Séminaire : Harsha S. Bhat

Revisiting the axioms in earthquake source mechanics

Abstract

The mechanics of earthquakes, and the more recently discovered slip dynamics of faults, have had their theoretical basis developed by a serendipitous collaboration between geologists, physicists, applied mathematicians, experimentalists of rock, solid & fluid mechanicians, and the nascent field of earthquake source mechanics. It is this collaboration that gave birth to our state-of-the-art understanding of earthquake source. However, I posit in this talk that we need to revisit them in light of new experimental and natural observations. While observations of earth, vis a vis fault dynamics, has exploded, we still rely on these ‘axioms’ to explain them. 
In this talk I will give a quick walk through on our group’s collaborative effort to explain the new observations that involves a synergistic discussion between all the fields that study faults albeit independent of each other.  Specifically, I will try to convince you theoretically/numerically, and where observations exists, that:

1. sometimes faults can open
2. slow slip and earthquakes can occur on the same segment of the fault
3. the volume around a fault is just as important as the fault itself
4. strike slip earthquakes can cause destructive tsunamis under certain conditions.

Short biography

Harsha S. Bhat is a CNRS Research Scientist working at the Laboratoire de Géologie in Ecole Normale Supérieure and a Professor at Laboratoire de Mécanique Solides, Ecole Polytechnique. He is also a visiting Professor at National Institute of Science Education and Research, India. 

Harsha S. Bhat mainly at the interface between Earthquake Physics and Solid Mechanics making occasional excursions into Rock Mechanics, Tectonics and Seismology. 

He is a solid mechanician and earthquake source physicist by training. He obtained my B. E. in Civil Engineering from Karnataka Regional Engineering College in India (now called the National Institute of Technology Karnataka, Surathkal). He then proceeded to obtain my Ph. D. from Harvard University, under the supervision of Prof. James R. Rice and Dr. Renata Dmowska. He did his postdoctoral studies jointly between at Caltech and the University of Southern California where he worked with Prof. Ares J. Rosakis and Prof. Charles G. Sammis. 

He joined CNRS in Jan. 2012 as a Grade 1 Research Scientist, and began working at the Institut de Physique du Globe de Paris (IPGP) until Apr. 2016. 

HE have been awarded the Prix Michel Gouilloud Schlumberger from the Academié des Sciences. You can watch the ceremony here. He was also awarded an European Research Council Consolidator Grant for the amount of 2.0M€ for my project PERSISMO.