QuakeIndex

Earthquake · reviewed by a seismologist

M 1.5md

Earthquake near Lompico, CA

No earthquake was likely felt in Lompico in the 24 hours to 3:42 am PST (11:42 UTC). The last one was M 2.3, 6 km (4 mi) ENE, at 2:58 am PDT on 9 October 2026, estimated intensity II (weak) in town; 3 felt reports to USGS. Every earthquake near Lompico

This page: a magnitude 1.5 earthquake was recorded 4 km (3 mi) north-northeast of Lompico, CA, at 8:02 am PST on 26 December 2023 (16:02 UTC), 12 km deep.

USGS: 4 km NNE of Lompico, CA

26 km (16 mi) SW of San Jose, CA · 19 km (12 mi) N of Santa Cruz, CA

8:02 am PST, Dec 26, 2023 · · 12 km deep · released about 5.9 lb of TNT

10 km30 km60 km120 km N Santa Cruz County 15 kmSanta Clara County 32 kmSan Mateo County 42 kmAlameda County 57 kmContra Costa County 87 kmStanislaus County 103 kmSan Benito County 103 kmSan Francisco County 109 kmSan Joaquin County 111 km
Distance rings around the epicentre, with the nearest towns at their true direction and later quakes as coloured dots. Not a shaking map — see the USGS ShakeMap for that.
When
8:02 am PST on 26 December 2023 ()
Where
4 km (3 mi) north-northeast of Lompico, CA · earthquakes near Lompico
Magnitude
M 1.5 (md)
Depth
12 km below the surface
Felt
no reports yet
Nearest
Santa Cruz County, 15 km S
Nearest mapped fault
Zayante-Vergeles fault, 2 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 1044 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

At this magnitude and depth it was probably too small to be felt, even directly above it. In Lompico, 4 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: Lexington Hills, Brookdale, Ben Lomond, Boulder Creek, Mount Hermon, Scotts Valley.

How big was it?

This earthquake released about 5.9 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.5 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 2,500,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,800,000× the energy of this one
  3. Around the size people start to feel M 3.0 160× the energy of this one
  4. This earthquake M 1.5 about 5.9 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 5.1 on 2022-10-25 — about 200,000 times the energy of this one.

Before 2016, the USGS record lists 28 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.9 The 1989 Loma Prieta, California Earthquake · 18 km SE of this epicentre
  2. 6.5 Near Morgan Hill, California · 36 km E of this epicentre
  3. 6.3 22 km S of Davenport, California · 40 km SSW of this epicentre
  4. 6.3 16 km SW of Davenport, California · 36 km SW of this epicentre
  5. 6.2 Near San Jose, California · 27 km NE 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 37.1427, -122.0367. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Santa Cruz County, CA 15 km (9 mi) S earthquakes near Santa Cruz County
Santa Clara County, CA 32 km (20 mi) ENE earthquakes near Santa Clara County
San Mateo County, CA 42 km (26 mi) NW earthquakes near San Mateo County
Alameda County, CA 57 km (36 mi) N earthquakes near Alameda County
Contra Costa County, CA 87 km (54 mi) N earthquakes near Contra Costa County
Stanislaus County, CA 103 km (64 mi) ENE earthquakes near Stanislaus County

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

Aftershocks so far

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

  1. 2.2 16 km E of Seven Trees, CA
  2. 1.6 7 km N of Day Valley, CA
  3. 2.8 16 km E of Seven Trees, CA
  4. 1.6 8 km ENE of Gilroy, CA
  5. 1.5 16 km N of Morgan Hill, CA
  6. 2.4 8 km NE of Gilroy, CA
  7. 1.7 7 km ENE of Gilroy, CA
  8. 2.7 8 km NE of Gilroy, CA
  9. 1.6 15 km SSW of Bonny Doon, CA
  10. 2.1 1 km ESE of Aromas, CA
  11. 3.0 15 km N of Morgan Hill, CA
  12. 2.5 6 km SSW of Gilroy, CA
  13. 2.1 10 km NNE of Milpitas, CA
  14. 1.7 16 km E of Seven Trees, CA
  15. 1.7 10 km NE of Milpitas, 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

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.