QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8md

Earthquake near Hayward, CA

No earthquake was likely felt in Hayward in the 24 hours to 3:20 am PST (11:20 UTC). The last one was M 1.9, 9 km (6 mi) E, at 10:32 am PST on 2 November 2026, estimated intensity II (weak) in town. Every earthquake near Hayward

This page: a magnitude 1.8 earthquake was recorded 5 km (3 mi) southeast of Hayward, CA, at 10:20 pm PDT on 18 July 2018 (05:20 UTC), 4.0 km deep. 4 people have reported feeling it to USGS.

USGS: 3km E of Hayward, CA

6 km (4 mi) ENE of Hayward, CA · in Union City, CA

10:20 pm PDT, Jul 18, 2018 · · 4.0 km deep · released about 17 lb of TNT

10 km30 km60 km120 km N Alameda County 11 kmContra Costa County 32 kmSan Mateo County 38 kmSanta Clara County 56 kmSanta Cruz County 70 kmSolano County 70 kmSan Joaquin County 75 kmMarin County 77 kmSan Francisco County 88 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
10:20 pm PDT on 18 July 2018 ()
Where
5 km (3 mi) southeast of Hayward, CA · earthquakes near Hayward
Magnitude
M 1.8 (md)
Depth
4.0 km below the surface
Felt
4 reports · strongest reported intensity III
Nearest
Alameda County, 11 km E
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 3037 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 13 km (8 mi) from the epicentre. In Hayward, 5 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: Hayward 5 km, intensity II · Union City 5 km, intensity II · Castro Valley 7 km, intensity II · San Lorenzo 9 km, intensity II · Fremont 11 km, intensity II · Dublin 12 km, intensity II · Newark 12 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 17 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.8 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 870,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 620,000× the energy of this one
  3. Around the size people start to feel M 3.0 55× the energy of this one
  4. This earthquake M 1.8 about 17 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 6,500 times the energy of this one.

Before 2016, the USGS record lists 11 earthquakes of M5 or more within 50 km; the five largest:

  1. 7.9 The 1906 San Francisco, California Earthquake · 46 km WNW of this epicentre
  2. 6.2 Near San Jose, California · 43 km SSE of this epicentre
  3. 6.2 The 1984 Morgan Hill, California Earthquake · 49 km SE of this epicentre
  4. 5.8 The 1980 Livermore, California Earthquake · 33 km NE of this epicentre
  5. 5.7 15 km NE of East Foothills, California · 36 km ESE 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 37.6408, -122.0415. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Alameda County, CA 11 km (7 mi) E earthquakes near Alameda County
Contra Costa County, CA 32 km (20 mi) NNE earthquakes near Contra Costa County
San Mateo County, CA 38 km (24 mi) SW earthquakes near San Mateo County
Santa Clara County, CA 56 km (35 mi) SE earthquakes near Santa Clara County
Santa Cruz County, CA 70 km (43 mi) S earthquakes near Santa Cruz County
Solano County, CA 70 km (44 mi) N earthquakes near Solano County

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

Aftershocks so far

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

  1. 1.5 3km ESE of Berkeley, CA
  2. 1.7 3km NW of Diablo, CA
  3. 2.3 16km SSE of Livermore, CA
  4. 1.6 3km WSW of San Francisco Zoo, CA
  5. 1.6 4km NNW of San Leandro, CA
  6. 1.8 6km ESE of San Ramon, CA
  7. 1.9 18km SSE of Livermore, CA
  8. 1.6 6km ESE of San Ramon, CA
  9. 1.6 9km WSW of Brentwood, CA
  10. 2.0 4km SW of Colma, CA
  11. 1.6 4km WSW of Daly City, CA
  12. 1.9 2km N of San Leandro, CA
  13. 1.8 2km E of San Leandro, CA
  14. 1.8 5km S of Alameda, CA
  15. 1.8 11km ESE of Sunol, 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.