Abstract
By examining bathymetric and seismic reflection data in the shelf-slope region offshore northeast of Taiwan, the morphology of the Huapinghsu Channel/Mienhua Canyon System was refined and the occurrence of axial incision in the major erosional trough of the Mienhua Canyon was identified. The Huapinghsu Channel extends from its head at a water depth of 120 m seaward across the shelf-slope region and merges with the Mienhua Canyon before finally emptying into the Southern Okinawa Trough. This review with a new idea illustrates this channel/canyon system as a sediment conduit transporting sediments from western Taiwan rivers to the Southern Okinawa Trough. Within the proximal reach of the Mienhua Canyon, in situ suspended particles were found associated with bottom nepheloid layers, which transport resuspended particles along the canyon course, and eventually into the Southern Okinawa Trough even during sea-level highstand. The shelf area around the channel head is subject to the influence of frequent occurrences of large typhoons and seasonal migrations of oceanic currents. Numerical examinations indicate that the flow velocities related with large waves or currents satisfy the critical values to the threshold of the motion of fine sand, implying gravity flows occur around the channel head, sweep unconsolidated sediments in the channel head, or even incise the channel floor at the present day. In this paper, sea level changes from the Last Glacial Maximum (LGM, ∼21 ka BP) to the present and sediment input to the head of the Huapinghsu Channel head are considered the major factors in the control of the Huapinghsu Channel/Mienhua Canyon system, which functions as a sediment conduit in the study area. Tectonics and climate are the minor factors that contribute to shelf sediment transport to the Southern Okinawa Trough via this channel/canyon system.
Highlights
Submarine canyons and channels are important conduits for transporting modern sediments from shelf to deep sea during both sea-level highstands and lowstands (Gardner, 1989; Covault et al, 2007; Piper and Normark, 2009; Canals et al, 2013; Normandeau et al, 2015; Puig et al, 2017; Chiang et al, 2020)
We propose a hypothesis that a channel/canyon system is serving as the sediment conduit transporting sediments from western Taiwan rivers to the Southern Okinawa Trough (SOT)
This hypothesis pays attention to the possibility of a connection of the head of the Huapinghsu Channel to the sediments derived from Taiwanese rivers on the ECS shelf and to the nature of the channel/canyon transition where sediments within the channel course are delivered via the Mienhua Canyon to the SOT (Figure 1)
Summary
Submarine canyons and channels are important conduits for transporting modern sediments from shelf to deep sea during both sea-level highstands and lowstands (Gardner, 1989; Covault et al, 2007; Piper and Normark, 2009; Canals et al, 2013; Normandeau et al, 2015; Puig et al, 2017; Chiang et al, 2020). We propose a hypothesis that a channel/canyon system is serving as the sediment conduit transporting sediments from western Taiwan rivers to the SOT This new idea regarding this channel/canyon system as a sediment conduit has not been mentioned in source-to-sink studies in the region offshore northeast of Taiwan before. This hypothesis pays attention to the possibility of a connection of the head of the Huapinghsu Channel to the sediments derived from Taiwanese rivers on the ECS shelf and to the nature of the channel/canyon transition where sediments within the channel course are delivered via the Mienhua Canyon to the SOT (Figure 1)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
