Abstract Title: Application of Broadband Seismology in the Basin and Range and 
Surrounding Regions for Estimating Earthquake Source Parameters and Regional 
Velocity Models

Abstract Author(s): Ichinose, Gene (URS) - Thio, Hong Kie (URS) - Saikia, 
Chandan (URS)  

Abstract: The Basin and Range (BR) has a complex distribution of faulting along 
its western margin (e.g., Eastern California Shear Zone, Walker Lane Belt, and 
Sierra Nevada Micro-plate). While gravitational collapse of the BR is proposed 
as the main tectonic driving force it is being discovered from geodesy that a 
comparable amount of lateral shear partitioned from the San Andreas Fault is 
also playing a major role in shaping the BR landscape. This feature makes it 
necessary to have real-time databases of earthquake source-parameters available 
to researchers and the public. We have estimated earthquake moment tensors for 
this region using long-period regional-waves since 1990. The database currently 
contains information on over 150 earthquakes with magnitudes above 3.5. 
US-Array and permanent backbone stations will provide the opportunity to study 
propagation of broadband regional-waves in the greatest of detail and will help 
to improve this database for the studying future and past earthquakes. We will 
show examples of iterative waveform inversion methods used to calibrate 1-D 
layered regional velocity models using Japanese F-net and K-net stations 
(analogous to US-Array). A similar study in the BR will enable us to obtain 
high quality moment tensors solutions using fewer stations down to lower 
magnitudes. Another interesting parallel avenue of research is to examine how 
Earth velocity models obtained from regional-waves, body and surface wave 
tomography, and inversion of body-wave travel-times are related. Better earth 
models will also help in predicting higher frequency ground motions, which is 
important in predicting ground motions from large earthquakes.