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In current practices of determining continental shelf area, the measured sediment thickness data do not effectively reflect the distribution of sediments across the area due to its dispersed nature. This issue raises potential limitations in unknown optimal survey line layout strategies for maximizing the posterior determination area. This paper adopts the binary search algorithm, relies on existing sediment thickness grid data, and uses geodetic formulas to build an ellipsoidal surface grid distance calculation model. This model quickly screens potential areas for the 1% sediment thickness line candidate points set. By constraining the azimuth parameter values during the construction process of the ellipsoidal point feature buffer zones, efficiently select the candidate points set for the 1% sediment thickness line. Furthermore, by elucidating the essential meanings of points on the formula limit and combining the candidate points set of the foot of the continental slope (FOS)+60 n mile line, the polygon minimal convex hull construction technique and a baseline points optimization algorithm with a length threshold are used to efficiently select points on formula limit. Experimental results demonstrate that this method can effectively assist coastal states in optimizing the determination of continental shelf area to the fullest extent under the length threshold requirements of the United Nations Convention on the Law of the Sea. Experiments have proven that compared to the traditional intersection method, the method presented in this paper can help coastal countries delineate a larger continental shelf area. In typical application scenarios, the gain in area can reach 77,278,427 m2 accounting for 0.51% of the total area. [ABSTRACT FROM AUTHOR]

Cabral, A.P. and Noernberg, M.A., 2024. Morphological characteristics of an open shelf ridge at Rio Grande do Norte continental shelf, NE Brazil. Journal of Coastal Research, 40(6), 1166–1181. Charlotte (North Carolina), ISSN 0749-0208. This paper describes for the first time the occurrence of an open shelf ridge (OSR) in the South Atlantic Ocean, evidencing morphological differences with respect to occurrences in other regions. The unique configuration of this OSR derives from the characteristics of the shallow continental shelf frontal to the Calcanhar Cape, Rio Grande do Norte State, Brazil, where it is located. It is a shallow, narrow, stepped shelf with an escarpment corresponding to a drowned shoreline around the 35 m isobath. There are extensive siliciclastic and carbonate sand deposits, sand ribbons, subaqueous dune fields, coral reefs, and calcareous algae patches. The high transparency of the water allows the use of multitemporal optical satellite images from remote sensors in the bathymetric modeling and morphodynamic description, in conjunction with echo sounder surveys, in situ sampling, and modeling. The metocean conditions of the region were determined from current and wind data obtained in situ, as well as data from the Hybrid Coordinate Ocean Model (HYCOM) and Regional Ocean Modeling System (ROMS) numerical models. Combining these data allowed the identification, characterization, and analysis of the metocean patterns over the OSR. Superimposed onto the OSR, there is a field of asymmetric subaqueous dunes transverse to the ridge axis with wavelengths between 150 m and 2 km and heights between 2.5 m and 9 m, with a tendency for sediment transport offshore northwestward of the OSR crest. The synergistic effect of the dominant NE winds and the North Brazil Current with tidal currents drives the main metocean forcings. The hydrodynamic pattern for the main sedimentary deposit areas is described, and the effect of the OSR on general subaqueous dune field configuration is presented. [ABSTRACT FROM AUTHOR]

Quaternary sea level fluctuations have greatly affected the sediment budgets of the continental shelves. Previous studies suggested that this caused a considerable increase in the net loss of shelf sediments. Since sediment accumulation and erosion are closely tied to the formation and re-oxidation of pyrite, we use a high resolution record of sulfur isotope ratios (34S=32S) of marine sulfate to evaluate the implications of the so called "shelf sediment offoading" on the global sulfur cycle. Modeling of our δ34S record suggests that erosion during sea level lowstands was only partly compensated by increased sedimentation during times of rising sea level and sea level highstands. Furthermore, our data suggests that shelf systems reached a new equilibrium state about 700 kyr ago, which considerably slowed or terminated shelf sediment offoading. [ABSTRACT FROM AUTHOR]

This paper presents a recently developed Operational Forecast Platform (OFP) for prevailing sea conditions at very important ports worldwide (Accu-Waves). The OFP produces reliable high-resolution predictions of wave characteristics in and around ocean ports. Its goal is to support safer navigation, predict possible port downtime, assist vessel approaching, enhance management of towing services, and bolster secure ship maneuvering in busy ports around the globe. Accu-Waves OFP is based on integrated, high-resolution wave modelling over the continental shelf and in coastal areas that incorporates data from global- and regional-scale, open-sea wave and ocean circulation forecasts as boundary conditions. The coupling, nesting, calibration, and implementation of the models are reported and discussed in this paper, concerning 50 selected areas near and inside significant port basins. The detailed setup of the Accu-Waves OFP and its sub-system services is also provided regarding three-day forecasts at three-hourly intervals. The validation of the wave forecast system against in situ observations from wave buoys in coastal areas of the USA, Belgium, and Spain, as well as other model predictions by established OFPs, seems very promising, with performance skill scores ranging from adequate to very good. An exceptional case of stormy seas under severe marine weather conditions with very high wave maxima (>10 m) in the port of Algeciras is further discussed, confirming the good performance of the Accu-Waves OFP. [ABSTRACT FROM AUTHOR]

