Hawaii Institute of Geophysics radiocarbon dates I.

Abstract

These samples are initial results from a long-term study designed to use magmatic (dead) CO (sub 2) as a tracer for volcanic product distribution (Chatters et al., 1969) and to estimate total volcanic emission on the basis of CO (sub 2) dilution contours. Samples collected on a grid around Kilauea volcano on Hawaii Island, and, unless otherwise specified, are of recent growth shoots of ubiquitous Metrosideros tree. Samples $lt;3 mos old (Lamoreaux and Porter, 1971, Dept. Botany, Univ. Hawaii, oral commun.). HIG-15. Kilauea I-8a dC14 = -7 + or - 13% Coll. 13 April 1971 in Sulfur Banks area of Volcano Natl. Park (19 degrees 26'2"N Lat, 155 degrees 15'51"W Long). Trees were on a bank above and ca. 3 m downwind of an active fumarole. Moderate to heavy vegetation, noticeable warmth and moisture and some vegetation damage from fumarolic gases. Alt. 2600 m. HIG-16. Kilauea I-11 dC14 = +462 + or - 16% Coll. 14 April 1971 on Mauna Loa Summit trail NW of Kilauea (19 degrees 30'N Lat, 155 degrees 25'W Long). Area sparsely wooded, dry. Alt. 4100 m. General Comment: HIG-16 should be relatively free of volcanic effects, but is at alt. of trade-wind inversion and may not fully represent unperturbed conditions at alt. of volcano. HIG-15 is depleted ca. 32% relative to HIG-16, suggesting an equivalent apparent age of ca. 3000 yr under pre-bomb conditions. Well, shaft, and spring water samples are regularly analyzed for radiocarbon, tritium, and chemical content for both geochemical research and water resource evaluation. These samples are from tunnels or shafts in the Koolau range on Oahu I. The geologic environment is almost exclusively basaltic, and heavily compartmented by dikes. Ground surfaces have abundant vegetation and virtually no human modification. The area receives large amounts of rain and is one of the major recharge areas for Oahu's ground water.