The influence of the geomorphological and sedimentological settings on the distribution of epibenthic assemblages on a flat topped hill on the over-deepened shelf of the western Weddell Sea (Southern Ocean)

Epibenthos communities play an important role in the marine ecosystems of the Weddell Sea. Information on the factors controlling their structure and distribution are, however, still rare. In particular, the interactions between environmental factors and biotic assemblages are not fully understood. Nachtigaller Hill, a newly discovered seabed structure on the over-deepened shelf of the northwest Weddell Sea (Southern Ocean), offers a unique site to study these interactions in a high-latitude Antarctic setting. Based on high-resolution bathymetry and georeferenced biological data, the effect of the terrain and related environmental parameters on the epibenthos was assessed. At Nachtigaller Hill, both geomorphological and biological data showed complex distribution patterns, reflecting local processes such as iceberg scouring and locally amplified bottom currents. This variability was also generally reflected in the variable epibenthos distribution patterns although statistical analyses did not show strong correlations between the selected environmental parameters and species abundances. By analysing the interactions between environmental and biological patterns, this study provides crucial information towards a better understanding of the factors and processes that drive epibenthos communities on the shelves of the Weddell Sea and probably also on other Antarctic shelves

Virtual Works – Actual Things: Essays in Music Ontology

"Beyond musical works: new perspectives on music ontology and performance What are musical works? How are they constructed in our minds? Which material things allow us to speak about them in the first place? Does a specific way of conceiving musical works limit their performative potentials? Which alternative, more productive images of musical work can be devised? Virtual Works – Actual Things addresses contemporary music ontological discourses, challenging dominant musicological accounts, questioning their authoritative foundation and moving towards dynamic perspectives devised by music practitioners and artist researchers. Specific attention is given to the relationship between the virtual multiplicities that enable the construction of an image of a musical work and the actual, concrete materials that make such a construction possible. With contributions by prominent scholars, this book is a wide-ranging and fascinating collection of essays, which will be of great interest for artistic research, contemporary musicology, music philosophy, performance studies and music pedagogy alike. Contributors: David Davies (McGill University, Montreal), Andreas Dorschel (University of the Arts Graz), Lydia Goehr (Columbia University, New York), Kathy Kiloh (OCAD University, Toronto), Jake McNulty (Columbia University, New York), Gunnar Hindrichs (University of Basel), John Rink (University of Cambridge)

Big Data Analytics. Analyse der prädiktiven Fähigkeit von Twitter-Sentiments auf die Entwicklung des Börsenkurses von Technologieunternehmen

Die Datenmengen vervielfachen sich in der heutigen Zeit konstant, was zum Begriff Big Data geführt hat. Durch diese Datenmengen entsteht ein neues Potenzial, Fragen zu beantworten. Eine dieser Fragestellungen, welche mithilfe von Big Data untersucht werden kann, ist, inwiefern die Social-Media-Daten die Veränderung von Börsenkursen voraussagen können. Diese Studie untersucht die prädiktive Fähigkeit von Twitter-Nachrichten im Zusammenhang mit einem Technologieunternehmen und dessen Börsenkurs anhand von zwei Anwendungsfällen. Konkret wird anhand der Twitter-Nachrichten mithilfe einer Sentimentanalyse die Stimmung der Twitter-Nutzer mit den Veränderungen des Börsenkurses verglichen. Diese Analyse wird anhand der Technologieunternehmen Facebook und Amazon vorgenommen. In einem ersten Schritt wird untersucht, ob eine Beziehung zwischen den Twitter-Sentiments und dem Börsenkurs besteht. In einem zweiten Schritt, ob die Twitter-Sentiments eine Voraussagekraft für die Veränderung des Börsenkurses haben. Die Auswertung zeigt bei beiden Unternehmen eine positive Korrelation der Twitter-Sentiments und des Börsenkurses auf. Weiter konnte mithilfe der Granger-Analyse eine signifikante Voraussagekraft der Twitter-Sentiments für die Börsenkurse beider Unternehmen ermittelt werden. Die Twitter-Sentiments können die Börsenkurse 13 h voraussagen

