QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1ml

Earthquake near Sinking Spring, PA

No earthquake was likely felt in Sinking Spring in the 24 hours to 3:24 am EST (08:24 UTC). The last one was M 1.9, 4 km (2 mi) SE, at 4:36 pm EDT on 19 April 2024, estimated intensity II (weak) in town; 59 felt reports to USGS. Every earthquake near Sinking Spring

This page: a magnitude 2.1 earthquake was recorded 2 km (1 mi) west-southwest of Sinking Spring, PA, at 10:47 pm EST on 12 November 2021 (03:47 UTC), 3.0 km deep. 180 people have reported feeling it to USGS.

USGS: 2 km WSW of Sinking Spring, Pennsylvania

10 km (6 mi) WSW of Reading, PA · 84 km (52 mi) WNW of Philadelphia, PA

10:47 pm EST, Nov 12, 2021 · · 3.0 km deep · released about 43 lb of TNT

10 km30 km60 km120 km N Berks County 14 kmLancaster County 36 kmLebanon County 37 kmChester County 45 kmSchuylkill County 46 kmLehigh County 50 kmMontgomery County 58 kmDauphin County 65 kmDelaware County 70 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
10:47 pm EST on 12 November 2021 ()
Where
2 km (1 mi) west-southwest of Sinking Spring, PA · earthquakes near Sinking Spring
Magnitude
M 2.1 (ml)
Depth
3.0 km below the surface
Felt
180 reports · strongest reported intensity V
Nearest
Berks County, 14 km NE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 950 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 28 km (17 mi) from the epicentre. In Sinking Spring, 2 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: Whitfield, West Lawn, West Wyomissing, Wernersville, Montrose, Lincoln Park.

How big was it?

This earthquake released about 43 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 5.8 350,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 250,000× the energy of this one
  3. Around the size people start to feel M 3.0 22× the energy of this one
  4. This earthquake M 2.1 about 43 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 40.3176, -76.0356. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Berks County, PA 14 km (9 mi) NE earthquakes near Berks County
Lancaster County, PA 36 km (22 mi) SSW earthquakes near Lancaster County
Lebanon County, PA 37 km (23 mi) W earthquakes near Lebanon County
Chester County, PA 45 km (28 mi) SSE earthquakes near Chester County
Schuylkill County, PA 46 km (28 mi) NNW earthquakes near Schuylkill County
Lehigh County, PA 50 km (31 mi) NE earthquakes near Lehigh County

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

Aftershocks so far

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

  1. 1.9 0 km W of Shillington, Pennsylvania
  2. 1.7 1 km SSW of Alburtis, Pennsylvania

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.