QuakeIndex

Earthquake · reviewed by a seismologist

M 2.6ml

Earthquake near Portland, ME

No earthquake was likely felt in Portland in the 24 hours to 6:32 am EST (11:32 UTC). The last one was M 3.8, 70 km (44 mi) SSW, at 10:22 am EST on 27 January 2025, estimated intensity III (weak) in town; 42,440 felt reports to USGS. Every earthquake near Portland

This page: a magnitude 2.6 earthquake was recorded 44 km (27 mi) south-southeast of Portland, ME, at 5:12 am EST on 7 December 2021 (10:12 UTC), 10 km deep. 3 people have reported feeling it to USGS.

USGS: 38 km SE of Old Orchard Beach, Maine

39 km (24 mi) SSE of Portland, ME · 136 km (84 mi) NE of Boston, MA

5:12 am EST, Dec 7, 2021 · · 10 km deep · released about 240 lb of TNT

10 km30 km60 km120 km N York County 55 kmCumberland County 61 kmSagadahoc County 69 kmStrafford County 83 kmLincoln County 86 kmRockingham County 96 kmAndroscoggin County 97 kmEssex County 102 kmKnox County 113 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
5:12 am EST on 7 December 2021 ()
Where
44 km (27 mi) south-southeast of Portland, ME · earthquakes near Portland
Magnitude
M 2.6 (ml)
Depth
10 km below the surface
Felt
3 reports · strongest reported intensity IV
Nearest
York County, 55 km WNW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1735 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage.

At this magnitude and depth, people at rest would likely notice it out to about 50 km (31 mi) from the epicentre. In Portland, 44 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 240 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.6 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 63,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 45,000× the energy of this one
  3. Around the size people start to feel M 3.0 4× the energy of this one
  4. This earthquake M 2.6 about 240 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 43.3084, -70.0048. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
York County, ME 55 km (34 mi) WNW earthquakes near York County
Cumberland County, ME 61 km (38 mi) NNW earthquakes near Cumberland County
Sagadahoc County, ME 69 km (43 mi) N earthquakes near Sagadahoc County
Strafford County, NH 83 km (52 mi) W earthquakes near Strafford County
Lincoln County, ME 86 km (53 mi) NNE earthquakes near Lincoln County
Rockingham County, NH 96 km (59 mi) WSW earthquakes near Rockingham County

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

Aftershocks so far

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

  1. 2.1 34 km SE of York Beach, Maine
  2. 2.0 13 km SE of York Harbor, Maine
  3. 2.4 42 km SE of Old Orchard Beach, Maine

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.