TY - JOUR
T1 - An adjoint data assimilation method for optimizing frictional parameters on the afterslip area
AU - Kano, Masayuki
AU - Miyazaki, Shin'ichi
AU - Ito, Kosuke
AU - Hirahara, Kazuro
N1 - Funding Information:
Acknowledgments. We thank T. Ochi for useful comments that helped to improve the manuscript. This work was supported by JSPS Fellows (23-1546), by MEXT KAKENHI (21340127) and by MEXT projects of “New Research Project for the Evaluation of Seismic Linkage around the Nankai Trough” and of “Observation and Research Program for Prediction of Earthquakes and Volcanic Eruptions”. We used Generic Mapping Tools (Wessel and Smith, 1998) to produce the figures.
PY - 2013
Y1 - 2013
N2 - Afterslip sometimes triggers subsequent earthquakes within a timescale of days to several years. Thus, it may be possible to predict the occurrence of such a triggered earthquake by simulating the spatio-temporal evolution of afterslip with estimated frictional parameters. To demonstrate the feasibility of this idea, we consider a plate interface model where afterslip propagates between two asperities following a rate-and-state friction law, and we adopt an adjoint data assimilation method to optimize frictional parameters. Synthetic observation data are sampled as the slip velocities on the plate interface during 20 days. It is found that: (1) all frictional parameters are optimized if the data sets consists not only of the early phase of afterslip or acceleration, but also of the decaying phase or deceleration; and (2) the prediction of the timing of the triggered earthquake is improved by using adjusted frictional parameters.
AB - Afterslip sometimes triggers subsequent earthquakes within a timescale of days to several years. Thus, it may be possible to predict the occurrence of such a triggered earthquake by simulating the spatio-temporal evolution of afterslip with estimated frictional parameters. To demonstrate the feasibility of this idea, we consider a plate interface model where afterslip propagates between two asperities following a rate-and-state friction law, and we adopt an adjoint data assimilation method to optimize frictional parameters. Synthetic observation data are sampled as the slip velocities on the plate interface during 20 days. It is found that: (1) all frictional parameters are optimized if the data sets consists not only of the early phase of afterslip or acceleration, but also of the decaying phase or deceleration; and (2) the prediction of the timing of the triggered earthquake is improved by using adjusted frictional parameters.
KW - Adjoint method
KW - Afterslip
KW - Data assimilation
KW - Earthquake cycle simulation
KW - Frictional parameters
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U2 - 10.5047/eps.2013.08.002
DO - 10.5047/eps.2013.08.002
M3 - Article
AN - SCOPUS:84894495785
VL - 65
SP - 1575
EP - 1580
JO - Earth, Planets and Space
JF - Earth, Planets and Space
SN - 1343-8832
IS - 12
ER -