Depression chains in seafloor of contrasting morphology, Atacama Trench margin: a comment on Marsh et al. (2018)

This comment presents acoustic and visual data showing deep seafloor depression chains similar to those reported in Marsh et al. (R. Soc. open sci. 5: 180286), though from a different deep-sea setting. Marsh et al. present data collected during cruise JC120 from polymetallic nodule rich sites within the Clarion-Clipperton Fracture Zone (CCFZ), at water depths of between 3999 and 4258 m. Within this comment, we present data collected with equivalent acoustic and imaging devices on-board the RV Sonne (SO261—March/April 2018) from the Atacama Trench, approximately 4000 m depth, which shows comparable depression chains in the seafloor. In contrast with the CCFZ observations, our study area was wholly free of polymetallic nodules, an observation therefore weakening the ‘ballast collection’ by deep-sea diving mammals formation hypothesis discussed in their paper. We support their alternate hypothesis that if these features are indeed generated by deep-diving megafauna, then they are more likely the resultant traces of infauna feeding or marks made during opportunistic capture of benthic fish/cephalopods. We observed these potential prey fauna with lander and towed camera systems during the cruise, with example images of these presented here. Both the SO261 and JC120 cruises employed high-resolution sidescan systems at deployment altitudes seldom used routinely until the last few years during scientific deep-sea surveys. Given that both cruises found these depression chains in contrasting physical regions of the East Pacific, they may have a more ubiquitous distribution than at just these sites. Thus, the impacts of cetacean foraging behaviour on deep seafloor communities, and the potential relevance of these prey sources to deep-diving species, should be considered

The southwest Indian Ocean Bathymetric Compilation (swIOBC)

We present a comprehensive regional bathymetric data compilation for the southwest Indian Ocean (swIOBC) covering the area from 4°S to 40°S and 20°E to 45°E with a spatial resolution of 250 m. For this, we used multibeam and singlebeam data as well as data from global bathymetric data compilations. We generated the swIOBC using an iterative approach of manual data cleaning and gridding, accounting for different data qualities and seamless integration of all different kinds of data. In comparison to existing bathymetric charts of this region, the new swIOBC benefits from nearly four times as many data-constrained grid cells and a higher resolution, and thus reveals formerly unseen seabed features. In the central Mozambique Basin a surprising variety of landscapes were discovered. They document a deep reaching influence of the Mozambique Current eddies. Details of the N-S trending Zambezi Channel could be imaged in the central Mozambique Basin. Maps are crucial not only for orientation but also to set scientific processes and local information in a spatial context. For most parts of the ocean seafloor, maps are derived from satellite data with only kilometer resolution. Acoustic depth measurements from ships provide more detailed seafloor information in tens to hundreds of meters resolution. For the southwest Indian Ocean, all available depth soundings from a variety of sources and institutes are combined in one coherent map. Thus, in areas where depth soundings exist, this map shows the seafloor in so-far unknown detail. This detailed map forms the base for subsequent studies of e.g. the direction of ocean currents, geological and biological processes in the southwest Indian Ocean

Geophysical and geochemical survey of a large marine pockmark on the Malin Shelf, Ireland

