Deciphering tectonic phases of the Amundsen Sea Embayment shelf, West Antarctica, from a magnetic anomaly grid

► A first magnetic anomaly grid of the shelf of the Amundsen Sea Embayment reveals a distinct anomaly pattern. ► At least 3 different tectonic phases and a zone of mafic dykes characterize the Amundsen Sea Embayment. ► Tectonic lineaments correlate with bathymetric trends. ► Some glacial pathways follow tectonic lineaments.