An Overview of the Role of Long-Term Tectonics and Incoming Plate Structure on Segmentation of Submarine Mass Wasting Phenomena Along the Middle America Trench

摘要

We study mass wasting along the Middle America Trench (MAT), a subduction zone dominated by tectonic erosion, using a comprehensive data set of seafloor relief. We integrate previous studies of long-term tectonic processes to analyze how they influence the evolution of the slope structure and precondition the continental slope for mass wasting. We have used the distribution of an inventory of 147 slope failure structures along the MAT to discuss their relation to subduction erosion. We interpret that preconditioning of the slope by long-term tectonics, interacts in a shorter-term scale with features on the under-thrusting oceanic plate to modulate the abundance and types of mass wasting phenomena. The complex origin of the incoming oceanic plate has produced abrupt lateral changes in plate age, crustal thickness, relief, and response to bending deformation at the trench, leading to its partitioning into six segments. We found that the continental-slope failure style and abundance are partitioned into six segments that spatially match the ocean plate segments.