Evolution of a high-latitude sediment drift inside a glacially-carved trough based on high-resolution seismic stratigraphy (Kveithola, NW Barents Sea)

Published version, source at http://doi.org/10.1016/j.quascirev.2016.02.007. License CC BY-NC-ND 4.0.Kveithola is a glacially-carved, E-W trending trough located in the NW Barents Sea, an epicontinental shelf sea of the Arctic Ocean located off northern Norway and Russia. A set of confined sediment drifts (the “Kveithola Drift”) is located in the inner part of the trough. In general, drift deposits are commonly characterized by high lateral continuity, restricted occurrence of hiatuses and relatively high accumulation rates, and thus represent excellent repositories of paleo-environmental information. We provide for the first time a detailed morphological and seismostratigraphic insight into this sediment drift, which is further supported by some preliminary lithological and sedimentological analyses. The complex morphology of the drift, imaged by combining all available multibeam data, includes a main and a minor drift body, two drift lenses in the outer part of the trough, more or less connected drift patches in the innermost part and small perched sediment patches in a structurally-controlled channel to the north. The seismic (PARASOUND) data show that the main and minor drift bodies are mainly well-stratified, characterized by sub-parallel reflections of moderate to high amplitude and good lateral continuity. The reflectors show an abrupt pinch-out on the northern edge where a distinct moat is present, and a gradual tapering to the south. Internally we identify the base of the drift and four internal horizons, which we correlate throughout the drift. Two units display high amplitude reflectors, marked lensoidal character and restricted lateral extent, suggesting the occurrence of more energetic sedimentary conditions. Facies typical for contourite deposition are found in the sediment cores, with strongly bioturbated sediments and abundant silty/sandy mottles that contain shell fragments. These characteristics, along with the morphological and seismic information, suggest a strong control by a bottom current flowing along the moat on the northern edge of the drift. Though both Atlantic and Arctic waters are known to enter the trough, from the west and the north respectively, brine-enriched shelf water (BSW) produced during winter and flowing westward in the moat, is suggested to be responsible for the genesis of the Kveithola Drift. The formation of BSW is inferred to have started around 13 cal ka BP, the onset of drift deposition, suggesting that conditions leading to atmospheric cooling of the surface waters and/or the presence of coastal polynyas and wind or floating ice shelves have persisted on the western Barents Shelf since that time. The units inferred to have been deposited under more energetic sedimentary conditions (tentatively dated to the Younger Dryas and to 8.9–8.2 cal ka BP) are suggestive of stronger BSW formation. In general, we infer that variations in the bottom current regime were mainly related to BSW formation due to atmospheric changes. They could also have been a response to successive episodes of grounded and sea ice retreat that allowed for a first limited, later open shelf current, which progressively established on the western Barents Sea shelf

Glacial, \ufb02uvioglacial and \ufb02uvial sedimentary discharge in the northwestern coastal sectorof the Ross Sea continental margin since upper Miocene to LGM

