Geomorphological reconstruction and morphometric modelling applied to past volcanism

Abstract

Accurate and precise morphometric modelling can be extended to past eruptions after a careful palaeogeomorphological reconstruction of volcanic landforms in an oceanic island. This reconstruction was used to derive the pre-, post-eruption and present-day digital elevation models (DEM). The correct pixel size, interpolation method and quality of these DEMs are discussed. The process in a Geographical Information System framework of the geological information of cone, lava flow and tephra fall deposits together and the aforementioned DEMs allowed the determination of main morphological features of these volcanic landforms and their derivatives. The calibration and validation of morphometric modelling were performed on simulated volcanic landforms, and verified by a case study: a typical Holocene monogenetic basaltic eruption at Gran Canaria Island (Spain).