QuakeIndex

Earthquake · reviewed by a seismologist

M 1.7md

Earthquake near Guadalupe, CA

No earthquake was likely felt in Guadalupe in the 24 hours to 10:21 am PST (18:21 UTC). The last one was M 4.1, 68 km (42 mi) NNW, at 9:54 am PST on 18 November 2025, estimated intensity II (weak) in town; 1,099 felt reports to USGS. Every earthquake near Guadalupe

This page: a magnitude 1.7 earthquake was recorded 15 km (9 mi) west of Guadalupe, CA, at 8:46 am PDT on 21 March 2019 (15:46 UTC), 1.8 km deep.

USGS: 15km W of Guadalupe, CA

27 km (16 mi) W of Santa Maria, CA

8:46 am PDT, Mar 21, 2019 · · 1.8 km deep · released about 11 lb of TNT

10 km30 km60 km120 km N San Luis Obispo County 53 kmSanta Barbara County 80 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
8:46 am PDT on 21 March 2019 ()
Where
15 km (9 mi) west of Guadalupe, CA · earthquakes near Guadalupe
Magnitude
M 1.7 (md)
Depth
1.8 km below the surface
Felt
no reports yet
Nearest
San Luis Obispo County, 53 km NNE
Nearest mapped fault
Hosgri fault, 5 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 2793 days ago

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 12 km (7 mi) from the epicentre. In Guadalupe, 15 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: Callender, Oceano, Grover Beach, Pismo Beach, Arroyo Grande, Avila Beach.

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.

  1. Mineral, Virginia 2011 M 5.8 1,300,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 930,000× the energy of this one
  3. Around the size people start to feel M 3.0 83× the energy of this one
  4. 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

No earthquake of M4 or more has been recorded within 50 km since our catalogue begins in 2016.

Before 2016, the USGS record lists 4 earthquakes of M5 or more within 50 km:

  1. 6.9 The 1927 Lompoc, California Earthquake · 32 km S of this epicentre
  2. 5.8 Near Los Alamos, California · 36 km ESE of this epicentre
  3. 5.8 Near Los Alamos, California · 49 km SE of this epicentre
  4. 5.0 5 km SSW of Nipomo, California · 21 km E 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 34.9697, -120.7315. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
San Luis Obispo County, CA 53 km (33 mi) NNE earthquakes near San Luis Obispo County
Santa Barbara County, CA 80 km (49 mi) SE earthquakes near Santa Barbara County

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

Aftershocks so far

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

  1. 1.9 6km ENE of Lompoc, CA
  2. 1.9 28km WSW of Lompoc, CA
  3. 2.1 4km ESE of Orcutt, CA
  4. 1.8 5km W of Santa Margarita, CA
  5. 1.8 5km NE of Lompoc, CA
  6. 1.6 3km SSE of Avila Beach, CA
  7. 2.4 44km WSW of Guadalupe, CA
  8. 2.9 41km WSW of Guadalupe, CA
  9. 2.1 8km WSW of Morro Bay, CA
  10. 2.3 11km WSW of Morro Bay, CA
  11. 2.0 13km SW of Guadalupe, CA
  12. 2.0 3km ENE of Vandenberg Village, CA
  13. 1.6 10km SSE of Orcutt, CA
  14. 1.5 10km SSE of Orcutt, CA
  15. 2.3 6km E of Vandenberg Village, 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.