2013 Volume 52 Issue 4 Pages 173-187
Ancient tephra fall units are important for Quaternary research, but most of the units have been only utilized as key beds and few attempts have been taken to quantitate eruption parameters such as erupted mass or column height, which are also important to obtain secular change of volcanic activity. Tephra2 is a code to simulate deposit distributions caused by pyroclastic eruptions (Connor et al., 2001 ; Bonadonna et al., 2005). The code, which is based on an advection-diffusion model, has a potential to reconstruct ancient eruptions from limited deposit data. In this article, the theoretical background and recent progress in research using the code are reviewed. The author also compares the source column models of Tephra2 and the gravity current model (e.g. Bursik et al., 1992). Based on the discussion, the author proposes that introduction of umbrella fallout to the code and analyses for vertical variation of particle release are keys to improve the simulation result.
