Earthquake · reviewed by a seismologist
M 2.5md
Earthquake near Saratoga, CA
No earthquake was likely felt in Saratoga in the 24 hours to 9:22 am PST (17:22 UTC). The last one was M 2.0, 7 km (4 mi) NW, at 9:23 am PST on 10 November 2026, estimated intensity II (weak) in town; 4 felt reports to USGS. Every earthquake near Saratoga
This page: a magnitude 2.5 earthquake was recorded 4 km (2 mi) southwest of Saratoga, CA, at 12:36 am PDT on 21 August 2019 (07:36 UTC), 9.2 km deep. 112 people have reported feeling it to USGS.
USGS: 4km SW of Saratoga, CA
22 km (14 mi) WSW of San Jose, CA · 8 km (5 mi) S of Cupertino, CA
- When
- 12:36 am PDT on 21 August 2019 ()
- Where
- 4 km (2 mi) southwest of Saratoga, CA · earthquakes near Saratoga
- Magnitude
- M 2.5 (md)
- Depth
- 9.2 km below the surface
- Felt
- 112 reports · strongest reported intensity IV
- Nearest
- Santa Cruz County, 26 km S
- Nearest mapped fault
- San Andreas 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 2635 days ago
Earthquake alerts for Saratoga, CA
Get a notification in this browser when USGS records an earthquake near Saratoga, 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 small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage.
At this magnitude and depth, people at rest would likely notice it out to about 21 km (13 mi) from the epicentre. In Saratoga, 4 km away, the estimate is intensity III (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: Saratoga 4 km, intensity III · Los Gatos 8 km, intensity II · Cupertino 9 km, intensity II · Campbell 11 km, intensity II · Sunnyvale 14 km, intensity II · Boulder Creek 14 km, intensity II · Santa Clara 15 km, intensity II · Mountain View 16 km, intensity II. Estimated for each town centre; each link is that town's own record.
How big was it?
This earthquake released about 200 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.5 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 75,000× the energy of this one
- Magna, Utah 2020 M 5.7 53,000× the energy of this one
- Around the size people start to feel M 3.0 4.7× the energy of this one
- This earthquake M 2.5 about 200 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 4.1 on 2017-10-10 — about 200 times the energy of this one.
Before 2016, the USGS record lists 25 earthquakes of M5 or more within 50 km; the five largest:
- 6.9 The 1989 Loma Prieta, California Earthquake · 28 km SE of this epicentre
- 6.5 Near Morgan Hill, California · 40 km ESE of this epicentre
- 6.3 16 km SW of Davenport, California · 44 km SW of this epicentre
- 6.2 Near San Jose, California · 24 km ENE of this epicentre
- 6.2 The 1984 Morgan Hill, California Earthquake · 34 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 37.2438, -122.0577. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Santa Cruz County, CA | 26 km (16 mi) | S | earthquakes near Santa Cruz County |
| Santa Clara County, CA | 33 km (20 mi) | E | earthquakes near Santa Clara County |
| San Mateo County, CA | 34 km (21 mi) | NW | earthquakes near San Mateo County |
| Alameda County, CA | 47 km (29 mi) | NNE | earthquakes near Alameda County |
| Contra Costa County, CA | 76 km (47 mi) | N | earthquakes near Contra Costa County |
| Stanislaus County, CA | 100 km (62 mi) | ENE | earthquakes near Stanislaus County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
32 earthquakes have been recorded within 50 km since this one.
- 1.7 9km ENE of Morgan Hill, CA
- 1.6 1km SSE of Palo Alto, CA
- 1.5 4km E of Los Gatos, CA
- 2.7 8km ENE of San Martin, CA
- 1.6 11km WSW of Saratoga, CA
- 1.5 13km SE of Sunol, CA
- 2.0 15km E of Seven Trees, CA
- 1.7 12km WSW of Portola Valley, CA
- 1.8 9km NE of Morgan Hill, CA
- 2.5 8km NNE of Alum Rock, CA
- 2.8 8km NNE of Alum Rock, CA
- 1.6 8km E of Sunol, CA
- 2.0 8km ENE of Alum Rock, CA
- 2.7 3km W of Cupertino, CA
- 1.7 2km NE of Union City, 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.