An Airborne Magnetometer Survey for Shipwrecks and Associated Underwater Test Excavations

摘要

During June, 1978, the Underwater Archeological Research Section of the Texas Antiquities Committee carried out a magnetometer survey in Search of historic shipwreck sites in two areas of Matagorda Bay, Texas. Portions of the survey areas were inaccessible to our survey vessel, being obstructed by sandbars and breakers or consisting of shallow water, mud flat, and beach areas. A helicopter was therefore selected as the best vehicle for systematic coverage of the search areas. An instrumentation package was utilized consisting of the full complement of a proton magnetometer interfaced with a microprocessor and microwave radar positioning system. The magnetometer survey was followed by a six week campaign of checking anomalies by underwater site test excavation in July and August, 1978. Twelve anomalies were tested and five of these proved to be shipwreck sites.