%0 Journal Article %1 li_malin:2008 %A Li, Yong-Gang %A Malin, Peter E. %D 2008 %J Geophysical Research Letters %K geophysics seismology %N 8 %P L08304+ %R 10.1029/2007GL032924 %T San Andreas Fault damage at SAFOD viewed with fault-guided waves %U http://dx.doi.org/10.1029/2007GL032924 %V 35 %X Highly damaged rocks within the San Andreas fault zone at Parkfield form a low-velocity waveguide for seismic waves, giving rise to fault-guided waves. Prominent fault-guided waves have been observed at the San Andreas Fault Observatory at Depth (SAFOD) site, including a surface array across the fault zone and a borehole seismograph placed in the SAFOD well at a depth of \~2.7 km below ground. The resulting observations are modeled here using 3-D finite-difference methods. To fit the amplitude, frequency, and travel-time characteristics of the data, the models require a downward tapering, 30-40-m wide fault-core embedded in a 100-200-m wide jacket. Compared with the intact wall rocks, the core velocities are reduced by \~40\% and jacket velocities by \~25\%. Based on the depths of earthquakes generating guided waves, we estimate that the low-velocity waveguide along the fault at SAFOD extends at least to depths of \~7 km, more than twice the depth reported in pervious studies.

@article{li_malin:2008, abstract = {Highly damaged rocks within the San Andreas fault zone at Parkfield form a low-velocity waveguide for seismic waves, giving rise to fault-guided waves. Prominent fault-guided waves have been observed at the San Andreas Fault Observatory at Depth (SAFOD) site, including a surface array across the fault zone and a borehole seismograph placed in the SAFOD well at a depth of \~{}2.7 km below ground. The resulting observations are modeled here using 3-D finite-difference methods. To fit the amplitude, frequency, and travel-time characteristics of the data, the models require a downward tapering, 30-40-m wide fault-core embedded in a 100-200-m wide jacket. Compared with the intact wall rocks, the core velocities are reduced by \~{}40\% and jacket velocities by \~{}25\%. Based on the depths of earthquakes generating guided waves, we estimate that the low-velocity waveguide along the fault at SAFOD extends at least to depths of \~{}7 km, more than twice the depth reported in pervious studies.}, added-at = {2012-09-01T13:08:21.000+0200}, author = {Li, Yong-Gang and Malin, Peter E.}, biburl = {https://www.bibsonomy.org/bibtex/28d2efe1ead71ac1f2fe94f51b58c6945/nilsma}, day = 19, doi = {10.1029/2007GL032924}, interhash = {5e2beb2751feab5d617c91ca201f0fed}, intrahash = {8d2efe1ead71ac1f2fe94f51b58c6945}, issn = {0094-8276}, journal = {Geophysical Research Letters}, keywords = {geophysics seismology}, month = apr, number = 8, pages = {L08304+}, timestamp = {2021-02-09T13:22:13.000+0100}, title = {San Andreas Fault damage at SAFOD viewed with fault-guided waves}, url = {http://dx.doi.org/10.1029/2007GL032924}, volume = 35, year = 2008 }