An Analysis of Ground-Penetrating Radar's Ability to Discover and Map Buried Archaeological Sites in Hawai'i

Abstract

The near-surface geophysical method called ground-penetrating radar (GPR) has to date seen limited use in Hawai'i for the discovery and mapping of buried archaeological sites. Its success in other areas of the world with similar ground conditions to Hawai'i, however, suggests that it could be utilized more extensively in the islands. Working with the Joint POW/MIA Accounting Command's Central Identification Laboratory QPAC-CIL) to examine the effectiveness of GPR in Hawai'i, we studied the method's resolution and depth of investigation at a number of test sites on the islands of O'ahu and Hawai'i. The various sites had different ground conditions where varying environmental and moisture regimes and bedrock types affected the method's efficacy. The goal was to compare and contrast depth ofGPR energy penetration and buried feature resolution in these various areas as a way to evaluate its potential effectiveness throughout the island chain. In this process, windward and leeward tests were made in both weathered and fresh basalt, deep clay soils, as well as coral bedrock and unconsolidated coral sand. The results of those tests, as well as an analysis of the ground conditions encountered, as they pertain to the effectiveness of GPR, are discussed here as a first step in building predictive models for the method's usefulness throughout Hawai'i.