Speaker: Cecile Piret
“Earthquakes are manifested always in unexpected manner because of the nature of the nonlinear properties of crustal material, where a critical temperature separates a stable creeping regime from a domain where fracture instabilities can develop. This temperature depends sensitively on the material properties and is different by 200 to 250 degrees, for crustal and mantle substances. Therefore, thermal and chemical effects are important.
We will go over several important concepts in the generation of brittle-ductile instabilities leading to slow earthquakes. We will then review the governing non-linear evolutionary partial differential equations needed to model the brittle-ductile instabilities by taking explicitly thermo-mechanical feedback into account. Then we will also discuss some ongoing laboratory experiments, which will call our attention to the potentially important role played by volatiles and strain-localization in fracturing the crust. Other catastrophic near-surface events , such as landslides and ice-quakes wlll also be discussed within this general framework of instabilites viewed from a physical standpoint.”