New estimates of the 1815 Tambora eruption volume

•Tambora Plinian ash fall volume is larger and more intense than previously assumed.•New Tambora ash fall thickness measurements provided for a revised isopach map•Tambora total volume estimate is 41 ± 4 km3 DRE.

Volume estimates of the 1815 Tambora eruption were re-analysed using new ash thickness data and new methods, giving a range of possible volumes for the different eruption phases. Volume calculations include ash fall extrapolation and caldera size approximations, as well as volume estimates from mass eruption rates and eruption duration, to find the most likely range of volumes consistent with the different methods and possible eruption dynamics. The results give a total volume of about 41 ± 4 km3 DRE, made of 23 ± 3 km3 DRE ash fall and 18 ± 6 km3 DRE pyroclastic flows. The ash fall volume can be further divided into 11 ± 2 km3 DRE Plinian ash fall and 12 ± 4 km3 DRE co-ignimbrite, making the Plinian ash fall larger than previously assumed, and more intense due to a higher mass eruption rate of 2 × 109 kg/s.