Effects of Magma Supply on Normal Fault Evolution and Eruption Dynamics along the Galápagos Spreading Center



I propose to participate in a funded NSF field program to the western Galápagos Spreading Center (GSC) to study the role of magma supply on faulting and eruption dynamics.  The cruise will map two distinct ~20-km long regions of the ridge axis that vary in magma supply, axial morphology, fault size and spacing, depth to axial magma chambers, and eruptive style.  The primary goal of this proposal is to leverage future funding for two geodynamical modeling studies that will be based on the data collected during this field program.  The first study will be focused on the mechanisms by which a fissure eruption localizes into a series of discrete eruptive vents during an eruptive episode.  Specifically the mapping and sampling program will be used to distinguish between different models for the processes that drive vent localization.  The goal of the second study is to determine the three-dimensional response of faulting to along-axis variations in magma supply.  The familiarity with the data derived from participation in the GSC field program will facilitate these modeling studies and yield better long-term scientific results than would independent studies that decouple data acquisition from modeling.