Oregon

Michael Bostock showed results of the seismologic imaging effort at the University of British Columbia at an invited lecture given to the Stanford Geophysics Department on March 14, 2002. His group utilized a data set collected by John Nabalek of the University of Oregon. The 1993 data was collected with the IRIS-PASSCAL equipment and is freely available. The array is 300 km long with 69 broadband seismometers every four km. Bostock inverts 31 earthquake event records across the array from many azimuths and teleseismic incidence angles to image crustal structure from the subducting oceanic crust into the volcanic back-arc basin across strike of the central Oregon Cascades region.

By inverting 31 earthquake events with dominate energies arriving with two second periods, his results have kilometer scale resolution. While the field equipment and experiment design limit the study to well below the resolution required for applications envisioned by this group, it does stand as a proof of concept for the linear experiment.