Stochastic modeling of seismic wave propagation beneath island-arcs and volcanoes

• Applicant: Professor Dr. Michael Korn
• Subject Area: Geophysics
• Term: from 2002 to 2006
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 5352571

The crust and the upper mantle beneath island arcs and volcanoes are known to be very heterogeneous. The structural inhomogeneity including the fine structure of the subducting oceanic slab and the mantle wedge has been revealed from velocity tomography analyses. This method, which is based on the travel time reading of P and S wave onsets, disregards waveform information completely. Even though the spatial resolution of the velocity inhomogeneity has been improved recently by using data of new dense seismic networks, it is inherently difficult for this analysis to image short wavelength heterogeneities with scale length much shorter than the station separation. In contrast to the deterministic approach, there is an alternative, stochastic approach. The objective of this project is to propose theoretical models to explain wave propagation through highly inhomogeneous media and to develop methods for analyzing high frequency seismograms observed in island arcs and volcanoes. We use both analytical methods and numerical methods for the study of wave propagation in randon media, where we introduce a statistical treatment of the wave equation. Existing methods will be further developed in cooperation with our Japanese research partners of Tohoku University, and sample data sets from Merapi volcano will be studied.

• DFG Programme: Research Grants
• Participating Person: Professor Dr. Ulrich Wegler