Distinct lake level lowstand in Lake Prespa (SE Europe) at the time of the 74 (75) ka Toba eruption

摘要

The 74 (75) ka Toba eruption in Sumatra, Indonesia, is considered to be oneof the largest volcanic events during the Quaternary. Tephra from the Tobaeruption has been found in many terrestrial and marine sedimentary deposits,and acidity peaks related to the eruption have been used to synchronize icecore records from Greenland and Antarctica. Seismic profiles andsedimentological data from Lake Prespa on the Balkan Peninsula, SE Europe,indicate a lake level lowstand at 73.6 ± 7.7 ka based on ESR dating ofshells. Tephrostratigraphy, radiocarbon dating and tuning of the totalorganic carbon content with the NGRIP isotope record, corroborate that the lake levellowstand was a short-term event superimposed on the general cooling trend atthe end of MIS 5, most likely at the onset of the Greenland Stadial GS-20.Acknowledging that tectonic events or karst processes could have triggeredthis lake level lowstand, the chronological correspondence between thelowstand and the Toba eruption is intriguing. Therefore a Toba-drivenshort-term shift to aridity in the Balkan region, leading to lake levelchanges and triggering spatial expansion events in one of the lake's mostabundant benthic species, the carino mussel Dreissena presbensis,cannot be excluded.