QuakeIndex

Earthquake · reviewed by a seismologist

M 2.7md

Earthquake near San Martin, CA

Yes: an earthquake was likely felt in San Martin in the last 24 hours. M 2.6, 22 km (14 mi) S of San Martin, at 11:40 am PST on 12 November 2026 (19:40 UTC); the estimated shaking in San Martin was intensity II (weak). Every earthquake near San Martin

This page: a magnitude 2.7 earthquake was recorded 11 km (7 mi) east-northeast of San Martin, CA, at 5:48 pm PDT on 18 April 2019 (00:48 UTC), less than 1 km deep. 2 people have reported feeling it to USGS.

USGS: 11km ENE of San Martin, CA

14 km (9 mi) NE of Gilroy, CA · 36 km (22 mi) SE of San Jose, CA

5:48 pm PDT, Apr 18, 2019 · · -0.1 km deep · released about 330 lb of TNT

10 km30 km60 km120 km N Santa Clara County 22 kmSanta Cruz County 47 kmSan Benito County 66 kmStanislaus County 67 kmMerced County 69 kmAlameda County 71 kmSan Mateo County 85 kmSan Joaquin County 94 kmMonterey County 97 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
5:48 pm PDT on 18 April 2019 ()
Where
11 km (7 mi) east-northeast of San Martin, CA · earthquakes near San Martin
Magnitude
M 2.7 (md)
Depth
-0.1 km below the surface
Felt
2 reports · strongest reported intensity III
Nearest
Santa Clara County, 22 km NW
Nearest mapped fault
Calaveras fault, 5 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 2765 days ago

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. In San Martin, 11 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: Gilroy 13 km, intensity III · Morgan Hill 15 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 330 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.7 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 46,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 33,000× the energy of this one
  3. Around the size people start to feel M 3.0 2.9× the energy of this one
  4. This earthquake M 2.7 about 330 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 200 times the energy of this one.

Before 2016, the USGS record lists 29 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.9 The 1989 Loma Prieta, California Earthquake · 35 km WSW of this epicentre
  2. 6.5 Near Morgan Hill, California · 13 km W of this epicentre
  3. 6.2 Near San Jose, California · 35 km NW of this epicentre
  4. 6.2 The 1984 Morgan Hill, California Earthquake · 28 km NW of this epicentre
  5. 6.1 Near San Jose, California · 29 km WNW 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 37.1048, -121.4928. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Santa Clara County, CA 22 km (14 mi) NW earthquakes near Santa Clara County
Santa Cruz County, CA 47 km (29 mi) WSW earthquakes near Santa Cruz County
San Benito County, CA 66 km (41 mi) SSE earthquakes near San Benito County
Stanislaus County, CA 67 km (42 mi) NE earthquakes near Stanislaus County
Merced County, CA 69 km (43 mi) E earthquakes near Merced County
Alameda County, CA 71 km (44 mi) NNW earthquakes near Alameda County

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

Aftershocks so far

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

  1. 1.5 8km ENE of Alum Rock, CA
  2. 1.6 8km N of Day Valley, CA
  3. 1.8 10km S of Tres Pinos, CA
  4. 1.9 6km S of Gilroy, CA
  5. 2.0 4km W of San Juan Bautista, CA
  6. 1.5 8km SSE of San Juan Bautista, CA
  7. 1.7 2km NNW of Aromas, CA
  8. 1.5 16km N of Morgan Hill, CA
  9. 2.4 8km NE of Alum Rock, CA
  10. 1.6 16km N of Morgan Hill, CA
  11. 1.6 6km SW of Gilroy, CA
  12. 1.5 13km NNE of Morgan Hill, CA
  13. 2.5 8km ENE of Alum Rock, CA
  14. 2.2 8km ENE of Alum Rock, CA
  15. 2.0 8km ENE of Alum Rock, 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.