Marinière Judith, Beauval Céline, Nocquet Jean-Mathieu, Chlieh Mohamed, Yepes H. (2021). Earthquake recurrence model for the colombia-Ecuador subduction zone constrained from seismic and geodetic data, implication for PSHA. Bulletin of the Seismological Society of America, 111 (3), p. 1508-1528. ISSN 0037-1106.
Titre du document
Earthquake recurrence model for the colombia-Ecuador subduction zone constrained from seismic and geodetic data, implication for PSHA
Marinière Judith, Beauval Céline, Nocquet Jean-Mathieu, Chlieh Mohamed, Yepes H.
Source
Bulletin of the Seismological Society of America, 2021,
111 (3), p. 1508-1528 ISSN 0037-1106
Probabilistic seismic hazard assessment relies on long-term earthquake forecasts and ground-motion models. Our aim is to improve earthquake forecasts by including information derived from geodetic measurements, with an application to the Colombia-Ecuador megathrust. The annual rate of moment deficit accumulation at the interface is quantified from geodetically based interseismic coupling models. We look for Gutenberg-Richter recurrence models that match both past seismicity rates and the geodetic moment deficit rate, by adjusting the maximum magnitude. We explore the uncertainties on the seismic rates (a- and b-values, shape close to M-max) and on the geodetic moment deficit rate to be released seismically. A distribution for the maximum magnitudeMmax bounding a series of earthquake recurrence models is obtained for the Colombia-Ecuador megathrust. Models associated with Mmax values compatible with the extension of the interface segment are selected. We show that the uncertainties mostly influencing the moment-balanced recurrence model are the fraction of geodetic moment released through aseismic processes and the form of the Gutenberg-Richter model close to M-max. We combine the computed moment-balanced recurrence models with a ground-motion model, to obtain a series of uniform hazard spectra representative of uncertainties at one site on the coast. Considering the recent availability of a massive quantity of geodetic data, our approach could be used in other well-instrumented regions of the world.
Plan de classement
Sciences fondamentales / Techniques d'analyse et de recherche [020]
;
Géophysique interne [066]
