My primary research interest
is the study of the structure of the Earth's interior. My focus is to
understand the dynamics and evolution of the Earth. In this pursuit,
seismological data is my major source of information, but I also
include information from sister disciplines into my studies. As a
remote sensing tool
seismology is able to provide us with the information needed to better
understand the evolution, constitution and dynamics of the Earth, the
forces that drive plate tectonics and the magnetic field, and the
processes that form Earth's surface. To understand these processes is
the ultimate goal of my research.
The area of greatest interest
to me is the study of deep-Earth structure, especially the boundary
layer structure of the Earth's crust, mantle and core. My research
especially focuses on resolving upper mantle and transition zone
discontinuity structure and the core-mantle, and the inner-outer core
boundaries. To understand Earth's internal dynamical motions and
evolution it is important to get a better understanding of the
processes that occur at its boundary layers. These topics lend
themselves to a multidisciplinary approach including seismology,
geodynamics, mineralphysics and geochemistry.
The focus of my research has
predominantly been on improving the seismic resolution of the Earth by
developing new methods, adapting established methods from exploration
seismology to global seismology, and increasing the sampling of the
Earth's interior by using new datasets and new seismic phases to probe
the Earth.
To increase the resolution of
regional, passive source studies of the deep Earth, I use recordings of
seismic arrays and networks and array processing techniques. For more information on seismic arrays please check out http://array-seismology.asu.edu .The term
array is typically employed to refer to a seismometer network that
permits analysis of Earth structure with some form of time series
stacking to enhance the amplitude of the coherent part of the
seismogram over incoherent energy. Array measurements also allow the
measurement of the wavefield incidence angle at the array, therefore
allowing the use of powerful array processing tools adopted from
exploration seismology. Arrays can be used like an antenna to probe the
small-scale features of the Earth.
I work with data from
permanent and temporary array installations. Many of the permanent
arrays were built for the detection and analysis of underground nuclear
explosions and are part of
the International Monitoring System to determine compliance with the
Comprehensive Test Ban Treaty. These arrays are best suited to detect
high-frequency P-waves which are ideal for
high-resolution
studies. With increasing numbers of temporary array installations and
existing high quality permanent array installations, new datasets for
array seismology are readily at hand and my expertise in array processing makes me well
positioned to use these high quality datasets.
My research of the last few
years includes studies of the lithosphere and upper mantle, the
core-mantle and the inner core boundaries.