The Borchgrevink Coast stretches from the Coulman Island northward to the Cape Adare for at least 200 km, bordering the western side of the northern Drygalski Trough. The early phase of the acquisition objectives of the PNRAProjectGlevors(GlacialEvolutioninthenorthwesternRossSea,offshoreNorthVictoriaLand,Antarctica) was accomplished in the north western coastal sector of the Ross Sea continental margin along the Borchgrevink Coast, from Coulman Island to Cape Hallett. Single channel seismic and sub bottom pro\ufb01les, swath bathymetry and gravity cores were collected during the Austral summer of 2016/2017, by the scienti\ufb01c research vessel OGS/Explora. The studied area along this segment of the Borchgrevink Coast documents, by the analysis and the interpretation of available geophysical, geological and oceanographic data, the paleo ice discharge and ice \ufb02owing patterns of the inferred Mariner-Borchgrevink and Tucker coastal glaciers, since at least the Upper Miocene until the Holocene Time. The repeated and possibly asynchronous oscillations of these valley glaciers from the North Victoria Land coast, at least about tens km offshore, and their interaction with fast \ufb02owing ice streams from the south are recorded. In particular, the analysis of the architecture and of the geometrical relationship of the interpreted seismic facies and units allows to infer past glacial and interglacial environments. Modelling of paleo environments and related climate condition is achieved despite the age constrain uncertainty of local seismic stratigraphy and of biostrathigraphic correlations to coeval sediment section in southern Ross Sea inner-shelf sector (McMurdo Sound), and besides the acoustic facies ambiguity due to not enough data resolution. The interpreted shallower and Holocene-Present glacial related features are simple or composite ice-marginal landforms, with overstepping smaller recessional deposits on top or behind. They testify the coastal glaciers grounded events and the ice retreat modality during the pre-LGM and the LGM. We infer that northern coastal glaciers, from the Tucker glacier northward, about 72\u25e6 latitude, did not advance or reach the northwestern Ross Sea shelf edge at the LGM, but possibly before. The grounding line of NVL coastal glaciers would correlate with the pre-LGM grounding lineament reconstructed for the major ice-streams \ufb02owing from the south. More ancient and buried wedge, underlying the main composite Grounding Zone Wedge (GZW) system raises the issue if it was possible the formation and the preservation as a pinning point, of a previously developed GZW or of the upper part of a \ufb02uvioglacial delta in late Miocene or Pliocene time. Moreover, further offshore from the coast, the evidence, of an ancient buried glacial/\ufb02uvioglacial or \ufb02uvial delta, embedded within the glaciomarine clinoforms of the Trough Mouth Fans (TMFs) deposits \ufb01lling the Northern Drygalski Trough, suggest climate change and an inferred preceding coastal open-sea condition

The International Bathymetric Chart of the Arctic Ocean (IBCAO) Version 3.0

[1] The International Bathymetric Chart of the Arctic Ocean (IBCAO) released its first gridded bathymetric compilation in 1999. The IBCAO bathymetric portrayals have since supported a wide range of Arctic science activities, for example, by providing constraint for ocean circulation models and the means to define and formulate hypotheses about the geologic origin of Arctic undersea features. IBCAO Version 3.0 represents the largest improvement since 1999 taking advantage of new data sets collected by the circum-Arctic nations, opportunistic data collected from fishing vessels, data acquired from US Navy submarines and from research ships of various nations. Built using an improved gridding algorithm, this new grid is on a 500 meter spacing, revealing much greater details of the Arctic seafloor than IBCAO Version 1.0 (2.5 km) and Version 2.0 (2.0 km). The area covered by multibeam surveys has increased from ∼6% in Version 2.0 to ∼11% in Version 3.0

The discovery of the southernmost ultra-high-resolution Holocene paleoclimate sedimentary record in Antarctica

The response of the Antarctic ice sheet to climate warming is the main source of uncertainty regarding future global sea level rise, since little is known about its present and past dynamics. The last deglaciation is the most recent interval of large-scale climate warming, during which the Northern and Southern Hemisphere ice sheets retreated, and sea level rose globally, although at a non-uniform rate. Geologic records from the polar regions are fundamental in determining the factors that caused the major changes in ice sheets during the last deglacial under different boundary conditions. Here, we combine morpho-bathymetric and seismic data with sediment cores and oceanographic measurements to reconstruct the processes that influenced the deposition of the southernmost, most extensive, ultrahigh-resolution record of the Holocene in Edisto Inlet fjord (Ross Sea, Antarctica). We find that post-glacial sedimentation resulted in a layered diatom mud up to 110 m thick that was locally redistributed by bottom currents over confined drifts-moats in the central part of the fjord. After the Holocene climatic optimum, the fjord was not carved by ground ice, and there continued to be internal fjord water circulation associated with Ross Sea circulation. These results support a retreat of coastal glaciers by about 11 kiloyears ago (ka) from the continental shelf of North Victoria Land

