Development of Geophysical Methodologies
Inprovements on used methodologies and newlly designed approches are
being devellope by the research personnel some of these leading edge
methods include:
- Developments in three-component signal processing
techniques. We
are developing advanced automatic processing methods to separate signal
from noise, based on coherence measurements and determination of
attributes such as polarisation or instantaneous phase. The aim is to
minimize noise and to identify any type of signal from its velocity,
propagation direction, polarization or dispersion properties.
Particular attention will be devoted to identification of weak signals
in the coda of P and S phases, which are related to different
heterogeneities and discontinuities usually not resolved with
tomographic approaches.
- New approaches to tomographic inversion of seismic
data. Methods of
travel time and full-waveform 2-D and 3-D tomographic inversions at
local, regional and global scales will be considered, including
advanced aspects such as parameterization of irregular cells.
Particular attention will be devoted to S-wave tomography using
surface-wave dispersion data.
- New approaches to subsurface seismic imaging
Pre-Stack depth
Migration. The scientist in this research line are developing research
in this field through the cooperation with service companies (REPSOL,
CGG-Veritas). The computational requirements of this type of research
are provided by: the in-house hardware/software and also the close
collaboration with the Barcelona supercomputing center and/or the Spanish Supercomputing National
Network . The team is developing this research also through
the
Barcelona Center for Subsurface Imaging
- New approaches to earthquake location. More accurate
methods of
earthquake location such as double differences and 3-D velocity models
will be considered, including as first stage improvement in arrival
time pickings using waveform cross-correlations. We will approach the
location of events outside the recording network, having more reliable
error location estimations by using density probability functions.
- Probing the Earth structure from seismic arrays. A
new methodology
consists in using an array of stations as a seismic antenna through
advanced data processing, inversion and modelling procedures, providing
new information on the fine structure of the Earth (topography from
focussing-defocusing models, thicknesses of discontinuities from
reflection/transmission coefficients, etc.).
- Use of level sets as markers of the kinematic
evolution of
interfaces. This technique, which has been recently developed and
applied in engineering research is now being incorporated by our group
to large-scale geodynamic problems. The aim is to model subduction and
delamination processes with eventual slab break-off of the subducting
slab or delaminated mantle. This leading-edge work is done in
cooperation with the Laboratory of Numerical Calculations (LACAN) of
the Polytechnic University of Catalonia
Links to Research Projects:
