Slip-rate measurements on the Karakorum Fault may imply secular variations in fault motion.
Beryllium-10 surface exposure dating of offset moraines on one branch of the Karakorum Fault west of the Gar basin yields a long-term (140- to 20-thousand-year) right-lateral slip rate of approximately 10.7 +/- 0.7 millimeters per year. This rate is 10 times larger than that inferred from recent InSAR analyses ( approximately 1 +/- 3 millimeters per year) that span approximately 8 years and sample all branches of the fault. The difference in slip-rate determinations suggests that large rate fluctuations may exist over centennial or millennial time scales. Such fluctuations would be consistent with mechanical coupling between the seismogenic, brittle-creep, and ductile shear sections of faults that reach deep into the crust.
Chevalier
M-L
ML
Laboratoire de Tectonique, Mécanique de la Lithosphère, Unité Mixte de Recherche (UMR) 7578, CNRS, Institut de Physique du Globe de Paris, 75252 Paris Cedex 05, France.
Ryerson
F J
FJ
Tapponnier
P
P
Finkel
R C
RC
Van Der Woerd
J
J
Haibing
Li
L
Qing
Liu
L