Postseismic relaxation along the San Andreas fault at Parkfield from continuous seismological observations.
نویسندگان
چکیده
Seismic velocity changes and nonvolcanic tremor activity in the Parkfield area in California reveal that large earthquakes induce long-term perturbations of crustal properties in the San Andreas fault zone. The 2003 San Simeon and 2004 Parkfield earthquakes both reduced seismic velocities that were measured from correlations of the ambient seismic noise and induced an increased nonvolcanic tremor activity along the San Andreas fault. After the Parkfield earthquake, velocity reduction and nonvolcanic tremor activity remained elevated for more than 3 years and decayed over time, similarly to afterslip derived from GPS (Global Positioning System) measurements. These observations suggest that the seismic velocity changes are related to co-seismic damage in the shallow layers and to deep co-seismic stress change and postseismic stress relaxation within the San Andreas fault zone.
منابع مشابه
Thirty-Five-Year Creep Rates for the Creeping Segment of the San Andreas Fault and the Effects of the 2004 Parkfield Earthquake: Constraints from Alignment Arrays, Continuous Global Positioning System, and Creepmeters
We present results from differential Global Positioning System (GPS) surveys of seven alignment arrays and four continuous GPS sites along the creeping segment of the San Andreas fault. Surveys of four alignment arrays from the central creeping segment yield 33to 36-year average minimum slip rates of 21–26 mm/yr. These rates are consistent with previous alignment array surveys spanning a 10-yea...
متن کاملChange of apparent segmentation of the San Andreas fault around Parkfield from space geodetic observations across multiple periods
[1] Sequences of earthquakes are commonly represented as a succession of periods of interseismic stress accumulation followed by coseismic and postseismic phases of stress release. Because the recurrence time of large earthquakes is often greater than the available span of space geodetic data, it has been challenging to monitor the evolution of interseismic loading in its entire duration. Here ...
متن کاملCoseismic and postseismic deformation associated with the 2003 Chengkung, Taiwan, earthquake
T61B-1277. Chen, H. Y., Yu, S. B., Kuo, L. C. & Liu, C. C. 2006. Coseismic and postseismic surface displacements of the 10 December 2003 (M-w 6.5) Chengkung, eastern Taiwan, earthquake, Earth planets Space, 58, 5–21. Chen, K. H., Nadeau, R. M. & Rau, R. J. 2007. Towards a universal rule on the recurrence interval scaling of repeating earthquakes?, Geophys. Res. Lett., 34, doi:10.1029/2007GL0305...
متن کاملLow-velocity damaged structure of the San Andreas Fault at Parkfield from fault zone trapped waves
[1] We used dense linear seismic arrays across and along the San Andreas Fault (SAF) at Parkfield, California to record fault zone trapped waves generated by explosions and microearthquakes in 2002. Prominent trapped waves appeared at stations close to the SAF main fault trace while some energy was trapped in the north strand at the array site. Observations and 3-D finitedifference simulations ...
متن کاملSpatially variable fault friction derived from dynamic modeling of aseismic afterslip due to the 2004 Parkfield earthquake
[1] We investigate fault friction from dynamic modeling of fault slip prior to and following the Mw 6.0 earthquake which ruptured the Parkfield segment of the San Andreas Fault in 2004. The dynamic modeling assumes a purely rate-strengthening friction law, with a logarithmic dependency on sliding rate: m 1⁄4 m þ a b ð Þ ln v v . The initial state of stress is explicitly taken into account, and ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Science
دوره 321 5895 شماره
صفحات -
تاریخ انتشار 2008