| Popis: |
The processes involved with mass transport through a volcanic plumbing system are poorly understood. Through the use of potential field studies, this thesis aims to identify volcanic structures, processes and Earth properties that control volcanic activity. Gravity and total magnetic surveys at Kĩlauea (Hawaii, USA), Masaya (Nicaragua) and South Sister (Oregon, USA) volcanoes, allowed for development of models to investigate magma transport at different spatial and temporal resolutions. At Kĩlauea rapid, short term mass flux perturbations were characterized within the shallow plumbing system and long term mass increases were inferred in the creation of a large intrusive complex. Constraints on crustal viscosity were obtained at South Sister through gravity and deformation models. At Masaya, constraints were obtained for void space in the active crater and shallow geologic properties. Potential field studies at active volcanoes can clearly bring insight into the fundamental processes of magma transport and emplacement. |
