Integrated geophysical approach for stone decay diagnosis in cultural heritage

This paper reports the results of a geophysical survey (self-potential and seismic refraction) combined with IR thermography and identification of decay products and quantification of soluble salts in a Portuguese artistic tomb made of a porous limestone that presents severe decay phenomena. The aim of this work was to study microenvironmental conditions, especially the moisture distribution and its relationship to stone decay. The self-potential and IR thermography survey allowed verifying that southern part of the tomb is more humid than the northern part and that moisture is related to atmospheric moisture. Seismic refraction showed there is no interface between sound and weathered stone, that limestone is soft and the strength is slightly lower in the most humid zones.