[A-CG35_28PO1] 陸海相互作用－沿岸生態系に果たす水・物質循環の役割－

[ACG35-P04] 222Rnを用いた沿岸海底湧水の空間調査：別府湾・大槌湾・小浜湾をモデルフィールドに

*本田 尚美¹、杉本 亮¹、富永 修¹、小林 志保²、宮田 洋実²、小野 昌彦³、大沢 信二⁴、谷口 真人⁵ (1.福井県立大学海洋生物資源学部、2.京都大学フィールド科学教育研究センター、3.産業技術総合研究所、4.京都大学地球熱学研究施設、5.総合地球環境学研究所)

キーワード：海底湧水, ラドン, 陸海相互作用

Submarine groundwater discharge (SGD) is important as a major pathway for freshwater and nutrients loads from land to ocean. Various natural tracers of SGD have been applied to quantify local to regional SGD fluxes. Radon-222 (²²²Rn) is a naturally occurring radioactive gas that is typically 2-3 orders of magnitude higher in groundwater than surface waters. Therefore, it is a powerful tracer of groundwater inputs to oceans. We have applied the continuous ²²²Rn monitoring survey to three local scale coasts (Beppu Bay, Obama Bay and Otsuchi Bay), which have large amounts of groundwater resources in each watershed. As a result, spatial distributions of ²²²Rn and other parameters displayed not only influence of submarine groundwater discharge but also possibility of submarine hotspring discharge.