The W-Bohemia/Vogtland region is characterized by spatially clustered swarm earthquake activity with a typical source depth of 6-12 km. Degassing of upper mantle derived fluids, correlating with seismicity, is observed as well as temporal variations in the amount and composition of the emitted gas, isotope composition, and in earthquake source processes. Evidence for fluid-controlled earthquake triggering was found from earthquake source studies and inter-event relationships. Fluid reservoirs have been proposed for the upper crust as well as for the crust-mantle transition zone, but their direct observation is still missing. Epicentres and gas springs are spatially separated and the pathways of fluids to the surface remain unresolved as are their relations to the crustal seismic structure. These features make the Eger Rift/Vogtland area a prime site for scientific drilling. In this project spatial and temporal imaging of crustal seismic structures and fluid dynamics will be achieved by various approaches. We will test the hypothetical existence of a fluid reservoir and estimate its spatial extent using seismic velocity and attenuation tomography as well as coda studies. We will measure the temporal evolution of stress and fluid dynamics giving information about changes in the upper crust during a swarm earthquake cycle. The 3D and 4D seismological models delivered by this project will constrain the decision for an optimal ICDP drilling location in the Eger Rift system.
DFG Programme
Infrastructure Priority Programmes
International Connection
Denmark
