Abstract

The Himalaya is exceptional example of an active mountain range where the processes which have shaped the range over tens of millions of years can be observed at work. In this presentation, I will give an overview of what we have been learned from using a variety of different techniques to investigate its structure and current activity. I’ll describe and how the various observations and data (seismicity, geodesy, morphotectonics) can be reconciled from a simple model which involves recurring large earthquakes, aseismic deformation and some coupling between crustal deformation and erosion. A most intriguing observation is that strain and seismic activity in the Himalaya varies seasonally: as the Himalaya rises in response to the huge forces generated by Earth internal dynamics, it also shows a surprising sensitivity to very small climate-driven stress changes. I will discuss what can be learned from these observations with regard to earthquake nucleation process and how our understanding of earthquake physics combined with improved numerical simulation capabilities can help evaluate the probability and characteristics of future large earthquakes in the Himalaya.