[1] Seafloor fault scarps and near-surface deformation of late Quaternary seismic reflectors occur along the eastern margin of the Wanganui Basin, 200 km behind the active Hikurangi subduction front, southern North Island, New Zealand. The offshore scarps are associated with the low-strain, compressional Kapiti-Manawatu Fault System (KMFS), which comprises high-angle (> 60 degrees) reactivated reverse and normal faults oriented NE-SW, highly oblique to the coast. Seafloor scarps range from < 10 to 50 km in length with vertical seafloor offsets of 2 to 30 m. The longest structure is the Mascarin Fault, with maximum late Quaternary vertical slip rates of 3 mm a(-1) (where a is years). Other faults in the KMFS have typical rates of < 1 mm a(-1),... |