QuakeIndex

Earthquake · reviewed by a seismologist

M 3.0ml

22km W of Bonny Doon, CA

· 8.8 km deep · released about 990 lb of TNT

10 km30 km60 km120 km N Santa Cruz County 35 kmSan Mateo County 38 kmSanta Clara County 64 kmAlameda County 76 kmSan Francisco County 92 kmContra Costa County 102 kmMarin County 113 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 3.0 (ml)
Depth
8.8 km below the surface
Felt
59 reports · strongest reported intensity III
Nearest
Santa Cruz County, 35 km ESE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2131 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage. 59 people have reported feeling it to USGS.

How big was it?

This earthquake released about 990 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.0 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 340,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 15,000× the energy of this one
  3. Magna, Utah 2020 M 5.7 11,000× the energy of this one
  4. This earthquake M 3.0 about 990 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 37.0745, -122.3892. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Santa Cruz County, CA 35 km (21 mi) WNW of here earthquakes near Santa Cruz County
San Mateo County, CA 38 km (24 mi) S of here earthquakes near San Mateo County
Santa Clara County, CA 64 km (40 mi) WSW of here earthquakes near Santa Clara County
Alameda County, CA 76 km (47 mi) SSW of here earthquakes near Alameda County
San Francisco County, CA 92 km (57 mi) SE of here earthquakes near San Francisco County
Contra Costa County, CA 102 km (63 mi) SSW of here earthquakes near Contra Costa County

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

Aftershocks so far

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

  1. 1.6 6km SSE of Portola Valley, CA
  2. 2.5 6km SSE of Portola Valley, CA
  3. 2.2 34km W of Bonny Doon, CA
  4. 2.0 4km SSE of Highlands-Baywood Park, CA
  5. 1.9 11km SW of Bonny Doon, CA
  6. 1.7 22km W of Bonny Doon, CA
  7. 2.7 5km SSW of Lexington Hills, CA
  8. 1.6 3km SSW of Half Moon Bay, CA
  9. 2.2 3km SSW of Half Moon Bay, CA
  10. 1.6 3km SSW of Half Moon Bay, CA
  11. 1.7 4km S of Portola Valley, CA
  12. 1.7 4km S of Portola Valley, CA
  13. 1.7 23km WNW of Bonny Doon, CA
  14. 1.6 3km W of Fruitdale, CA
  15. 1.5 11km WSW of Saratoga, 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.