Particle Dynamics in a Managed Navigation Channel Under Different Tidal Conditions as Determined Using Multiple Radionuclide Tracers

Abstract

Estuaries represent the passageway for 95% of the terrestrial sediment flux entering oceans and serve as the most active interface between land and ocean systems (Syvitski et al., 2005). A portion of riverine sediments undergo multiple deposition-resuspension-transportation-redeposition processes under the combined action of estuarine dynamics and boundary conditions. These sedimentary particles help shape the aquatic morphology while carrying various pollutants and nutrients (Wang et al., 2015; Zhang et al., 2007). Thus, particle dynamics play significant roles in sedimentological and geomorphological processes as well as biogeochemical cycles in estuaries. Estuary morphic evolution is not a purely natural process, as it is jointly controlled by natural influences including riverine discharge, tides, waves, catastrophic events, and

Luminescence characteristics of muddy sediments in the turbidity maximum zone of the Yangtze River mouth and implications for the depositional mechanisms

“…The less depleted δ 13 C values observed in both cores KZ01-A and KZ02 are indicative of a major contribution from marine-sourced organic carbon in the delta front setting (Figure 5; Niu et al, 2021). The offshore inputs into the Yangtze River mouth have been reported in many previous studies (e.g., Du et al, 2010;Ge et al, 2020;Wang et al, 2021) and surficial sediments in the subaqueous delta have yielded OSL ages exceeding 1,000 a (e.g., core A5-4 in Cheng et al, 2020; see Figure 1B for the core location). When older sediments are imported into the river mouth by processes such as tidal pumping, estuarine circulation induced by saltwater intrusion, and storm events (Warner et al, 2008;Cho et al, 2012;Li et al, 2016;Burchard et al, 2018;Wang et al, 2020), they are less likely to be bleached because the stratified water column suppresses turbulence and the sediments have no chance to be dispersed to the water surface.…”

A global dataset of atmospheric <sup>7</sup>Be and <sup>210</sup>Pb measurements: annual air concentration and depositional flux

“…In aquatic environments, 210 Pb is most widely used for dating recent sediments (e.g., Appleby, 2008). Meanwhile, 7 Be and 210 Pb are also widely used as tracers of sediment source identification and particle dynamics in rivers (e.g., Bonniwell et al, 1999;Jweda et al, 2008;Mudbidre et al, 2014;Baskaran et al, 2020), lakes (e.g., Dominik et al, 1987;Schuler et al, 1991;Vogler et al, 1996), and estuaries and coasts (e.g., Baskaran et al, 1997;Huang et al, 2013;Wang et al, 2016). 7 Be deposited on open ocean is further used as a tracer for diagnosing ocean ventilation and subduction (Kadko, 2000;Kadko and Olson, 1996), inferring upwelling rates (Kadko and Johns, 2011), and estimating the deposition of trace metals (Kadko et al, 2015;Shelley et al, 2017;Buck et al, 2019).…”