Slip-rates on active faults from offset end-glacial features, central Italy: Data for seismic hazard mapping.
by
Ioannis D. Papanikolaou
Benfield Greig Hazard Research Centre, The Research School of Geological and Geophysical Sciences, Birkbeck College and University College London
Coauthors: Gerald P. Roberts (The Research School of Geological and Geophysical Sciences, Birkbeck College and University College London, Gower Street, London, WC1E 6BT, UK), Alessandro M. Michetti (Universita dell’Insubria, Dipartimento di Scienze, MM.FF.CC., Via Lucini, 3, 22100, Como, Italia.), Patience Cowie (Department of Geology and Geophysics, The University of Edinburgh, West Mains Road, Edinburgh, EH9 3JW, UK)

New types of high resolution seismic hazard maps have been constructed using geological fault slip rate data rather than historical or instrumental seismicity data. These hazard maps show the way geological data can improve seismic hazard assessment by providing quantitative assessments through measurement of geologically recorded slip on active faults. Lazio-Abruzzo provides an exceptional opportunity to collect such throw rate data through construction of scarp profiles, using as a reference the last major glacial retreat phase that started 18,000 years ago. The large number of scarp profiles supported by published throw rates from trenching studies, offer a full spatial view of the slip distribution along each fault. After using relationships between coseismic slip values, rupture lengths and earthquake magnitudes, as well as relationships between earthquake magnitude and intensity distributions, we present a seismic hazard map for Lazio-Abruzzo. Our study provides a map showing how many times each location has been shaken at intensity IX or higher during the last 18,000 years, which can be easily transformed to a map of recurrence intervals. These maps do not suffer from the incompleteness of the historical catalogues or temporal earthquake clustering problems because of the long time period considered, provide high spatial resolution and consider the influence of bedrock geology and local soil condition on the intensity distribution.

Date received: March 12, 2002

Copyright © 2002 by the author(s). The author(s) of this document and the organizers of the conference have granted their consent to include this abstract in Atlas Conferences Inc. Document # caiq-78.