QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8md

8km WSW of Gilroy, CA

· 5.6 km deep · released about 14 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Santa Clara County 26 kmSanta Cruz County 32 kmSan Benito County 65 kmAlameda County 77 kmSan Mateo County 80 kmMerced County 85 kmStanislaus County 86 kmMonterey County 88 kmContra Costa County 107 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
5.6 km below the surface
Felt
no reports yet
Nearest
Santa Clara County, 26 km N
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3078 days ago

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

How big was it?

This earthquake released about 14 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 5.7 790,000× the energy of this one
  3. Around the size people start to feel M 3.0 70× the energy of this one
  4. This earthquake M 1.8 about 14 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 36.9857, -121.6485. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Santa Clara County, CA 26 km (16 mi) S of here earthquakes near Santa Clara County
Santa Cruz County, CA 32 km (20 mi) E of here earthquakes near Santa Cruz County
San Benito County, CA 65 km (40 mi) NW of here earthquakes near San Benito County
Alameda County, CA 77 km (48 mi) SSE of here earthquakes near Alameda County
San Mateo County, CA 80 km (50 mi) SE of here earthquakes near San Mateo County
Merced County, CA 85 km (53 mi) WSW of here earthquakes near Merced County

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

Aftershocks so far

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

  1. 2.3 15km E of Seven Trees, CA
  2. 1.6 8km E of Alum Rock, CA
  3. 1.6 9km E of San Martin, CA
  4. 3.0 16km E of Seven Trees, CA
  5. 3.1 15km SSE of Tres Pinos, CA
  6. 2.1 10km SSW of Ridgemark, CA
  7. 2.7 10km SSW of Ridgemark, CA
  8. 2.0 8km ENE of Gilroy, CA
  9. 1.7 3km SSW of San Juan Bautista, CA
  10. 2.3 3km SSW of San Juan Bautista, CA
  11. 2.3 9km ENE of San Martin, CA
  12. 2.0 15km N of Morgan Hill, CA
  13. 3.1 14km N of Morgan Hill, CA
  14. 1.8 4km SSE of San Juan Bautista, CA
  15. 1.8 5km NNW of Aromas, 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 4.2 on 2016-07-19 — it released about 4,700 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.