Distal tephra reveal new MIS 5e Kos eruptions: Implications for the chronology and volcanic evolution histories in the Eastern Mediterranean region

The Kos Plateau Tuff (KPT), was an enormous caldera forming eruption originating from a vent within the Kos/Nisyros/Yali volcanic complex, occurring at 161 ka. It is the largest recognised Late Quaternary eruption in the Eastern Mediterranean. With its distinctive, highly silicic chemical composition, the resulting ash deposits have been used both as a synchronous marker for palaeoenvironmental records in the region, and to provide information on eruption processes and magnitude. Here, we describe ash layers detected at multiple sites (deep-sea sequences and a terrestrial archaeological site) with ages generated by radiometric dating and sapropel correlation, to demonstrate the existence of a later, but geochemically similar eruption from the Kos volcano which has not previously been identified in proximal volcanic units. This eruption is dated to MIS 5e (∼124–129 ka), i.e. ∼40 kyr younger than the KPT. This tephra marks the start of MIS5e, and presents a rare opportunity to independently and precisely align paleoenvironmental records and archaeological sites during a time of rapid warming and sea level rise analogous to the present day. The presence of multiple tephras also implies the possibility of multiple eruptions during this period. This adds to our knowledge of the active and hazardous nature of Kos/Nisyros/Yali volcanic complex.