Volcanic geomorphology—an overview

Abstract

The review examines the role of geomorphology in analyzing the volcanoes on Earth. Five objectives are stressed. First, classifications of volcanic landforms should be improved to take care of the complexity in volcanic landform generation as magmatic systems, style of eruption, and the erupted material all influence the morphology. Second, geomorphology should contribute to the science of volcanology through its capability in reconstructing growth `stages' in complex volcanoes, and also in analyzing the structural factors which contribute to the catastrophic collapse of volcanoes. Third, geomorphology can contribute to physical volcanology by assessing the effects of topography on transport, erosion, and deposition of volcanogenic flows and identifying the sources and climatic/tectonic conditions which govern the emplacement of volcaniclastic deposits. Fourth, volcanic geomorphology (a) identifies sedimentary facies associations, (b) constructs facies models for dynamic volcano delivery systems, and (c) analyzes the characteristics of sediment gravity flows in order to determine relevant parameters for modelling their behaviour. Fifth, process-oriented geomorphology is critical in developing accurate methods for measuring rates of geomorphic processes that shape ephemeral volcanic constructs, and for evaluating and comparing geomorphic impacts on disturbed catchments and the related hydrologic response before, during, and after eruptions. This should help to refine parameters for the exponential decay model. Finally, volcanic geomorphology is essential for risk assessment through geomorphic hazard zonation and composite risk zonation. Such treatments are necessary in order to face the enhanced challenge posed by the combination of natural hazards and the increasing number of people who are at risk around volcanoes.