Central Geophysical Project for prospecting of archaeological sites in the onshore-offshore transition zone ("amphibic geophysics")

提交的研究提案的目的是对位于两栖地带的考古遗址进行地球物理勘探。对该地区的调查显然是优先方案主题--港口结构的考古调查--的中心问题之一。与这一主题相关的是许多考古和地质考古应用，目的是调查建筑物遗迹以及可能的港口地点的地质边界条件。计划对与本提案同时提交的8个伙伴项目提出的25个不同地点进行调查。有关工作组已事先商定了合作和地球物理调查计划。勘探两栖地带的具体要求意味着规划项目的进一步方法目标：根据相关实地实例进一步发展和优化现有调查方法，并根据战略规划方案1630第一阶段获得的经验，通过新的仪器和解释方法补充现有方法。在第一个资助期内开展的工作导致确定了关于港口地点调查的以下问题。地质雷达和大地电学显示，在部分淤积、部分淹没的地区(如盐沼或泻湖)，在高电导率地区经常发生的深度渗透很少或没有深度渗透。针对地质考古目标的陆上测量往往存在这样的问题：一方面是高分辨率的地质雷达和地电学能够探测到的浅层深度，另一方面是深度穿透的地震折射或反射调查。海岸线附近的水深变化可能导致地磁测量中地面信号的强烈衰减和失真，以及地震勘探中水柱中突出的复杂混响，这些混响可能覆盖来自地下结构的所需反射。解决这些问题的目的是明确中心地球物理工程二期工程在研发方面的要求。建议的解决方法包括在海底应用面波、地震波形层析成像、多源和传感器水力学(阵列技术)和适应海底的近海磁学。波形层析成像代表了最有希望的现代地震解释方法，它将被有条不紊地采用，并首次应用于考古勘探。

The aim of the submitted research proposal is geophysical prospection of archaeological sites located in the amphibic zone. The investigation of this zone is clearly one of the central questions regarding the theme of the priority program - the archaeological investigation of harbor structures. Connected with this theme are many archaeological and geoarchaeological applications aiming at surveying remains of buildings as well as geological boundary conditions of possible harbor sites. It is planned to investigate 25 different locations proposed by 8 partner projects submitted in parallel to the present proposal. Cooperation and geophysical investigation plans have been agreed upon beforehand between the involved working groups. The concrete requirements of prospecting the amphibic zone imply further methodical objectives of the planned project: Further development and optimization of existing survey methods based on relevant field examples as well as complementing existing methods through new instrumentation and interpretation meth-ods based on the experience gained in Phase 1 of SPP 1630. The work performed in the first funding peri-od led to identifying the following problems regarding the investigation of harbor sites. Georadar and geoe-lectrics show little or no depth penetration in areas of high electric conductivity occurring frequently in case of partly silted partly flooded areas (such as salt marsh or lagunes). Onshore measurements aiming at geo-archaeological targets often suffer from a prospection gap between, on the one hand, the shallow depths accessible by georadar and geoelectrics in high resolution and, on the other hand, deeply penetrating seis-mic refraction or reflection surveys. Water depth variation near the shoreline may lead to strong attenuation and distortion of ground signals in magnetic measurements and to prominent complicated reverberations in the water column in seismic prospecting that may cover the desired reflections from subsurface structures. The aim of solving these problems defines the requirements in research and development of the Central Geophysical Project in the second project phase. The suggested solution approaches include the applica-tion of surface waves at the sea floor, seismic waveform tomography, multi-source-and-sensor hydroacous-tics (array technique) and seafloor-adapted offshore magnetics. Waveform tomography represents the most promising modern approach of seismic interpretation that would be methodically adapted and applied to archaeological prospecting for the first time.