Event/Activity EPM164 - Geophysical Survey, Governor's Green, Portsmouth

GSB Prospection Ltd carried out a geophysical survey at Governor's Green in May 2009, as part of a wider archaeological assessment on the site for the Channel 4 series Time Team. This assessment involved an archaeological evaluation to investigate any surviving remains of the 13th century 'Domus Dei' (Hospital of St John and St Nicholas) and the 16th century Governor's House that replaced it. The aim of the geophysical survey was to try and establish the extent of sub-surface archaeological remains. Three geophysical techniques were used during the survey: magnetometer (Geoscan FM36/256 and Bartington Grad 601-2); resistance - twin probe (Geoscan RM15 Meter); Ground Penetrating Radar (Sensors & Software Noggin plus Smart Cart 250MHz). Only Ground Penetrating Radar (GPR) was used in an area directly to the south of the Garrison Church. The survey detected anomalies thought to be associated with the medieval Domus Dei, although due to rubble and debris across the site it was not possible to identify specific buildings. A former road which crossed the site was visible in the magnetic and resistance data. The GPR survey to the south of the Garrison Church identified anomalies which appeared to coincide with the position of buildings as shown in a 16th century drawing of the site. Due to a lack of definition in the anomaly spread, and the fact that excavations to the south had revealed a significant depth of made ground built on to natural gravels, it was thought likely that archaeological deposits in this area had been destroyed. Accession number: 2009/108