Time-laps tomography in volcanic regions – means of better understanding volcanic and earthquake processes

Time period: 2008-12-01 to 2011-12-31

Project leader: Ari Tryggvason

Funder: Swedish Research Council

Type of award: Project grant

Total fundning: 888 000 SEK

The proposed project aims at developing a new generation of inversion and resolution algorithms for interpretation of massive 3D geophysical data sets. This is important, as many inversion problems today are solved without proper analysis of the models obtained in terms of robustness and resolution. Building on recent theoretical developments in our unit, new methods for the inversion and interpretation of massive combined geophysical data sets will be implemented. The methods will be applied to time lapse seismic tomography, where variations are believed to correspond to changes in state variables (e.g. pore pressure, fluid saturation, and temperature). New seismological data will be collected to enhance resolution in space and time to capture the changes observed in the preliminary data analysis using 4D local earthquake tomographic methods on southwest Iceland. It has been suggested that pore pressure does play a significant role in controlling earthquake aftershock activity, thus the intriguing possibility arises that main-shock activity may also be triggered by pore pressure changes due to the influx of fluid from below. If, as the Icelandic data suggest, pore pressure changes can be detected using seismic tomography, then a combined analysis of seismicity and tomography may reveal important and fundamental new information about how earthquakes work. The project is an important development improving our ability to image geological structure at all crustal levels.