Genesis and character of thin-bedded turbidites associated with submarine channels

Acknowledgements We acknowledge the support of the PRACSS Joint Industry Project at University of Aberdeen, funded by BG Group, BP, DONG, RWE Dea, Petrochina, Statoil and Tullow Oil. We also acknowledge the entire crew of the Urania Research vessel which was used to acquire the CHIRP lines, bathymetric data and gravity cores from the Tyrrhenian Sea, Italy. Our colleagues Michal Janocko and Mike Mayall are thanked for the discussions and comments. Our colleagues Pan Li, Amanda Santa Catharina, Guilherme Bozetti and Matheus Silveira Sobiesiak are thanked for their assistance during field work where some of the ideas in this paper were synthesized. Finally we thank one anonymous reviewer and Brian Romans for their invaluable feedback which made some of the ideas introduced in this review much more succinct.

Hydrocarbon analyses of submarine mud volcanoes (MV) in the Kumano forearc basin

Twelve submarine mud volcanoes (MV) in the Kumano forearc basin within the Nankai Trough subduction zone were investigated for hydrocarbon origins and fluid dynamics. Gas hydrates diagnostic for methane concentrations exceeding solubilities were recovered from MVs 2, 4, 5, and 10. Molecular ratios (C1/C2<250) and stable carbon isotopic compositions (d13C-CH4 >-40 per mil V-PDB) indicate that hydrate-bound hydrocarbons (HCs) at MVs 2, 4, and 10 are derived from thermal cracking of organic matter. Considering thermal gradients at the nearby IODP Sites C0009 and C0002, the likely formation depth of such HCs ranges between 2300 and 4300 m below seafloor (mbsf). With respect to basin sediment thickness and the minimum distance to the top of the plate boundary thrust we propose that the majority of HCs fueling the MVs is derived from sediments of the Cretaceous to Tertiary Shimanto belt below Pliocene/Pleistocene to recent basin sediments. Considering their sizes and appearances hydrates are suggested to be relicts of higher MV activity in the past, although the sporadic presence of vesicomyid clams at MV 2 showed that fluid migration is sufficient to nourish chemosynthesis-based organisms in places. Distributions of dissolved methane at MVs 3, 4, 5, and 8 pointed at fluid supply through one or few MV conduits and effective methane oxidation in the immediate subsurface. The aged nature of the hydrates suggests that the major portion of methane immediately below the top of the methane-containing sediment interval is fueled by current hydrate dissolution rather than active migration from greater depth.

Military objectives in cyber warfare

This Chapter discusses the possible problems arising from the application of the principle of distinction under the law of armed conflict to cyber attacks. It first identifies when cyber attacks qualify as ‘attacks’ under the law of armed conflict and then examines the two elements of the definition of ‘military objective’ contained in Article 52(2) of the 1977 Protocol I additional to the 1949 Geneva Conventions on the Protection of Victims of War. The Chapter concludes that this definition is flexible enough to apply in the cyber context without significant problems and that none of the challenges that characterize cyber attacks hinders the application of the principle of distinction.

Sedimentology, structure and age estimate of five continental slope submarine landslides, eastern Australia

Sedimentological and accelerator mass spectrometry (AMS) 14C data provide estimates of the structure and age of five submarine landslides (∼0.4–3 km3) present on eastern Australia's continental slope between Noosa Heads and Yamba. Dating of the post-slide conformably deposited sediment indicates sediment accumulation rates between 0.017 m ka–1 and 0.2 m ka–1, which is consistent with previous estimates reported for this area. Boundary surfaces were identified in five continental slope cores at depths of 0.8 to 2.2 m below the present-day seafloor. Boundary surfaces present as a sharp colour-change across the surface, discernible but small increases in sediment stiffness, a slight increase in sediment bulk density of 0.1 g cm–3, and distinct gaps in AMS 14C ages of at least 25 ka. Boundary surfaces are interpreted to represent a slide plane detachment surface but are not necessarily the only ones or even the major ones. Sub-bottom profiler records indicate that: (1) the youngest identifiable sediment reflectors upslope from three submarine landslides terminate on and are truncated by slide rupture surfaces; (2) there is no obvious evidence for a post-slide sediment layer draped over, or burying, slide ruptures or exposed slide detachment surfaces; and (3) the boundary surfaces identified within the cores are unlikely to be near-surface slide surfaces within an overall larger en masse dislocation. These findings suggest that these submarine landslides are geologically recent (<25 ka), and that the boundary surfaces are either: (a) an erosional features that developed after the landslide, in which case the boundary surface age provides a minimum age for the landslide; or (b) detachment surfaces from which slabs of near-surface sediment were removed during landsliding, in which case the age of the sediment above the boundary surface indicates the approximate age of landsliding. While an earthquake-triggering mechanism is favoured for the initiation of submarine landslides on the eastern Australian margin, further evidence is required to confirm this interpretation.

