Earthquake near Interlaken, 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 44 km (27 mi) from the epicentre. In Interlaken, 6 km away, the estimate is intensity III (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: Watsonville 9 km, intensity III · Gilroy 11 km, intensity III · Prunedale 19 km, intensity III · Morgan Hill 21 km, intensity II · Capitola 25 km, intensity II · Hollister 26 km, intensity II · Live Oak 28 km, intensity II · Salinas 30 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 1,700 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.2 would have released about 32 times as much.

1. Northridge, California 1994 M 6.7 200,000× the energy of this one
2. Mineral, Virginia 2011 M 5.8 9,100× the energy of this one
3. Magna, Utah 2020 M 5.7 6,500× the energy of this one
4. This earthquake M 3.2 about 1,700 lb of TNT
5. Around the size people start to feel M 3.0 this one released 1.7× more

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 210 times the energy of this one.

Before 2016, the USGS record lists 33 earthquakes of M5 or more within 50 km; the five largest:

1. 6.9 The 1989 Loma Prieta, California Earthquake · 21 km WNW of this epicentre Oct 18, 1989
2. 6.5 Near Morgan Hill, California · 19 km N of this epicentre Jul 1, 1911
3. 6.3 22 km S of Davenport, California · 50 km WSW of this epicentre Oct 22, 1926
4. 6.2 Near San Jose, California · 41 km NNW of this epicentre Aug 3, 1903
5. 6.2 The 1984 Morgan Hill, California Earthquake · 41 km N of this epicentre Apr 24, 1984

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 36.9438, -121.6710. Map © OpenStreetMap contributors.

Nearby places

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

Aftershocks so far

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

1. 3.3 12km S of Tres Pinos, CA 04:57 UTC
2. 2.3 12km S of Tres Pinos, CA 00:46 UTC
3. 2.2 6km E of Alum Rock, CA 09:07 UTC
4. 1.5 14km S of Tres Pinos, CA 17:34 UTC
5. 2.0 4km S of San Juan Bautista, CA 08:19 UTC
6. 2.4 12km SSE of Tres Pinos, CA 16:55 UTC
7. 1.6 5km SSW of Gilroy, CA 12:45 UTC
8. 1.6 15km E of Seven Trees, CA 20:46 UTC
9. 2.8 14km SSE of Tres Pinos, CA 15:00 UTC
10. 2.0 2km SW of Ridgemark, CA 13:34 UTC
11. 2.6 4km S of San Juan Bautista, CA 17:30 UTC
12. 1.8 5km ESE of Interlaken, CA 02:04 UTC
13. 1.6 14km SE of Tres Pinos, CA 06:08 UTC
14. 2.9 11km SW of Ridgemark, CA 22:55 UTC
15. 1.7 16km SSE of Tres Pinos, CA 23:08 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 11:48 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.