Earthquake Impact on Active Margins: Tracing Surficial Remobilization and Seismic Strengthening in a Slope Sedimentary Sequence.

ABSTRACT: Strong earthquakes at active ocean margins can remobilize vast amounts of surficial slope sediments and dynamically strengthen the margin sequences. Current process understanding is obtained from resulting event deposits and low-resolution shear strength data, respectively. Here we directly target a site offshore Japan where both processes are expected to initiate, that is, at the uppermost part (15 cm) of a sedimentary slope sequence. Based on a novel application of short-lived radionuclide data, we identified, dated, and quantified centimeter-scale gaps related to surficial remobilization. Temporal correlation to the three largest regional earthquakes attest triggering by strong earthquakes (M _w >8). Also, extremely elevated shear strength values suggest a strong

SUBMITTER: Molenaar A 

PROVIDER: S-EPMC6686709 | biostudies-literature | 2019 Jun

REPOSITORIES: biostudies-literature