Earthquake · reviewed by a seismologist
M 1.7md
Earthquake near Milpitas, CA
No earthquake was likely felt in Milpitas in the 24 hours to 4:37 am PST (12:37 UTC). The last one was M 1.6, 9 km (5 mi) NNE, at 5:49 am PDT on 4 October 2026, estimated intensity II (weak) in town. Every earthquake near Milpitas
This page: a magnitude 1.7 earthquake was recorded 9 km (6 mi) northeast of Milpitas, CA, at 1:11 am PDT on 26 April 2018 (08:11 UTC), 8.2 km deep.
USGS: 9km NE of Milpitas, CA
20 km (13 mi) N of San Jose, CA · 8 km (5 mi) NE of Milpitas, CA
- When
- 1:11 am PDT on 26 April 2018 ()
- Where
- 9 km (6 mi) northeast of Milpitas, CA · earthquakes near Milpitas
- Magnitude
- M 1.7 (md)
- Depth
- 8.2 km below the surface
- Felt
- no reports yet
- Nearest
- Alameda County, 20 km NNW
- Nearest mapped fault
- Calaveras fault, 3 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 3115 days ago
Earthquake alerts for Milpitas, CA
Get a notification in this browser when USGS records an earthquake near Milpitas, CA. No account or email needed.
Alerts are on for .
Not a warning. An alert comes after USGS publishes a quake, usually minutes after the shaking. For early warning use ShakeAlert, through your phone's Wireless Emergency Alerts or the MyShake app.
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 9 km (6 mi) from the epicentre. In Milpitas, 9 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: Milpitas 9 km, intensity II. Estimated for each town centre; each link is that town's own record.
How big was it?
This earthquake released about 10 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.7 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 1,500,000× the energy of this one
- Magna, Utah 2020 M 5.7 1,000,000× the energy of this one
- Around the size people start to feel M 3.0 92× the energy of this one
- This earthquake M 1.7 about 10 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 4.1 on 2017-10-10 — about 4,000 times the energy of this one.
Before 2016, the USGS record lists 18 earthquakes of M5 or more within 50 km; the five largest:
- 6.9 The 1989 Loma Prieta, California Earthquake · 50 km S of this epicentre
- 6.5 Near Morgan Hill, California · 44 km SSE of this epicentre
- 6.2 Near San Jose, California · 20 km S of this epicentre
- 6.2 The 1984 Morgan Hill, California Earthquake · 23 km SE of this epicentre
- 6.1 Near San Jose, California · 31 km S 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 37.4800, -121.8260. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Alameda County, CA | 20 km (12 mi) | NNW | earthquakes near Alameda County |
| Santa Clara County, CA | 31 km (19 mi) | SSE | earthquakes near Santa Clara County |
| San Mateo County, CA | 49 km (30 mi) | W | earthquakes near San Mateo County |
| Contra Costa County, CA | 50 km (31 mi) | NNW | earthquakes near Contra Costa County |
| Santa Cruz County, CA | 54 km (34 mi) | SSW | earthquakes near Santa Cruz County |
| San Joaquin County, CA | 70 km (44 mi) | NE | earthquakes near San Joaquin 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.
- 1.8 5km SSW of Loyola, CA
- 2.8 6km SSW of Loyola, CA
- 1.8 5km SSW of Loyola, CA
- 1.6 2km NW of Diablo, CA
- 1.7 2km E of Danville, CA
- 2.4 2km E of Danville, CA
- 1.7 2km ESE of Danville, CA
- 2.8 2km ESE of Danville, CA
- 2.3 15km E of Seven Trees, CA
- 1.6 8km E of Alum Rock, CA
- 1.5 9km ENE of Milpitas, CA
- 3.0 16km E of Seven Trees, CA
- 1.8 3km NW of Diablo, CA
- 1.7 2km NW of Diablo, CA
- 1.8 3km NW of Diablo, 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
- The official USGS event page — the source of record for every value above
- Did you feel it? Report it to USGS — reports go to USGS, not to us
- ShakeMap for this event, when USGS has produced one
QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.