The newly discovered Odyssea Drift (Ross Sea): preliminary results

The Hillary Canyon is one of the main conduits for dense shelf water forming in the Ross Sea, over-flowing the shelf edge and transforming into the Antarctic Bottom Water (AABW). The main changes in past ocean circulation are recorded in the adjacent sediment drift. A wealth of data was acquired on the drift west of the Hillary Canyon during the 2017 OGS Explora expedition, which included the PNRA ODYSSEA and EUROFLEETS ANTSSS projects. The multi-disciplinary dataset acquired includes: single channel seismics, sub-bottom profiling, multibeam bathymetry, gravity and box cores, XBT launching, water sampling, CTD, L-ADCP, ADCP-VM, turbidity and florescence profiling. The sediment drift, which we named Odyssea Drift, is elongated in the NNE direction with dimensions of several tens of km. Prominent landslide scars and a giant landslide deposit, over 70 ms thick and spanning 200 km2, are visible on the drift. The sediment cores evidence well-developed cross beddings suggesting the effect of vigorous bottom currents. The oceanographic data show a ⇠200 m thick layer, near the bottom, with AABW characteristics (potential temperature < 0 C). The deeper layer displays also a strong velocity, mainly flowing along the isobaths. The energetic mixing between the along slope currents, mainly CDW, and the RSBW coming from the basin interior increase the turbidity of the bottom boundary layer. Our results will be merged with those obtained from the 2018 IODP drilling expedition 374 to develop a conceptual model of sediment deposition relating to marine-based ice sheet and oceanic processes along the Ross Sea continental margin occurring through the Neogene and Quaternary

SOME PRODUCTION AND NUTRITION PARAMETERS IN VARIOUS SYSTEMS OF COW KEEPING IN EARLY LACTATION

Analizirani su proizvodni pokazatelji i utrošak hrane po jedinici proizvoda u dvije grupe od po 26 grla muznih krava, holštajn-frizijske pasmine koje su se telile u siječnju 1989. godine. Ispitivanja su vršena na farmi slobodnog sistema držanja, kapaciteta 1000 grla s instaliranom kompjuterskom opremom za rukovođenje procesima proizvodnje. Životinje su praćene od telenja do 35. dana laktacije. Ogledna grupa je od 6. dana laktacije bila u slobodnom sistemu držanja, dok je kontrolna grupa bila tokom čitavog trajanja ogleda u klasičnoj staji na vezu. Željelo se ustanoviti mogućnost uvoda krava u mlječnost u slobodnom sistemu držanja s hranidbom koncentrata preko automatskih hranilica i mužnjom u izmuzištu, sa automatikom za individualno praćenje proizvodnje. Ustanovljeno je da kompjuterski sistem omogućava uvod krava u mlječnost u slobodnom sistemu držanja,bez negativnih posljedica na proizvodnju, te da se ostvaruje utrošak hrane po jedinici proizvoda isti kao u klasičnoj staji na vezu.Production indicators and food consumption per product unit in two groups of 26 Holstein-Frisian dairy cows calved in January 1989 were analyzed. Investigations were carried out on a free system dairy farm, capacity a 1000 head, with a computer installed to follow\u27 the production processes. The cows were followed from calčvng until 35- day of lactation. The trial group was kept free from the 6rh lactation day hile the control group was kept tied in a traditional shed during the trial period. The aim was to establish a possibility of introducing the cows to being milked in a free system and fed on concentrates by means of automatic feeding system and milked in the milking parlour; each animal as followed by the computer system. It as established that the computer system enabled initiations of cows into milking in the free keeping system without negative effects on production and that the food consumption per production unit as the same as when the cows were kept tied in a traditional shed

From shallow to very shallow image of the highly active Kefalonia - Zakynthos fault system

4 pages, 2 figuresIn May 2022 and June 2023 two oceanographic cruises were carried out around the Ionian Islands with the aim of defining the real geometry of the strike-slip fault system of Kefalonia and of the reverse faults present south of Zakynthos. The acquired multidisciplinary and multiresolution data will also allow to understand the dynamics of the area offshore the Peoloponnese peninsula, the deformation of the surface sediments at the transition of the two systems, i.e. from reverse fault system to strike-slip fault system, and the relationship between the recorded seismicity and mapped fault activity. To date, the analysis of the processed data has allowed us to define the tectonic and morphological complexity of the fault system affecting the investigated area. [...]Thanks to the CNR for supporting the cruise with time ship, IONIANS 2022 project. Interpretation of seismic profile has been done using the Kindgom IHS Markit. Poseidon project has been supported by Eurofleet+ SEA02_13_POSEIDONPeer reviewe

