Dr. Julian C. Lozos has been granted a NSF Earth Sciences Postdoctoral Fellowship to carry out a research and outreach plan at Stanford University and the USGS Menlo Park campus. This project aims to improve our understanding of the physical processes that determine how seismic rupture negotiates a junction between major faults, and by extension, our understanding of fault segmentation. Dr. Lozos will conduct dynamic rupture models to produce a suite of scenario earthquakes for the junctions between the San Andreas Fault and three other faults: the San Jacinto Fault, the Garlock Fault, and the Calaveras Fault respectively. Each of these junctions represents different types of geometrical, geological, and stress complexity, and each poses a significant seismic hazard to its surrounding area. Thus, the focus on the San Andreas system will improve understanding of general fault physics, as well as of seismic hazard in California. Previous studies have focused on these faults individually, or on generalizations and simplifications of the types of geometries represented by these junctions. This study will consist of more realistic and detailed modeling of the study areas, by incorporating many types of complexity into the model inputs. Complex fault geometry, velocity structure, and initial stresses will be informed by fault geology and seismicity literature, as well as by static stress modeling. Once the scenario modeling is completed, Dr. Lozos will compare the results to paleoseismic and historical data, both to constrain the modeling results against known past fault behavior, and to provide insight into the sizes and extents of earthquakes at these fault junctions in the past.
Many people live in the vicinity of the study areas, and thus, this project includes an education and outreach program focused on informing the public of the basic science of earthquakes, the related hazard, and on how to prepare for them. Dr. Lozos will give a series of public talks in communities near his study areas. Through Stanford, he will help lead field trips for K-12 students to local fault zones, and through the USGS, he will participate in additional public outreach events. In addition to public outreach, Dr. Lozos will also assist in developing a graduate-level course on fault physics at Stanford, which will help prepare him for a future career in academia.