back Back to all Seminars

Observed Ground-Motion Variabilities and Implication for Source Properties and Seismic Hazard Evaluation

Start Date: March 1, 2017 - 04:15 PM
End Date: March 1, 2017 - 05:15 PM

By  Prof. Fabrice Cotton
GFZ German Research Centre for Geosciences and Potsdam University, Potsdam, Germany
Host: Prof. Martin Mai
Venue: Lecture Hall 1 (2322), Engineering and Science Hall (Building 9)

More Information:

​Abstract: One of the key challenges of seismology is to be able to calibrate and analyze the physical factors that control earthquake and ground-motion variabilities. Indeed, the random ground-motion-prediction variability associated with a given earthquake scenario (a chosen magnitude–distance earthquake) strongly influences the seismic hazard computation, in particular for long return periods. I will show that the exponential growth of seismological near-field records and modern ground-motion analysis technics allow to calibrate and analyze the physical factors that control the earthquakes and the ground-motion variability I will for example show that we can calibrate between-events variabilities using recent high-quality global accelerometric datasets (NGA2, Resorce) and datasets from recent earthquakes sequences (Aquila, Iquique, Kunamoto). The obtained between-events variabilities will be used to evaluate the variability of earthquake stress-drops but also the variability of source properties which cannot be explained by a classical Brune stress-drop variations. We will finally use recent ground-motion variability analysis to evaluate the regional variations of source properties and discuss the strategies to calibrate future physics based ground-motions simulations and associated probabilistic seismic hazard assessments.

Bio: Fabrice Cotton is Professor at the University of Potsdam and the head of the seismic hazard and stress-field section of the German Research Centre for Geosciences (GFZ).  He is actually chairing the science board of the Global Earthquake Model Foundation. He was a Professor of Geophysics at the University Joseph Fourier (Grenoble, France) from 2001 to 2015 and a scientist of the French Institute for Radiological Protection and Nuclear Safety from 1996 to 2001.  He received his Ph.D. from The Grenoble University in 1996 and he was nominated junior fellow of “Institut Universitaire de France” in 2006. Prof. Cotton research interests concern the analysis of earthquake source properties, the characterization of strong ground-motions and the improvement of probabilistic seismic hazard models. His main tools are the analysis of earthquake near-field data (accelerograms, GPS). He has co-authored 90 publications in peer reviewed journals. He has been involved in a number of national and international projects involving seismic hazard assessments in France, Germany, Switzerland and South Africa.  He has been coordinating several research programs and he is actually the PI of the working group in charge of the strong ground-motion modeling for the new European Hazard map (SERA and EPOS-IP European projects).