The Finicky Nature of Earthquake Shaking‐Triggered Submarine Sediment Slope Failures and Sediment Gravity Flows

Abstract

Submarine sedimentary slope failures lead to the largest mass flows on Earth and can be larger by two orders of magnitude in both volume and run-out distance than terrestrial landslides (Urlaub et al., 2013). Some flows travel hundreds of kilometers, transporting a major fraction of global sediments from the coastal environment to the deep ocean (Mountjoy et al., 2018;Talling et al., 2013;Urlaub et al., 2015) and threatening global communication cables and other infrastructure (Talling et al., 2014). In addition to the latter hazard, the preserved sedimentary deposits left behind when the flows slow and cease (called "turbidites") play a key positive role facilitating the assessment of earthquake hazard, because turbidites serve as key geologic recorders of past earthquakes when the initiation of their formation can be attributed to earthquake shaking (

Interannual Bottom-Intensified Current Thickening Observed on the Continental Slope Off the Southeastern Coast of Hokkaido, Japan

“…For example, bottom currents suspend sediments from the seabed [1]. Besides short-term sediment gravity flows [2], the cumulative effects of long-term variations in deep and bottom currents, even those that are very weak, are thought to have substantial impacts on the distribution of suspended sediments, e.g., [3]. In addition to corrosion, deep and bottom currents impact the construction and maintenance of marine and offshore structures and deep sea drilling, e.g., [4].…”