QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8md

5km SSW of Gilroy, CA

· 7.4 km deep · released about 15 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Santa Clara County 30 kmSanta Cruz County 37 kmSan Benito County 60 kmAlameda County 81 kmMerced County 81 kmMonterey County 84 kmStanislaus County 85 kmSan Mateo County 85 kmContra Costa 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
Magnitude
M 1.8 (md)
Depth
7.4 km below the surface
Felt
3 reports · strongest reported intensity II
Nearest
Santa Clara County, 30 km NNW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3060 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage. 3 people have reported feeling it to USGS.

How big was it?

This earthquake released about 15 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 1,000,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 730,000× the energy of this one
  3. Around the size people start to feel M 3.0 65× the energy of this one
  4. This earthquake M 1.8 about 15 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.

Where

Epicentre 36.9628, -121.5917. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Santa Clara County, CA 30 km (19 mi) SSE of here earthquakes near Santa Clara County
Santa Cruz County, CA 37 km (23 mi) E of here earthquakes near Santa Cruz County
San Benito County, CA 60 km (37 mi) NW of here earthquakes near San Benito County
Alameda County, CA 81 km (50 mi) SSE of here earthquakes near Alameda County
Merced County, CA 81 km (51 mi) WSW of here earthquakes near Merced County
Monterey County, CA 84 km (52 mi) NNW of here earthquakes near Monterey County

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

Aftershocks so far

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

  1. 1.5 4km ENE of Boulder Creek, CA
  2. 2.0 10km SW of Ridgemark, CA
  3. 1.6 6km NNW of Aromas, CA
  4. 2.1 12km SSE of Tres Pinos, CA
  5. 1.7 6km NNW of Aromas, CA
  6. 1.5 6km NNW of Aromas, CA
  7. 2.0 16km NW of Pinnacles, CA
  8. 1.8 16km NW of Pinnacles, CA
  9. 2.1 16km NW of Pinnacles, CA
  10. 2.8 6km SE of Tres Pinos, CA
  11. 1.5 9km E of Alum Rock, CA
  12. 2.6 9km E of Alum Rock, CA
  13. 1.8 15km NW of Pinnacles, CA
  14. 2.0 15km E of Seven Trees, CA
  15. 1.7 10km NE of San Martin, 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.

For this area

The largest earthquake within 50 km in our catalogue was M 4.6 on 2017-11-13 — it released about 15,000 times the energy of this one.

From the QuakeIndex catalogue, built from the USGS FDSN event service.

On USGS

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