Extraction system and determination of PAH in seawater and it implementation in submarine vehicles

[EN]Policyclyc aromatic hydrocarbons (PAHs) are a potential risk for human health and marine biota in general that make necessary the monitorization of them. A miniaturized extraction system capable to extract PAHs from seawater was developed and optimized with the objective of implement it in an oceanographic buoy in the future. An analytical method was optimized by high performance liquid chromatography for the determination of extracted PAHs by the extraction system. The analytical method was validated and applicated to real samples of differents points of Gran Canaria. The method has enough sensitivity to detect and quantify concentrations below the concentrations established in the legislation. In some places where samples were taken some compounds exceed the legislation while other compounds follow it

Warfare in the West Highlands and Isles of Scotland, c. 1544-1615

Warfare has long been associated with Scottish Highlanders and Islanders, especially in the period known in Gaelic tradition as ‘Linn nan Creach’ (the ‘Age of Forays’), which followed the forfeiture of the Lordship of the Isles in 1493. The sixteenth century in general is remembered as a particularly tumultuous time within the West Highlands and Isles, characterised by armed conflict on a seemingly unprecedented scale. Relatively little research has been conducted into the nature of warfare however, a gap filled by this thesis through its focus on a series of interconnected themes and in-depth case studies spanning the period c. 1544-1615. It challenges the idea that the sixteenth century and early seventeenth century was a time of endless bloodshed, and explores the rationale behind the distinctive mode of warfare practised in the West Highlands and Isles. The first part of the thesis traces the overall ‘Process of War’. Chapter 1 focuses on the mentality of the social elite in the West Highlands and Isles and demonstrates that warfare was not their raison d'être, but was tied inextricably to chiefs’ prime responsibility of protecting their lands and tenants. Chapter 2 assesses the causation of warfare and reveals that a recurrent catalyst for armed conflict was the assertion of rights to land and inheritance. There were other important causes however, including clan expectation, honour culture, punitive government policies, and the use of proxy warfare by prominent magnates. Chapter 3 takes a fresh approach to the military capacity of the region through analysis of armies and soldiers, and the final thematic chapter tackles the conduct of warfare in the West Highlands and Isles, with analysis of the tactics and strategy of militarised personnel. The second part of this thesis comprises five case studies: the Clanranald, 1544-77; the Colquhouns of Luss and the Lennox, 1592-1603; the MacLeods of Harris and MacDonalds of Sleat, 1594-1601; the Camerons, 1569-1614; and the ‘Islay Rising’, 1614-15. This thesis adopts a unique approach by contextualising the political background of warfare in order to instil a deeper understanding of why early modern Gaelic Scots resorted to bloodshed. Overall, this period was defined by a sharp rise in military activity, followed by an even sharper decline, a trajectory that will be evidenced vividly in the final case study on the ‘Islay Rising’. Although warfare was widespread, it was not unrestrained or continuous, and the traditional image of a region riven by perpetual bloodshed has been greatly exaggerated.

Submarine landform assemblages and sedimentary processes related to glacier surging in Kongsfjorden, Svalbard

High-resolution swath-bathymetry data from inner Kongsfjorden, Svalbard, reveal characteristic landform assemblages formed during and after surges of tidewater glaciers, and provide new insights into the dynamics of surging glaciers. Glacier front oscillations and overriding related to surge activity lead to the formation of overridden moraines, glacial lineations of two types, terminal moraines, associated debris lobes and De Geer moraines. In contrast to submarine landform assemblages from other Svalbard fjords, the occurrence of two kinds of glacial lineations and the presence of De Geer moraines suggest variability in the landforms produced by surge-type tidewater glaciers. All the landforms in inner Kongsfjorden were deposited during the last c. 150 years. Lithological and acoustic data from the innermost fjord reveal that suspension settling from meltwater plumes as well as ice rafting are dominant sedimentary processes in the fjord, leading to the deposition of stratified glacimarine muds with variable numbers of clasts. Reworking of sediments by glacier surging results in the deposition of sediment lobes containing massive glacimarine muds. Two sediment cores reveal minimum sediment accumulation rates related to the Kongsvegen surge from 1948; these were 30 cm a-1 approximately 2.5 km beyond the glacier front shortly after surge termination, and rapidly dropped to an average rate of 1.8 cm a-1 in ∼1950, during glacier retreat.

Applications of perceptron techniques to the submarine classification problem. Policy agreement project no. 208-LR-40. Combined progress and final report. Period: 1 June 1961 to 1 June 1962.

