Seismic reflections within the sea water column in the Southern Ocean, Antarctica

Recent studies have demonstrated that offshore seismic reflection data can be used to detect boundaries in the water column. This novel approach, called seismic oceanography , has produced clear pictures of water mass interfaces (i.e., thermoclines, internal waves, fronts, eddies) in different oceanic environments. Starting from 1988, Istituto Nazionale di Oceanografia e Geofisica Sperimentale - OGS, Italy, has been collecting a large amount of marine reflection seismic data in Antarctica with R/V OGS Explora and has participated to several scientific international collaborations in the Southern Ocean (Antarctica). As this region represents a key study area for climate due to deep water formation which triggers the Global Thermohaline Circulation, we began to reprocess seismic lines to investigate the presence of reflections in the seawater column. A first evaluation of the possibility of recognizing fine structures in the water column is positive: seismic lines acquired along the Wilkes Land continental margin (East Antarctica) show signals correlated with boundaries inferred by conventional oceanographic measurements.