The Continental Rise West of Porcupine Seabight, Northeast Atlantic

Abstract

Continental rises are believed to be depoeentres for terrigenous sediment fed from the continental shelf. The floor of the Bay of Biscay has well developed canyon mouth fans that are still active during the Holocene (Zaragosi et al. 2000) but little is known of the neighbouring rise, west of the Porcupine Seabight (Fig. 1). The Porcupine Seabight lies west of the Celtic Sea and the western Irish shelf. The Gollum Channel, an unusual tributary channel system draining the southern Porcupine Seabight, has been mapped by (1978). Initial study of cores (Kenyon et al. 1998), deep-towed sidescan sonar and high resolution seismic profiles (Wheeler et al., this volume) show that the Gollum Channel system is relatively inactive. The rise is mapped here for the first time by an EM12 swath bathymetry system (Charles Darwin Cruise 12), and further investigated by a high resolution seismic profile (Training through Research Cruise 10) and two cores.Fig. 1.Continental margin west of the Celtic Sea and Ireland. Bathymetry from the digital GEBCO map. The area covered by this survey and the area of bathymetry in Wheeler et al. (this publication) are shown, as is the area of Fig. 2