September 17, 1497 Tsunami: Baltic Sea, Poland

Reference #14181:

An enormous storm appeared in 1497, followed by a flood. A large of the Kolobrzeg town centre was submerged by water. A bridge on the Parseta River was destroyed. Destruction reached also mills the whole vicinity. Rising of the water was accompanied by a wind-storm. The church towers and the building roofs were also destroyed. A violent storm occurred at the coast between Kolobrzeg and Dadowo, i.e. along 50 km. The sea level raised by 3.0 m, as an analysis of the town's topography suggests.

'A chronicle reports that on the eight day after the Holy Mary's Nativity (17th of September) in 1497, on Friday noon, a storm arose from the NW direction and continued until the evening, causing a fatal flood. The fishermen settlement and the harbour in Darlowko have been completely destroyed. The ships moored in the Darlowko harbour have been thrown away on the land, for a distance of 3.0 km in the Darlowo direction (three ships), and of about 4.0 km in the Zukowo direction (one ship).

In Darlowo, two ships landed near the Carthusian monastery, and one ship in the St Gertrud chapel vicinity. The above mentioned monastery has been flooded. Within the monastery church, water reached the altars height. Also the monastery orchards, cloisters, and cellars have been flooded. Damages occurred on town's territory, as well. The Wieprzanska Gate, located in the lowermost place of all the town's gates, has been put out of order. The granaries were flooded. The building walls and windows have been fractured, the roof of the church's tower collapsed. People and animals have been killed, and dead fishes were thrown on the land.'

[…] the height of the wave can be assessed at the minimum of 3.0 m. If one would accept the information on a ship translocation during the storm into the St Gertrud chapel area literally, the wave's height could locally reach 20 m. It is possible, anyway, that that area located eastward of the town's walls could favour a local, short-lived piling of the waves.

The storm of the September 17, 1497, observed in the Darlowo vicinity, was caused by a tsunami what is suggested by the short-living of the phenomenon, the height of the water piling, and the phenomenon time coincidence with an earthquake in the Vanern lake region, in Sweden.

Note: reference #14181 suggests another possible explanation, “Explosions of methane bound in traps are the cause of tsunami. The Southern Baltic coast can be endangered by these phenomena, usually considered as extremely rare in that area. Methane explosions can be initiated by events of moderate seismicity.”