QuakeIndex

Earthquake · reviewed by a seismologist

M 2.2md

Earthquake near Woodside, CA

No earthquake was likely felt in Woodside in the 24 hours to 5:27 am PST (13:27 UTC). The last one was M 1.9, in Woodside, at 4:14 pm PDT on 11 October 2026, estimated intensity II (weak) in town; 1 felt report to USGS. Every earthquake near Woodside

This page: a magnitude 2.2 earthquake was recorded 3 km (2 mi) east-southeast of Woodside, CA, at 2:51 pm PST on 1 February 2024 (22:51 UTC), 3.7 km deep. 9 people have reported feeling it to USGS.

USGS: 3 km ESE of Woodside, CA

8 km (5 mi) WNW of Palo Alto, CA · 39 km (24 mi) WNW of San Jose, CA

2:51 pm PST, Feb 1, 2024 · · 3.7 km deep · released about 56 lb of TNT

10 km30 km60 km120 km N San Mateo County 13 kmAlameda County 38 kmSanta Cruz County 49 kmSanta Clara County 52 kmContra Costa County 61 kmSan Francisco County 79 kmMarin County 84 kmSolano County 98 kmSan Joaquin County 102 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
2:51 pm PST on 1 February 2024 ()
Where
3 km (2 mi) east-southeast of Woodside, CA · earthquakes near Woodside
Magnitude
M 2.2 (md)
Depth
3.7 km below the surface
Felt
9 reports · strongest reported intensity III
Nearest
San Mateo County, 13 km W
Nearest mapped fault
San Andreas fault, 3 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 1004 days ago

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

At this magnitude and depth, people at rest would likely notice it out to about 18 km (11 mi) from the epicentre. In Woodside, 3 km away, the estimate is intensity II (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: Menlo Park 6 km, intensity II · Palo Alto 8 km, intensity II · Redwood City 8 km, intensity II · East Palo Alto 9 km, intensity II · Los Altos 10 km, intensity II · San Carlos 11 km, intensity II · Belmont 12 km, intensity II · Mountain View 13 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 56 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.2 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 270,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 190,000× the energy of this one
  3. Around the size people start to feel M 3.0 17× the energy of this one
  4. This earthquake M 2.2 about 56 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 4.4 on 2018-01-04 — about 2,000 times the energy of this one.

Before 2016, the USGS record lists 15 earthquakes of M5 or more within 50 km; the five largest:

  1. 7.9 The 1906 San Francisco, California Earthquake · 47 km NW of this epicentre
  2. 6.2 Near San Jose, California · 40 km ESE of this epicentre
  3. 6.2 The 1984 Morgan Hill, California Earthquake · 50 km ESE of this epicentre
  4. 6.1 Near San Jose, California · 45 km ESE of this epicentre
  5. 5.8 7 km NNW of Boulder Creek, California · 26 km SSE 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 37.4158, -122.2247. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
San Mateo County, CA 13 km (8 mi) W earthquakes near San Mateo County
Alameda County, CA 38 km (23 mi) NE earthquakes near Alameda County
Santa Cruz County, CA 49 km (30 mi) SSE earthquakes near Santa Cruz County
Santa Clara County, CA 52 km (32 mi) ESE earthquakes near Santa Clara County
Contra Costa County, CA 61 km (38 mi) NNE earthquakes near Contra Costa County
San Francisco County, CA 79 km (49 mi) WNW earthquakes near San Francisco County

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

Aftershocks so far

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

  1. 1.8 7 km SSE of Sunol, CA
  2. 1.6 8 km NE of Alum Rock, CA
  3. 2.3 8 km NE of Alum Rock, CA
  4. 3.4 8 km NE of Alum Rock, CA
  5. 1.5 4 km NNW of Pacifica, CA
  6. 2.3 9 km ESE of Fremont, CA
  7. 1.5 2 km SW of Alamo, CA
  8. 2.2 4 km N of San Leandro, CA
  9. 2.1 3 km NE of San Leandro, CA
  10. 2.0 3 km N of San Leandro, CA
  11. 2.4 3 km N of San Leandro, CA
  12. 2.1 22 km WNW of Boulder Creek, CA
  13. 2.1 9 km E of Milpitas, CA
  14. 2.1 4 km NNE of Day Valley, CA
  15. 1.5 6 km ENE of Burlingame, 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.