1705 CE Quake

by al-Nabalusi

Aliases

• Until this year, 1117, I had never seen the like of the succession of earthquakes which occurred day and night
• They began on the night of Tuesday 7 Sha'ban
• The first earthquake occurred at ten at night and woke us up
• We were told that when the people of Damascus saw the roofs sway and heard the clatter, they thought that thieves were running on the roofs
• After 11 hours of the night had passed, a stronger earthquake occurred, driving us out into the yard
• This second earthquake lasted for two or three degrees
• Two or three degrees later a lighter quake occurred
• Things continued like this until Ramadan began, a light earthquake continuing every day and night, some people feeling them and some not
• The second above-mentioned earthquake caused some houses to fall, destroyed walls and shook roofs and buildings in Damascus and its surrounding villages to such an extent that many people were killed in the debris
• The top of the eastern minaret of the Umayyad Mosque was split and two stones fell from the top of the western minaret, but caused no damage.
• The upper portion of the Murshidiyah minaret fell in Salihiyah, as did the minaret of the Afram mosque and part of the buildings in Magharat al-Damm up on Mt Qasyun
• We heard that the Qastal fortress and its villages were destroyed, and also a monastery in Yabrud, and many houses in the villages
• Light earthquakes occurred which some felt and feared but others did not notice

• Damascus
• Qastal fortress and its villages (al-Qastal?)
• Yabrud and in the villages

Gomez et. al. (2003:15) dated Event A to between 1650 CE and the present and suggested that it was caused by the 1705 or 1759 CE earthquakes. Daëron et al (2005:531) proposed that the 30 October 1759 earthquake was caused by slip on the shorter (50 km) Rachaya fault, and the larger magnitude 25 November event was caused by slip on the longer (130 km) Serghaya fault, in keeping with the evidence of recent movement on both (Tapponnier et al., 2001), and the French consul’s letter from Saida. This, in turn, they said resolved the ambiguity of Event A in the Tekieh Trench. It was, according to Daëron et al (2005:531), caused by the 25 Nov. 1759 CE Baalbek Quake. Daëron et al (2005:531) discussed the triggered earthquakes of 1759 CE as follows:

We interpret the occurrence of two events in 1759 and the month long delay between them as a classic earthquake triggering example. Such triggered delayed rupture may be due to the presence of the Mount Hermon asymmetric push-up jog, a geometric irregularity that prevented immediate rupture propagation along the entire Rachaıya Serghaya fault system. Though not unique, this scenario is in keeping with scaling laws (Wells and Coppersmith, 1994; Ambraseys and Jackson, 1998) that predict (2-sigma) magnitudes of 6.4–7.3 and 7.0–8.0 respectively, compatible with those derived from historical accounts (6.6 and 7.4; Ambraseys and Barazangi, 1989) and from the ~2 m stream channel offset attributed to the last event on the Serghaya fault at Zebadani [i.e., Tekieh trenches] (7.0–7.2 for the November 1759 event; Gomez et al., 2003).

Nemer and Meghraoui (2006) date Event Z to after 84-239 CE. They suggested the Safed Earthquake of 1837 CE as the most likely candidate.

Nemer et al (2008) dated the most recent event (aka the Last Event) in the Faqaa Trench to between 1686 and 1924 CE and suggested it was most likely caused by the 25 Nov. 1759 CE Baalbek earthquake. They also noted that the 25 Nov. 1759 CE Baalbek earthquake may have been responsible for a seismic event observed in the Deir El-Achayer Excavation although the dating for this event is fraught with uncertainty.