QuakeIndex

Earthquake · reviewed by a seismologist

M 1.9ml

Earthquake near West Hartford, CT

No earthquake was likely felt in West Hartford in the 24 hours to 6:10 am EST (11:10 UTC). The last one was M 2.0, 12 km (7 mi) SSW, at 2:30 pm EDT on 20 May 2025, estimated intensity II (weak) in town; 10 felt reports to USGS. Every earthquake near West Hartford

This page: a magnitude 1.9 earthquake was recorded 4 km (2 mi) southwest of West Hartford, CT, at 1:14 am EST on 5 March 2021 (06:14 UTC), 1.8 km deep. 53 people have reported feeling it to USGS.

USGS: 3 km SW of West Hartford, Connecticut

8 km (5 mi) WSW of Hartford, CT · 7 km (4 mi) NNE of New Britain, CT

1:14 am EST, Mar 5, 2021 · · 1.8 km deep · released about 21 lb of TNT

Every earthquake near West Hartford Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Capitol Planning Region 18 kmNaugatuck Valley Planning Region 36 kmNorthwest Hills Planning Region 40 kmLower Connecticut River Valley Planning Region 42 kmHampden County 46 kmSouth Central Connecticut Planning Region 50 kmSoutheastern Connecticut Planning Region 62 kmNortheastern Connecticut Planning Region 67 kmHampshire County 68 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
1:14 am EST on 5 March 2021 ()
Where
4 km (2 mi) southwest of West Hartford, CT · earthquakes near West Hartford
Magnitude
M 1.9 (ml)
Depth
1.8 km below the surface
Felt
53 reports · strongest reported intensity III
Nearest
Capitol Planning Region, 18 km ENE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 952 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 21 km (13 mi) from the epicentre. In West Hartford, 4 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: Farmington, Newington, Hartford, New Britain, Avon, Wethersfield.

How big was it?

This earthquake released about 21 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.9 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 710,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 500,000× the energy of this one
  3. Around the size people start to feel M 3.0 45× the energy of this one
  4. This earthquake M 1.9 about 21 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 41.7355, -72.7692. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Capitol Planning Region, CT 18 km (11 mi) ENE earthquakes near Capitol Planning Region
Naugatuck Valley Planning Region, CT 36 km (22 mi) SW earthquakes near Naugatuck Valley Planning Region
Northwest Hills Planning Region, CT 40 km (25 mi) WNW earthquakes near Northwest Hills Planning Region
Lower Connecticut River Valley Planning Region, CT 42 km (26 mi) SSE earthquakes near Lower Connecticut River Valley Planning Region
Hampden County, MA 46 km (29 mi) NNE earthquakes near Hampden County
South Central Connecticut Planning Region, CT 50 km (31 mi) S earthquakes near South Central Connecticut Planning Region

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

Aftershocks so far

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

  1. 1.5 2 km SSW of Deep River Center, Connecticut
  2. 1.9 2 km NNE of East Haddam, Connecticut
  3. 2.2 1 km S of Moodus, Connecticut
  4. 1.9 2 km N of East Haddam, Connecticut
  5. 2.0 3 km E of Plainville, Connecticut
  6. 1.5 3 km NNW of Killingworth, Connecticut
  7. 1.6 2 km ENE of Newington, Connecticut
  8. 1.8 2 km SSW of Moodus, Connecticut
  9. 2.2 1 km NNE of Moodus, Connecticut
  10. 1.7 3 km SSE of East Hampton, Connecticut

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.