Geophysical insights into the Transition fault debate: Propagating strike slip in response to stalling Yakutat block subduction in the Gulf of Alaska

• Main Authors: Guliuck, Sean P.S., Lowe, Lindsay A, Pavlis, Terry l., Gardner, James V., Mayer, Larry A.
• Format: Text
• Language: unknown
• Published: University of New Hampshire Scholars' Repository 2007
• Subjects: collision; Alaska; Yakutat; oceanic plateau; Transition fault; subduction; Oceanography and Atmospheric Sciences and Meteorology; Fairweather; Gulf of Alaska; Pacific; Queen Charlotte
• Online Access: https://scholars.unh.edu/ccom/91; http://geology.gsapubs.org/content/35/8/763.abstract

On the basis of faulting mapped on seismic reflection and bathymetric data, seismicity, current plate motions, and evidence that the Yakutat block may be anomalously thick, we propose a tectonic model for Yakutat-Pacific interactions, including the often-debated Transition fault. To the east, deformation associated with the Queen Charlotte–Fairweather fault system is extending offshore, facilitating westward propagation of strike-slip motion along the eastern segment of the Transition fault. To the west, the oblique-slip Pamplona zone and Transition faults merge at an embayment in the continental margin, where a north-south dextral strike-slip fault within the Pacific plate, illuminated by the 1987–1992 earthquake swarm, intersects the Pacific-Yakutat tectonic boundary. These fault patterns are consistent with modern plate motions and reflect a plate boundary reorganization that may be caused by resistance to subduction by the Yakutat block, a possible moderate-sized oceanic plateau.