near Contra Costa County |
| Alameda County, CA | 20 km (12 mi) | SSE | earthquakes near Alameda County |
| Solano County, CA | 50 km (31 mi) | N | earthquakes near Solano County |
| San Mateo County, CA | 57 km (35 mi) | SW | earthquakes near San Mateo County |
| San Joaquin County, CA | 63 km (39 mi) | ENE | earthquakes near San Joaquin County |
| Santa Clara County, CA | 71 km (44 mi) | SSE | earthquakes near Santa Clara County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
56 earthquakes have been recorded within 50 km since this one.
- 1.6 4km N of Dublin, CA
- 1.6 4km NNE of Dublin, CA
- 2.2 4km N of Dublin, CA
- 2.8 4km N of Dublin, CA
- 1.8 4km NNE of Dublin, CA
- 1.6 4km NNE of Dublin, CA
- 2.6 4km NNE of Dublin, CA
- 1.6 3km SW of Clayton, CA
- 2.3 3km NE of Orinda, CA
- 1.6 4km N of Dublin, CA
- 1.6 4km NNE of Dublin, CA
- 1.6 4km NNE of Dublin, CA
- 2.0 4km N of Dublin, CA
- 1.9 4km N of Dublin, CA
- 1.8 4km NNE of Dublin, 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.