QuakeIndex

Earthquake · reviewed by a seismologist

M 1.6md

2km ENE of Pacifica, CA

· 12 km deep · released about 7.6 lb of TNT

10 km30 km60 km120 km N San Mateo County 25 kmAlameda County 49 kmSan Francisco County 51 kmMarin County 54 kmContra Costa County 56 kmSanta Cruz County 79 kmSanta Clara County 82 kmSolano County 85 kmNapa County 99 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 1.6 (md)
Depth
12 km below the surface
Felt
no reports yet
Nearest
San Mateo County, 25 km SSE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1684 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 7.6 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.6 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 2,000,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,400,000× the energy of this one
  3. Around the size people start to feel M 3.0 130× the energy of this one
  4. This earthquake M 1.6 about 7.6 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 37.6217, -122.4670. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
San Mateo County, CA 25 km (15 mi) NNW of here earthquakes near San Mateo County
Alameda County, CA 49 km (30 mi) W of here earthquakes near Alameda County
San Francisco County, CA 51 km (32 mi) ESE of here earthquakes near San Francisco County
Marin County, CA 54 km (33 mi) SSE of here earthquakes near Marin County
Contra Costa County, CA 56 km (35 mi) SW of here earthquakes near Contra Costa County
Santa Cruz County, CA 79 km (49 mi) NNW of here earthquakes near Santa Cruz County

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

Aftershocks so far

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

  1. 1.8 3km NW of Orinda, CA
  2. 1.9 3km ESE of Pacifica, CA
  3. 1.7 5km WSW of Colma, CA
  4. 1.8 3km NNE of San Leandro, CA
  5. 1.5 6km S of Portola Valley, CA
  6. 1.9 4km W of Pleasant Hill, CA
  7. 1.8 2km E of Walnut Creek, CA
  8. 1.5 4km WNW of Orinda, CA
  9. 1.6 6km WNW of Dublin, CA
  10. 1.7 3km ESE of Pacifica, CA
  11. 1.9 3km ESE of Pacifica, CA
  12. 1.8 3km ESE of Pacifica, CA
  13. 1.8 7km SSE of Portola Valley, CA
  14. 1.7 1km W of Pacifica, CA
  15. 2.2 1km WSW of Pacifica, 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 4.4 on 2018-01-04 — 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.