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Assessing land–ocean connectivity via submarine groundwater discharge (SGD) in the Ria Formosa Lagoon (Portugal): combining radon measurements and stable isotope hydrology

Natural radioactive tracer-based assessments of basin-scale submarine groundwater discharge (SGD) are well developed. However, SGD takes place in different modes and the flow and discharge mechanisms involved occur over a wide range of spatial and temporal scales. Quantifying SGD while discriminating its source functions therefore remains a major challenge. However, correctly identifying both the fluid source and composition is critical. When multiple sources of the tracer of interest are present, failure to adequately discriminate between them leads to inaccurate attribution and the resulting uncertainties will affect the reliability of SGD solute loading estimates. This lack of reliability then extends to the closure of local biogeochemical budgets, confusing measures aiming to mitigate pollution. Here, we report a multi-tracer study to identify the sources of SGD, distinguish its component parts and elucidate the mechanisms of their dispersion throughout the Ria Formosa – a seasonally hypersaline lagoon in Portugal. We combine radon budgets that determine the total SGD (meteoric + recirculated seawater) in the system with stable isotopes in water (δ2H, δ18O), to specifically identify SGD source functions and characterize active hydrological pathways in the catchment. Using this approach, SGD in the Ria Formosa could be separated into two modes, a net meteoric water input and another involving no net water transfer, i.e., originating in lagoon water re-circulated through permeable sediments. The former SGD mode is present occasionally on a multi-annual timescale, while the latter is a dominant feature of the system. In the absence of meteoric SGD inputs, seawater recirculation through beach sediments occurs at a rate of  ∼  1.4  ×  106 m3 day−1. This implies that the entire tidal-averaged volume of the lagoon is filtered through local sandy sediments within 100 days ( ∼  3.5 times a year), driving an estimated nitrogen (N) load of  ∼  350 Ton N yr−1 into the system as NO3−. Land-borne SGD could add a further  ∼  61 Ton N yr−1 to the lagoon. The former source is autochthonous, continuous and responsible for a large fraction (59 %) of the estimated total N inputs into the system via non-point sources, while the latter is an occasional allochthonous source capable of driving new production in the system.

Marine litter in the upper São Vicente submarine canyon (SW Portugal): abundance, distribution, composition and fauna interactions

Marine litter has become a worldwide environmental problem, tainting all ocean habitats. The abundance, distribution and composition of litter and its interactions with fauna were evaluated in the upper S. Vicente canyon using video images from 3 remote operated vehicle exploratory dives. Litter was present in all dives and the abundance was as high as 3.31 items100m(-1). Mean abundance of litter over rock bottom was higher than on soft substrate. Mean litter abundance was slightly higher than reported for other canyons on the Portuguese margin, but lower in comparison to more urbanized coastal areas of the world. Lost fishing gear was the prevalent type of litter, indicating that the majority of litter originates from maritime sources, mainly fishing activity. Physical contact with sessile fauna and entanglement of specimens were the major impacts of lost fishing gear. Based on the importance of this region for the local fishermen, litter abundance is expected to increase.

The 1998-2001 submarine lava balloon eruption at the Serreta Ridge (Azores archipelago): constraints from volcanic facies architecture, isotope geochemistry and magnetic data

The most recent submarine eruption observed offshore the Azores archipelago occurred between 1998-2001 along the submarine Serreta ridge (SSR), ~4-5 nautical miles WNW of Terceira Island. This submarine eruption delivered abundant basaltic lava balloons floating at the sea surface and significantly changed the bathymetry around the eruption area. Our work combines bathymetry, volcanic facies cartography, petrography, rock magnetism and geochemistry in order to (1) track the possible vent source at seabed, (2) better constrain the Azores magma source(s) sampled through the Serreta submarine volcanic event, and (3) interpret the data within the small-scale mantle source heterogeneity framework that has been demonstrated for the Azores archipelago. Lava balloons sampled at sea surface display a radiogenic signature, which is also correlated with relatively primitive (low) 4He/3He isotopic ratios. Conversely, SSR lavas are characterized by significantly lower radiogenic 87Sr/86Sr, 206Pb/204Pb and 208Pb/204Pb ratios than the lava balloons and the onshore lavas from the Terceira Island. SSR lavas are primitive, but incompatible trace-enriched. Apparent decoupling between the enriched incompatible trace element abundances and depleted radiogenic isotope ratios is best explained by binary mixing of a depleted MORB source and a HIMU­type component into magma batches that evolved by similar shallower processes in their travel to the surface. The collected data suggest that the freshest samples collected in the SSR may correspond to volcanic products of an unnoticed and more recent eruption than the 1998-2001 episode.

Enhancing the trust of location acquisition systems for critical applications and location-based security services

This paper identifies a number of critical infrastructure applications that are reliant on location services from cooperative location technologies such as GPS and GSM. We show that these location technologies can be represented in a general location model, such that the model components can be used for vulnerability analysis. We perform a vulnerability analysis on these components of GSM and GPS location systems as well as a number of augmentations to these systems.