2.3 Event relocation
The accuracy and reliability of seismic tomography are also dependent on
the quality of the location results of the earthquakes, which may
contain significant uncertainties since they are often obtained from
routine event determinations based on 1-D Earth models. To minimize the
biases in our tomography introduced by event location errors, we adopt
an iterative inversion process during which the 3-D P-wave velocity
model obtained from our inversion is used to relocate all of the
contributing events. The relocation uses P-wave travel times calculated
in the 3-D model by the multi-stage fast marching method (de Kool et
al., 2006) and the neighbourhood algorithm (Sambridge and Kennett, 2001)
in a global search for the hypocenters.