Mendocino Triple Junction Observatory - Connecting Cascadia to the San Andreas

Convenors: Kevin P. Furlong, Mark A. Hemphill-Haley

Location: Arcata, CA.

Date: October 20-22, 2016


The Mendocino Triple Junction (MTJ) region straddles the transition between two of the most important segments of the North American plate boundary, separating the Cascadia subduction zone from translational tectonics of the San Andreas plate boundary. The region is seismically active, undergoes rapid and spatially varying deformation, and involves many key plate boundary elements. Although the MTJ itself was not a primary EarthScope focus its location linking two of the major targets of both the PBO and USArray components means that a wealth of relevant new data have been acquired under EarthScope. All these data bear directly on the processes at work as the North American lithosphere undergoes a transition from being the long-lived upper plate of a megathrust system to a participant in the formation of a new lithosphere-cutting transform plate boundary. How that transition occurs has profound implications for both the behavior of the southern third of the Cascadia system and the development of the northern San Andreas plate boundary fault system. This workshop will bring together active scientists with a focus on understanding the unique setting of the MTJ and associated deformational and seismic processes along both critical plate boundary structures. It will inventory existing data collected under the EarthScope program, explore implications of those data and models, and delineate potential future experiments and projects that could build on this foundation.  The workshop will include a field excursion to key sites in the MTJ region. Participants will include researchers from a wide range of sub-disciplines including seismology, geodesy, paleoseismology, petrology/volcanology, geomorphology, and geodynamics. The MTJ and the associated tectonics systems it transforms serve as the core of plate tectonics education. This workshop will also explore the potential to develop and use educational materials that exploit the MTJ and environs to provide modern, well-constrained educational materials.


Workshop Summary Report