November 11, 1840 Tsunami: Philadelphia, Pennsylvania, United States
A tsunami caused by a magnitude 5.2 earthquake began at Philadelphia, Pennsylvania, United States on November 11, 1840. Its effects were recorded at 1 place.
Where the waves reached
The source (white) and every runup with a place, colored by the water height recorded there. A ring is a runup NCEI marks doubtful.
- Under 1 m
- 1 to 3 m
- 3 to 10 m
- 10 to 30 m
- 30 m and more
- Height not recorded
The tsunami
- Date
- November 11, 1840
- Source
- Philadelphia, Pennsylvania, United States
- Cause
- Earthquake
- Earthquake
- Magnitude 5.2
- Runups recorded
- 1
- Waters
- A lake or river, not the ocean
- How certain
- Probable tsunami
- Source location
- 39.800° N, 75.200° W
The toll
The record gives no deaths, injuries or damage for this tsunami.
What the record says
NCEI’s account, from the sources it cites.
On November 11, 1840, a severe shock was felt at Philadelphia, accompanied by a great and unusually sudden swell in the Delaware. On the fourteenth of the same month, there was a noise and shock observed in Philadelphia, but the members of the American Philosophical Society could not determine whether it was caused by an earthquake or a meteor. (reference #1511)
Reference #1128 lists two shocks on November 11 and 14, but References #236, #1511, #43 list the swell on the Delaware River on November 11, 1840 and Reference #541 lists the swell on November 14, 1840.
This was probably a seaquake.
Reference #236 and #541 lists as validity 3. Reference #12345 (accessed May 2024) lists as validity 2 (questionable).
Every runup
Nearest the source first. Heights are above sea level at the time; a tide gauge reads half the wave’s full height.
| Where | Country | Km from source | Water height, m | Inland, m | Measured by | First wave, UTC | Deaths |
|---|---|---|---|---|---|---|---|
| Philadelphia, PA, PA | United States | 17 | Eyewitness observation of water height |
More
Every tsunami in 1840The 1800sTsunamis of United StatesThe earthquakeThis day in weather historyAlerts in force
Sources
Tsunami events and runups from NOAA’s National Centers for Environmental Information, Global Historical Hazard Database, cited as NCEI/WDS, doi:10.7289/V5PN93H7. Public domain. Read 2026-09-24. NCEI tsunami event 2355.