Integrated GPR and passive seismic investigations at cultural heritage sites: Case studies in Malta

In this paper we report results from an integrated measurement campaign performed on the island of Malta. Both GPR and seismic noise data were gathered in two sites close to the sea, where two watchtowers built by the Order of St. John are located. The two investigations were performed on the top of the cliff inGolden Bay, close to the Ghajn Tuffieha Tower, and at the Madliena Tower in Pembroke. The main goal of the survey was to investigate the possible presence of natural or man-made elements that might affect the preservation of these monuments in the future. The investigations were therefore both on the two historical buildings and on a portion of soil nearby to also check the geological stability of the cliff since the towers are located right on its edge. The measurements were carried out with an innovative stepped frequency GPR system and with passive seismic instrumentation. In the following the main achievements will be presented.