Priority Organization for Innovation and Excellence, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555, Japan.
Environ Sci Technol. 2012 May 15;46(10):5319-26. doi: 10.1021/es2043867. Epub 2012 Apr 26.
To understand the local-scale distribution of submarine groundwater discharge (SGD) and dissolved nutrients, a multiple-detector (222)Rn monitoring survey was undertaken along the Mt. Chokai volcanic coast in northern Japan. The surveys revealed that the highest SGD (calculated to be 6.2 × 10(4) m(3) d(-1), within an area of 2 × 10(4) m(2)) with the greatest nutrient fluxes (sum of NO(3)(-), NO(2)(-), and NH(4)(+) (DIN): 9.2 × 10(2) mol d(-1); PO(4)(3-) (DIP): 56 mol d(-1)) is present at the edge of the youngest volcanic lava flow in the area. Recharged groundwater transports nutrients through porous volcanic flows and discharges as SGD near shore. Our results demonstrate that the spatial distribution of SGD in the study area is closely regulated by the local geology and topography. Furthermore, we show that continuous (222)Rn monitoring with a multidetector system at boat speeds of 1-2 knots provides details at a scale one order of magnitude greater than has been reported previously. In addition, the results of our study suggest that SGD-borne DIP may play an important role in the important local oyster production.
为了了解海底地下水排泄（SGD）和溶解养分的局部分布情况，在日本北部的 Mt. Chokai 火山海岸沿线进行了多探测器（222）Rn 监测调查。调查显示，最高的 SGD（计算为 6.2 × 10（4）m（3）d（-1），面积为 2 × 10（4）m（2））具有最大的养分通量（NO（3）（-），NO（2）（-）和 NH（4）（+）（DIN）的总和：9.2 × 10（2）mol d（-1）；PO（4）（3-）（DIP）：56 mol d（-1））位于该地区最新火山熔岩流的边缘。补给地下水通过多孔火山流输送养分，并在近岸处作为 SGD 排放。我们的结果表明，研究区 SGD 的空间分布受局部地质和地形的严格控制。此外，我们表明，以 1-2 节船速进行的多探测器系统的连续（222）Rn 监测可提供比以前报道的尺度大一个数量级的详细信息。此外，我们的研究结果表明，SGD 携带的 DIP 可能在当地重要的牡蛎生产中发挥重要作用。
