Earthquake near Ridgemark, CA

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 25 km (16 mi) from the epicentre. 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 6 km, intensity III. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 430 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.8 would have released about 32 times as much.

1. Mineral, Virginia 2011 M 5.8 35,000× the energy of this one
2. Magna, Utah 2020 M 5.7 25,000× the energy of this one
3. Around the size people start to feel M 3.0 2.2× the energy of this one
4. This earthquake M 2.8 about 430 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 4.2 on 2016-07-19 — about 150 times the energy of this one.

Before 2016, the USGS record lists 24 earthquakes of M5 or more within 50 km; the five largest:

1. 6.5 Near Morgan Hill, California · 41 km NW of this epicentre Jul 1, 1911
2. 5.9 10 km SE of Tres Pinos, California · 15 km SE of this epicentre Apr 9, 1961
3. 5.8 Near Watsonville, California · 34 km WNW of this epicentre Mar 11, 1910
4. 5.8 Near Paicines, California · 19 km SSE of this epicentre Aug 6, 1916
5. 5.8 The 1979 Coyote Lake, California Earthquake · 35 km NNW of this epicentre Aug 6, 1979

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 36.8197, -121.3523. Map © OpenStreetMap contributors.

Nearby places

Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.

Aftershocks so far

59 earthquakes have been recorded within 50 km since this one.

1. 2.2 12 km S of Tres Pinos, California 13:43 UTC
2. 1.9 24 km NE of Greenfield, California 19:56 UTC
3. 1.8 Central California 18:57 UTC
4. 2.0 11 km S of Tres Pinos, California 20:34 UTC
5. 1.9 2 km E of Aromas, California 00:56 UTC
6. 2.1 2 km SSW of San Juan Bautista, California 18:19 UTC
7. 1.7 6 km SW of Ridgemark, California 12:30 UTC
8. 2.7 17 km SSE of Tres Pinos, California 08:32 UTC
9. 1.9 22 km NE of Soledad, California 17:14 UTC
10. 1.7 12 km NNE of Hollister, California 02:57 UTC
11. 2.1 10 km S of Tres Pinos, California 23:47 UTC
12. 1.8 21 km NE of Soledad, California 14:47 UTC
13. 1.9 24 km ENE of Soledad, California 15:52 UTC
14. 2.0 Central California 11:21 UTC
15. 2.1 9 km SSW of Tres Pinos, California 21:45 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 23:05 UTC. 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.