TY  - JOUR
A1  - Weiss, Jonathan R.
A1  - Qiu, Qiang
A1  - Barbot, Sylvain
A1  - Wright, Tim J.
A1  - Foster, James H.
A1  - Saunders, Alexander
A1  - Brooks, Benjamin A.
A1  - Bevis, Michael
A1  - Kendrick, Eric
A1  - Ericksen, Todd L.
A1  - Avery, Jonathan
A1  - Smalley, Robert
A1  - Cimbaro, Sergio R.
A1  - Lenzano, Luis Eduardo
A1  - Baron, Jorge
A1  - Carlos Baez, Juan
A1  - Echalar, Arturo
T1  - Illuminating subduction zone rheological properties in the wake of a giant earthquake
JF  - Science Advances
N2  - Deformation associated with plate convergence at subduction zones is accommodated by a complex system involving fault slip and viscoelastic flow. These processes have proven difficult to disentangle. The 2010 M-w 8.8 Maule earthquake occurred close to the Chilean coast within a dense network of continuously recording Global Positioning System stations, which provide a comprehensive history of surface strain. We use these data to assemble a detailed picture of a structurally controlled megathrust fault frictional patchwork and the three-dimensional rheological and time-dependent viscosity structure of the lower crust and upper mantle, all of which control the relative importance of afterslip and viscoelastic relaxation during postseismic deformation. These results enhance our understanding of subduction dynamics including the interplay of localized and distributed deformation during the subduction zone earthquake cycle.
Y1  - 2019
U6  - https://doi.org/10.1126/sciadv.aax6720
SN  - 2375-2548
VL  - 5
IS  - 12
PB  - American Assoc. for the Advancement of Science
CY  - Washington
ER  - 
TY  - JOUR
A1  - Barbot, Sylvain
A1  - Weiss, Jonathan R.
T1  - Connecting subduction, extension and shear localization across the Aegean Sea and Anatolia
JF  - Geophysical journal international
N2  - The Eastern Mediterranean is the most seismically active region in Europe due to the complex interactions of the Arabian, African, and Eurasian tectonic plates. Deformation is achieved by faulting in the brittle crust, distributed flow in the viscoelastic lower-crust and mantle, and Hellenic subduction, but the long-term partitioning of these mechanisms is still unknown. We exploit an extensive suite of geodetic observations to build a kinematic model connecting strike-slip deformation, extension, subduction, and shear localization across Anatolia and the Aegean Sea by mapping the distribution of slip and strain accumulation on major active geological structures. We find that tectonic escape is facilitated by a plate-boundary-like, translithospheric shear zone extending from the Gulf of Evia to the Turkish-Iranian Plateau that underlies the surface trace of the North Anatolian Fault. Additional deformation in Anatolia is taken up by a series of smaller-scale conjugate shear zones that reach the upper mantle, the largest of which is located beneath the East Anatolian Fault. Rapid north-south extension in the western part of the system, driven primarily by Hellenic Trench retreat, is accommodated by rotation and broadening of the North Anatolian mantle shear zone from the Sea of Marmara across the north Aegean Sea, and by a system of distributed transform faults and rifts including the rapidly extending Gulf of Corinth in central Greece and the active grabens of western Turkey. Africa-Eurasia convergence along the Hellenic Arc occurs at a median rate of 49.8mm yr(-1) in a largely trench-normal direction except near eastern Crete where variably oriented slip on the megathrust coincides with mixed-mode and strike-slip deformation in the overlying accretionary wedge near the Ptolemy-Pliny-Strabo trenches. Our kinematic model illustrates the competing roles the North Anatolian mantle shear zone, Hellenic Trench, overlying mantle wedge, and active crustal faults play in accommodating tectonic indentation, slab rollback and associated Aegean extension. Viscoelastic flow in the lower crust and upper mantle dominate the surface velocity field across much of Anatolia and a clear transition to megathrust-related slab pull occurs in western Turkey, the Aegean Sea and Greece. Crustal scale faults and the Hellenic wedge contribute only a minor amount to the large-scale, regional pattern of Eastern Mediterranean interseismic surface deformation.
KW  - Seismic cycle
KW  - Space geodetic surveys
KW  - Europe
KW  - Joint inversion
KW  - Kinematics of crustal and mantle deformation
KW  - Rheology: crust and
KW  - lithosphere
Y1  - 2021
U6  - https://doi.org/10.1093/gji/ggab078
SN  - 0956-540X
SN  - 1365-246X
VL  - 226
IS  - 1
SP  - 422
EP  - 445
PB  - Blackwell
CY  - Oxford [u.a.]
ER  -