SCEC Award Number 10048 View PDF
Proposal Category Individual Proposal (Integration and Theory)
Proposal Title Rupture directivity of microearthquakes on a bimaterial interface
Name Organization
Allan Rubin Princeton University
Other Participants Wang, Enning Graduate Student
SCEC Priorities A9, A8, A10 SCEC Groups FARM, Seismology
Report Due Date 02/28/2011 Date Report Submitted N/A
Project Abstract
Intellectual Merit This project is most closely associated with science objective A9, assessing the predictability of rupture directivity on a fault with a large velocity contrast. A preferential propagation direction on such faults has been hypothesized from numerical and analytical modeling and inferred from asymmetric fault damage zones and aftershocks, but ours is the first work to quantify directivity directly using a large dataset. More generally, this work is an important step toward testing models of earthquake rupture with data from natural faults, as opposed to laboratory experiments and numerical simulations. Our work has shown that directivity can be determined reliably even for microearthquakes and that other factors such as asymmetry of prior stressing history are also important in influencing directivity.
Broader Impacts Because earthquakes that propagate in one direction produce stronger ground shaking in that direction, testing the hypothesized preference for propagation in one direction on faults with a large velocity contrast is important for seismic risk assessment. In our dataset we found that this tendency is obvious but not exclsusive.
Exemplary Figure N/A