In order to further constrain the structure
of the lithosphere I have worked on developing methods of using regional
wave propagation anomalies. Both
Lg and Sn are seismic phases with
propagate primarily through the crust and uppermost mantle respectively.
This research is very important
in determining how the international community will monitor a Comprehensive
Test Ban Treaty. In order to be able to effectively discriminate between explosive
sources and earthquakes. Because
Lg-Pg and Lg-Pn amplitude ratios
are typically used in earthquake discrimination it is critical that
we develop models that remove the paths effects for both of these two
phases. In order to do this I have worked on developing
a tomographic procedure of mapping Lg to Pg ratios.
In order to map
Sn attenuation we used a method of mapping
This technique uses a discrete or quantized data set rather than
a continous data set.
Tests indicate this method accurately
maps regions of Sn blockage.
Sn attenuation is a very strong indicator
of anomalous hot upper mantle. Combined
with uppermost mantle velocity estimates we have been able to accurately
determine regions of thin hot lithospheric
mantle beneath the Iranian and Anatolian Plateaus.
Click on the images for larger images.