Author Posting. © American Geophysical Union, 2012. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geochemistry Geophysics Geosystems 13 (2012): Q01011, doi:10.1029/2011GC003787.Marine pockmarks are a specific type of seabed geological setting resembling craters or pits and are considered seabed surface expressions of fluid flow in the subsurface. A large composite pockmark on the Malin Shelf, off the northern coast of Ireland was surveyed and ground truthed to assess its activity and investigate fluid related processes in the subsurface. Geophysical (including acoustic and electromagnetic) data confirmed the subsurface presence of signatures typical of fluids within the sediment. Shallow seismic profiling revealed a large shallow gas pocket and typical gas related indicators such as acoustic blanking and enhanced reflectors present underneath and around the large pockmark. Sulphate profiles indicate that gas from the shallow reservoir has been migrating upwards, at least recently. However, there are no chimney structures observed in the sub-bottom data and the migration pathways are not apparent. Electromagnetic data show slightly elevated electrical conductivity on the edges of the pockmarks and a drop below regional levels within the confines of the pockmark, suggesting changes in physical properties of the sediment. Nuclear Magnetic Resonance (NMR) experiments were employed to characterize the organic component of sediments from selected depths. Very strong microbial signatures were evident in all NMR spectra but microbes outside the pockmark appear to be much more active than inside. These observations coincide with spikes in conductivity and the lateral gas bearing body suggesting that there is an increase in microbial activity and biomass when gas is present.We wish to thank the Geological Survey of Ireland, the INtegrated Mapping FOr the Sustainable Development of Ireland’s MArine Resource (INFOMAR) program, the Irish Environmental Protection Agency, Science Foundation of Ireland, QUESTOR (Queens University Belfast) and the Irish Council for Science, engineering and technology for funding this research. AJS thanks NSERC, (Strategic and Discovery Programs), the Canada Foundation for Innovation (CFI), and the Ministry of Research and Innovation (MRI) for providing Canadian funding. The survey data utilized in the research has been co‐funded by the Geological Survey of Ireland and the Offshore Irish Petroleum Infrastructure Programme (PIP; Ref. No: IS05/16 Malin Basin EM).2012-07-1

Bathymetry and geological setting of the Drake Passage (Antarctica)

IX Congreso Geológico de España, Huelva, Septiembre 2016The Drake Passage is an oceanic gateway of about 850 km width located between South America and the Antarctic Peninsula that connects the southeastern Pacific and the southwestern Atlantic oceans and is an important gateway for mantle flow, oceanographic water masses, and migrations of biota. This gateway developed within the framework of geological evolution of the Scotia Arc. As a consequence of this and subsequent submarine processes, this region shows a varied physiography. The new detailed map in the Drake Passage region is mainly founded on a compilation of precise multibeam bathymetric data obtained on cruises between 1992 and 2014, and covers the area between parallels 52ºS and 63ºS and meridians 70ºW and 50ºW. The new map that we present is based in a DTM with 200 m cell resolution of the seafloor in Drake Passage that permits identification of the main seafloor features and the map includes additional useful geological information. This work constitutes an international cooperative effort and is part of IBCSO project (International Bathymetric Chart of the Southern Ocean), under the SCAR umbrella.Instituto Geológico y Minero de España, EspañaBritish Antarctic Survey, Reino UnidoDepartamento de Geodinámica, Universidad de Granada, EspañaInstituto Andaluz de Ciencias de la Tierra, Consejo Superior de Investigaciones Científicas, EspañaInstituto Andaluz de Ciencias de la Tierra, Universidad de Granada, EspañaJet Propulsion Laboratory M/S 300-323, Estados UnidosAlfred Wegener Institute, AlemaniaKorea Polar Research Institute, CoreaDepartamento de Geología y Geoquímica, Universidad Autónoma de Madrid, EspañaLamont-Doherty Earth Observatory, Columbia University, Estados Unido

Large-scale mass wasting in the western Indian Ocean constrains onset of East African rifting

Faulting and earthquakes occur extensively along the flanks of the East African Rift System, including an offshore branch in the western Indian Ocean, resulting in remobilization of sediment in the form of landslides. To date, constraints on the occurrence of submarine landslides at margin scale are lacking, leaving unanswered a link between rifting and slope instability. Here, we show the first overview of landslide deposits in the post-Eocene stratigraphy of the Tanzania margin and we present the discovery of one of the biggest landslides on Earth: the Mafia mega-slide. The emplacement of multiple landslides, including the Mafia mega-slide, during the early-mid Miocene is coeval with cratonic rifting in Tanzania, indicating that plateau uplift and rifting in East Africa triggered large and potentially tsunamigenic landslides likely through earthquake activity and enhanced sediment supply. This study is a first step to evaluate the risk associated with submarine landslides in the region