SEMINAR - Gareth Funning

Space geodesy in the San Francisco Bay Area: surface deformation, fault kinematics and creep

Gareth Funning
Department of Earth Science
Univeristy of California Riverside

Wednesday, November 14th, 1:00pm GMCS 422

Pacific-North America relative motion is accommodated north of San Francisco on a series of sub-parallel strike-slip faults. From GPS data, we understand the broad distribution of slip between these stuctures, but data are too sparse to map the deformation in detail. However, using an advanced form of InSAR processing - the Permanent Scatterer method - we can generate a dense spatial dataset of surface velocity measurements. There now exist three such datasets for the Bay Area, each from a different viewing geometry/satellite track.

We find a variety of nontectonic and tectonic signals in these data, ranging from ground subsidence and landsliding to strain accumulation and fault creep. I will prsent a series of case studies from around the Bay Area, showing how the different observation geometries can be used to make first order inferences of horizontal and vertical velocities in deforming areas, how the data were used to identify creep on a fault previously considered locked, and how using the pattern of creep on the Hayward fault - currently considered the most dangerous structure in the region - a series of locked asperities can be imaged geodetically.