QuakeIndex

Earthquake · reviewed by a seismologist

M 1.6md

Earthquake near San Leandro, CA

No earthquake was likely felt in San Leandro in the 24 hours to 3:43 am PST (11:43 UTC). The last one was M 2.6, 18 km (11 mi) NNW, at 6:23 pm PST on 1 November 2026, estimated intensity II (weak) in town; 114 felt reports to USGS. Every earthquake near San Leandro

This page: a magnitude 1.6 earthquake was recorded 6 km (4 mi) north of San Leandro, CA, at 12:44 pm PDT on 2 November 2021 (19:44 UTC), 9.0 km deep.

USGS: 6km N of San Leandro, CA

7 km (4 mi) E of Oakland, CA

12:44 pm PDT, Nov 2, 2021 · · 9.0 km deep · released about 8.1 lb of TNT

10 km30 km60 km120 km N Contra Costa County 23 kmAlameda County 26 kmSan Mateo County 45 kmSolano County 57 kmMarin County 60 kmSanta Clara County 74 kmSan Francisco County 78 kmSan Joaquin County 79 kmNapa County 82 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
12:44 pm PDT on 2 November 2021 ()
Where
6 km (4 mi) north of San Leandro, CA · earthquakes near San Leandro
Magnitude
M 1.6 (md)
Depth
9.0 km below the surface
Felt
no reports yet
Nearest
Contra Costa County, 23 km NE
Nearest mapped fault
Hayward fault, 2 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 1828 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 7 km (4 mi) from the epicentre. In San Leandro, 6 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: San Leandro 6 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 8.1 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 1,900,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,300,000× the energy of this one
  3. Around the size people start to feel M 3.0 120× the energy of this one
  4. This earthquake M 1.6 about 8.1 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 4.5 on 2019-10-15 — about 18,000 times the energy of this one.

Before 2016, the USGS record lists 5 earthquakes of M5 or more within 50 km:

  1. 7.9 The 1906 San Francisco, California Earthquake · 35 km W of this epicentre
  2. 5.8 The 1980 Livermore, California Earthquake · 34 km E of this epicentre
  3. 5.4 9 km NE of Livermore, California · 39 km E of this epicentre
  4. 5.3 The 1957 San Francisco, California Earthquake · 32 km WSW of this epicentre
  5. 5.1 11 km E of Blackhawk, California · 33 km E 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 37.7803, -122.1520. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Contra Costa County, CA 23 km (15 mi) NE earthquakes near Contra Costa County
Alameda County, CA 26 km (16 mi) SE earthquakes near Alameda County
San Mateo County, CA 45 km (28 mi) SSW earthquakes near San Mateo County
Solano County, CA 57 km (36 mi) NNE earthquakes near Solano County
Marin County, CA 60 km (37 mi) WNW earthquakes near Marin County
Santa Clara County, CA 74 km (46 mi) SSE earthquakes near Santa Clara County

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

Aftershocks so far

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

  1. 1.5 4km WSW of Colma, CA
  2. 1.7 5km WSW of Pacheco, CA
  3. 1.5 2km NE of Union City, CA
  4. 1.7 11km NE of Milpitas, CA
  5. 2.6 2km SW of Colma, CA
  6. 1.5 10km ENE of Milpitas, CA
  7. 1.5 2km S of Alamo, CA
  8. 2.3 4km NE of Fairview, CA
  9. 1.6 2km NE of San Ramon, CA
  10. 1.9 1km NW of Danville, CA
  11. 1.7 1km WNW of Danville, CA
  12. 2.0 1km N of Pacifica, CA
  13. 1.6 6km E of Vallejo, CA
  14. 1.6 3km SSW of Half Moon Bay, CA
  15. 2.3 2km SW of Discovery Bay, 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.