Program

Numerous tropical cyclones in the Western Pacific have confronted East Asian continental margin over the past years due to climate change, and storm-induced sediment source to sink processes characterize Holocene shelf deposits in many shelf environments. A field observation, comprising surface mounted instruments for the measurements of temperature, salinity and turbidity, and time-series river water and suspended sediment sampling, was carried out for 7-days at the tidal reach of Mulanxi River, Fujian Province. The measurements have captured the precipitation-runoff-sediment yield features during a huge rive discharge condition induced by Typhoon Meranti (1614) from Sep. 13 to Sep. 19, 2016. The temporal variation of nutrient concentration (DIN, DIP and DSi) decreased first and then increased during the storm associated with rainfall events, while NH4-N, NO2-N and NO3-N showed different patterns. The time-series major ions (e.g. Ca2+, Na+, Mg2+ and K+) concentration and ratios showed the similar trends as nutrient, and the higher values were possibly due to the response to carbonate weathering. We also analyzed radiogenic and stable Sr isotopic compositions (87Sr/86Sr and δ88/86Sr) in river water and suspended particles, and focused on the Sr isotope dynamics during the typhoon event. Our results could be helpful to elucidate the variation of Sr isotope ratios in shelf deposits.