QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1md

Earthquake near Bonny Doon, CA

No earthquake was likely felt in Bonny Doon in the 24 hours to 2:26 pm PST (22:26 UTC). The last one was M 3.8, 79 km (49 mi) N, at 8:30 am PDT on 13 August 2026, estimated intensity II (weak) in town; 7,876 felt reports to USGS. Every earthquake near Bonny Doon

This page: a magnitude 2.1 earthquake was recorded 11 km (7 mi) southwest of Bonny Doon, CA, at 6:47 am PDT on 5 July 2019 (13:47 UTC), 1.8 km deep.

USGS: 11km SW of Bonny Doon, CA

52 km (32 mi) SW of San Jose, CA · 19 km (12 mi) W of Santa Cruz, CA

6:47 am PDT, Jul 5, 2019 · · 1.8 km deep · released about 40 lb of TNT

10 km30 km60 km120 km N Santa Cruz County 22 kmSan Mateo County 49 kmSanta Clara County 56 kmAlameda County 79 kmContra Costa County 107 kmSan Francisco County 107 kmSan Benito County 112 kmMonterey County 118 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
6:47 am PDT on 5 July 2019 ()
Where
11 km (7 mi) southwest of Bonny Doon, CA · earthquakes near Bonny Doon
Magnitude
M 2.1 (md)
Depth
1.8 km below the surface
Felt
no reports yet
Nearest
Santa Cruz County, 22 km E
Nearest mapped fault
San Gregorio 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 2687 days ago

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 17 km (11 mi) from the epicentre. In Bonny Doon, 11 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.

Earthquakes near other towns within 30 km: Felton, Brookdale, Mount Hermon, Ben Lomond, Boulder Creek, Santa Cruz.

How big was it?

This earthquake released about 40 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.

  1. Mineral, Virginia 2011 M 5.8 380,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 270,000× the energy of this one
  3. Around the size people start to feel M 3.0 24× the energy of this one
  4. This earthquake M 2.1 about 40 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 15 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.9 The 1989 Loma Prieta, California Earthquake · 33 km E of this epicentre
  2. 6.3 22 km S of Davenport, California · 20 km SSE of this epicentre
  3. 6.3 16 km SW of Davenport, California · 11 km SW of this epicentre
  4. 6.1 Near San Jose, California · 47 km ENE of this epicentre
  5. 5.8 Near Watsonville, California · 49 km E 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 36.9868, -122.2513. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Santa Cruz County, CA 22 km (14 mi) E earthquakes near Santa Cruz County
San Mateo County, CA 49 km (30 mi) NNW earthquakes near San Mateo County
Santa Clara County, CA 56 km (35 mi) ENE earthquakes near Santa Clara County
Alameda County, CA 79 km (49 mi) NNE earthquakes near Alameda County
Contra Costa County, CA 107 km (67 mi) NNE earthquakes near Contra Costa County
San Francisco County, CA 107 km (67 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

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

  1. 1.8 2km SW of Los Altos Hills, CA
  2. 1.8 12km WNW of Boulder Creek, CA
  3. 1.7 3km SW of Lexington Hills, CA
  4. 1.9 14km SW of Santa Cruz, CA
  5. 1.8 30km SW of Bonny Doon, CA
  6. 1.7 2km ESE of Woodside, CA
  7. 1.7 6km SSE of Portola Valley, CA
  8. 1.6 3km WSW of Portola Valley, CA
  9. 2.0 3km WSW of Portola Valley, CA
  10. 1.6 5km NNW of Moss Landing, CA
  11. 2.6 12km W of Saratoga, CA
  12. 2.0 6km S of Loyola, CA
  13. 1.5 3km S of Loyola, CA
  14. 1.5 4km E of Los Gatos, CA
  15. 1.6 11km WSW of Saratoga, 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.