InSAR mission constraints for volcano deformation processes

Over the past decade interferometric synthetic aperture radar (InSAR) has been applied to a large number of volcanoes and volcano processes. This has led to a significant number of successful applications covering a range of spatial and temporal scales. These studies have demonstrated InSAR's ability to constrain the geometries of magma bodies, in some cases discovering sources of surface deformation that were previously unknown. In addition, these observations have provided a more detailed description of the source, and in some cases have discovered new modes of volcano deformation. The broad spatial coverage of InSAR at less than 100m pixel resolution has often constrained source properties that were often too subtle to detect or differentiate using existing ground-based geodetic networks (if they were in place). Our current InSAR-derived view of volcano deformation is based on the existing satellite data that is dominated by C-band sensors (ERS, Radarsat-1, and Envisat) with approximately monthly repeat intervals. The success stories for these sensors have generally occurred for highly active basaltic volcanoes and/or in sparse vegetation regions. The challenge for advancing our understanding of volcanoes and volcanic hazard lies in pushing InSAR into the realm of stratovolcanoes that often feature significant pre-eruptive vegetation cover for previously dormant (but highly explosive) volcanoes, yet require dense spatial sampling over short (daily) time intervals to capture catastrophic eruptions. I will provide an overview of past InSAR volcano results and recent in situ volcano measurements, coupled with some surface deformation models, to constraint spatial, temporal, and wavelength dependant requirements for future InSAR missions.