Widespread Tephra geochemistry, Lake Motosu Site MOT15-2 age model, and Mt. Fuji eruption ages

An 8,000-year lacustrine sediment record from Lake Motosu (Fuji Five Lakes) records several eruptions, including potentially unreported events, of the active Mt. Fuji volcano, which receives approximately 47 million annual visitors. A high-fidelity age model is constructed from tephra ages and high-density radiocarbon dating of terrestrial macrofossil and bulk organic matter. Variability in lake reservoir age is constrained by modern lake water radiocarbon measurement and reverse calibration of tephra calendar ages. We present more accurate ages for known eruptions, detect a wider distribution of ejecta for the most recent summit eruption, and potentially identify previously undetected flank eruptions. There are closely spaced scoria-fall layers that may be difficult to differentiate as separate events in land-based surveys. These results demonstrate the utility of lacustrine sediments as powerful tools for understanding characteristics of volcanic eruptions