Lg and Other Regional Phases in South America
Rept. for 1 Sep 1989-31 Aug 1990
OBSERVATORIO SAN CALIXTO LA PAZ (BOLIVIA)
Pagination or Media Count:
The research continues and expands upon that previously undertaken. Additionally, a study of Li and Rg between Peruvian epicenters and Bolivian LPB station has been completed. Results are presented through a paper forming part of this report Regional Phases Lg, Li and Rg across Peru and Bolivia, dealing with those phases produced by earthquakes with epicenters in the area 3.44 deg S-17.87 deg S, 68.10 deg W-80.80 deg W, and recorded at the LPB. Through particle motion, group velocity and amplitude of those waves, it is concluded that Li are shear waves transmitted through the lower earth crust Lg are shear waves transmitted through the upper earth crust Rg are Rayleigh waves. Preliminary value of Q sub S in the upper crust is found to be about 200. Part II introduces another chapter of research, that of regional phases in the P coda for earthquakes with epicenter in Southern Chile and Southern Argentina. A change of behavior was detected across a line particularly coincident with the parallel 42 deg S. This observation needs to be investigated further.