[A-CG53] Coastal Ecosystems - 1. Water Cycle and Land-Ocean Interactions

[ACG53-01] Submarine Groundwater Discharge and Groundwater Flow in the Yui Coastal Area, Oku-Suruga Bay

*Yasuhide Muranaka¹, Masahiko Ono², Sota Yamazaki¹, Takafumi Kamitani¹, Tetsuhiro Watano¹, Reo IKAWA² (1.Shizuoka Institute of Environment and Hygiene, 2.National Institute of Advanced Industrial Science and Technology)

Keywords:submarine groundwater discharge (SGD), Groundwater Flow Analysis, remotely operated vehicle (ROV)

Factors that regulate submarine groundwater discharge (SGD) include impermeable layers and faults in coastal areas. In Japan, about 20 SGD sites have been identified, but details of SGD due to faults are not clear. The authors have investigated SGD in the coastal areas of the Quaternary Formation and clarified that clay layers and lava are involved in groundwater discharge. In this study, we are investigating the coastal groundwater flow and SGD around faults in the Neogene strata. Specifically, we collected literature and data on the hydrological environment and hydrogeology in the area around Yui in the Oku-Suruga Bay, created a three-dimensional geological model of the area from the Ihara Mountains to Suruga Bay, and examined coastal groundwater flow through numerical studies. In addition, we conducted a terrestrial groundwater survey in the Yui area and a submarine groundwater survey using a remotely operated vehicle (ROV) in the sea area around the fault.

Acknowledgement: This study was carried out as a part of R&D supporting program entitled “The project for validating assessment methodology of geological disposal system in coastal region” under the contract with Ministry of Economy, Trade and Industry (METI) (Grant Number: JPJ007597; Fiscal year 2024)