The presence of a late Quaternary ice sheet/ice shelf over the East Siberian Sea has been proposed in several papers. Here, we further document its duration/resilience based on the sedimentary, bulk mineralogical, and geochemical (organic matter content and its stable isotopic composition, U‐Th series) properties of a core raised from the southernmost Mendeleev Ridge. The chronostratigraphy of the studied core was mainly built from the 230Th excess (230Thxs) distribution and decay downcore. At the core‐top, peaking 230Thxs values during the early MIS 3 and mid‐MIS 1 encompassing an MIS 2 hiatus were observed. As documented in several papers, these peaks suggest seasonally open ice conditions over proximal continental shelves. Below, the interval spanning MIS 4 and possibly MIS 5d records major ice‐rafting events illustrated by overall high coarse‐fraction contents. Underlying MIS 5e, down to MIS 11, the sediment depicts relatively low sand (1.7±2.5 dw%), high clay (33.5±4.7 dw%), and very low organic carbon (0.10±0.06 dw%) contents, and low δ13Corg values (−24.3±0.9‰). This section is interpreted as recording fine sediment transport by deep currents and/or meltwater plumes below a resilient ice cover, only interrupted by a few short‐duration events. These events include (i) detrital carbonate pulses assigned to deglacial events along the NW Laurentide Ice Sheet margin (Termination (T) III), and (ii) intervals with some planktonic foraminifer occurrences, likely relating to their advection from open areas of the Arctic Ocean (MIS 5e, 9 and 11). All Terminations, but TII and the early MIS 3, show peaking Mn/Al values linked to the submergence of Arctic shelves under a rising sea level. We conclude that the resilient ice cover, likely an ice shelf, has been present over the southern Mendeleev Ridge during most of the interval after the Mid‐Pleistocene Transition and was favoured by the low summer insolation of the MIS 14 to 10 interval. [ABSTRACT FROM AUTHOR]

Seasonal sea-ice cover has been decreasing in the southeastern Bering Sea shelf, which might affect ecosystem dynamics and availability of food resources to marine top predators breeding in the region. In this study, we investigated the foraging responses of two seabird species, surface-foraging red-legged kittiwakes Rissa brevirostris (hereafter, RLKI) and pursuit-diving foraging thick-billed murres Uria lomvia (TBMU) to the inter-annual change in environmental conditions. Between the study years, winter ice retreated earlier and summer water temperatures were warmer in 2014 compared to those in 2013. At-sea distributions of RLKI and TBMU breeding on St. George Island, the largest seabird colony in the region, were recorded using GPS loggers, and blood samples were taken to examine their physiological condition and isotopic foraging niche in a given year. RLKI foraging occurred mostly over the oceanic basin in both years. TBMU, however, foraged mostly over the shelf, but showed a relatively higher use of the shelf break and oceanic basin in the colder year, 2013. The foraging distances from the colony peaked at 250-300 km in 2013 and, bimodally, at 150-250 and 300-350 km in 2014 for RLKI, and tended to be farther in 2013 compared to those in 2014 for TBMU. Plasma levels of corticosterone did not differ between years in RLKI, but differed in TBMU, showing higher levels of physiological stress incurred by murres during the colder year, 2013. d13N (a proxy of trophic level of prey) did not differ between the years in either RLKI or TBMU, while d13C (a proxy of prey origin) were lower in 2014 than in 2013 in both species, suggesting possible differences in influx of oceanic prey items into foraging areas. These results suggest that the response of ecosystem dynamics to climate variability in the southeast Bering Sea may differ between the ocean basin and continental shelf regions, which, in turn, may generate differential responses in seabirds relying on those habitats for foraging. [ABSTRACT FROM AUTHOR]

This paper recommends end to end quality assurance methods and quality control tests for High Frequency Radar Networks. We focus on the network that is operated by the Mid Atlantic Regional Association Coastal Ocean Observing System (MARACOOS). The network currently consists of 38 radars making real-time measurements of the surface currents over the continental shelf for a variety of applications including search and rescue planning, oil spill trajectory modelling and providing a transport context for marine biodiversity observing networks. MARACOOS has been delivering surface current measurements to the United States Coast Guard (USCG) since May 2009. Data quality is important for all applications; however, since the USCG uses this surface current information to plan life-saving missions, delivery of the best quality data is crucial. We have mapped the components of the HF radar data processing chain onto the data levels presented in the NASA Earth Science Reference Handbook and have applied quality assurance and quality control techniques at each data level to achieve the highest quality data. There are approximately 400 High Frequency radars (HFRs) deployed globally and the presented techniques can provide a foundation for data quality checks and standardization of the data collected by the large number of systems operating today. [ABSTRACT FROM AUTHOR]

