Earthquake · reviewed by a seismologist
M 1.5ml
Earthquake near Killingworth, CT
No earthquake was likely felt in Killingworth in the 24 hours to 9:26 pm EST (02:26 UTC). The last one was M 1.9, 16 km (10 mi) NE, at 8:26 am EDT on 15 March 2026, estimated intensity II (weak) in town; 32 felt reports to USGS. Every earthquake near Killingworth
This page: a magnitude 1.5 earthquake was recorded 4 km (2 mi) north-northwest of Killingworth, CT, at 10:12 am EDT on 11 April 2025 (14:12 UTC), 5.5 km deep. 7 people have reported feeling it to USGS.
USGS: 3 km NNW of Killingworth, Connecticut
24 km (15 mi) SE of Meriden, CT · 140 km (87 mi) NE of New York, NY
- When
- 10:12 am EDT on 11 April 2025 ()
- Where
- 4 km (2 mi) north-northwest of Killingworth, CT · earthquakes near Killingworth
- Magnitude
- M 1.5 (ml)
- Depth
- 5.5 km below the surface
- Felt
- 7 reports · strongest reported intensity III
- Nearest
- Lower Connecticut River Valley Planning Region, 8 km ENE
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 516 days ago
Earthquake alerts for Killingworth, CT
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Alerts are on for .
Not a warning. An alert comes after USGS publishes a quake, usually minutes after the shaking. For early warning use ShakeAlert, through your phone's Wireless Emergency Alerts or the MyShake app.
This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.
At this magnitude and depth it was probably too small to be felt, even directly above it. In Killingworth, 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: Chester Center, Deep River Center, Higganum, East Haddam, Madison, Madison Center.
How big was it?
This earthquake released about 5.4 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.5 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 2,800,000× the energy of this one
- Magna, Utah 2020 M 5.7 2,000,000× the energy of this one
- Around the size people start to feel M 3.0 180× the energy of this one
- This earthquake M 1.5 about 5.4 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 41.3903, -72.5826. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Lower Connecticut River Valley Planning Region, CT | 8 km (5 mi) | ENE | earthquakes near Lower Connecticut River Valley Planning Region |
| South Central Connecticut Planning Region, CT | 24 km (15 mi) | WSW | earthquakes near South Central Connecticut Planning Region |
| Southeastern Connecticut Planning Region, CT | 41 km (26 mi) | ENE | earthquakes near Southeastern Connecticut Planning Region |
| Naugatuck Valley Planning Region, CT | 44 km (28 mi) | WNW | earthquakes near Naugatuck Valley Planning Region |
| Capitol Planning Region, CT | 47 km (29 mi) | N | earthquakes near Capitol Planning Region |
| Suffolk County, NY | 51 km (31 mi) | S | earthquakes near Suffolk County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
8 earthquakes have been recorded within 50 km since this one.
- 1.6 6 km SW of Niantic, Connecticut
- 1.5 2 km SSW of Deep River Center, Connecticut
- 1.9 2 km NNE of East Haddam, Connecticut
- 2.2 1 km S of Moodus, Connecticut
- 1.8 2 km W of Conning Towers-Nautilus Park, Connecticut
- 1.9 2 km N of East Haddam, Connecticut
- 2.0 3 km E of Plainville, Connecticut
- 1.8 1 km NNW of Essex Village, 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
- The official USGS event page — the source of record for every value above
- Did you feel it? Report it to USGS — reports go to USGS, not to us
- ShakeMap for this event, when USGS has produced one
QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.