Earthquake · reviewed by a seismologist
M 1.6md
Earthquake near Bonny Doon, CA
No earthquake was likely felt in Bonny Doon in the 24 hours to 1:31 pm PST (21:31 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 1.6 earthquake was recorded 18 km (11 mi) west-northwest of Bonny Doon, CA, at 2:03 am PDT on 29 October 2018 (09:03 UTC), 9.0 km deep. 1 person has reported feeling it to USGS.
USGS: 18km WNW of Bonny Doon, CA
50 km (31 mi) WSW of San Jose, CA · 31 km (19 mi) WNW of Santa Cruz, CA
- When
- 2:03 am PDT on 29 October 2018 ()
- Where
- 18 km (11 mi) west-northwest of Bonny Doon, CA · earthquakes near Bonny Doon
- Magnitude
- M 1.6 (md)
- Depth
- 9.0 km below the surface
- Felt
- 1 report · strongest reported intensity III
- Nearest
- Santa Cruz County, 31 km ESE
- 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 2936 days ago
Earthquake alerts for Bonny Doon, CA
Get a notification in this browser when USGS records an earthquake near Bonny Doon, 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 7 km (4 mi) from the epicentre. In Bonny Doon, 18 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: Boulder Creek, Brookdale, Ben Lomond, Felton, Lompico, Mount Hermon.
How big was it?
This earthquake released about 8.1 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.6 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 1,900,000× the energy of this one
- Magna, Utah 2020 M 5.7 1,300,000× the energy of this one
- Around the size people start to feel M 3.0 120× the energy of this one
- This earthquake M 1.6 about 8.1 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 14 earthquakes of M5 or more within 50 km; the five largest:
- 6.9 The 1989 Loma Prieta, California Earthquake · 41 km ESE of this epicentre
- 6.3 22 km S of Davenport, California · 37 km SSE of this epicentre
- 6.3 16 km SW of Davenport, California · 22 km S of this epicentre
- 6.1 Near San Jose, California · 48 km E of this epicentre
- 5.8 7 km NNW of Boulder Creek, California · 18 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 37.1215, -122.3315. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Santa Cruz County, CA | 31 km (19 mi) | ESE | earthquakes near Santa Cruz County |
| San Mateo County, CA | 33 km (20 mi) | N | earthquakes near San Mateo County |
| Santa Clara County, CA | 58 km (36 mi) | ENE | earthquakes near Santa Clara County |
| Alameda County, CA | 69 km (43 mi) | NNE | earthquakes near Alameda County |
| San Francisco County, CA | 91 km (57 mi) | NW | earthquakes near San Francisco County |
| Contra Costa County, CA | 95 km (59 mi) | NNE | earthquakes near Contra Costa County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
47 earthquakes have been recorded within 50 km since this one.
- 2.5 4km SW of Saratoga, CA
- 2.0 4km SW of Saratoga, CA
- 1.5 13km NNW of Boulder Creek, CA
- 1.8 32km WNW of Bonny Doon, CA
- 1.9 5km S of Portola Valley, CA
- 1.5 2km WSW of Los Altos Hills, CA
- 1.6 8km N of Day Valley, CA
- 1.7 10km WSW of Bonny Doon, CA
- 1.7 10km WSW of Bonny Doon, CA
- 2.1 11km SW of Bonny Doon, CA
- 1.6 10km N of Boulder Creek, CA
- 2.4 21km NW of Pacific Grove, CA
- 1.6 4km SE of Portola Valley, CA
- 2.3 2km E of Bonny Doon, CA
- 1.6 20km WNW of Boulder Creek, 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.