QuakeIndex

Earthquake · reviewed by a seismologist

M 2.3md

Earthquake near San Leandro, CA

No earthquake was likely felt in San Leandro in the 24 hours to 3:16 am PST (11:16 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 2.3 earthquake was recorded in San Leandro, CA, at 6:38 pm PST on 7 December 2019 (02:38 UTC), 4.3 km deep. 55 people have reported feeling it to USGS.

USGS: 2km ENE of San Leandro, CA

9 km (6 mi) ESE of Oakland, CA · in San Leandro, CA

6:38 pm PST, Dec 7, 2019 · · 4.3 km deep · released about 74 lb of TNT

10 km30 km60 km120 km N Alameda County 22 kmContra Costa County 27 kmSan Mateo County 41 kmSolano County 62 kmMarin County 64 kmSanta Clara County 69 kmSan Francisco County 79 kmSan Joaquin County 79 kmSanta Cruz County 81 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
6:38 pm PST on 7 December 2019 ()
Where
in San Leandro, CA · earthquakes near San Leandro
Magnitude
M 2.3 (md)
Depth
4.3 km below the surface
Felt
55 reports · strongest reported intensity III
Nearest
Alameda County, 22 km ESE
Nearest mapped fault
Hayward fault, under 1 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 2257 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 19 km (12 mi) from the epicentre. 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 in town, intensity III · Castro Valley 6 km, intensity II · San Lorenzo 6 km, intensity II · Hayward 8 km, intensity II · Alameda 12 km, intensity II · Oakland 14 km, intensity II · San Ramon 15 km, intensity II · Danville 16 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 74 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.3 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 200,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 140,000× the energy of this one
  3. Around the size people start to feel M 3.0 13× the energy of this one
  4. This earthquake M 2.3 about 74 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 2,000 times the energy of this one.

Before 2016, the USGS record lists 7 earthquakes of M5 or more within 50 km; the five largest:

  1. 7.9 The 1906 San Francisco, California Earthquake · 36 km W of this epicentre
  2. 5.8 The 1980 Livermore, California Earthquake · 35 km ENE of this epicentre
  3. 5.7 15 km NE of East Foothills, California · 48 km SE of this epicentre
  4. 5.5 6 km NNE of East Foothills, California · 46 km SE of this epicentre
  5. 5.4 9 km NE of Livermore, California · 38 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 37.7305, -122.1365. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Alameda County, CA 22 km (14 mi) ESE earthquakes near Alameda County
Contra Costa County, CA 27 km (17 mi) NE earthquakes near Contra Costa County
San Mateo County, CA 41 km (25 mi) SSW earthquakes near San Mateo County
Solano County, CA 62 km (39 mi) NNE earthquakes near Solano County
Marin County, CA 64 km (40 mi) NW earthquakes near Marin County
Santa Clara County, CA 69 km (43 mi) SE earthquakes near Santa Clara County

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

Aftershocks so far

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

  1. 2.1 1km NE of Diablo, CA
  2. 1.8 0km E of Diablo, CA
  3. 1.5 0km E of Diablo, CA
  4. 1.7 2km ESE of Woodside, CA
  5. 1.5 2km WNW of Concord, CA
  6. 1.7 3km ENE of San Ramon, CA
  7. 1.7 6km SSE of Portola Valley, CA
  8. 1.7 9km NNE of Alum Rock, CA
  9. 2.9 5km NE of Alum Rock, CA
  10. 1.6 3km WSW of Portola Valley, CA
  11. 2.0 3km WSW of Portola Valley, CA
  12. 1.9 2km SE of Pacheco, CA
  13. 1.7 5km NW of Sunol, CA
  14. 2.1 2km NW of Concord, CA
  15. 1.8 8km NE of Alum Rock, 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.