Large-Scale Slides on the Flanks of the Canary Islands

Abstract

The Canary Archipelago, located off the West African continental margin, is one of the largest oceanic island groups in the ocean basins (Fig. 1). A general but slightly diffuse westward age progression of the shield phases of the islands was interpreted as evidence for a hot spot origin of the Canary Islands (Wilson 1973; Schmincke 1982; Carracedo et al. 1998). During the last 15 years, morphological studies of the submarine flanks of ocean islands with swath bathymetry, sidescan sonar and high-resolution seismic systems have demonstrated that giant submarine landslides play an important role during the evolut ion of volcanic islands. Landslides on ocean islands are one of the most important transport processes of volcaniclastic material into the volcanic apron. They are a major geological hazard due to the sector collapses themselves as weil as triggering of tsunamis. Open image in new window Fig. 1. GLORIA mosaic (top) and combined EM12 multibeam and GLORIA swath bathymetry map (bottom) of Charles Darwin cruise CD109 around the Canary Islands. Dark tones in the GLORIA mosaic are areas of low backscatter. The bathymetric map is shaded by artificial illumination from the north-northeast, The contour interval is 0.5 km; the 1 km isolines are drawn in bold. Note the limited resolution of the GLORIA swath bathymetry