Kleiner Montiggler See study suggests 3rd-century seismic activity

Research conducted at the Kleiner Montiggler See in South Tyrol, Italy, provides paleoecological evidence regarding a potential seismic disturbance during Late Antiquity, specifically around the 3rd century AD. By analyzing a 148 cm sediment core, researchers examined the environmental and vegetation development of the region over the last 5,000 years.

The study focused on an event layer located between 64 and 69 cm in absolute sediment depth. While terrestrial pollen spectra showed a predominantly forested landscape with gradual changes and no evidence of abrupt land clearing, aquatic microproxies showed significant shifts. Specifically, a sharp decline in Volvocaceae was followed by a marked increase in dinoflagellate cysts, interpreted as a result of intense hypereutrophication in the lake system.

The findings correlate with a postulated earthquake event in the Egna region. The estimated age of this event is approximately 222 AD, with a 95% probability range spanning from 8 to 450 AD.