Harvard Seismology Group
Department of Earth and Planetary Sciences
My main research focus is seismic tomography for imaging both the elastic and anelastic properties of the earth in various scales; from meters in environmental, hydrogeological, geotechnical and archaeological problems, up to thousands of kilometers in the study of upper mantle and crust of subduction zones. My current work is on Japan's crust and upper mantle.
My research embraces different aspects of the tomographic problem. For example, it includes the development of algorithms to automate the extraction of useful information from seismic waveforms such as the arrival times of various seismic phases, S-wave splitting parameters and body wave dispersion data.
Furthermore, I am particularly interested in inverse problems. More specifically, I am working on the development of the necessary machinery, in terms of theory, methodology and software that will allow the assessment and the quantification of the uncertainty of large tomographic problems. My interest in inverse problems includes the study of joint inversion schemes that will allow the incorporation of complementary information from dissimilar datasets. Another focus of my research is the seismic forward problem. I am currently working on the development of forward modeling algorithms that exploit high performance computing facilities.
I am also interested in the study of the very low end of the seismic frequency spectrum, where the free oscillations of the Earth are observed. Such data provide significant insight into Earth’s internal structure but also into the properties of massive earthquakes.
Recently, I have been involved in an effort to digitize old analog seismograms of Harvard’s station. My main contribution is the development of DigitSeis software that converts scanned images of typical analog seismograms into readable digital time series.
Some of my other interests include exploring non-conventional inversion approaches based upon global optimization methods such as genetic algorithms, and studying wave propagation and seismic radiation of earthquakes in the very shallow part of subduction zones that is considered to be aseismic.
personal site: www.geophysics.gr (currently under reconstruction...)