Introduction to Earthquakes Seismology

Introduction to Earthquakes Seismology

Introduction to Earthquakes Seismology

Intervenants : Coefficient Crédits ECTS Heures UE

Luis RIVERA

Alessia MAGGI

2 3 40 elective

 

This class presents an introduction to the study of earthquakes. We develop an approach pairing theory and observations.

Introduction : Plate tectonics and earthquakes, plate kinematics, global seismicity, strain, stresses, rheology, fracture.

Elastodynamics : Elastodynamic equations, explosive source, punctual force, punctual dislocation, fault representation, equivalent forces, double couple, near and far field. Influence of the medium properties, P and S polarization and radiation pattern, variation with the distance, source time function.

Focal Mechanism : Fault classification, punctual fault parametrization, focal sphere, remarkable points and planes. Nodal point ambiguity, plane representation of the focal sphere.

Source spectrum : seismic moment, earthquake magnitudes (Ml, Ms, Mw), corner frequency, scaling laws, radiated energy, finite sources (directivity), stress drop.

Inverse problems : Focal mechanism from first motion polarities,stress tensor from focal mechanisms,  introduction to the wave form modeling for finite source inversion.

Seismological instrumentation : microseismic noise, Electromagnetic seismometer response, feed-back, A/D converters, decimation filters, Poles and zeros.