Geologic influence on groundwater salinity drives large seawater circulation through the continental shelf
Geologic influence on groundwater salinity drives large seawater circulation through the continental shelf
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DOI：
10.1002/2016gl070863
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发表时间：
2016-10
影响因子：
5.2
通讯作者：
H. Michael;K. Scott;Mohammad Koneshloo;Xuan Yu;M. R. Khan;Katie Li
中科院分区：
文献类型：
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作者：
H. Michael;K. Scott;Mohammad Koneshloo;Xuan Yu;M. R. Khan;Katie Li
对近海淡水和盐水沿沿着大陆架排放的观测对水资源、生态系统功能和海洋的组成具有重要意义，但无法用基本理论加以解释。我们表明，这些独立的观察是相互关联的，并来自于驱动变密度地下水流通过地质构造中普遍存在的空间异质性的过程。我们使用岩性数据开发地质统计模型，模仿沿海含水层的架构。通过这些随机实现的地下水流和盐输运模拟表明，即使在稳定状态下，异质性也会产生空间复杂的地下盐度分布，这些分布延伸到离岸数十公里处。相关的密度梯度驱动高含盐地下水循环率，不能预测等效均质模型。研究结果表明，这些现象可能在沿着大陆架一带很常见，可能改变海洋化学平衡的估计数，并影响子孙后代的沿海水管理。
Observations of offshore freshened groundwater and saline groundwater discharge along continental shelves have important implications for water resources, ecosystem function, and the composition of the ocean, but they cannot be explained by basic theory. We show that these independent observations are linked and result from processes that drive variable‐density groundwater flow through the spatial heterogeneity that is ubiquitous in geologic formations. We use lithologic data to develop geostatistical models that mimic the architecture of coastal aquifers. Simulation of groundwater flow and salt transport through these random realizations shows that heterogeneity produces spatially complex subsurface salinity distributions that extend tens of kilometers offshore, even at steady state. The associated density gradients drive high saline groundwater circulation rates that cannot be predicted by equivalent homogeneous models. Results suggest that these phenomena may be common along continental shelves, potentially altering estimates of ocean chemical budgets and impacting coastal water management for future generations.