SISMOTem-Antilles: an innovative pilot of macroseismic data close to seismic sensors

Abstract : In order to be efficient during seismic crisis management, authorities need to dispose of rapid assessment of the earthquake impacts. To answer to this need as well as to ensure quick information of the public, one can usually appeal to empirical relations allowing conversion of ground-motion parameters to intensity values and vice-versa: the so-called "GMICEs" (Ground Motion to Intensity Conversion Equations). Now, the problem is that GMICEs are usually derived from instrumental and macroseismic data independently collected within different geological contexts. These data allow producing only limited correlations, as the observed effects of earthquakes are not directly related to a corresponding seismic record. In that context, it appears essential to dispose of both types of data (instrumental and macroseismic) for close and homogeneous recording/observation sites in order to reduce uncertainty of GMICEs. As to do that, BRGM and BCSF are conducting an original and unique pilot experiment allowing a regular acquisition of macroseismic data close to permanent seismic sensors in French West-Indies (Caribbean): the SISMOTem-Antilles project. The innovative proposed approach consists in setting up a network of voluntary witnesses frequently present very close to seismic sensors, coupled to an online testimony process feeding into a database. This approach seems to be particularly well adapted to French West-Indies where many seismic sensors are located directly in administrative or educational buildings or in the vicinity of habitations. Regular presence of many peoples may facilitate constitution of such a network of witnesses. Theses data will improve research on GMICEs and their utilization.