In 1999, the Southern California Earthquake Center had a very active year. As the end of SCEC's formal existence as an NSF Science and Technology Center approaches, a number of activities aimed at maintaining a high level of cooperative organization of the earthquake research community are capturing more and more of the attention of SCEC members. The highlights of SCEC activities for the past year include the following categories, which are described in greater detail in the main body of the report. This is the first time such a transect has been produced through the entire plate boundary zone. Seismographs along the main corridor and along all cross lines recorded all of the shots.
Preliminary results indicate the data are generally quite good, and some are remarkable.
Travel time and amplitude anomalies are evident in first arrivals near the San Andreas fault, and reflections from the middle and lower crust are apparent in raw shot gathers. We are now well past the midpoint on our way to the goal of 250 continuously operating GPS stations in southern California, and are ready to complete the final major phase of network installation in the year 2000. This is an important step toward getting the State of California and surveying community involved directly in the use and operation of dense GPS networks. Phase III Report. This effort was described in recent reports, and papers are now in review for collective publication in the Bulletin of the Seismological Society of America in 2000.