Earthquake · reviewed by a seismologist
M 1.6md
Earthquake near Ridgemark, CA
Yes: an earthquake was likely felt in Ridgemark in the last 24 hours. M 1.6, 11 km (7 mi) S of Ridgemark, at 11:35 pm PST on 11 November 2026 (07:35 UTC); the estimated shaking in Ridgemark was intensity II (weak). Every earthquake near Ridgemark
This page: a magnitude 1.6 earthquake was recorded 11 km (7 mi) southwest of Ridgemark, CA, at 9:45 am PST on 4 December 2020 (17:45 UTC), 7.4 km deep.
USGS: 11km SW of Ridgemark, CA
68 km (43 mi) SSE of San Jose, CA · 17 km (11 mi) ENE of Salinas, CA
- When
- 9:45 am PST on 4 December 2020 ()
- Where
- 11 km (7 mi) southwest of Ridgemark, CA · earthquakes near Ridgemark
- Magnitude
- M 1.6 (md)
- Depth
- 7.4 km below the surface
- Felt
- no reports yet
- Nearest
- San Benito County, 37 km ESE
- Nearest mapped fault
- San Andreas fault, 4 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 2157 days ago
Earthquake alerts for Ridgemark, CA
Get a notification in this browser when USGS records an earthquake near Ridgemark, 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 8 km (5 mi) from the epicentre. In Ridgemark, 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: Hollister, San Juan Bautista, Prunedale, Salinas, Boronda, Chualar.
How big was it?
This earthquake released about 6.6 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 2,300,000× the energy of this one
- Magna, Utah 2020 M 5.7 1,600,000× the energy of this one
- Around the size people start to feel M 3.0 140× the energy of this one
- This earthquake M 1.6 about 6.6 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 4.7 on 2019-10-15 — about 53,000 times the energy of this one.
Before 2016, the USGS record lists 25 earthquakes of M5 or more within 50 km; the five largest:
- 6.9 The 1989 Loma Prieta, California Earthquake · 49 km NW of this epicentre
- 6.5 Near Morgan Hill, California · 43 km NNW of this epicentre
- 5.9 10 km SE of Tres Pinos, California · 21 km E of this epicentre
- 5.8 Near Watsonville, California · 31 km NW of this epicentre
- 5.8 Near Paicines, California · 21 km ESE 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 36.7502, -121.4578. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| San Benito County, CA | 37 km (23 mi) | ESE | earthquakes near San Benito County |
| Santa Clara County, CA | 56 km (35 mi) | NNW | earthquakes near Santa Clara County |
| Santa Cruz County, CA | 57 km (35 mi) | WNW | earthquakes near Santa Cruz County |
| Monterey County, CA | 58 km (36 mi) | SSE | earthquakes near Monterey County |
| Merced County, CA | 82 km (51 mi) | NE | earthquakes near Merced County |
| Stanislaus County, CA | 99 km (61 mi) | NNE | earthquakes near Stanislaus County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
58 earthquakes have been recorded within 50 km since this one.
- 2.2 12km NW of Pinnacles, CA
- 1.8 12km NW of Pinnacles, CA
- 2.6 12km NW of Pinnacles, CA
- 1.7 13km NW of Pinnacles, CA
- 2.1 12km NW of Pinnacles, CA
- 1.6 10km NW of Pinnacles, CA
- 2.2 12km NW of Pinnacles, CA
- 2.5 10km NW of Pinnacles, CA
- 1.8 12km NW of Pinnacles, CA
- 2.0 12km NW of Pinnacles, CA
- 2.5 11km NW of Pinnacles, CA
- 1.5 11km NW of Pinnacles, CA
- 2.4 10km NW of Pinnacles, CA
- 1.7 11km NW of Pinnacles, CA
- 4.3 10km NW of Pinnacles, 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.