Mireille Laigle



  • 2015 : grant from the Simone and Cino del Duca Foundation of the Institut de France


Dr. Laigle, a researcher with the CNRS, is the head of the team "Dynamics of convergent margins" in the Géoazur Earth Science laboratory (UNS/CNRS/OCA). She is a specialist in the geophysical imaging of major seismic subduction faults, with the scientific objective of understanding how the structure of these faults controls the occurrence and amplitude of the strong seismic events that they create. Dr. Laigle has been in charge of numerous geophysical campaigns, both in the sea and on land, as well as of several large projects funded by the ANR and the European Union.  


Dr Laigle, and her team of young researchers in the Géoazur laboratory and the University of the French West Indies and Guiana, has received a grant from the Simone and Cino del Duca Foundation of the Institut de France for their project aiming to better quantify the maximum potential magnitudes of major seismic events in the Petites Antilles subduction zone. This analysis is highly important, as subduction zones produce the largest earthquakes but it is very difficult to determine their potential magnitudes ahead of time, as was tragically seen in the devastating and unanticipated Tokohu-Fukushima earthquake of 2011. 


To carry out their work, Dr. Laigle and her team have at their disposal an exceptional database that includes geophysical imaging data obtained from the sea, as well as instrumental seismic data recorded on land and in the sea, obtained during multiple missions as well as from more than 60 years of monitoring of the Antilles subduction zone by national Observatories. 


To anticipate the magnitude of an earthquake, it is necessary to know a certain number of properties of both the fault at risk and its immediate environment, notably the 3D architecture of the fault, its frictional properties, the elastic properties of the adjacent area, and the different agents that could modify these properties of either the fault or its surroundings (for example, fluids, fracturing, etc.) 


Their project aims to exploit the rich information contained in the database, in particular by performing a joint inversion of all of the experimental and natural data available for the region between Antigua and Martinique. This inversion will produce a 3D image of the fault zone, 400 km long and 100 km deep, at an unprecedented level of resolution. The model will be faced with data identifying the interfaces, discontinuities, and major faults within the zone, which will allow its refinement. This will be the first time ever that such a wide, deep, and high resolution 3D image will be produced of a seimogenic fault.