Regional groundwater flow system in a stratovolcano adjacent to a coastal area: a case study of Mt. Fuji and Suruga Bay, Japan

Masahiko Ono,Isao Machida,Atsunao Marui,Yasuhide Muranaka,Reo Ikawa,Koichi Oyama,Takafumi Kamitani,Akira Ito

doi:10.1007/s10040-018-1889-9

Abstract

Groundwater movement through the slope area of Mt. Fuji to the coastal area of Suruga Bay (central Japan) was investigated using spatially dense geochemical data, as a case study for elucidating the groundwater flow system in a stratovolcano adjacent to the coast. Spatial distributions of the hydrogen stable isotope ratio, vanadium concentration, and water temperature in the groundwater showed anomalies at the coastal area of Suruga Bay. The anomalies were characterized as depleted isotope ratio, high vanadium concentration, and low water temperature relative to surroundings. This can be explained as a regional deep groundwater flow from the slope of Mr. Fuji to the coastal area of Suruga Bay because groundwater recharged at higher elevation has a depleted isotope ratio caused by the altitude effect and high vanadium concentration as a result of dissolution from the basaltic aquifer. These characteristics also imply a hierarchical flow system, which is incorporated into a hydrogeological model of the coastal aquifer.

Highlights

Groundwater is a valuable water resource in volcanic regions, especially volcanic islands, and has been used for domestic, agricultural, and industrial purposes (Meinzer 1930; Stern and Macdonald 1947; D’Alessandro and Vita 2003)
Geochemical analysis to determine the groundwater flow system for the study area was based on the results from July 2014 to January 2015 which cover the whole of the study area and contain tritium data
The horizontal distribution of isotopes, inorganic ions, vanadium, and water temperature revealed that the characteristics of groundwater derived from the volcanic aquifer of Mt

Summary

Introduction

Groundwater is a valuable water resource in volcanic regions, especially volcanic islands, and has been used for domestic, agricultural, and industrial purposes (Meinzer 1930; Stern and Macdonald 1947; D’Alessandro and Vita 2003). There is a long history of international hydrogeological research into volcanoes. Mink (1976) showed the hydrogeological cross sections in Guam (Western Pacific), in which all the exploitable groundwater occurs in the permeable limestone while volcanic rock plays the role of hydraulic basement. Macdonald et al (1983) showed that the occurrence of groundwater on the Hawaiian island of Oahu (Central Pacific) is characterized by the presence of basal groundwater, perched groundwater, and dykeimpounded groundwater; and that the discontinuity of these groundwater types is responsible for the occurrence of high- From geological exploration on the basaltic island of Tenerife in the Spanish Canary Islands, Ecker (1976) determined the occurrence of aquifers formed by compartments (voids) and secondary fractures. Mink (1976) showed the hydrogeological cross sections in Guam (Western Pacific), in which all the exploitable groundwater occurs in the permeable limestone while volcanic rock plays the role of hydraulic basement. Macdonald et al (1983) showed that the occurrence of groundwater on the Hawaiian island of Oahu (Central Pacific) is characterized by the presence of basal groundwater, perched groundwater, and dykeimpounded groundwater; and that the discontinuity of these groundwater types is responsible for the occurrence of high-

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Discussion

Conclusion