Ancient sources indicate that Tyre may have been severely affected by a major earthquake along the Phoenician coast, possibly the Posidonius Quake. John of Antioch , whose chronology is inconsistent and unrelaible, records that during the reign of Antiochus IX Kyzikenos (r. 116–96 BCE) “a great earthquake happened in the East and a countless number of Syrians perished,” while “the city of Tyre on the coast was submerged into the sea.” The report suggests significant coastal subsidence or marine inundation affecting Tyre.

Other ancient writers may refer to the same event, though they describe it mainly through its effects on nearby Sidon. According to Strabo, citing Posidonius, an earthquake in Phoenicia caused a city above Sidon to be swallowed up and nearly two-thirds of Sidon itself to be engulfed. The shaking is described as extending across Syria and even reaching parts of the Aegean world, although this latter detail may reflect conflation with a separate event. Seneca the Younger repeated Posidonius’ report that Sidon had been swallowed by the sea. The date of the Posidonius Quake remains uncertain. Ambraseys (2009) places it in the second century BCE and estimates a date around 199 BCE. Most earthquake catalogues list 199 or 198 BCE, though a few instead assign the event to 525 BCE, a date for which the evidentiary basis remains unclear.