The International Bathymetric Chart of the Arctic Ocean Version 4.0

Funder: The Nippon Foundation of Japan, grant Seabed 2030Funder: Open access funding provided by Stockholm UniversityAbstract: Bathymetry (seafloor depth), is a critical parameter providing the geospatial context for a multitude of marine scientific studies. Since 1997, the International Bathymetric Chart of the Arctic Ocean (IBCAO) has been the authoritative source of bathymetry for the Arctic Ocean. IBCAO has merged its efforts with the Nippon Foundation-GEBCO-Seabed 2030 Project, with the goal of mapping all of the oceans by 2030. Here we present the latest version (IBCAO Ver. 4.0), with more than twice the resolution (200 × 200 m versus 500 × 500 m) and with individual depth soundings constraining three times more area of the Arctic Ocean (∼19.8% versus 6.7%), than the previous IBCAO Ver. 3.0 released in 2012. Modern multibeam bathymetry comprises ∼14.3% in Ver. 4.0 compared to ∼5.4% in Ver. 3.0. Thus, the new IBCAO Ver. 4.0 has substantially more seafloor morphological information that offers new insights into a range of submarine features and processes; for example, the improved portrayal of Greenland fjords better serves predictive modelling of the fate of the Greenland Ice Sheet

Downslope and alongslope sedimentary processes on a high latitude continental margin: NW Barents Sea

Rui, L. ... et al.-- PAST GATEWAYS 2016, 4th International Conference, 23-27 May 2016, Trondheim, NorwayThe development of high latitude continental margin has been mainly controlled by glacigenic processes during the glacial maxima. Superimposed to these, there are both downslope and alongslope sedimentary processes (turbidites and contourites). This study is part of a PhD project, aiming to study the relationships between the glacial sedimentary input and the water circulation in NW Barents Sea (Kveithola to Isfjorden Trough Mouth Fans). This portion of the Barents Sea has been the target of several surveys in the last decade: SVAIS (R/V Hesperides) in 2007, EGL ACOM (R/V OGS Explora) in 2008, GLACIBAR (R/V Jan Mayen) in 2009, CORIBAR (R/V Maria S. Merian) in 2013, PREPARED (R/V G.O. Sars) in 2014 and the EDIPO and DEGLABAR cruises (R/V OGS Explora) in 2015. These cruises allowed the acquisition of a wealth of new multibeam data that are now jointly processed at OGS (Figure 1). During the most recent EDIPO and the DEGLABAR cruises, from 20th September to 5th October 2015, we have been able to collect geophysical data, in particular Multibeam data, Sub-bottom profiles and Multichannel seismic profiles, as well as oceanographic data, including CTD and ADCP profiles. The EDIPO/DEGLABAR cruise focused the study of two areas in particular: the first one being the one W-SW of Isfjorden, on the Isfjorden TMF; the second one at SW of the Kveithola trough, on the INBIS channel. The INBIS channel originates from a series of tributary canyons, converging in a trunk-type channel, leading to a deep sea lobe system. The INBIS channel is inferred to have been produced by turbidity flows, flowing from tributary canyons incising the upper part of the continental slope between Bear Island TMF and Kveithola TMF. The INBIS channel is a very peculiar structure in the Barents Sea; channel systems are in fact rare on the Northern Norwegian margin and confined to the INBIS and Lofoten Basin channels. At W-SW of Isfjorden there is the evidence of alongslope sedimentary process, in the form of the Isfjorden drift. This structure is asymmetric, with a limited vertical relief. It is elongated alongslope, subparallel to the contour, due to the main current in that area, the north-flowing West Spitsbergen current. The analysis of the EDIPO/DEGLABAR data, integrated with all the other available information will allow to contribute to the comprehension of the relationships between the glacial sedimentary input and the water circulation in NW Barents SeaPeer Reviewe

Downslope and alongslope sedimentary processes on a high latitude continental margin: NW Barents Sea

Rui, L. ... et al.-- Final Conference ARCA PROJECT : ARctic: present Climatic change and pAst extreme events, 11 October, 2016, Rome.-- 3 pages, 3 figuresThe development of high latitude continental margin has been mainly controlled by glacigenic processes during the glacial maxima. Superimposed to these, there are both downslope and alongslope sedimentary processes (turbidites and contourites). [...]Peer Reviewe