Earthquake · reviewed by a seismologist
M 1.6ml
Earthquake near South Portland, ME
USGS: 7 km SE of South Portland, Maine
5 km (3 mi) S of Portland, ME · 122 km (76 mi) ENE of Manchester, NH
- When
- 4:37 am EDT on 2 September 2017 ()
- Where
- 8 km (5 mi) SE of South Portland, ME · earthquakes near South Portland
- Magnitude
- M 1.6 (ml)
- Depth
- 5.0 km below the surface
- Felt
- no reports yet
- Nearest
- Cumberland County, 27 km NNW
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 3230 days ago
A magnitude 1.6 earthquake was recorded 8 km (5 mi) SE of South Portland, ME, at 4:37 am EDT on 2 September 2017 (08:37 UTC). This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.
Earthquakes near other towns within 30 km: Portland, Scarborough, South Portland Gardens, West Scarborough, Falmouth, Falmouth Foreside.
How big was it?
This earthquake released about 7.6 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.6 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 2,000,000× the energy of this one
- Magna, Utah 2020 M 5.7 1,400,000× the energy of this one
- Around the size people start to feel M 3.0 130× the energy of this one
- This earthquake M 1.6 about 7.6 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 43.5865, -70.1830. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Cumberland County, ME | 27 km (17 mi) | NNW | earthquakes near Cumberland County |
| York County, ME | 43 km (27 mi) | WSW | earthquakes near York County |
| Sagadahoc County, ME | 46 km (28 mi) | NE | earthquakes near Sagadahoc County |
| Androscoggin County, ME | 65 km (40 mi) | N | earthquakes near Androscoggin County |
| Lincoln County, ME | 70 km (44 mi) | NE | earthquakes near Lincoln County |
| Strafford County, NH | 76 km (47 mi) | WSW | earthquakes near Strafford County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
9 earthquakes have been recorded within 50 km since this one.
- 1.8 2 km SW of Gray, Maine
- 1.9 8 km ENE of Lake Arrowhead, Maine
- 1.9 3 km WSW of Dayton, Maine
- 2.4 42 km SE of Old Orchard Beach, Maine
- 2.6 38 km SE of Old Orchard Beach, Maine
- 2.1 8 km SE of South Portland, Maine
- 2.7 50 km ESE of Old Orchard Beach, Maine
- 1.6 6 km ESE of Casco, Maine
- 1.6 5 km NE of Raymond, 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
- 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.