QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8md

Earthquake near Ahwahnee, CA

No earthquake was likely felt in Ahwahnee in the 24 hours to 6:02 pm PST (02:02 UTC). The last one was M 2.7, 17 km (11 mi) SW, at 7:57 pm PDT on 28 April 2026, estimated intensity II (weak) in town; 25 felt reports to USGS. Every earthquake near Ahwahnee

This page: a magnitude 1.8 earthquake was recorded 16 km (10 mi) west-southwest of Ahwahnee, CA, at 2:27 am PST on 20 February 2019 (10:27 UTC), 27 km deep. 1 person has reported feeling it to USGS.

USGS: 16km WSW of Ahwahnee, CA

60 km (37 mi) N of Fresno, CA · 42 km (26 mi) NNE of Madera, CA

2:27 am PST, Feb 20, 2019 · · 27 km deep · released about 16 lb of TNT

10 km30 km60 km120 km N Madera County 17 kmMariposa County 29 kmFresno County 65 kmMerced County 74 kmTuolumne County 79 kmStanislaus County 101 kmMono County 112 kmCalaveras County 113 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
2:27 am PST on 20 February 2019 ()
Where
16 km (10 mi) west-southwest of Ahwahnee, CA · earthquakes near Ahwahnee
Magnitude
M 1.8 (md)
Depth
27 km below the surface
Felt
1 report · strongest reported intensity III
Nearest
Madera County, 17 km SE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2823 days ago

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 Ahwahnee, 16 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: Yosemite Lakes, Coarsegold, Mariposa, Oakhurst, Midpines.

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.

  1. Mineral, Virginia 2011 M 5.8 930,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 660,000× the energy of this one
  3. Around the size people start to feel M 3.0 59× the energy of this one
  4. 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 37.3148, -119.8967. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Madera County, CA 17 km (11 mi) SE earthquakes near Madera County
Mariposa County, CA 29 km (18 mi) N earthquakes near Mariposa County
Fresno County, CA 65 km (41 mi) SSE earthquakes near Fresno County
Merced County, CA 74 km (46 mi) W earthquakes near Merced County
Tuolumne County, CA 79 km (49 mi) N earthquakes near Tuolumne County
Stanislaus County, CA 101 km (63 mi) WNW earthquakes near Stanislaus County

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

Aftershocks so far

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

  1. 1.6 12km N of North Fork, CA
  2. 1.6 10km S of Bootjack, CA
  3. 1.9 10km SSE of Bootjack, CA
  4. 1.6 11km SSE of Bootjack, CA
  5. 2.1 10km SSE of Bootjack, CA
  6. 1.9 12km WSW of Madera, CA
  7. 2.0 9km SW of Mariposa, CA
  8. 1.6 10km W of Ahwahnee, CA
  9. 1.8 3km SSW of Parkwood, CA
  10. 1.9 7km W of Yosemite Lakes, CA
  11. 1.6 7km NNE of Oakhurst, CA
  12. 1.6 18km SSW of Bootjack, CA
  13. 2.3 19km WNW of Yosemite Lakes, CA
  14. 1.8 3km W of Madera Acres, CA
  15. 2.3 6km W of Madera, 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.