One of the deadliest earthquakes in recorded history, killing an estimated 200,000 people in 9th-century Iran.
Key Facts
- Estimated Magnitude
- 7.9 Mw
- Maximum Intensity
- X (Extreme) Mercalli scale
- Estimated Death Toll
- ~200,000 deaths
- Meizoseismal Area Length
- ~350 km
- USGS Historical Rank
- 6th deadliest earthquake in recorded history
By the Numbers
Location
Cause → Event → Consequence
The earthquake resulted from seismic activity along the southern edge of the eastern Alborz mountain range in the Khorasan province of the Abbasid Caliphate. The region sits in a tectonically active zone where compressional forces have historically produced large-magnitude events.
On 22 December 856, a magnitude 7.9 earthquake struck near Damghan, then the capital of the Persian province of Qumis. The maximum damage zone extended approximately 350 kilometres along the Alborz foothills, encompassing parts of Tabaristan and Gorgan, with a peak Mercalli intensity of X.
The earthquake killed an estimated 200,000 people, though this figure has been contested by scholars. It ranks among the most lethal seismic events in recorded history and is listed by the USGS as the sixth deadliest earthquake ever documented.
Human Cost
Each dot represents approximately 10,000 deaths. Total estimated: 200,000 (earthquake)