FATES-KP 宿命 Axial incision,channel meandering and sediment transfer of the Kaoping Canyon offshore SW Taiwan Cheng-Shing Chiang a and Ho-Shing Yu b a Hsiuping Institute of Technology, Taichung, Taiwan b Institute of Oceanography, National Taiwan University, Taipei, Taiwan

FATES-KP 宿命 Introduction Submarine canyon types:  Infilled canyons  Transgression  Empty canyons  Bypass  Incised canyons  Axial incision and canyon’s major valley  Significant fluvial input  Turbidity current or hyperpycnal flow

FATES-KP 宿命 Erosion of a stream bed The escarpment is about 3 m-high, located about 2 km from the river mouth.(After Mulder et al.,2003) Escarpment

FATES-KP 宿命 Type of density flow ρfρf ρwρw ρfρf ρwρw ρfρf Ρ w = ρ f ρ f <ρ w ρ f >ρ w

FATES-KP 宿命 Marine hyperpycnal flow Modified from Mulder et al.,1998,2003 Erosion seafloor

FATES-KP 宿命 Incised canyons Simplified bathymetric map of the western Gulf of Lion. (Baztan et al.,2005) Axial incision Canyon’s major valley

FATES-KP 宿命 Two main erosive features (Baztan et al., 2005) Canyon’s major valley Axial incision

FATES-KP 宿命 Axial incision Axial incision observed in the sea floor as the imprint of turbidity currents that eroded the floor of canyons during phases of connection to rivers (hyperpycnal turbidity current). (Baztan et al., 2005)

FATES-KP 宿命 Map of the study area

FATES-KP 宿命 Kaoping Canyon Kaoping River Small mountains river Dirty river high sediment yield (11,000 t /km /yr ) The Kaoping River － Submarine Canyon system River-Canyon Connection Increasing the frequency of hyperpycnal flow formation !!!

FATES-KP 宿命 Typhoon pathways

FATES-KP 宿命 Track lines map

FATES-KP 宿命 Track lines map

FATES-KP 宿命 Cross-sectional morphology of the Kaoping Canyon

FATES-KP 宿命 Track lines map (detail bathymetry)

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Track lines map (seismic profile 340-4)

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Track lines map (seismic profile 340-7)

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Track lines map (seismic profile 340-8)

FATES-KP 宿命 Mud Diapir Terrace

FATES-KP 宿命 Track lines map (Chirp Sonar Profiles C1&C2)

FATES-KP 宿命 Levee

FATES-KP 宿命 Sedimentary features of the Kaoping Canyon

FATES-KP 宿命 Conclusion(1) The axial incision provided an indirect evidence of input by gravity flows to the canyon head, contributing to the possibility of generation of hyperpycnal flows during the present highstand of sea level. The axial incision provided an indirect evidence of input by gravity flows to the canyon head, contributing to the possibility of generation of hyperpycnal flows during the present highstand of sea level.

FATES-KP 宿命 Conclusion(2) Axial incision is well observed in the distal meandering segment and occurs at outer bends. Axial incision height ranges from m, much greater than m in relief of axial incision of submarine canyons of Gulf of Lion, reflecting additional effects of the maintained river- canyon connection and structural disturbance of local mud diapiric uplift on the axial incision. Axial incision is well observed in the distal meandering segment and occurs at outer bends. Axial incision height ranges from m, much greater than m in relief of axial incision of submarine canyons of Gulf of Lion, reflecting additional effects of the maintained river- canyon connection and structural disturbance of local mud diapiric uplift on the axial incision.

FATES-KP 宿命 Thank you for your attention