Seismological Study of the crust and upper mantle of the western Tibet
Participants:
Steven Roecker (RPI)
Peter Molnar
(U. Colorado, Boulder)
Vadim Levin,
Guo-Chin (Dino) Huang (postdoc)
Ayda Razi (graduate student)
Udergraduates:
Ben Marshall, Maria Shakhnovich,
Helen Janiszewski
(Rutgers)
Project is performed in collaboration with the Tibetan Bureau of the China Earthquake Administration
Funded by NSF-Geophysics
A key goal of this work is to understand what happens with the lithosphere when two continents collide. A number of competing models exist. A cartoon shows a few most commonly invoked. Our project aims to discriminate between them, by creating detailed images of the upper mantle, constraining crustal thickness, and probing the deformation texture of the lithosphere and the mantle beneath it.
Since the summer of 2007 our project collected data in the western Tibet. Additional sites were installed in August of 2009, and remained in the field through the spring of 2011. The configuration of the network is shown on this map. Field work was completed in May of 2011. Data will reside in IRIS DMC, and will become public in 2014.
EARLY RESULTS:
We used some previously collected data to study the anisotropic seismic wave speed in the crust and the upper mantle of the area. A paper describing our findings was published in Tectonophysics in 2008.
Records of 2008 Sichuan earthquake aftershocks were used to probe surface wave dispersion in the Tibetan plateau. Results confirmed previously noted finding of intense radial anisotropy at mid-crustal depth. A GRL paper describes this work.
