Site Event/Activity record ESF30843 - Geophysical Survey - Sibton Abbey

Ground Penetrating Radar (GPR), fluxgate gradiometer and earth resistance surveys were conducted at Sibton Abbey, Sibton, Suffolk, as part of a wider noninvasive study of the site. For the magnetometer survey, measurements were recorded over a series of 30m grids established with a Trimble R8s GNSS using a Bartington Grad 601 dual fluxgate gradiometer. Readings were taken at 0.25 m intervals along parallel traverses separated by 1.0 m. The resistance survey was focused on the area in the immediate vicinity of the standing remains where surface obstructions, overgrown vegetation or the abbey walls themselves prevented coverage with the vehicle towed GPR array. Measurements were recorded over a series of 30m grids established with a Trimble R8s GNSS (Figure 1) using a Geoscan RM85 resistance meter, internal multiplexer, and a PA5 electrode frame in the Twin-Electrode configuration, to allow two separate surveys, with electrode separations of 0.5m and 1.0m, to be collected simultaneously. Or the GPR survey, a 3d-Radar MkIV GeoScope Continuous Wave Step Frequency (CWSF) Ground Penetrating Radar (GPR) system was used to conduct the survey collecting data with a multi element DXG1820 vehicle towed, ground coupled antenna array (Linford et al. 2010; Eide et al. 2018). A roving Trimble R8s Global Navigation Satellite System (GNSS) receiver was mounted on the GPR antenna array, that together with a second R8s base station was used to provide continuous positional control for the survey collected along the instrument swaths. Data were acquired at a 0.075m x 0.075m sample interval across a continuous wave stepped frequency range from 40MHz to 2.99GHz in 4MHz increments using a dwell time of 2ms.