Cryptotephra from a ~120 ka Tondano eruption in a sediment core from Lake Towuti (Indonesia)

Southeast Asia is one of the most volcanically active regions in the world, yet their long-term eruptive history has been comparatively little studied. In particular, little work has explored the potential of sedimentary archives to record distal cryptotephra, which may help in identifying some of the region's larger Quaternary eruptions. Here, we report the finding of cryptotephra in a sediment core from Lake Towuti (Sulawesi, Indonesia). Based on glass geochemistry and core stratigraphy, we attribute the deposit to a ~120 ka eruption of Tondano, a large caldera situated on the Minahasa peninsula of Sulawesi. The minimal (~38 shards per gram) amount of tephra deposition hints at the limited ecological impact and/or magnitude of the eruption as well as establishing a new isochron that may enable synchronisation of late-Pleistocene sedimentary archives.