Marine Chemistry in the Coastal Environment: Principles, Perspective and Prospectus
Marine Chemistry in the Coastal Environment: Principles, Perspective and Prospectus
复制标题
沿海环境中的海洋化学：原理、前景和简介
作者：
T. Church
沿海环境的海洋化学从岩石风化的原理开始，利用碳酸来动员元素，其中只有一些元素构成了海盐的大部分。主要原因是逆风化作用，在沿海沃茨中广泛存在，并将大多数元素返回到新形成的胶体或矿物中，同时将二氧化碳再循环到大气中。这包括海洋深处广阔的沉积物成岩作用，加上热液羽流和随之而来的低温玄武岩蚀变。在河口和扩展陆架制度，保守和非保守的过程可以区分和建模，以确定风化元素传输到海洋或消耗的反向风化的比例。从概念上讲，导致海水组成的稳态过程可以被视为溶解成分和固体矿物产品之间的非均匀平衡，需要数十万年。然而，在河口和沿海环境的初始过程的特点是较短期的清除与无机和有机胶体。这些循环的时间尺度与河口冲刷和海岸与海洋的交换相称的碳和微量元素。天然铀和钍衰变系列提供了强有力的工具，定量河口过程的速率，包括那些在地下水和地下河口。未来，新的质谱和核磁共振技术将有助于定义新形成的河口胶体的分子性质，就像对溶解有机物所做的那样。随着沿海环境以变暖和海平面上升的形式受到气候变化的影响，今后的研究应探讨这些因素将如何影响沿海环境作为二氧化碳和相关有机物质的净源或汇的化学性质。
Marine chemistry of the coastal environment starts with principles of rock weathering that use carbonic acid to mobilize elements, only some of which comprise the majority of sea salt. The principle reason is reverse weathering, extensively represented in coastal waters, and returns most elements to newly formed colloids or minerals while recycling carbon dioxide to the atmosphere. This includes the deeper ocean expanse of sediment diagenesis, plus hydrothermal plumes and attendant low-temperature basalt alteration. Within the estuarine and extended shelf regimes, both conservative and non-conservative processes can be distinguished and modeled to determine proportions of weathered elements transmitted to the sea or consumed by reverse weathering. Conceptually, the steady-state processes that lead to the composition of seawater can be viewed as heterogeneous equilibria between dissolved constituents and solid mineral products taking hundreds of millennia. However, initial processes in the estuarine and coastal environment are characterized by shorter term scavenging associated with inorganic and organic colloids. These recycle both carbon and trace elements on timescales commensurate with estuarine flushing and coastal exchange with the ocean. The natural uranium and thorium decay series provide powerful tools for quantifying the rates of estuarine processes, including those within groundwater and the subterranean estuary. In the future, new mass spectrometric and nuclear magnetic resonance techniques will help to define the molecular nature of newly formed estuarine colloids as has been done for dissolved organic matter. As the coastal environment undergoes the forces of climate change in the form of warming and sea level rise, future research should address how these will impact chemistry of the coastal environment as a net source or sink of carbon dioxide and associated organic material.