Affiliation:
1. Université de Paris, Institut de physique du globe de Paris, CNRS, F-75005 Paris, France
2. Université Côte d’Azur, IRD, CNRS, Observatoire de la Côte d’Azur, Géoazur, 06560 Valbonne, France
Abstract
SUMMARY
The eastern offshore of Martinique is one of the active areas of the Lesser Antilles Subduction Zone (LASZ). Although its seismicity is moderate compared to other subduction zones, LASZ is capable of generating a M 7+ interplate earthquake and recent studies and historical events, such as the M 8 1839 and M 7–7.5 1946 earthquakes, confirm this possibility. Given the high risk that Martinique can face in case of unpreparedness for such a M 7+ earthquake, and the lack of a regional seismic hazard study, we investigated through numerical modelling how ground motion can vary for a hypothetical Mw 7.5 interplate earthquake. Our main objective is to highlight the major factors related to earthquake source that can cause the highest variation in ground motion at four broad-band seismic stations across Martinique. For this purpose, we generated 320 rupture scenarios through a fractal kinematic source model, by varying rupture directivity, source dimension, slip distribution. We computed the broad-band ground motion (0.5–25 Hz) by convolution of source–time functions with empirical Green’s functions (EGFs), that we selected from the analysis of moderate events (M 4–4.5) recorded in the area of interest since 2016 by the West Indies network. We found that the fault geometry and the spatial extension of the largest slip patch are the most influential factors on ground motion. The significance of the variation of the predicted ground motion with respect to ground motion prediction equations (GMPEs) depends on the evaluated frequency of ground motion and on the station. Moreover, we concluded that the EGF selection can be another significant factor controlling the modelled ground motion depending on station. Our results provide a new insight for the seismic source impact on ground motion across Martinique and can guide future blind seismic hazard assessment studies in different regions.
Funder
Institut de Physique du Globe de Paris
European Regional Development Fund
Publisher
Oxford University Press (OUP)
Subject
Geochemistry and Petrology,Geophysics
Reference73 articles.
1. Nonlinearity, liquefaction, and velocity variation of soft soil layers in Port Island, Kobe, during the Hyogo-ken Nanbu earthquake;Aguirre;Bull. seism. Soc. Am.,1997
2. Scaling law of seismic spectrum;Aki;J. geophys. Res.,1967
3. Caribbean USGS network;Albuquerque Seismological Laboratory (ASL)/USGS,2006
4. Uncertainties in strong ground-motion prediction with finite-fault synthetic seismograms: an application to the 1984 M 5.7 Gubbio, central Italy, earthquake;Ameri;Bull. seism. Soc. Am.,2009
Cited by
5 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献