Hydrogeology of the Hawaii Scientific Drilling Project borehole KP-1 2. Groundwater geochemistry and regional flow patterns

Author:

Conrad, M.E., Paillet, Frederick L., Thomas, D.M.

Title:

Hydrogeology of the Hawaii Scientific Drilling Project borehole KP-1 2. Groundwater geochemistry and regional flow patterns

Periodical:

Journal of Geophysical Research

Year:

1996

Volume:

101

Pages:

11,683-11,694

Subject:

Ground water Mauna Kea Hawaii Scientific Drilling Project Hydrology Mauna Kea

Summary:

Samples taken from the 1-km-deep KP-1 borehole that is located on the eastern flank of the island of Hawaii showed salinities nearly equivalent to seawater but having anomalous cation concentrations that are attributed to ion exchange between formation fluids and residual drilling mud clays. Fluid samples from 310 m in the borehole demonstrate that a freshwater aquifer is present at the Mauna Kea/Mauna Loa interface. Light stable isotope data indicate that the fresh water at 320 m is derived from rainfall recharge entering the island at an average elevation of 2000 m. A regional water flow model suggests that the fresh water found at the 320-111 depth is derived from rainfall recharge from the middle elevations of Mauna Kea volcano. The preliminary result indicates that the intervolcano and interflow aquicludes can have a substantial impact on water circulation and discharge from young island volcanoes.

Collection:

Periodicals