Office of Renewable Energy

Strong magnetic field perturbations resulting from Earth-directed solar events, collectively referred to as geomagnetic storms, can adversely affect many aspects of marine archaeological survey. The immediate onset of geomagnetic storms and the fast compression of the magnetopause creates a short-duration, high amplitude spike in Earth’s magnetic field that appears similar to the signature of an archaeological anomaly. Aggressive processing, analysis, and comparison of single instrument, total field marine magnetometer survey and observatory datasets collected during geomagnetic storms on days of Kp 5 or greater resulted in no demonstrable ability to isolate and remove the storm sudden onset signature. Of the 34 storms analyzed, 34 possessed onset signatures that were considered to be potentially misleading, resulting in possible aliasing of temporal variation (the storm sudden onset signature) for spatial variation (archaeological anomalies of interest). Based on a 95% confidence level, it is estimated that 89.7 to 100 percent of geomagnetic storms occurring on days of Kp 5 or greater will generate signatures that may be misinterpreted as archaeological sites. Recommendations are made for marine magnetic data collection and processing methods that may adequately account for geomagnetic storms, allowing for improved precision in analytical interpretation and thus improved management of archaeological resources.

Abstract Ecological metrics derived from habitat surveys can provide information necessary to understand population, community, and ecosystem processes. Here, we present a case study on the feasibility of extracting ecological metrics from archeological studies of shipwrecks. Even though shipwrecks that are the focus of archeological surveys also form habitat for diverse flora and fauna, shipwrecks are often studied separately by archeologists and ecologists. Conducting joint archeological and ecological surveys promises to maximize research resources and outputs, yet this cross‐disciplinary approach is rare. Here, we test the feasibility of extracting ecological metrics from archeological surveys of two historically significant and deep (200 m) shipwrecks, the German U‐boat U‐ 576 and the Nicaraguan freighter SS Bluefields , which sank in close proximity to one another on the continental shelf of North Carolina, USA during World War II. First, we assessed fish density, community composition, behavior, and spatial distribution on these shipwrecks using video and laser‐line scanning data collected from human‐occupied submersibles during archeological surveys. Second, we examined the ecological benefits and biases of pairing laser‐line scanning and video surveys designed for archeological specifications. Our approach allowed us to pinpoint locations of fish around the shipwrecks and to identify these fish to fine taxonomic levels. The extracted ecological data revealed that both shipwrecks hosted high densities (U‐ 576 38.2 ± 4.0; SS Bluefields 32.0 ± 18.0 per along‐ship transect) of demersal fishes, including grouper species, and that fish concentrated around high‐relief shipwreck features. More broadly, our findings demonstrate the utility and benefits of collecting multipurpose and cross‐disciplinary data and provide a proof‐of‐concept for conducting joint archeological and ecological studies.

Abstract Archaeologists are employing a variety of digital tools to develop new methodological frameworks that combine computational and experiential approaches which is leading to new multisensory research. In this article, we explore vision, sound, and movement at the ancient Maya city of Copan from a multisensory and multiscalar perspective bridging concepts and approaches from different archaeological paradigms. Our methods and interpretations employ theory-inspired variables from proxemics and semiotics to develop a methodological framework that combines computation with sensory perception. Using GIS, 3D, and acoustic tools we create multisensory experiences in VR with spatial sound using an immersive headset (Oculus Rift) and touch controllers (for movement). The case study simulates the late eighth and early ninth-century landscape of the ancient Maya city of Copan to investigate the role of landscape in facilitate movement, send messages, influence social interaction, and structure cultural events. We perform two simulations to begin to study the impact of vegetation on viewsheds and soundsheds of a stela at ancient Copan. Our objectives are twofold: (1) design and test steps towards developing a GIS computational approach to analyse the impact of vegetation within urban agrarian landscapes on viewsheds and soundsheds and (2) explore cultural significance of Stela 12, and more generally the role of synesthetic experience in ancient Maya society using a multisensory approach that incorporates GIS and VR.

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