Current Magnitude and Mechanisms of Groundwater Discharge in the Arctic: Case Study from Alaska.
Current Magnitude and Mechanisms of Groundwater Discharge in the Arctic: Case Study from Alaska.
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DOI：
10.1021/acs.est.5b02215
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发表时间：
2015-10
影响因子：
11.4
通讯作者：
N. Dimova;A. Paytan;J. Kessler;K. Sparrow;Fenix Garcia‐Tigreros Kodovska;A. Lecher;Joseph Murray;S. Tulaczyk
中科院分区：
文献类型：
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作者：
N. Dimova;A. Paytan;J. Kessler;K. Sparrow;Fenix Garcia‐Tigreros Kodovska;A. Lecher;Joseph Murray;S. Tulaczyk
为了更好地了解高纬度地区地下水-地表水的动态变化，我们在阿拉斯加的三个不同永久冻土覆盖率的地点进行了实地研究。用天然地下水示踪剂(222Rn，氡)评价地下水流量，用电阻率层析成像(ERT)研究地下混合动力学。这些地点的地下水排放受到不同的控制。在零星分布的多年冻土区(卡西斯纳湾)，由于潮汐波动很大，海底地下水排放的主要驱动力是潮汐抽水，而在巴罗点，一个连续的多年冻土和较小的潮汐幅度，通量主要受季节性冻土融化的影响。近岸地下大面积的低电阻率和地表水中的高氡表明，地下水-地表水的相互作用可能会加强热量向更深的永久冻土层的输送，促进多年冻土的融化，从而增加地下水的排放。
To better understand groundwater-surface water dynamics in high latitude areas, we conducted a field study at three sites in Alaska with varying permafrost coverage. The natural groundwater tracer ((222)Rn, radon) was used to evaluate groundwater discharge, and electrical resistivity tomography (ERT) was used to examine subsurface mixing dynamics. Different controls govern groundwater discharge at these sites. In areas with sporadic permafrost (Kasitsna Bay), the major driver of submarine groundwater discharge is tidal pumping, due to the large tidal oscillations, whereas at Point Barrow, a site with continuous permafrost and small tidal amplitudes, fluxes are mostly affected by seasonal permafrost thawing. Extended areas of low resistivity in the subsurface alongshore combined with high radon in surface water suggests that groundwater-surface water interactions might enhance heat transport into deeper permafrost layers promoting permafrost thawing, thereby enhancing groundwater discharge.