Technical Report No. 28
AEROMAGNETIC, GRAVITY, AND ELECTRICAL RESISTIVITY EXPLORATION BETWEEN PAHALA AND PUNALUU, HAWAII
William M. Adams, Surendra P. Mathur, Richie D. Huber – February 1970
ABSTRACT
Aeromagnetic, electrical resistivity, and gravity surveys were conducted in the area between Pahala and Punaluu, Hawaii to delineate barriers to ground-water movement. The geophysical data are interpreted and compared to determine the sectors of relatively low gradient ground water between the barriers. In the Pahala area, two barriers to lateral ground-water movement have been located: the Kolea barrier, which trends roughly east to west, and the second barrier, associated with a “crack” used as the Pahala dump, designated by this study as the Pahala dump barrier. The Pahala dump barrier definitely appears to terminate at the Kolea barrier. These barriers are defined by magnetic, gravity, and electrical sounding and profiling observations. In the Punaluu area, electrical sounding and profiling observations agree with the conclusions of an earlier infra-red study that a large fresh-water outflow, associated with a relatively high head of the water table, occurs. Magnetic and gravity observations agree on the presence of a skewed prismatic body with the top of the body being close to the ground surface. Two test holes have been drilled in the area. The findings verify the geophysical predictions.