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Spatial Variation of Slip Behavior Beneath the Alaska Peninsula Along Alaska‐Aleutian Subduction Zone
Author(s) -
Li Shanshan,
Freymueller Jeffrey T.
Publication year - 2018
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/2017gl076761
Subject(s) - geology , subduction , induced seismicity , slip (aerodynamics) , seismology , peninsula , global positioning system , geodesy , plate tectonics , spatial distribution , tectonics , geography , remote sensing , physics , archaeology , thermodynamics , telecommunications , computer science
We resurveyed preexisting campaign Global Positioning System (GPS) sites and estimated a highly precise GPS velocity field for the Alaska Peninsula. We use the TDEFNODE software to model the slip deficit distribution using the new GPS velocities. We find systematic misfits to the vertical velocities from the optimal model that fits the horizontal velocities well, which cannot be explained by altering the slip distribution, so we use only the horizontal velocities in the study. Locations of three boundaries that mark significant along‐strike change in the locking distribution are identified. The Kodiak segment is strongly locked, the Semidi segment is intermediate, the Shumagin segment is weakly locked, and the Sanak segment is dominantly creeping. We suggest that a change in preexisting plate fabric orientation on the downgoing plate has an important control on the along‐strike variation in the megathrust locking distribution and subduction seismicity.