BURSTER: BOTTOM CURRENTS IN A STAGNANT ENVIRONMENT

• Main Authors: Lucchi R. G., Kovacevic V., De Vittor C., Bazzaro M., Bensi M., De Ponte D., Laterza R., Musco M. E., Relitti F., Rui L., Morigi C., GAMBOA-SOJO, VIVIANA MARÍA, Sabbatini A., Caridi F., Graziani S., Ruggiero L., Mazzini A., Krueger M., Zoch D., Carbonara K., Langone L., Le Gall C., Topchiy M., Povea P., Tagliaferro M., Wiberg D., Dominiczak A., Sánchez Guillamón O., Biebow N., Rebesco M.
• Other Authors: Lucchi, R. G., Kovacevic, V., De Vittor, C., Bazzaro, M., Bensi, M., De Ponte, D., Laterza, R., Musco, M. E., Relitti, F., Rui, L., Morigi, C., Sabbatini, A., Caridi, F., Graziani, S., Ruggiero, L., Mazzini, A., Krueger, M., Zoch, D., Carbonara, K., Langone, L., Le Gall, C., Topchiy, M., Povea, P., Tagliaferro, M., Wiberg, D., Dominiczak, A., Sánchez Guillamón, O., Biebow, N., Rebesco, M.
• Format: Other/Unknown Material
• Language: English
• Published: 2016
• Subjects: Andreassen; Barents Sea; Bear Island; Svalbard; Tromsø; Storfjorden
• Online Access: http://hdl.handle.net/11568/920384

The glacigenic Kveithola Trough is an abrupt and narrow (100 km-long and 13 kmwide) sedimentary system located in the NW Barents Sea (Rebesco et al., 2011; Ruther et al., 2012; Bjarnadóttir et al., 2013). Along with the larger Storfjorden glacial system, it hosted, during the last glaciation, ice streams draining ice from the southern Svalbard in the north and Bear Island in the south (Andreassen et al., 2008; Pedrosa et al., 2011). During the CORIBAR Cruise on board RV Maria S. Merian (16.07. - 15.08.2013; Tromsø - Tromsø) a wealth of geophysical data including PARASOUND sub-bottom profiles and multibeam, and sediment samples retrieved by gravity-, multi-, boxcorer, and the seafloor drill rig MeBo (Hanebuth et al., 2013) were collected on the Kveithola Drift, a complex morphological and depositional feature confined in the innermost part of the glacially-erode Kveithola Trough. The internal seismic reflections of the drift show a drastic thinning and termination towards the north. Here a distinct moat can be identified, which implies the strong influence of dense bottom currents, inferred to flow (or at least to have flown in the past) towards the outer shelf. The highly dynamic environment depicted from the morphological and structural characteristics of the sediment drift is in contrast with the sediment facies and preserved biota observed in surface sediments. The retrieved sediments have a strong smell of H2S and are mostly black, organic matter-rich, with abundant black worm tubes (Pogonophora worms), and occasionally with living reddish polychaetes (possibly ampharetid polychaetes). The recent and living benthic foraminiferal assemblage observed in the sediments is characterized by the presence of typically oxygen-depleted environmental taxa. Any bottom current-related sedimentary structure was observed on surface sediments. The Kveithola Drift that formed under persistent dense bottom currents appears today as a “stagnant environment” strongly affected by low-oxygen conditions with likely ongoing seep ...