Qumis (Damghan) Earthquake of 22 December 856, Mw=7.9

Qumis (Damghan) Earthquake of 22 December 856, Mw=7.9

The 856 Damghan earthquake or the 856 Qumis earthquake occurred on 22 December, 856 AD (242 A.H.) with an estimated magnitude of Ms=7.9. The meizoseismal area (area of maximum damage) extended for about 350 kilometers along the southern edge of the eastern Alborz mountains of present-day Iran including parts of Tabaristan and Gorgan. The earthquake’s epicenter is estimated to be close to the city of Damghan with coordination of 36.2°N and 54.3°E, which was then the capital of the Persian province of Qumis. The total death toll for the earthquake is reported as 200,000, with 45,096 casualties in Damghan alone. It caused approximately 200,000 deaths and is listed by the USGS as the sixth deadliest earthquake in recorded history. Aftershocks affected the area for several years, probably including a damaging earthquake in western Khurasan. The area of significant damage extended along the Alborz for about 350 kilometres, including the towns of Ahevanu, Astan, Tash, Bastam and Shahrud, with almost all the villages in the area severely damaged. Hecatompylos, now called Šahr-e Qumis, the former capital of Parthia, was destroyed. Half of Damghan and a third of the town of Bustam were also destroyed. The earthquake badly affected water supplies in the Qumis area, partly due to springs and qanats drying up, but also because of landslides damming streams. (Ambraseys and Melville, 2005).

The most important worldwide earthquakes (M>7) on this day

Date	Time	Y	X	Depth	Mw	Region	Refrence
856/12/22	–	36.20	54.30	–	7.8	Ghumas	Amb
1906/12/22	18:21:11	44.284	85.572	15	7.8	northern Xinjiang, China	USGS
1964/12/22	4:36:35	28.12	56.8	42	6.1	Iran	Amb
1997/12/22	2:05:50	-5.495	147.867	179.3	7.2	eastern New Guinea region, Papua New Guinea	USGS