Earthquakes in Armstrong County, Pennsylvania
The most recent earthquake of M2.5 or more near Armstrong County was M 2.9, 5 km WSW of Bolivar, Pennsylvania, 53 km (33 mi) SSE of the centre of Armstrong County, at 12:30 am EDT on 6 October 2020, 1 km deep. 10 people reported feeling it to USGS. The estimated shaking at the centre of Armstrong County was intensity II (weak), felt by some people at rest indoors. 2 smaller earthquakes have been recorded near Armstrong County since.
No earthquake of M1.5 or more was recorded within 100 km (62 mi) of the centre of Armstrong County in the last 24 hours.
- Last 24 hours
- 0
- Last 7 days
- 0
- Last 30 days
- 0 · since 2016, about one every 14 months
- Last 12 months
- 0
- Since 2016
- 9 earthquakes of M1.5 or more
- Largest since 2016
- M 2.9 on 6 October 2020, 5 km WSW of Bolivar, Pennsylvania
Latest quake, 24 hours and 7 days: the QuakeIndex database, which reads USGS every 30 seconds, read at ; 30 days and 12 months: the QuakeIndex catalogue, counted to · earthquakes of M1.5 or more within 100 km (62 mi) of the centre of Armstrong County · shaking is estimated for the centre with the intensity equation USGS Did You Feel It? uses
Earthquakes are rare here
3 earthquakes of M1.5 or larger have been recorded within 100 km in 10 years, and most weeks have none. There have been none in the last 7 days.
With so few, a QuakeIndex score — this week as a percentile of Armstrong County, Pennsylvania's own weeks — would only say whether anything happened at all, so none is shown. That is a statement about Armstrong County, Pennsylvania, not about our data.
USGS catalogue · updated
If you felt one
- Was that an earthquake? — checks what was recorded near you in the last hour
- Report what you felt to USGS — reports go to USGS, not to us, and they are what produces the intensity maps
- Expect aftershocks, and be ready to Drop, Cover, and Hold On if you feel one; if you are in a damaged building, go outside and move away from it (Ready.gov, FEMA; what to do during and after an earthquake)
QuakeIndex does not issue warnings or forecasts. For earthquake early warning see ShakeAlert and the MyShake app.
The last 30 days
Show these earthquakes on your own site: a free card with this strip and the latest quakes near Armstrong County, Pennsylvania, for a local news site, school or neighborhood page.
Live · last 7 days
Latest earthquakes within 100 km
None within 100 km in the latest snapshot we hold; the full 7 days load from USGS as this page opens.
Source USGS · snapshot of
The last 7 days on the map
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The centre is 40.812, -79.464, the Census internal point of Armstrong County, Pennsylvania from the US Census Bureau Gazetteer (2024). Activity on this page is measured within 100 km of it — the dashed circle.
Largest on record nearby
The strongest shaking this record implies at the centre of Armstrong County, Pennsylvania is intensity II (weak), from the M 2.9 of 2020, 53 km away. At that level a few people indoors notice it; most do not.
| Magnitude | When | Where | Shaking here (est.) |
|---|---|---|---|
| M 2.9 | 5 km WSW of Bolivar, Pennsylvania · felt by 10 | II · Weak | |
| M 2.3 | 3 km S of Cooperstown, Pennsylvania · felt by 8 | I · Not felt | |
| M 2.1 | 4 km E of Pleasantville, Pennsylvania | I · Not felt | |
| M 2.1 | 4 km NE of Bessemer, Pennsylvania | I · Not felt | |
| M 2.1 | 2 km ESE of Rimersburg, Pennsylvania | II · Weak | |
| M 2.0 | 3 km NE of Bessemer, Pennsylvania | I · Not felt | |
| M 1.9 | 3 km NE of Bessemer, Pennsylvania | I · Not felt | |
| M 1.9 | 2 km ESE of Lowellville, Ohio | I · Not felt |
From the QuakeIndex catalogue, built from the USGS FDSN event service · within 100 km of the centre above. Shaking is an estimate for the centre from magnitude, depth and distance, with the intensity equation USGS Did You Feel It? uses (Atkinson & Wald, 2007), on the Modified Mercalli scale. Ground conditions change it locally; it is a description of the past, not a hazard rating.
Before 2016
The USGS record from 1900 to 2015 lists no earthquake of M5 or more within 100 km of the centre of Armstrong County, Pennsylvania.
USGS ComCat, M5+ from 1900 to 2015. Epicentres of early earthquakes are estimates. This is the record, not a forecast.
Be ready
Earthquakes cannot be predicted, here or anywhere, so the useful step is the one taken beforehand. The advice below is from the agencies responsible for it.
- Ready.gov: earthquakes (FEMA) — what to do before, during and after, including Drop, Cover, and Hold On
- Build a kit (FEMA) — water, food and supplies for several days; our summary
- USGS: preparedness — the hazard behind the advice, from the agency that records every quake on this page
- The Great ShakeOut — the yearly earthquake drill, with material for homes, schools and workplaces