[PDF] Séismes et volcans: Observer pour comprendre les processus et

ABSTRACT Millions of people and the economy of entire countries can be impacted by natural hazards such as volcanic eruptionsF earthquakesF landslides or tsunamisg Considerable progress has been made to understand their causes and consequen ces and to improve their mon itoringg HoweverF ev en though these advances have directly benefited societyF geophysicists and geologists are not yet able to accurately predict the timingF locationF and magnitude of earthquakes as they cannot predict the onsetF intensityF or duration of an eruptiong After the giant earthquakes of 2rr4 in Indonesia and 2ree in Japan and the characterization of several super eruptions Ohaving had climatic impactsUF the major stakes in seismology and volcanology are to improve the knowledge of the seismic and volcani c history of the earth and to particula r to understand the pr ocesses that occur in the subduction zonesg In generalF natural hazards are the result of largeiscale geological processes that evolve over particularly long time intervalsg Research in this area therefore relies heavily on permanentF semiipermanent or oneioff multiparameter observation networks located in disasteriprone regionsg For exampleF the IPGP operates volcanoF seismologica lF magnetic observatories and erosion processesF all over the planet and is officially responsible for the permanent observa tion o f the three active volc anoes in Franceg While the observation networks are currently booming and have made it possible to cross important milestones in scienceF it is essential to continue their development by focusing in particular on borehole instrumentationF marine instrumentation and the development of modelling coupled with machine learningg It is essential to develop research on the Earth system to impulse a society of prevention rather than foster a society of repairg

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