Understanding basaltic explosive volcanism
|Director of thesis|
|Co-director of thesis|
|Summary of thesis||
This project is focused on the characterization of the dynamics of basaltic explosive eruptions, with the main goal of creating a comprehensive database for the development of a conceptual model that can describe the triggering and the dynamics of basaltic explosive eruptions. In particular, I will study a strong strombolian eruption from Villarrica volcano in Chile (Chaimilla deposit), 2 subplinian eruptions from Cotopaxi volcano (Ecuador) and a Plinian eruption from Masaya volcano area in Nicaragua (Fontana Lapilli formation). I will characterize: (1) the physical parameters of each eruption (column height, erupted volume, mass discharge rate); (2) grain size and density of the associated products; (3) chemistry of the juvenile clasts (EMP, FTIR and SIMS analyses of glass, crystals and pre- and post-eruptive volatiles); (4) microtextures of the juvenile clasts (microlite and vesicle content and shape) applying both 2D and 3D image techniques (SEM and X-ray Tomography). Decompression experiments will be also carried out with a shock tube apparatus in order to characterize bubbles and flow regimes as a function of pressure drop, decompression rate, solid concentration and volatile content, with the aim of constraining the role of these individual parameters on the eruption dynamic (collaboration with the University of Bristol). Until the triggering and the dispersal of explosive basaltic volcanism are better understood, the risk it poses to populations living in close proximity to these volcanoes will always be underestimated.
|Administrative delay for the defence|