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 4:24 am PST (12:24 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 4 km (3 mi) north-northwest of San Leandro, CA, at 3:52 am PDT on 2 October 2018 (10:52 UTC), 9.8 km deep.

USGS: 4km NNW of San Leandro, CA

in Oakland, CA

3:52 am PDT, Oct 2, 2018 · · 9.8 km deep · released about 8.1 lb of TNT

10 km30 km60 km120 km N Contra Costa County 26 kmAlameda County 26 kmSan Mateo County 42 kmMarin County 60 kmSolano County 60 kmSanta Clara County 74 kmSan Francisco County 76 kmSan Joaquin County 82 kmNapa County 84 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
3:52 am PDT on 2 October 2018 ()
Where
4 km (3 mi) north-northwest of San Leandro, CA · earthquakes near San Leandro
Magnitude
M 1.6 (md)
Depth
9.8 km below the surface
Felt
no reports yet
Nearest
Contra Costa County, 26 km NE
Nearest mapped fault
Hayward fault, 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 2963 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 6 km (4 mi) from the epicentre. In San Leandro, 4 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 4 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 4.4 on 2018-01-04 — about 14,000 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 · 33 km W of this epicentre
  2. 5.8 The 1980 Livermore, California Earthquake · 37 km ENE of this epicentre
  3. 5.4 9 km NE of Livermore, California · 41 km E of this epicentre
  4. 5.3 The 1957 San Francisco, California Earthquake · 29 km WSW of this epicentre
  5. 5.1 11 km E of Blackhawk, California · 36 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 37.7622, -122.1743. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Contra Costa County, CA 26 km (16 mi) NE earthquakes near Contra Costa County
Alameda County, CA 26 km (16 mi) ESE earthquakes near Alameda County
San Mateo County, CA 42 km (26 mi) SSW earthquakes near San Mateo County
Marin County, CA 60 km (37 mi) WNW earthquakes near Marin County
Solano County, CA 60 km (37 mi) NNE earthquakes near Solano County
Santa Clara County, CA 74 km (46 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

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

  1. 2.3 1km NNW of San Pablo, CA
  2. 1.6 5km SW of Dublin, CA
  3. 1.7 1km E of Pacheco, CA
  4. 2.0 3km ENE of San Leandro, CA
  5. 1.6 5km E of San Ramon, CA
  6. 1.5 3km S of Loyola, CA
  7. 2.4 2km NW of Pittsburg, CA
  8. 1.5 2km ENE of Hayward, CA
  9. 1.5 3km SSW of Loyola, CA
  10. 2.5 1km WNW of Crockett, CA
  11. 1.6 9km ENE of Milpitas, CA
  12. 1.5 3km S of Loyola, CA
  13. 1.5 3km S of Loyola, CA
  14. 1.7 9km NNE of Milpitas, CA
  15. 1.6 5km E of Fremont, 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.