Images of Sliding and Slumping Along the Porcupine and SW Rockall Trough Margins

Abstract

The Rockall Trough is a major deep water basin along the western continental margins of Ireland and Britain. Its margins are of complex bathymetry and morphology (Fig. 1), reflecting the spatial and temporal variability and influence of tectonic and paleoceanographic conditions and their related sedimentary processes (Stoker et al. 2001). High resolution single and multichannel seismic profiling investigations of the SE and SW margins of the Rockall Trough by NIOZ in 1987, and subse quently during the ENAM II project (1996–1999, lines shown in Fig. 1) showed the presence of large scale sliding and slumping along both the SW Rockall Trough and the Porcupine margins. These observations confirm and extend earlier observations by (1972) and (1979) regarding the SW Rockall Trough margin slope instability and sliding events, and by (1987) and (2000) for the SE Rockall Trough and Porcupine margins.Fig. 1.Generalized bathymetry of the Rockall Trough area and adjacent continental margins (based on GEBCO 1997). Lines perpendicular to bathymetry represent seismic lines acquired during ENAM II and NA87 surveys by NIOZ. Sections indicated in bold are represented in Figs. 2–5