Structure and Dynamics of the Porcupine Magma-Poor Continental Margin from new Ocean Bottom Seismometer Data

The Porcupine Basin, offshore Ireland, provides a unique natural laboratory for studying the evolution of magma-poor rifts. This project aims to develop a high-resolution seismic velocity model to better understand crustal thinning, hyper-extension, and mantle serpentinisation in the basin. While the northern basin is well studied, the nature of the crust in the southern part remains uncertain, with ongoing debate about its composition and the extent of continental breakup.

The research focuses on the 226-km-wide-angle seismic profile PORO-CLIM Profile 2 in the southern Porcupine Basin. It aims to better constrain crustal structure and quantify variations in extension across the basin. The study integrates newly acquired ocean bottom seismometer (OBS) data with industry multi-channel seismic (MCS) data to refine models of crustal architecture and basin evolution.

Using joint refraction and reflection modelling, the project applies forward modelling with RAYINVR and travel-time tomography with TOMO2D to construct a detailed seismic velocity model. A basin-wide grid of reprocessed 2D MCS data (PAD-13, PAD-14, SPB-97) from the Irish Department of Environment, Climate and Communications will help map fault systems, crustal thinning, and mantle serpentinisation. This will provide new insights into rift symmetry and how water enters the mantle during continental break-up.

To test theories on magma-poor rift evolution, the results will be compared with seismic data from the Goban Spur margin, East Orphan Basin, and Galicia Margin (Spain). This will refine broader models for rifted margins and improve our understanding of the processes controlling continental extension, offering critical insights into the geodynamic mechanisms that shape magma-poor basins.