NBW: Numerical Simulation of Wave Propagation in Seismically Active Regions
The deterministic short-term prediction of the time, magnitude, and location of large earthquakes is not within reach. The crust is thought to be permanently in a critical state which implies that even small perturbations of stress may trigger earthquakes which may at any time cascade into larger ones. Therefore, the only way to prevent dammage seems to be a reliable prediction of likely ground motion for realistic earthquake scenarions and appropriate measures for buildings and large constructions (dams, bridges, power plants, etc.). Local 3-D structures (particularly low seismic velocity sedimentary structures) have the most important effects on ground motion. Once this structure is known (which at present is not often the case) one can simulatio wave propagation for likely earthquake scenarios as the location and size of possible earthquakes is known quite well. However, a reliable estimate of shaking hazard is not possible with a single earthquake simulation for a particular region. Only a large number of simulations and a probabilistic combination of the resulting data can lead to a representative picture of the shaking risk. In this project we intend to carry out such a large-scale large-number of earthquake scenarios for the first time. The simulations will be carried out for a region where the velocity structure is known in great detail (e.g. Los Angeles or San Francisco basins, Cologne basin). The ultimate goal is to provide reliable estimates of seismic hazard which can be used by local authorities.
- initial KONWIHR funding: 06/2001-05/2004
- Prof. Dr. Heiner Igel, Institut für Allgemeine und Angewandte Geophysik, LMU-München
- H. Wang, H. Igel, F. Gallovi, A. Cochard, M. Ewald: Source-related variations of ground motions in 3-D media: Application to the Newport-Inglewood fault, Los Angeles Basin, Technical Report, (2008).
- G. B. Brietzke, A. Cochard, H. Igel: Dynamic rupture along bimaterial interfaces in 3D, Geophysical Research Letters, 34 (2007) L11305. DOI: 10.1029/2007GL029908, 2007
- M Ewald, Heiner Igel, K.-G. Hinzen, F. Scherbaum: Basin-related effects on ground motion for earthquake scenarios in the Lower Rhine Embayment, Geophys. J. Int., 166 (2006) 197-212. DOI: 10.1111/j.1365-246X.2006.02909.x
- H. Igel, U. Schreiber, A. Flaws, B. Schuberth, A. Velikoseltsev, A. Cochard: Rotational motions induced by the M8.1 Tokachi-oki earthquake, September 25, 2003, Geophysical Research Letters, 32 (2005) L08309. DOI: 10.1029/2004GL022336
- M. Fohrmann, H. Igel, G. Jahnke, Y. Ben-Zion: Guided Waves from sources outside faults: An indication for shallow fault zone structure?, Pure and Applied Geophysics, 161 (2004) 21225-2137. DOI: 10.1007/s00024-004-2553-y