CONSUMER-GRADE DRONE MAPPING AND CENTIMETER-LEVEL INTERTIDAL GEOMORPHIC CHANGES AT THE SEABROOK MARSH SITE, HAMPTON, NEW HAMPSHIRE

Summary

The Seabrook Marsh site [SBM] in Hampton, New Hampshire is a ca. 3500-4500 BP multi-component site beneath 1-2 meters of salt marsh peat and exposed at a rapidly eroding shoreface. Like most intertidal archaeological sites SBM occupies a dynamic environment. Daily tidal fluctuations slightly modify surficial sediments, but on a monthly, seasonal, or annual scale the magnitude of changes is quite significant. The resulting landscape modifications range from minor erosion and deposition to catastrophic failure of shoreline elements through undercutting and rotational slumping. To quantify on-going erosion at SBM we used a consumer-grade drone and with three surveys recorded 12 months of intertidal geomorphic changes at 6-month intervals. Photographs were collected at 10m altitude within 1-hour of low tide. We then used digital photogrammetry software to create orthophotograph mosaics and digital elevation models [DEMs]. Our data exhibited roughly 8mm resolution and were sufficient to resolve bootprints and minuscule features in DEMs. Data processing in ArcGIS ensured exceptional spatial congruity between surveys. GIS-based spatial comparisons resolved centimeter-level intertidal sediment dynamics and landscape alterations. These data provided a high-resolution assessment of critical areas at SBM that will be the target of upcoming excavations.

This Resource is Part of the Following Collections

• Society for American Archaeology 82nd Annual Meeting, Vancouver, BC (2017)   •
• Teaching through the Past: Advances in Technological Analysis of the Archaeological Record

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Record Identifiers

Abstract Id(s): 16984