Regional Seismic Event Location in Asia


Regionalized Lop Nor Relocations

To simulate regional seismic event location in western China, we relocate 10 nuclear blasts at Lop Nor, using only the 10 closest reporting stations. Using these 10 stations, we sequentially eliminate the most distant one, relocating each time until only 3 stations are left (or 4 if we don't constrain depth). Relocations then are compared either to Gupta's (1986) satellite JED locations or to the teleseismic location derived from hundreds of stations as reported by the NEIC. The locations are plotted in Figures 17-20 versus maximum azimuthal gap and the number of stations used in our relocation. Both the depth constrained and depth unconstrained cases are shown. Figures 17 and 18 show mislocations when PPCs are not used. Figures 19 and 20 show mislocations when PPCs are used.

               


For two of the 10 nuclear explosions considered, these figures show a map of the 10 stations used in our relocations along with a map showing mislocation for each of the runs using 10, 9, 8...3 stations. Green diamonds and blue boxes are for depth constrained and unconstrained respectively, but no PPCs. Red circles and black triangles are for depth constrained and unconstrained with the use of PPCs. Mislocations outside the box are not shown.

       


Introduction | Seismicity of Asia | Station Variances | Example PPC Surfaces
Regionalized Lop Nor Relocations | Grid Search Locations | Preliminary Pn Back-Projection Results | Conclusions