QuakeIndex

Earthquake · reviewed by a seismologist

M 2.6md

Earthquake near Saratoga, CA

No earthquake was likely felt in Saratoga in the 24 hours to 1:46 am PST (09:46 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 2.6 earthquake was recorded 8 km (5 mi) west-southwest of Saratoga, CA, at 1:43 pm PDT on 17 August 2020 (20:43 UTC), 14 km deep. 47 people have reported feeling it to USGS.

USGS: 8km WSW of Saratoga, CA

27 km (17 mi) WSW of San Jose, CA · 11 km (7 mi) SSW of Cupertino, CA

1:43 pm PDT, Aug 17, 2020 · · 14 km deep · released about 280 lb of TNT

10 km30 km60 km120 km N Santa Cruz County 26 kmSan Mateo County 31 kmSanta Clara County 37 kmAlameda County 49 kmContra Costa County 78 kmSan Francisco County 99 kmStanislaus County 104 kmMarin County 107 kmSan Joaquin County 107 km
Distance rings around the epicentre, with the nearest towns at their true direction and later quakes as coloured dots. Not a shaking map — see the USGS ShakeMap for that.
When
1:43 pm PDT on 17 August 2020 ()
Where
8 km (5 mi) west-southwest of Saratoga, CA · earthquakes near Saratoga
Magnitude
M 2.6 (md)
Depth
14 km below the surface
Felt
47 reports · strongest reported intensity IV
Nearest
Santa Cruz County, 26 km SSE
Nearest mapped fault
Butano 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 2210 days ago

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 20 km (12 mi) from the epicentre. In Saratoga, 8 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: Saratoga 8 km, intensity II · Los Gatos 12 km, intensity II · Boulder Creek 12 km, intensity II · Cupertino 12 km, intensity II · Campbell 15 km, intensity II · Sunnyvale 17 km, intensity II · Los Altos 17 km, intensity II · Mountain View 17 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 280 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.6 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 55,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 39,000× the energy of this one
  3. Around the size people start to feel M 3.0 3.5× the energy of this one
  4. This earthquake M 2.6 about 280 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 150 times the energy of this one.

Before 2016, the USGS record lists 23 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.9 The 1989 Loma Prieta, California Earthquake · 30 km SE of this epicentre
  2. 6.5 Near Morgan Hill, California · 44 km ESE of this epicentre
  3. 6.3 22 km S of Davenport, California · 48 km S of this epicentre
  4. 6.3 16 km SW of Davenport, California · 40 km SSW of this epicentre
  5. 6.2 Near San Jose, California · 28 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 37.2308, -122.1065. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Santa Cruz County, CA 26 km (16 mi) SSE earthquakes near Santa Cruz County
San Mateo County, CA 31 km (19 mi) NW earthquakes near San Mateo County
Santa Clara County, CA 37 km (23 mi) E earthquakes near Santa Clara County
Alameda County, CA 49 km (31 mi) NNE earthquakes near Alameda County
Contra Costa County, CA 78 km (48 mi) N earthquakes near Contra Costa County
San Francisco County, CA 99 km (61 mi) NW earthquakes near San Francisco County

Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.

Aftershocks so far

41 earthquakes have been recorded within 50 km since this one.

  1. 1.8 8km SSW of Loyola, CA
  2. 1.9 11km NE of Milpitas, CA
  3. 1.9 11km NE of Milpitas, CA
  4. 2.7 7km N of Boulder Creek, CA
  5. 1.7 11km NE of Milpitas, CA
  6. 2.2 10km NE of Milpitas, CA
  7. 2.2 7km WSW of Gilroy, CA
  8. 1.9 10km NE of Milpitas, CA
  9. 2.1 10km NE of Milpitas, CA
  10. 2.0 11km NE of Milpitas, CA
  11. 2.9 10km NE of Milpitas, CA
  12. 1.7 10km NE of Milpitas, CA
  13. 2.6 10km NNE of Milpitas, CA
  14. 3.3 10km NE of Milpitas, CA
  15. 2.9 10km NE of Milpitas, 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

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.