The Sula Reef Complex, Norwegian shelf

Abstract

Cool-water carbonates in the aphotic zone of deep shelf and continental margin settings in the Northeast Atlantic are produced by the deep-water coral reefs withLophelia pertusa as the major framework builder. Through a compilation of side scan sonar, airgun and manned submersible surveys from several cruises to the mid-Norwegian Sula Reef Complex (SRC), the facies pattern and zonation of one of the largest deep-water reefs in the Northeast Atlantic is described in relation to the overall seabed topography. The late glacial to early postglacial iceberg scour on the crest and shoulder of the Sula Ridge provides settling ground for the scleractinian corals already in the early Holocene. Since then coral growth continues until today but was supposed to be disturbed by an environmental hazard, the so-called second Storegga event. The distinct distribution pattern of individualLophelia reefs on the Sula Ridge has stimulated a discussion on intrinsic environmental controls such as the bentho-pelagic coupling and the alternative hydrocarbon-based nutrition hypothesis.