The area examined is part of an active tectonic collision zone in which the northern margin of the Australian plate is being subducted beneath the South Bismarck plate. The edge of the South Bismarck plate has been uplifted 4,000 m since the late Pliocene, forming the Finisterre Range on Huon Peninsula. The record of relative emergence and submergence is seen in subaerially exposed Quaternary marine sediments and in drowned carbonate reefs. The merged radar and sonar imagery clearly indicate rapid erosion and deformation, both on land and under water. The imagery shows details of sediment transport and depositional systems, which are generating large terrestrial fluvial/alluvial plains, coastal fan deltas, and submarine channel deposystems. Fault structures and outcrops of bedrock units are clearly delineated both on land and on the seabed. These observations help explain patterns of onshore and submarine outcrops in terms of interactions between modern offshore sedimentation patterns and progressive deformation.
