title: Spatial distribution of submarine groundwater discharge and associated nutrients within a local coastal area.
abstract: 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.
authors.affiliation: Priority Organization for Innovation and Excellence, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555, Japan. hosono@kumamoto-u.ac.jp
authors.forename: Takahiro
authors.initials: T
authors.lastname: Hosono
authors.forename: Masahiko
authors.initials: M
authors.lastname: Ono
authors.forename: William C
authors.initials: WC
authors.lastname: Burnett
authors.forename: Takahiro
authors.initials: T
authors.lastname: Tokunaga
authors.forename: Makoto
authors.initials: M
authors.lastname: Taniguchi
authors.forename: Tomoya
authors.initials: T
authors.lastname: Akimichi
mesh_terms: D000818:Animals; D059001:Aquatic Organisms; D061006:Bays / Q000737:chemistry; D004784:Environmental Monitoring; D005843:Geography; D060587:Groundwater / Q000737:chemistry*; D007564:Japan; D009584:Nitrogen / Q000032:analysis*; D010758:Phosphorus / Q000032:analysis*; D011886:Radon; D045483:Rivers / Q000737:chemistry; D012623:Seawater / Q000737:chemistry*; D012767:Ships; D013997:Time Factors; D014872:Water Movements
chemical_list: D010758:Phosphorus; D009584:Nitrogen; D011886:Radon