Material Fluxes from a Coral Reef Framework

先前的研究表明，在珊瑚礁等海洋碳酸盐框架中，微生物介导的好氧和厌氧成岩作用广泛存在。在这些沉积体系中，平流和湍流水流，而不是扩散，主导着框架间隙水与上覆海水之间的溶解物质交换。然而，成岩作用的速度足以导致最终产物（如无机营养物和H2S）浓度升高。从礁格架到邻近环境的成岩最终产物的总通量将被确定。将开展以下工作：1)扩大瓦胡岛Checker Reef间隙水采样的空间尺度，详细检查珊瑚礁框架上部1米的区域；2)直接测量礁架与周围环境之间若干点的成岩反应物和生成物的平流通量和扩散通量；3)收集数据，校正礁内间隙水平流水文模型；4)继续测量礁内无机和有机成岩反应物/产物的时空分布，特别注意短链有机氮化合物；5)利用第4项的浓度数据与水文模型结合，估算了礁架内发生的有机和无机成岩反应的速率。

Previous research has demonstrated the widespread occurrence of microbially mediated aerobic and anaerobic diagenesis within marine carbonate frameworks such as coral reefs. In these sedimentary systems, advective and turbulent water flow, rather than diffusion, dominates the exchange of dissolved material between the framework interstitial water and the overlying seawater. Nevertheless, diagenesis is rapid enough to result in elevated concentrations of end products such as inorganic nutrients and H2S. The overall fluxes of diagenetic end products from a reef framework to the neighboring environment will be determined. Work will be done to 1) extend the spatial scale of the interstitial water sampling at Checker Reef, Oahu to examine in detail the upper 1 m of the reef framework; 2) directly measure the advective and diffusive fluxes of diagenetic reactants and products between the reef framework and the surrounding environment at several points across the reef; 3) collect data to calibrate a hydrological model of the advection of interstitial water within the reef; 4) continue measurements of the spatial and temporal distribution or inorganic and organic diagenetic reactants/products within the reef, with particular attention to short-chain organic nitrogen compounds; and 5) use the concentration data from item 4) with the hydrological model to estimate the rates of organic and inorganic diagenetic reactions occurring within the reef framework.