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M. Herak, S. Markušić, D. Herak Department of Geophysics, Faculty of Science University of Zagreb, Zagreb. Croatian FAULT-plane solutions (fps) database. Source detail is needed for NGA. Application of modern GMPE requires DETAILED knowledge of source properties.
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M. Herak, S. Markušić, D. Herak Department of Geophysics, Faculty of Science University of Zagreb, Zagreb Croatian FAULT-plane solutions (fps) database
Source detail is needed for NGA... Application of modern GMPE requires DETAILED knowledge of source properties. For instance: Abrahamson & Silva (2008), M = 7, Rrup = 5 km, RJB = 5 km, FHW = 1, W = 15 km: dip = 45° PGA = 0.48 gdip = 80° PGA = 0.39 g
Croatian FPS database • 216 solutions • 1909–2012 • Excel-database • 161 FPS computed by us (first motion polarity) • 6 by CMT Harvard, MEDNET, ZUR_RMT • 31 by Pondrelli et al. • 18 by ARSO, Slovenia
Croatian FPS database • P-axis (horizontal projection) – only quality 2 and better • Tectonic stresses are directed SW–NE (in the southern and eastern regions) to S–N (in the northern and western parts). • This reflects counter-clockwise motions of Adria and its compression against the Dinarides. • Most of solutions indicate reverse or strike-slip faulting.
Croatian FPS database Zagreb and Pokupsko areas (M > 3.45) Banja Luka region (M> 3.95) In general, solutions agree with tectonics and mapped faults quite well.
Croatian FPS database – conclusions • The database is regularly updated at least twice a year. • The database is now good enough to roughly define geometry of faulting in many (but not all!) Croatian and neighbouring regions. • Rapid and easy access to data of neighbouring networks would greatly improve solutions (past and future!). • An effort to adopt routine moment-tensor computation for local and regional earthquakes is needed! • All software is written by us and is free to anyone.