Core photos, Hole 2 (KMA-1), Humu‘ula Groundwater Research Project

Abstract

Also known as “PTA” or “Saddle Road Project,” the Humuʻula Groundwater Research Project (HGRP) aimed to research the groundwater resources in the Hawaiʻi Island ‘Saddle’ region between Mauna Loa and Mauna Kea volcanoes by drilling two test holes on Army Garrison Hawaii land. Results include the discovery of: i) groundwater at a much shallower depth than expected, ii) a dike-impounded aquifer, and iii) a potential geothermal reservoir. By using the diamond wireline core drilling technology, we collected a continuous sequence of rock core. We documented our progress in a blog and made a complete stratigraphic record of the region. This continuous stratigraphic sequence contained subaerial shield-stage and post-shield-stage lava rock and ash samples from the Mauna Kea Volcano, documenting the area’s environmental, geologic, hydrologic, and thermal history.