QuakeIndex

Earthquake · reviewed by a seismologist

M 2.2md

Earthquake near Portola, CA

No earthquake was likely felt in Portola in the 24 hours to 5:55 am PST (13:55 UTC). The last one was M 2.7, 8 km (5 mi) N, at 8:16 am PST on 10 November 2026, estimated intensity III (weak) in town; 9 felt reports to USGS. Every earthquake near Portola

This page: a magnitude 2.2 earthquake was recorded 18 km (11 mi) southwest of Portola, CA, at 2:23 am PST on 5 March 2019 (10:23 UTC), less than 1 km deep.

USGS: 6km WSW of Valley Ranch, CA

69 km (43 mi) WNW of Reno, NV

2:23 am PST, Mar 5, 2019 · · -1.1 km deep · released about 58 lb of TNT

10 km30 km60 km120 km N Sierra County 17 kmPlumas County 36 kmNevada County 47 kmPlacer County 72 kmYuba County 78 kmButte County 84 kmCarson City 98 kmStorey County 99 kmEl Dorado County 103 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
2:23 am PST on 5 March 2019 ()
Where
18 km (11 mi) southwest of Portola, CA · earthquakes near Portola
Magnitude
M 2.2 (md)
Depth
-1.1 km below the surface
Felt
no reports yet
Nearest
Sierra County, 17 km SSE
Nearest mapped fault
Mohawk Valley fault, 4 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 2810 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 18 km (11 mi) from the epicentre. In Portola, 18 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: Portola 18 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 58 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.2 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 260,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 180,000× the energy of this one
  3. Around the size people start to feel M 3.0 16× the energy of this one
  4. This earthquake M 2.2 about 58 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 6 earthquakes of M5 or more within 50 km; the five largest:

  1. 5.9 West of Downieville, California · 39 km SW of this epicentre
  2. 5.9 9 km NW of Truckee, California · 47 km SE of this epicentre
  3. 5.6 5 km NE of Loyalton, California · 37 km E of this epicentre
  4. 5.3 11 km N of Soda Springs, California · 37 km SSE of this epicentre
  5. 5.2 3 km N of Blairsden, California · 11 km N 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 39.7093, -120.6285. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Sierra County, CA 17 km (11 mi) SSE earthquakes near Sierra County
Plumas County, CA 36 km (22 mi) NNW earthquakes near Plumas County
Nevada County, CA 47 km (29 mi) SSW earthquakes near Nevada County
Placer County, CA 72 km (45 mi) S earthquakes near Placer County
Yuba County, CA 78 km (49 mi) SW earthquakes near Yuba County
Butte County, CA 84 km (52 mi) W earthquakes near Butte County

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

Aftershocks so far

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

  1. 2.8 17km NNW of Truckee, CA
  2. 2.4 18km NNW of Truckee, CA
  3. 3.7 17km NNW of Truckee, CA
  4. 2.1 8km W of La Porte, CA
  5. 2.3 22km SW of Whitehawk, CA
  6. 2.8 8km WNW of Lake Davis, CA
  7. 1.8 5km ESE of Taylorsville, CA
  8. 1.8 5km ESE of Taylorsville, CA
  9. 1.6 6 km S of Taylorsville, California
  10. 2.0 21km NW of Truckee, CA
  11. 1.6 8km W of La Porte, CA
  12. 2.4 5km SE of Chilcoot-Vinton, CA
  13. 1.5 9 km NNW of Truckee, California
  14. 1.5 16 km SE of Sierraville, California
  15. 2.1 19km W of Truckee, 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.