QuakeIndex

Earthquake · reviewed by a seismologist

M 1.9md

Earthquake near San Leandro, CA

No earthquake was likely felt in San Leandro in the 24 hours to 12:52 am PST (08:52 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 1.9 earthquake was recorded in San Leandro, CA, at 11:40 pm PST on 25 December 2020 (07:40 UTC), 7.0 km deep. 1 person has reported feeling it to USGS.

USGS: 2km NNE of San Leandro, CA

8 km (5 mi) ESE of Oakland, CA · in San Leandro, CA

11:40 pm PST, Dec 25, 2020 · · 7.0 km deep · released about 25 lb of TNT

10 km30 km60 km120 km N Alameda County 23 kmContra Costa County 26 kmSan Mateo County 41 kmSolano County 62 kmMarin County 63 kmSanta Clara County 70 kmSan Francisco County 78 kmSan Joaquin County 80 kmSanta Cruz 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
11:40 pm PST on 25 December 2020 ()
Where
in San Leandro, CA · earthquakes near San Leandro
Magnitude
M 1.9 (md)
Depth
7.0 km below the surface
Felt
1 report · strongest reported intensity I
Nearest
Alameda County, 23 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 2140 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 14 km (9 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 II · San Lorenzo 7 km, intensity II · Castro Valley 7 km, intensity II · Hayward 10 km, intensity II · Alameda 11 km, intensity II · Oakland 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 25 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.9 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 620,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 440,000× the energy of this one
  3. Around the size people start to feel M 3.0 39× the energy of this one
  4. This earthquake M 1.9 about 25 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 6,000 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 · 35 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 · 50 km SE of this epicentre
  4. 5.5 6 km NNE of East Foothills, California · 47 km SE of this epicentre
  5. 5.4 9 km NE of Livermore, California · 39 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 37.7390, -122.1482. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Alameda County, CA 23 km (14 mi) ESE earthquakes near Alameda County
Contra Costa County, CA 26 km (16 mi) NE earthquakes near Contra Costa County
San Mateo County, CA 41 km (26 mi) SSW earthquakes near San Mateo County
Solano County, CA 62 km (38 mi) NNE earthquakes near Solano County
Marin County, CA 63 km (39 mi) WNW earthquakes near Marin County
Santa Clara County, CA 70 km (44 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

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

  1. 1.6 6km ESE of Fairview, CA
  2. 1.6 3km WSW of Blackhawk, CA
  3. 1.6 2km N of San Ramon, CA
  4. 1.9 6km E of Milpitas, CA
  5. 2.3 2km SE of Danville, CA
  6. 1.8 2km ESE of Berkeley, CA
  7. 2.1 11km NE of Milpitas, CA
  8. 2.6 1km ENE of Union City, CA
  9. 1.6 8km ESE of Fremont, CA
  10. 1.8 4km NE of Pleasanton, CA
  11. 2.7 8km ESE of Fremont, CA
  12. 1.9 6km N of Alum Rock, CA
  13. 2.0 0km SE of Pleasant Hill, CA
  14. 2.1 8km ESE of Fremont, CA
  15. 2.0 11km NE of Milpitas, 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.