GPR investigations on active faults in urban areas: the Georisc-NZ project in Wellington, New Zealand

Abstract : This paper presents preliminary results for three GPR profiles acquired across the Wellington active strike-slip fault within the Wellington urban area. In this sector, it is suggested that the subsurface geometry (8-10 m) of the fault comprises twomain deforming strands that bound narrow transpressive and transtensive sections. The location of fault planes interpreted from radargrams closely corresponds with the inferred location of the main fault at the ground surface. Despite noise due to the urban settings, GPR proved to be a technique capable of locating fault strands, thus potentially providing useful data in targeting areas for palaeoseismic studies, such as trenching.