Earthquake · reviewed by a seismologist
M 2.6md
Earthquake near Day Valley, CA
No earthquake was likely felt in Day Valley in the 24 hours to 4:43 am PST (12:43 UTC). The last one was M 1.8, 10 km (6 mi) NNW, at 10:49 pm PDT on 29 October 2026, estimated intensity II (weak) in town. Every earthquake near Day Valley
This page: a magnitude 2.6 earthquake was recorded 2 km (1 mi) south-southeast of Day Valley, CA, at 10:15 pm PST on 29 December 2018 (06:15 UTC), 16 km deep. 220 people have reported feeling it to USGS.
USGS: 2km SSE of Day Valley, CA
13 km (8 mi) NNW of Watsonville, CA · 31 km (19 mi) S of San Jose, CA
- When
- 10:15 pm PST on 29 December 2018 ()
- Where
- 2 km (1 mi) south-southeast of Day Valley, CA · earthquakes near Day Valley
- Magnitude
- M 2.6 (md)
- Depth
- 16 km below the surface
- Felt
- 220 reports · strongest reported intensity III
- Nearest
- Santa Cruz County, 14 km W
- Nearest mapped fault
- Zayante-Vergeles 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 2792 days ago
Earthquake alerts for Day Valley, CA
Get a notification in this browser when USGS records an earthquake near Day Valley, 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 18 km (11 mi) from the epicentre. In Day Valley, 2 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: Capitola 11 km, intensity II · Live Oak 12 km, intensity II · Watsonville 15 km, intensity II · Scotts Valley 15 km, intensity II · Santa Cruz 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 270 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.
- Mineral, Virginia 2011 M 5.8 57,000× the energy of this one
- Magna, Utah 2020 M 5.7 40,000× the energy of this one
- Around the size people start to feel M 3.0 3.6× the energy of this one
- This earthquake M 2.6 about 270 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 31 earthquakes of M5 or more within 50 km; the five largest:
- 6.9 The 1989 Loma Prieta, California Earthquake · 3 km NW of this epicentre
- 6.5 Near Morgan Hill, California · 21 km ENE of this epicentre
- 6.3 22 km S of Davenport, California · 39 km SW of this epicentre
- 6.3 16 km SW of Davenport, California · 45 km WSW of this epicentre
- 6.2 Near San Jose, California · 32 km N 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 37.0187, -121.8483. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Santa Cruz County, CA | 14 km (9 mi) | W | earthquakes near Santa Cruz County |
| Santa Clara County, CA | 27 km (17 mi) | NNE | earthquakes near Santa Clara County |
| San Mateo County, CA | 64 km (40 mi) | NW | earthquakes near San Mateo County |
| Alameda County, CA | 70 km (44 mi) | N | earthquakes near Alameda County |
| San Benito County, CA | 82 km (51 mi) | ESE | earthquakes near San Benito County |
| Stanislaus County, CA | 96 km (60 mi) | NE | earthquakes near Stanislaus 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.
- 2.5 12km NNE of Morgan Hill, CA
- 2.3 12km NNE of Morgan Hill, CA
- 1.9 3km S of San Juan Bautista, CA
- 2.5 8km SSE of San Juan Bautista, CA
- 2.9 12km NNE of Morgan Hill, CA
- 1.9 7km WSW of Gilroy, CA
- 1.5 3km S of Loyola, CA
- 2.3 8km E of Alum Rock, CA
- 2.0 5km WSW of Ridgemark, CA
- 2.5 12km NNE of Morgan Hill, CA
- 1.5 6km SW of Gilroy, CA
- 2.4 2km SW of San Juan Bautista, CA
- 1.8 11km SW of Ridgemark, CA
- 1.8 8km SSE of Portola Valley, CA
- 2.1 3km SW of Monte Sereno, 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.