Based on the contemporaneous account of Myrinaei Historiarum by Agathias which described seismic shaking in the Nile Delta due to the 551 CE Beirut Quake,
Ambraseys (2009) suggested that there might be archeoseismic evidence for the 551 CE Beirut Quake at Damietta.
Although Damietta was far from the epicenter, the possibility of seismic amplification due to a site effect in certain parts of Damietta is likely. A simple google search for
"subsidence in Damietta" reveals numerous reports of modern subsidence which speaks to weak underlying sediments.