29 March, 2012 – Seminar

When: 4pm on Thursday, March 29th, 2012
Where: DIAS, Geophysics Section, 5 Merrion Square, Dublin 2, (library)

Speaker: Professor Andrew Curtis from the School of GeoSciences, University of Edinburgh
Title: The Extraordinary Theory of Seismic Interferometry.

Abstract:

The field of Seismic Interferometry exploded onto the earthquake and industrial seismological scene within the past eight years. It allows seismic tomography of the Earth’s subsurface to be performed using only background vibrational noise (with no identifiable sources of energy), seismometers to be turned into virtual (imagined) sources of energy that produce real seismograms, and I will show that real energy sources (e.g., earthquakes) can be turned into virtual seismometers deep inside the solid Earth (without the need for invasive drilling) – that is, we can use one earthquake as a seismometer to record seismograms from another earthquake.

I will also show how interferometry provides novel schemas for computational wavefield modelling using a wide variety of standard methods (finite difference, finite element, etc.), and provides an industrial solution for direct and scattered ground roll removal in reflection seismology.

Our most recent advances have shown how interferometry provides generalised, nonlinear methods to form images of the Earth’s interior, and that interferometry embodies completely new Optical Theorems of Physics. What is more, we can now record earthquakes on seismometers that were only installed (perhaps years) after the earthquake occurred. Bizarre, but true; and it’s very new.

I will provide a clear explanation for a general Geoscience audience of what interferometry is, how it works, and (most of) the advances listed above.