A GIS-based application for volume estimation and spatial distribution analysis of tephra fallout: a case study of the 122 BC Etna eruption

摘要: In this study, we demonstrate the use of a geo-spatial information system for volume estimation fallout deposits and identification syn-eruptive post-eruptive depositional mechanisms. For first time, present thickness distribution maps, isopachs deposit volumes single stratigraphic units (A-F) 122 BC Plinian eruption Etna, most powerful volcano in historical times. Thickness data collected during field survey were organized into geo-referenced database, several interpolation algorithms used to calculate six layers (units A-F). The results are compared with those obtained using Pyle method, which bases calculations on exponential thickness-decay law deposits. Differences two methods analyzed through applying two-dimensional (2D) 3D geo-statistical analysis data, an 'ideal' as reference. Our approach allowed both sections where affected by secondary erosional or accumulation phenomena, assessment whether processes caused local morphologic conditions variations eruptive dynamics (e.g., rotation dispersal axis direction).