Evolutionary Dynamics of Subduction Zones

California Institute Of Technology, Pasadena CA

Investigators

Abstract

This project involves the study of subduction zones which are the sites for plate tectonic driving forces and most of the volcanic activity and geological hazards found around the world. Unfortunately, our understanding of subduction zone processes is still poorly developed. One of the principal reasons is that multiple processes, such as solid deformation deep in the earth and fluid migration associated with magmatism, are intimately coupled together. It is likely that what we see observationally results from a fine dynamic balance. The investigators and their collaborators will develop dynamic models for the evolution of subduction zones, from initiation to their transition into maturity. Recent numerical advances in modeling combinations of material behavior have allowed the investigators to make significant progress toward understanding subduction initiation. They will build upon these advances to develop a more complete quantification of the conditions and forces needed to successfully initiate subduction. By following the evolution of a subduction zone from its initiation into maturity, the group will assess how features developed during inception influence mature subduction. They will also couple fluid migration with mantle deformation. While fluid migration pathways have been examined previously, in this project, fluid migration will be included in dynamic models with deformable slabs, hence allowing the feedback between fluids and slab dynamics to be fully expressed. Though much of the work involves modeling, the models will provide tangible predictions that will be used to test hypotheses through comparisons to both geological and geophysical observations. There are several broader impacts of the proposed research, including the training of scientific manpower through support of a postdoctoral scholar and wide dissemination of computer animations of subduction dynamics on the internet Finally, this work will enhance scientific infrastructure by being a test bed for the GeoFramework system, which will be used to facilitate integration of plate reconstructions into geodynamic models. In the future, GeoFramework will be a system to enhance scientific discovery by allowing non-specialists to use advanced computational tools to interpret geophysical and geological data. Send a message to our press officer at <mailto:cdybas@nsf.gov>cdybas@nsf.gov.