QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1md

Earthquake near Portola, CA

No earthquake was likely felt in Portola in the 24 hours to 9:08 am PST (17:08 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 2.1 earthquake was recorded 31 km (19 mi) southwest of Portola, CA, at 1:02 am PDT on 13 June 2019 (08:02 UTC), less than 1 km deep.

USGS: 19km SSW of Whitehawk, CA

1:02 am PDT, Jun 13, 2019 · · -0.1 km deep · released about 51 lb of TNT

10 km30 km60 km120 km N Sierra County 13 kmNevada County 33 kmPlumas County 48 kmPlacer County 58 kmYuba County 68 kmButte County 81 kmEl Dorado County 89 kmCarson City 92 kmStorey County 99 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
1:02 am PDT on 13 June 2019 ()
Where
31 km (19 mi) southwest of Portola, CA · earthquakes near Portola
Magnitude
M 2.1 (md)
Depth
-0.1 km below the surface
Felt
no reports yet
Nearest
Sierra County, 13 km E
Nearest mapped fault
Mohawk Valley fault, 17 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 2710 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, 31 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.

How big was it?

This earthquake released about 51 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.1 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 300,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 210,000× the energy of this one
  3. Around the size people start to feel M 3.0 19× the energy of this one
  4. This earthquake M 2.1 about 51 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 7 earthquakes of M5 or more within 50 km; the five largest:

  1. 5.9 West of Downieville, California · 30 km WSW of this epicentre
  2. 5.9 9 km NW of Truckee, California · 41 km ESE of this epicentre
  3. 5.6 5 km NE of Loyalton, California · 43 km ENE of this epicentre
  4. 5.3 11 km N of Soda Springs, California · 29 km SE of this epicentre
  5. 5.2 3 km N of Blairsden, California · 26 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 39.5813, -120.6695. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Sierra County, CA 13 km (8 mi) E earthquakes near Sierra County
Nevada County, CA 33 km (20 mi) SSW earthquakes near Nevada County
Plumas County, CA 48 km (30 mi) NNW earthquakes near Plumas County
Placer County, CA 58 km (36 mi) S earthquakes near Placer County
Yuba County, CA 68 km (42 mi) WSW earthquakes near Yuba County
Butte County, CA 81 km (50 mi) W earthquakes near Butte 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.

  1. 1.9 20km SW of Whitehawk, CA
  2. 1.9 3km NNW of Johnsville, CA
  3. 1.5 Northern California
  4. 2.0 8km ESE of Challenge-Brownsville, CA
  5. 2.0 10 km SSW of Kingvale, California
  6. 2.2 8km ESE of Challenge-Brownsville, CA
  7. 1.9 5km NNE of Greenhorn, CA
  8. 1.7 6km NNE of East Quincy, CA
  9. 1.8 7km N of Greenhorn, CA
  10. 2.5 20km NW of Truckee, CA
  11. 1.5 6 km ENE of East Quincy, California
  12. 2.2 14km SW of Whitehawk, CA
  13. 2.6 15km NW of Truckee, CA
  14. 2.1 16km NW of Truckee, CA
  15. 2.0 3km NNE of Spring Garden, 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.