Earthquake · automatic estimate, may change
M 1.8md
Earthquake near Boulder Creek, CA
Yes. A magnitude 1.8 earthquake was recorded 19 km (12 mi) WNW of Boulder Creek, CA, at 5:26 pm PDT on 6 October 2026 (00:26 UTC), 4.7 km deep. The magnitude and location are an automatic first estimate and may change.
This was on 6 October 2026. The latest near Boulder Creek: M 4.6 on 2 April 2026.
USGS: 19 km WNW of Boulder Creek, CA
44 km (27 mi) W of San Jose, CA · 24 km (15 mi) SW of Palo Alto, CA
- When
- 5:26 pm PDT on 6 October 2026 ()
- Where
- 19 km (12 mi) WNW of Boulder Creek, CA · earthquakes near Boulder Creek
- Magnitude
- M 1.8 (md)
- Depth
- 4.7 km below the surface
- Felt
- no reports yet
- Nearest
- San Mateo County, 23 km NNW
- Nearest mapped fault
- San Gregorio fault, 4 km from its surface trace — near is not the same as on
- Status
- Automatic — a machine’s first estimate, which may change
USGS · last changed by USGS · we first saw it 6 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 13 km (8 mi) from the epicentre. In Boulder Creek, 19 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: Portola Valley, Brookdale, Ladera, Los Altos Hills, Loyola, Bonny Doon.
How big was it?
This earthquake released about 17 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.8 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 900,000× the energy of this one
- Magna, Utah 2020 M 5.7 640,000× the energy of this one
- Around the size people start to feel M 3.0 57× the energy of this one
- This earthquake M 1.8 about 17 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 4.6 on 2026-04-02 — about 14,000 times the energy of this one.
Before 2016, the USGS record lists 15 earthquakes of M5 or more within 50 km; the five largest:
- 6.9 The 1989 Loma Prieta, California Earthquake · 43 km ESE of this epicentre
- 6.3 22 km S of Davenport, California · 46 km S of this epicentre
- 6.3 16 km SW of Davenport, California · 33 km S of this epicentre
- 6.2 Near San Jose, California · 46 km ENE of this epicentre
- 6.1 Near San Jose, California · 45 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 37.2177, -122.3048. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| San Mateo County, CA | 23 km (14 mi) | NNW | earthquakes near San Mateo County |
| Santa Cruz County, CA | 35 km (22 mi) | SE | earthquakes near Santa Cruz County |
| Santa Clara County, CA | 54 km (34 mi) | E | earthquakes near Santa Clara County |
| Alameda County, CA | 59 km (37 mi) | NE | earthquakes near Alameda County |
| Contra Costa County, CA | 84 km (52 mi) | NNE | earthquakes near Contra Costa County |
| San Francisco County, CA | 86 km (53 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
2 earthquakes have been recorded within 50 km since this one.
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.