Abstract Seismic, sidescan sonar, bathymetric multi- beam and ODP (Ocean Drilling Program) data obtained in the submarine channel between the volcanic islands of Gran Canaria and Tenerife allow to identify constructive features and destructive events during the evolution of both islands. The most prominent constructive features are the submarine island flanks being the acoustic base- ment of the seismic images. The build-up of Tenerife started following the submarine stage of Gran Canaria because the submarine island flank of Tenerife onlaps the steeper flank of Gran Canaria. The overlying sedi- ments in the channel between Gran Canaria and Tenerife are chaotic, consisting of slumps, debris flow deposits, syn-ignimbrite turbidites, ash layers, and other volcani- clastic rocks generated by eruptions, erosion, and flank collapse of the volcanoes. Volcanic cones on the sub- marine island flanks reflect ongoing submarine volcanic activity. The construction of the islands is interrupted by large destructive events, especially by flank collapses resulting in giant landslides. Several Miocene flank collapses (e.g., the formation of the Horgazales basin) were identified by combining seismic and drilling data whereas young giant landslides (e.g., the Güimar debris avalanche) are documented by sidescan, bathymetric and drilling data. Sediments are also transported through numerous submarine canyons from the islands into the volcaniclastic apron. Seismic profiles across the channel do not show a major offset of reflectors. The existence of a repeatedly postulated major NE–SW-trending fault zone between Gran Canaria and Tenerife is thus in doubt. The sporadic earthquake activity in this area may be related to the regional stress field or the submarine volcanic activity in this area. Seismic reflectors cannot be correlated through the channel between the sedimen- tary basins north and south of Gran Canaria because the channel acts as sediment barrier. The sedimentary basins to the north and south evolved differently following the submarine growth of Gran Canaria and Tenerife in the Miocene. Keywords Canary Islands · Landslides · Ocean islands · Submarine volcanism · Volcanic evolution Introduction Major oceanic islands appear as large volcanic structures when only viewed above sea level. When stripped of the water column, they emerge as colossal mountains whose height dwarfs high peaks on land and whose basal diam- eter approaches that of some mountain chains. Intraplate volcanic oceanic islands are generally believed to be generated above rising mantle plumes (Morgan 1972; Wilson 1973). They grow by magmatic/volcanic activity, but destructive events such as giant landslides are close- ly linked to the construction of volcanic islands (e.g., Moore et al. 1989; Krastel et al. 2001b; Masson et al. 2002). Major oceanic archipelagos, such as the Canary Islands and the Hawaiian Islands, typically form island chains defining the trace of a mantle plume relative to the moving plate. Major islands are separated by chan- nels, which can vary in depth and width. The structure and the deposits in such channels greatly aid in elucidat- ing the evolution of the adjacent islands. For example, what determines the width of these channels, in other words, the distance between the islands? What are the origins of the channels? Are they structural features characterized by underlying basement lineaments and/or younger faults, or are they the result of a shift of chan- nelized magma ascent between the islands as first order foci of magma rise? Is there a clear onlap of a younger island flank on top of an older one, which would help to understand the temporal evolution of an island chain? S. Krastel ( ✉ ) · H.-U. Schmincke GEOMAR Forschungszentrum, Abteilung Vulkanologie und Petrologie, Wischhofstr. 1–3, 24148 Kiel, Germany e-mail: skrastel@uni-bremen.de Tel.: +49-421-2184598, Fax: +49-421-2187179 Present address: S. Krastel, Bremen University, Fachbereich 5, Geowissenschaften, P.O. Box 330440, 28334 Bremen, Germany Int J Earth Sci (Geol Rundsch) (2002) 91:629–641 DOI 10.1007/s00531-002-0285-8 ORIGINAL PAPER Sebastian Krastel · Hans-Ulrich Schmincke The channel between Gran Canaria and Tenerife: constructive processes and destructive events during the evolution of volcanic islands Received: 3 August 2001 / Accepted: 4 April 2002 / Published online: 28 June 2002 © Springer-Verlag 2002