Earthquake · reviewed by a seismologist
M 2.3md
Earthquake near Ridgemark, CA
No earthquake was likely felt in Ridgemark in the 24 hours to 1:35 pm PST (21:35 UTC). The last one was M 2.4, 8 km (5 mi) S, at 8:53 pm PST on 5 November 2026, estimated intensity II (weak) in town; 1 felt report to USGS. Every earthquake near Ridgemark
This page: a magnitude 2.3 earthquake was recorded 10 km (6 mi) west-southwest of Ridgemark, CA, at 11:30 am PST on 6 January 2023 (19:30 UTC), 4.9 km deep. 2 people have reported feeling it to USGS.
USGS: 10km WSW of Ridgemark, CA
67 km (42 mi) SSE of San Jose, CA · 18 km (11 mi) ENE of Salinas, CA
- When
- 11:30 am PST on 6 January 2023 ()
- Where
- 10 km (6 mi) west-southwest of Ridgemark, CA · earthquakes near Ridgemark
- Magnitude
- M 2.3 (md)
- Depth
- 4.9 km below the surface
- Felt
- 2 reports · strongest reported intensity III
- Nearest
- San Benito County, 38 km ESE
- Nearest mapped fault
- San Andreas fault, 3 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 1399 days ago
Earthquake alerts for Ridgemark, CA
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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 20 km (12 mi) from the epicentre. In Ridgemark, 10 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: Hollister 11 km, intensity II · Prunedale 19 km, intensity II. Estimated for each town centre; each link is that town's own record.
How big was it?
This earthquake released about 98 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.3 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 150,000× the energy of this one
- Magna, Utah 2020 M 5.7 110,000× the energy of this one
- Around the size people start to feel M 3.0 9.8× the energy of this one
- This earthquake M 2.3 about 98 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 3,600 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 · 48 km NW of this epicentre
- 6.5 Near Morgan Hill, California · 42 km NNW of this epicentre
- 5.9 10 km SE of Tres Pinos, California · 22 km E of this epicentre
- 5.8 Near Watsonville, California · 30 km NW of this epicentre
- 5.8 Near Paicines, California · 22 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 36.7648, -121.4607. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| San Benito County, CA | 38 km (23 mi) | ESE | earthquakes near San Benito County |
| Santa Clara County, CA | 55 km (34 mi) | NNW | earthquakes near Santa Clara County |
| Santa Cruz County, CA | 56 km (35 mi) | WNW | earthquakes near Santa Cruz County |
| Monterey County, CA | 60 km (37 mi) | SSE | earthquakes near Monterey County |
| Merced County, CA | 81 km (50 mi) | NE | earthquakes near Merced County |
| Stanislaus County, CA | 98 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.
- 2.0 9km ENE of San Martin, CA
- 2.0 8km S of Tres Pinos, CA
- 2.0 2km N of Pinnacles, CA
- 1.7 2km NE of Pinnacles, CA
- 1.8 11km NW of Pinnacles, CA
- 1.8 8km ENE of Gilroy, CA
- 1.5 11km SW of Ridgemark, CA
- 2.1 5km SSE of San Juan Bautista, CA
- 2.1 4km NNW of Hollister, CA
- 2.0 12km SSW of Tres Pinos, CA
- 2.4 7km WSW of Gilroy, CA
- 2.4 7km ESE of Pinnacles, CA
- 2.4 10km NW of Pinnacles, CA
- 1.8 9km SSE of San Juan Bautista, CA
- 1.8 3km WSW of San Juan Bautista, 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.