Arc scale distributions of small and large volcanoes: implications for magma supply
Karen Bemis
Affiliations: Department of Marine and Coastal Sciences, Rutgers, The State University of New Jersey, New Brunswick, NJ, USA
Presentation type: Poster
Presentation time: Thursday 16:30 - 18:30, Room Poster Hall
Poster Board Number: 4
Programme No: 3.7.11
Abstract
Small volcanoes are by far the most numerous of volcanoes at continental arcs. Small volcanoes include scoria cones, maars, small domes, and small shield volcanoes. Most are monogenetic, meaning that they erupt once over a relatively short time. In contrast, large volcanoes, including composite and large shield volcanoes, account for most of the erupted volume at arcs. This study investigates the spatial and temporal patterns of eruption for several continental arcs. Preliminary results are based on extant data from the Cascades and the northern Central American Arc; work will be extending to the southern Central American Arc and possibly arcs in Chile and Japan. The morphology of all identifiable volcanoes along each arc was collected using a combination of manual analysis of maps, literature surveys, and digital analysis; satellite images and field interpretations guided the identification of volcanoes and classification into types. Summed eruptive volume and the number of vents for each segment along the arc vary significantly. The implications of the Castruccio model connecting magma chamber size, cone height, and basal radius are assessed on an arc scale. Where sufficient dating is available, all measures will be assessed for changes over time. The goal of this study is to understand how eruptive volumes vary along arcs, to investigate the implications of distributed volcanism within arcs, and to consider whether there are clues to magma chamber behavior in the morphology and size of volcanic edifices.