QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8md

Earthquake near Pacific Grove, CA

No earthquake was likely felt in Pacific Grove in the 24 hours to 2:46 pm PST (22:46 UTC). The last one was M 3.9, 66 km (41 mi) E, at 3:19 am PDT on 11 August 2026, estimated intensity II (weak) in town; 34 felt reports to USGS. Every earthquake near Pacific Grove

This page: a magnitude 1.8 earthquake was recorded 6 km (4 mi) northwest of Pacific Grove, CA, at 12:18 am PST on 23 February 2023 (08:18 UTC), 16 km deep.

USGS: 6km NW of Pacific Grove, CA

72 km (45 mi) S of San Jose, CA · 29 km (18 mi) W of Salinas, CA

12:18 am PST, Feb 23, 2023 · · 16 km deep · released about 13 lb of TNT

10 km30 km60 km120 km N Santa Cruz County 39 kmSanta Clara County 67 kmMonterey County 74 kmSan Benito County 78 kmSan Mateo County 92 kmAlameda County 110 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
12:18 am PST on 23 February 2023 ()
Where
6 km (4 mi) northwest of Pacific Grove, CA · earthquakes near Pacific Grove
Magnitude
M 1.8 (md)
Depth
16 km below the surface
Felt
no reports yet
Nearest
Santa Cruz County, 39 km N
Nearest mapped fault
Monterey Bay- Tularcitos 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 1354 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 Pacific Grove, 6 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: Del Monte Forest, Monterey, Seaside, Carmel-by-the-Sea, Del Rey Oaks, Marina.

How big was it?

This earthquake released about 13 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.8 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,100,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 810,000× the energy of this one
  3. Around the size people start to feel M 3.0 72× the energy of this one
  4. This earthquake M 1.8 about 13 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 2021-01-17 — about 4,600 times the energy of this one.

Before 2016, the USGS record lists 19 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.9 The 1989 Loma Prieta, California Earthquake · 42 km N of this epicentre
  2. 6.3 22 km S of Davenport, California · 27 km NW of this epicentre
  3. 6.3 16 km SW of Davenport, California · 45 km NW of this epicentre
  4. 5.8 Near Watsonville, California · 40 km NE of this epicentre
  5. 5.7 Monterey Bay area, California · 20 km NW 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 36.6593, -121.9592. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Santa Cruz County, CA 39 km (25 mi) N earthquakes near Santa Cruz County
Santa Clara County, CA 67 km (42 mi) NNE earthquakes near Santa Clara County
Monterey County, CA 74 km (46 mi) SE earthquakes near Monterey County
San Benito County, CA 78 km (49 mi) E earthquakes near San Benito County
San Mateo County, CA 92 km (57 mi) NNW earthquakes near San Mateo County
Alameda County, CA 110 km (68 mi) N earthquakes near Alameda County

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

Aftershocks so far

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

  1. 2.0 6 km SW of Gilroy, CA
  2. 1.6 7 km ESE of Prunedale, CA
  3. 1.9 1 km ENE of Aromas, CA
  4. 1.5 2 km E of Aromas, CA
  5. 1.8 3 km E of Aromas, CA
  6. 1.6 5 km NNW of Aromas, CA
  7. 1.6 8km ESE of Prunedale, CA
  8. 1.6 6km SW of Gilroy, CA
  9. 1.9 6km SW of Hollister, CA
  10. 1.6 7km WSW of Gilroy, CA
  11. 1.5 6km SW of Hollister, CA
  12. 1.5 2km E of Aromas, CA
  13. 2.6 7km WSW of Gilroy, CA
  14. 2.6 6km SSW of Gilroy, CA
  15. 1.9 5km NNW of Day Valley, 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.