October 11, 368 Tsunami: Lake Ascania (Iznik), Turkey

368, October 11, Nicaea. A rather large earthquake affected much of Bithynia, where it ruined Nicaea (lznik) and other unnamed towns in that province […] John of Nikiu claims that, when the earthquake happened in Nicaea, where the holy council had been held, 'the sea rose against if and overwhelmed it'. This detail is not known from other sources and it is probably a rhetorical exaggeration or resulted from conflating some of the effects of the earthquake of AD 365. He places the event 'in the days of ... Valens', so he may have syncretised it with the earthquake and tsunami of AD 365 (which did not affect Nicaea) (cf. Georgios Monachos. discussed in the previous entry). Nicaea is located about 30 km inland, on the shore of the shallow Lake Ascania, the size of which renders it unlikely to be capable of creating such a destructive wave. ldatius a near contemporary dates this event to 5th Ides Oct (11 October) during the second consulships of Valentinian and Valens = 11 October 368. Socrates Scholasticus, also a near contemporary, agrees with this date but erroneously adds that this 'was twelve years after the fall of Nicorriedea'. Sozomen, also a near contemporary, mentions a freak storm of giant hailstones “in many places ... and very great earthquakes overthrew other cities, especially Nicaea”. Saint Jerome, the Chronicle of Serl and the Chronicon Paschale date this event to 11 October 368, whereas Malalas gives September 368. Pseudo-Dionysius of Tell Mahre syncretises this event with the earthquake in Germe in November 368(?), as does Georgios Monachos. Guidaboni et al. (1994, 274-275) include in the description of this event data from sources such as Eli. Nis. BR 102 and DE 23 that in fact refer to the earthquake in Nicomedea of 28 Ab 669 a.S. (August 28 358) and also associate the event with a seismic sea wave. (reference #9116)

368. 40o30'N, 29o36'E, earthquake magnitude 6.4, intensity VIII. Sea wave in Bithynia. (reference #2427)