Morpho-sedimentary features and sediment dispersal systems of the southwest end of the Ryukyu Trench: a source-to-sink approach

X-ray fluorescence core scanning, magnetic signatures, and organic geochemistry analyses of Ryukyu Trench sediments: turbidites and hemipelagites

“…2), implying sediment deposition rather than erosion in this area. The connection between the Hualien Canyon, east of Taiwan, and the Ryukyu Trench is a major seaward transport route for orogenic sediments shed from the island of Taiwan (Hsiung et al 2017). The sediment flux delivered to the ocean from eastern Taiwanese rivers has been estimated to be about 44 Mt/year (Dadson et al 2005) to 79.4 ± 13.8 Mt/year (Kao and Milliman 2008).…”

“…Large volumes of orogenic sediment eroded from the Taiwan orogenic belt are transported seaward and deposited as a~4 km-thick sequence in the confined Huatung Basin. The major sediment transport routes from Taiwan to the southwestern Ryukyu Trench floor have been determined from bathymetric and seismic reflection data (Hsiung et al 2017). The different water depths in the Huatung Basin (~4000 m) and the West Philippine Sea Basin (~6300 m) imply that the Gagua Ridge is a natural boundary preventing the transport of sediments farther eastward (Van Avendonk et al 2014;Lehu et al 2015).…”

“…1) is an ideal location for studying trench deposits within a source-to-sink framework because of the distinct sediment transport routes from their terrestrial source in Taiwan to their ultimate sink in the trench. Hsiung et al (2017) suggested that deposits in the western end of the Ryukyu Trench record the accumulation of sediments derived from the distal source in Taiwan, transported mainly by turbidity currents down the Hualien and Taitung Canyons. To date, those trench turbidite deposits have mainly been interpreted on the basis of seismic facies characteristics and major sedimentary features, but these interpretations lack constraints from core samples (Hsiung et al 2017).…”

“…Hsiung et al (2017) suggested that deposits in the western end of the Ryukyu Trench record the accumulation of sediments derived from the distal source in Taiwan, transported mainly by turbidity currents down the Hualien and Taitung Canyons. To date, those trench turbidite deposits have mainly been interpreted on the basis of seismic facies characteristics and major sedimentary features, but these interpretations lack constraints from core samples (Hsiung et al 2017). The main objective of this study is therefore to verify the provenance of Ryukyu Trench sediments based on analyses of core samples acquired by the Japan Agency for Marine-Earth Science and Technology (JAMSTEC) in 2015.…”

Seafloor morphology and sediment magnetic fabric in a putative 1771 Meiwa tsunami source region in the southern Ryukyu Islands, SW Japan

“…The oblique subduction in the west has generated complex deformation in the outer accretionary wedge as a result of trench-parallel right-lateral shear zones (Kao 1998;Lallemand et al 1999;Hsu et al 2013). The west Ryukyu subduction zone is characterized by a large area of the forearc basin (Okamura et al 2017; that is divided into subsedimentary basins (Lallemand et al 1999;Font et al 2001;Izumi et al 2016;Hsiung et al 2017). The Hateruma Basin is located south of Iriomote-jima and Ishigaki-jima ( Fig.…”