Earthquake · reviewed by a seismologist
M 1.7md
Earthquake near Milpitas, CA
No earthquake was likely felt in Milpitas in the 24 hours to 5:38 am PST (13:38 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) north-northeast of Milpitas, CA, at 5:32 am PST on 5 December 2018 (13:32 UTC), 7.0 km deep.
USGS: 9km NNE of Milpitas, CA
22 km (14 mi) N of San Jose, CA · 8 km (5 mi) NNE of Milpitas, CA
- When
- 5:32 am PST on 5 December 2018 ()
- Where
- 9 km (6 mi) north-northeast of Milpitas, CA · earthquakes near Milpitas
- Magnitude
- M 1.7 (md)
- Depth
- 7.0 km below the surface
- Felt
- no reports yet
- Nearest
- Alameda County, 18 km NNW
- Nearest mapped fault
- Hayward fault, 4 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 2898 days ago
Earthquake alerts for Milpitas, CA
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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 10 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 11 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 1,300,000× the energy of this one
- Magna, Utah 2020 M 5.7 930,000× the energy of this one
- Around the size people start to feel M 3.0 83× the energy of this one
- This earthquake M 1.7 about 11 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 3,600 times the energy of this one.
Before 2016, the USGS record lists 16 earthquakes of M5 or more within 50 km; the five largest:
- 6.5 Near Morgan Hill, California · 47 km SSE of this epicentre
- 6.2 Near San Jose, California · 22 km SSE of this epicentre
- 6.2 The 1984 Morgan Hill, California Earthquake · 26 km SE of this epicentre
- 6.1 Near San Jose, California · 33 km S of this epicentre
- 5.8 7 km NNW of Boulder Creek, California · 43 km SW 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 37.4962, -121.8515. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Alameda County, CA | 18 km (11 mi) | NNW | earthquakes near Alameda County |
| Santa Clara County, CA | 34 km (21 mi) | SSE | earthquakes near Santa Clara County |
| San Mateo County, CA | 47 km (29 mi) | W | earthquakes near San Mateo County |
| Contra Costa County, CA | 48 km (30 mi) | N | earthquakes near Contra Costa County |
| Santa Cruz County, CA | 56 km (35 mi) | SSW | earthquakes near Santa Cruz County |
| San Joaquin County, CA | 71 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
49 earthquakes have been recorded within 50 km since this one.
- 1.7 3km WNW of Diablo, CA
- 1.5 3km S of Loyola, CA
- 2.3 8km E of Alum Rock, CA
- 1.7 11km SE of Livermore, CA
- 2.5 12km NNE of Morgan Hill, CA
- 2.7 3km NNE of San Ramon, CA
- 2.8 3km NE of Oakland, CA
- 2.4 17km ESE of Livermore, CA
- 1.8 8km SSE of Portola Valley, CA
- 2.1 3km SW of Monte Sereno, CA
- 2.0 11km NNE of Alum Rock, CA
- 1.8 12km SSW of Mountain House, CA
- 1.7 12km SSW of Mountain House, CA
- 1.6 14km ESE of Livermore, CA
- 2.0 10km ENE of Blackhawk, 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.