Earthquake · reviewed by a seismologist
M 1.6md
Earthquake near Modesto, CA
No earthquake was likely felt in Modesto in the 24 hours to 9:19 pm PST (05:19 UTC). The last one was M 3.5, 47 km (29 mi) WSW, at 7:21 am PDT on 27 September 2026, estimated intensity II (weak) in town; 8 felt reports to USGS. Every earthquake near Modesto
This page: a magnitude 1.6 earthquake was recorded 27 km (17 mi) west of Modesto, CA, at 9:23 am PDT on 19 March 2020 (16:23 UTC), 10 km deep.
USGS: 10km WNW of Westley, CA
56 km (35 mi) NE of San Jose, CA · 20 km (13 mi) SE of Tracy, CA
- When
- 9:23 am PDT on 19 March 2020 ()
- Where
- 27 km (17 mi) west of Modesto, CA · earthquakes near Modesto
- Magnitude
- M 1.6 (md)
- Depth
- 10 km below the surface
- Felt
- no reports yet
- Nearest
- Stanislaus County, 26 km E
- Nearest mapped fault
- Great Valley thrust fault system, 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 2428 days ago
Earthquake alerts for Modesto, CA
Get a notification in this browser when USGS records an earthquake near Modesto, 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 3 km (2 mi) from the epicentre. In Modesto, 27 km away, the estimate is intensity I (not felt). 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.
Earthquakes near other towns within 30 km: Patterson, Tracy, Riverdale Park, Ripon, Salida, West Modesto.
How big was it?
This earthquake released about 6.4 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.5 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 2,400,000× the energy of this one
- Magna, Utah 2020 M 5.7 1,700,000× the energy of this one
- Around the size people start to feel M 3.0 150× the energy of this one
- This earthquake M 1.6 about 6.4 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 4.3 on 2019-07-16 — about 14,000 times the energy of this one.
Before 2016, the USGS record lists 7 earthquakes of M5 or more within 50 km; the five largest:
- 6.2 The 1984 Morgan Hill, California Earthquake · 46 km SW of this epicentre
- 5.8 The 1980 Livermore, California Earthquake · 50 km NW of this epicentre
- 5.7 15 km NE of East Foothills, California · 37 km WSW of this epicentre
- 5.5 6 km NNE of East Foothills, California · 46 km WSW of this epicentre
- 5.4 9 km NE of Livermore, California · 40 km WNW 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 37.5918, -121.2962. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Stanislaus County, CA | 26 km (16 mi) | E | earthquakes near Stanislaus County |
| San Joaquin County, CA | 38 km (24 mi) | N | earthquakes near San Joaquin County |
| Santa Clara County, CA | 54 km (33 mi) | SW | earthquakes near Santa Clara County |
| Alameda County, CA | 55 km (34 mi) | W | earthquakes near Alameda County |
| Merced County, CA | 67 km (42 mi) | SE | earthquakes near Merced County |
| Contra Costa County, CA | 68 km (42 mi) | WNW | earthquakes near Contra Costa 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.
- 1.8 10km E of Alum Rock, CA
- 1.8 10km ENE of Milpitas, CA
- 1.5 9km WSW of Mountain House, CA
- 1.6 8km WSW of Mountain House, CA
- 1.6 8km NE of Alum Rock, CA
- 2.1 10km NE of Milpitas, CA
- 1.6 10km NE of Milpitas, CA
- 2.1 10km NE of Milpitas, CA
- 2.9 10km NE of Milpitas, CA
- 3.5 10km NE of Milpitas, CA
- 1.9 9km E of Alum Rock, CA
- 1.9 15km E of Seven Trees, CA
- 3.0 8km NE of Alum Rock, CA
- 2.5 11km SSW of Brentwood, CA
- 2.6 11km ENE 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
- 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.