Earthquake · reviewed by a seismologist
M 1.8ml
4 km NNE of Susquehanna Trails, Pennsylvania
- When
- Magnitude
- M 1.8 (ml)
- Depth
- 5.0 km below the surface
- Felt
- 2 reports · strongest reported intensity III
- Nearest
- Lancaster County, 29 km NNE
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 3340 days ago
This was a minor earthquake. Quakes this small are rarely felt and do not cause damage. 2 people have reported feeling it to USGS.
How big was it?
This earthquake released about 17 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.8 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 900,000× the energy of this one
- Magna, Utah 2020 M 5.7 640,000× the energy of this one
- Around the size people start to feel M 3.0 57× the energy of this one
- This earthquake M 1.8 about 17 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.
Where
Epicentre 39.7963, -76.3518. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction | |
|---|---|---|---|
| Lancaster County, PA | 29 km (18 mi) | SSW of here | earthquakes near Lancaster County |
| Harford County, MD | 29 km (18 mi) | N of here | earthquakes near Harford County |
| York County, PA | 35 km (22 mi) | ESE of here | earthquakes near York County |
| Cecil County, MD | 44 km (27 mi) | NW of here | earthquakes near Cecil County |
| Baltimore County, MD | 45 km (28 mi) | NNE of here | earthquakes near Baltimore County |
| Chester County, PA | 55 km (34 mi) | WSW of here | earthquakes near Chester 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.
- 1.7 3 km S of Rising Sun, Maryland
- 2.1 2 km W of Rising Sun, Maryland
- 2.4 8 km NE of Bel Air North, Maryland
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.