An earthquake, or possibly a series of earthquakes, affected the Syrian littoral around 1063 CE. The sources, none of which are contemporaneous, disagree about both the precise date and whether the event consisted of a single earthquake or several shocks. Despite these uncertainties, the accounts broadly agree on the affected locations, particularly Antioch, Tripoli, Latakia, Tyre, and Akko. Many reports state that the walls of Tripoli were damaged during the shaking. Two of the earlier authors, Ibn al-Jawzi and Ibn al-Athir, date the earthquake to Sha'ban A.H. 455, corresponding to 30 July–27 August 1063 CE. This date is commonly used in the scientific literature and may be the most probable, although it cannot be considered certain. Matthew of Edessa instead places the earthquake(s) in 1053/1054 CE, roughly a decade earlier. Although Matthew is the earliest author and may have had access to eyewitness reports, his account contains substantial embellishment as well as polemical and supernatural elements. It is therefore possible that he adjusted the chronology to support a theological interpretation¹. Reading across the various accounts leaves the impression either of multiple earthquakes or of an extended sequence of energetic aftershocks lasting perhaps several weeks. Several authors claim that many places were destroyed, though the degree of independence among these reports is difficult to assess. Islamic authors in particular tend to repeat similar narrative elements, suggesting some degree of shared sourcing.

Because the specifically located damage reports come almost entirely from coastal sites, Ambraseys (2009) suggested that the earthquake may have resulted from faulting offshore of Cyprus, southeast of the island. Another possibility is uplift along the Roum–Tripoli thrust fault², which runs offshore just south of Beirut before returning on land near Tripoli. Potential corroborating geological evidence comes from Byblos, where Morhange et al. (2006:91) reported possible coastal uplift dating to the 10th or 11th century CE. Byblos lies approximately 40 km SSW of Tripoli and roughly midway between Tripoli and Beirut.

The 1068 CE Quake(s), which struck farther south perhaps half a decade later, may be geomechanically related to the Fallen Walls of Tripoli Quake(s).

Footnotes

1 His date for the earthquake closely coincides with the Great Schism, when the Roman Catholic and Eastern Orthodox churches split. Although Matthew was not a member of either sect, his passage shows clear antipathy toward the Eastern Orthodox church.

2 For the location of the Roum–Tripoli thrust, see Fig. 2 in Morhange et al. (2006:91) or Fig. 1 in Elias et al. (2007), where the fault is approximately mapped as part of the Mount Lebanon thrust system. Fig. 4 in Elias et al. (2007) also proposes that the Fallen Walls of Tripoli Quake(s) of about 1063 CE may have been generated by rupture along the Rankine–Aabdeh, Aakkar thrust, and/or Tripoli thrust faults.