1. From John Milliman Fluvial Discharge of Sediments from Taiwan = 380 Mt/yr (Dadson et al., 2003) A prelude 380 Mt/yr  36,000 km 2 = 10,555 ton km -2 yr -1

2. Sedimentation Dynamics in the Gaoping Submarine Canyon off SW Taiwan: Radiochemical, Sediment Trap, Sediment Core and Current Meter Observations C.-A. Huh, J. T. Liu, H.-L. Lin and J. Xu

3. Sediment burial flux in the covered area: ~6.6 Mt/yr

4. Journal of Marine Systems - FATES Special issue

5. Gaoping River Catchment Taiwan Strait South China Sea Pacific Ocean Gaoping Submarine Canyon Taiwan Pacific Ocean Taiwan Strait South China Sea The Gaoping Submarine Canyon is an effective conduit for sediment transport

6. From Hsu et al (2008) TAO 19, 767-772

7. A mooring containing a sediment trap and a current meter was deployed on Jan. 10, 2008. T6KP

8. Sediment Trap Retrieval on March 20, 2008

10. A quick estimate of the accumulation rate: 82 cm/70 d = 1.17 cm/day 82 cm 124356 The 6 faces of the trap material

11. 77 cm 60 cm 40 cm 20 cm 0 cm 70 cm

12. Spring tide  hi along-canyon velocity  hi-E  coarse grained  low 210 Pb and 234 Th Neap tide  low along-canyon velocity  lo-E  fine grained  high 210 Pb and 234 Th Spring tide Neap tide S = 0.887 cm/d or 0.0101 cm/d normalized to the collection area 3/20 T6KP 1/10 ~ 3/20, 2008 234 Th ex ( dpm/g ) 210 Pb ex ( dpm/g ) 234 Th ex / 210 Pb ex wt. %H 2 O along-canyon velocity (cm/s)

13. T7KP

14. T7KP trap 7/8-9/11/2008 2-m

15. T7KP 07/08 ~ 09/11 Progressive vector

16. Current_meter Progress_vector Current_meter Progress_vector T7KP 07/08 ~ 09/11 T6KP 01/10 ~ 03/20

17. T7KP upper trap (270 m) LADCP Progress_vector LADCP Progress_vector 234 Th ex ( dpm/g ) 210 Pb ex ( dpm/g ) mass flux (g m -2 d -1 ) Divergent transport at different depths!

18. Seasonality in sediment flux and radionuclide activities* * Nuclide activities are decay-corrected mean values. Mean sedimentation rate over the open shelf/slope/basin = 6 g m -2 d -1 T6KP 1/10-3/20/2008 tide-dominated T7KP 7/8-9/11/2008 flood-dominated mass flux (g m -2 d -1 ) 210 Pb (dpm/g) 234 Th (dpm/g) mass flux (g m -2 d -1 ) 210 Pb (dpm/g) 234 Th (dpm/g) 270 m---7212.6103 ~600 m 650 m 110 595 9.9 7.4 44.5 18 7200 high 1.0 1.8 3.5 4

19. T6 KP January 10 - March 20, 2008 Flux at: trap (597 m): 110 g m -2 d -1 bottom (650 m): 595 g m -2 d -1 T7KP July 7 - September 11, 2008 Flux at: upper trap (267 m): 72 g m -2 d -1 lower trap (608 m): 7200 g m -2 d -1 bottom: very high

21. -The Gaoping Submarine Canyon is an effective conduit for sediment transport over time. -Sediment transport in the GPSC is: tide-dominated in the dry season, and flood-dominated in the wet season. - Divergent transport btw: (1) the canyon and open shelf/slope; (2) upper and lower levels of the KPSC. Thank you