QuakeIndex

Earthquake · reviewed by a seismologist

M 3.0ml

Earthquake near Fontana, CA

No earthquake was likely felt in Fontana in the 24 hours to 9:15 pm PST (05:15 UTC). The last one was M 1.6, 5 km (3 mi) W, at 6:17 am PDT on 26 October 2026, estimated intensity II (weak) in town. Every earthquake near Fontana

This page: a magnitude 3.0 earthquake was recorded 15 km (10 mi) north of Fontana, CA, at 2:09 am PDT on 30 March 2017 (09:09 UTC), 9.1 km deep. 125 people have reported feeling it to USGS.

USGS: 5km SE of Lytle Creek, CA

13 km (8 mi) N of Fontana, CA · 91 km (56 mi) ENE of Los Angeles, CA

2:09 am PDT, Mar 30, 2017 · · 9.1 km deep · released about 860 lb of TNT

10 km30 km60 km120 km N Orange County 68 kmLos Angeles County 74 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
2:09 am PDT on 30 March 2017 ()
Where
15 km (10 mi) north of Fontana, CA · earthquakes near Fontana
Magnitude
M 3.0 (ml)
Depth
9.1 km below the surface
Felt
125 reports · strongest reported intensity IV
Measured shaking
intensity IV (ShakeMap)
Nearest
Orange County, 68 km SSW
Nearest mapped fault
San Jacinto fault, under 1 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 3435 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage.

At this magnitude and depth, people at rest would likely notice it out to about 34 km (21 mi) from the epicentre. In Fontana, 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.

Likely felt in: Muscoy 13 km, intensity III · Fontana 15 km, intensity II · Rialto 16 km, intensity II · Rancho Cucamonga 18 km, intensity II · San Bernardino 21 km, intensity II · Wrightwood 22 km, intensity II · Colton 22 km, intensity II · Upland 23 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 860 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.0 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 390,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 18,000× the energy of this one
  3. Magna, Utah 2020 M 5.7 12,000× the energy of this one
  4. This earthquake M 3.0 about 860 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 8 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.2 3 km SE of San Bernardino, California · 24 km SE of this epicentre
  2. 5.8 The 1991 Sierra Madre, California Earthquake · 49 km W of this epicentre
  3. 5.6 7km ENE of Running Springs, CA · 39 km E of this epicentre
  4. 5.5 The 1990 Upland, California Earthquake · 24 km WSW of this epicentre
  5. 5.4 5km S of Chino Hills, CA · 42 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 34.2282, -117.4598. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Orange County, CA 68 km (42 mi) SSW earthquakes near Orange County
Los Angeles County, CA 74 km (46 mi) W earthquakes near Los Angeles County
San Bernardino County, CA 136 km (85 mi) ENE earthquakes near San Bernardino County

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

Aftershocks so far

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

  1. 1.5 0km SSW of Loma Linda, CA
  2. 1.5 6km E of Running Springs, CA
  3. 2.2 8km N of Rancho Cucamonga, CA
  4. 1.5 6km E of Running Springs, CA
  5. 1.5 5km SE of Home Gardens, CA
  6. 2.8 2km SE of Loma Linda, CA
  7. 1.6 2km ESE of Loma Linda, CA
  8. 1.8 5km SSE of Lytle Creek, CA
  9. 2.1 12km SE of Running Springs, CA
  10. 1.6 14km NNE of Running Springs, CA
  11. 1.6 1 km ESE of Loma Linda, California
  12. 1.5 6 km SSE of Lytle Creek, California
  13. 2.0 8 km ENE of San Antonio Heights, California
  14. 1.6 3 km ENE of El Cerrito Corona, California
  15. 1.6 9 km E of Running Springs, California

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.