Earthquake · reviewed by a seismologist
M 1.8md
Earthquake near Mariposa, CA
No earthquake was likely felt in Mariposa in the 24 hours to 11:51 am PST (19:51 UTC). The last one was M 5.7, 222 km (138 mi) NNE, at 6:29 pm PDT on 13 April 2026, estimated intensity II (weak) in town; 6,515 felt reports to USGS. Every earthquake near Mariposa
This page: a magnitude 1.8 earthquake was recorded 13 km (8 mi) south of Mariposa, CA, at 4:36 pm PDT on 23 March 2021 (23:36 UTC), 27 km deep.
USGS: 13km S of Mariposa, CA
67 km (42 mi) NNW of Fresno, CA · 43 km (27 mi) E of Merced, CA
- When
- 4:36 pm PDT on 23 March 2021 ()
- Where
- 13 km (8 mi) south of Mariposa, CA · earthquakes near Mariposa
- Magnitude
- M 1.8 (md)
- Depth
- 27 km below the surface
- Felt
- no reports yet
- Nearest
- Mariposa County, 24 km NNE
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 2060 days ago
Earthquake alerts for Mariposa, 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 it was probably too small to be felt, even directly above it. In Mariposa, 13 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.
Earthquakes near other towns within 30 km: Midpines, Ahwahnee, Le Grand, Yosemite Lakes, Coarsegold, Planada.
How big was it?
This earthquake released about 16 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.
- Mineral, Virginia 2011 M 5.8 930,000× the energy of this one
- Magna, Utah 2020 M 5.7 660,000× the energy of this one
- Around the size people start to feel M 3.0 59× the energy of this one
- This earthquake M 1.8 about 16 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
No earthquake of M4 or more has been recorded within 50 km since our catalogue begins in 2016.
Before 2016, the USGS record since 1900 lists no earthquake of M5 or more within 50 km.
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 37.3677, -119.9948. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Mariposa County, CA | 24 km (15 mi) | NNE | earthquakes near Mariposa County |
| Madera County, CA | 28 km (17 mi) | SE | earthquakes near Madera County |
| Merced County, CA | 67 km (42 mi) | WSW | earthquakes near Merced County |
| Tuolumne County, CA | 73 km (45 mi) | N | earthquakes near Tuolumne County |
| Fresno County, CA | 74 km (46 mi) | SSE | earthquakes near Fresno County |
| Stanislaus County, CA | 92 km (57 mi) | WNW | earthquakes near Stanislaus County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
54 earthquakes have been recorded within 50 km since this one.
- 2.2 7km NE of Bonadelle Ranchos-Madera Ranchos, CA
- 1.5 3km WSW of Oakhurst, CA
- 1.7 9km ENE of Midpines, CA
- 2.2 22km ENE of Le Grand, CA
- 2.1 5km ENE of Bonadelle Ranchos-Madera Ranchos, CA
- 2.2 13km SSW of Mariposa, CA
- 1.8 12km NNE of North Fork, CA
- 2.1 6km NE of Bonadelle Ranchos-Madera Ranchos, CA
- 2.4 21km SSW of Mariposa, CA
- 1.7 21km E of Le Grand, CA
- 1.9 6km ENE of Bonadelle Ranchos-Madera Ranchos, CA
- 2.1 19km SSW of Mariposa, CA
- 2.0 7km NE of Bonadelle Ranchos-Madera Ranchos, CA
- 2.0 17km SSW of Bootjack, CA
- 2.0 8km W of North Fork, 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.