Different timescale contributions to the sea‐level variation in the South China Sea (SCS) are evaluated in this paper. On seasonal timescale, the large variance of the sea‐level anomaly (SLA) could account for more than 70% of the monthly sea‐level variation in the western shallow continental shelf and the area of Luzon cold eddy. Besides, the seasonal explained variance percentage (skill) has 2 weak centres (50%–70%) off eastern Vietnam, which is related to the summertime eddy pair in the SCS. On interannual‐to‐decadal (low‐frequency) timescale, the skill has two large‐value regions (Zone A and Zone B). Zone A is characterized by double centres off eastern Vietnam, but the meridional position of the double centres is farther north than that of the eddy pair. The skill in Zone A is in the range of 35%–55%, and about 50%–70% of the low‐frequency variation comes from the steric effect. Zone B is off the west coast of the Philippines. The skill in Zone B increases southward, and it is dominated by the wind‐induced dynamic process which is attributed to the remote Rossby wave from the tropical Pacific. Based on the S‐EOF analysis, the SEOF‐1 mode mainly portrays the decadal variation of the SLA, while the SEOF‐2 mode reflects the interannual variation of the SLA. In Zone B, almost all of the low‐frequency variation could be attributed to ENSO and PDO, especially to PDO which has a larger contribution. However, the double centres in Zone A are governed by the SCS summer monsoon, instead of ENSO and PDO. [ABSTRACT FROM AUTHOR]

Our paper deals with gas-geochemical measurements of CH4 and CO2, as well as the first measurements of dissolved H2 and He in the waters of the eastern shelf of Sakhalin Island, obtained during cruise 68 on the R/V Akademik Oparin (OP68) on 12–18 August 2023. The shallow eastern shelf has high concentrations of dissolved methane and helium in the water. The combined anomalies of methane and helium indicate the presence of an ascending deep fluid. The sources of methane in the studied area are the underlying oil- and gas-bearing rocks extending to the coast of the island. The deep faults of the region and the minor discontinuities that accompany them along the eastern coast of Sakhalin Island create a fluid-permeable geological environment both on the shallow shelf and on the coastal part of the island. East Sakhalin current and counter-current influence gases that migrate from lithospheric sources; these currents form a special hydrological regime that ensures high solubility of the gases released and their transfer under the lower boundary of the seasonal pycnocline to the east, where they are involved in the general circulation of the Sea of Okhotsk. [ABSTRACT FROM AUTHOR]

The Cambrian pre-salt dolomite sequence in the Tarim Basin is a target zone of great strategic significance for hydrocarbon exploration in the basin. Using the results of the interpretation of 3D seismic data from Lunnan and 2D seismic data covering the whole basin, and based on a synthesis of outcrop data, drilling data, well logs, core data, and thin-section data, and the findings from previous studies, this paper studies the characteristics of the facies of the Middle–Lower Cambrian in the platform area in the Tarim Basin, the formation and evolution of platform margins, and the sedimentary characteristics, lithofacies, and paleogeographic characteristics of the Middle–Lower Cambrian series. Based on the types of lithofacies and the seismic facies analysis, the sedimentary facies of the Middle–Lower Cambrian strata can be classified into the five types. From bottom to top, the Middle–Lower Cambrian have experienced several development stages, including the deposition of continental shelf sediments of the Yuertusi Formation, gently sloping non-rimmed platform margin sediments of the Xiaoerbulake Formation, weakly rimmed platform margin sediments of the Wusongger and Shayilike formations, and strongly rimmed platform margin sediments of the Awatage Formation. In each stage, the platform margin shifted further east relative to its location in the previous stage. Based on these results and previous studies, the lithofacies and paleogeography maps of the Middle–Lower Cambrian in the Tarim Basin are modified, and the implications for hydrocarbon exploration in this area are discussed. [ABSTRACT FROM AUTHOR]

This paper presents two metazoan zooplankton datasets obtained by imaging samples collected on the Bay of Biscay continental shelf in spring during the PELGAS (PELagique GAScogne) integrated surveys over the 2004–2019 period. The samples were collected at night with a 200 µm mesh-size WP2 net fitted with a Hydrobios (back-run stop) mechanical flowmeter and hauled vertically from the sea floor to the surface, with the maximum depth set at 100 m when the bathymetry was deeper than this. The first dataset originates from samples collected from 2004 to 2016 and imaged on land with the ZooScan and is composed of 1 153 507 imaged and measured objects. The second dataset originates from samples collected from 2016 to 2019 and imaged onboard the R/V Thalassa with the ZooCAM and is composed of 702 111 imaged and measured objects. The imaged objects are composed of zooplankton individuals, zooplankton pieces, non-living particles and imaging artefacts ranging from 300 µm to 3.39 mm in equivalent spherical diameter which were individually imaged, measured and identified. Each imaged object is geolocated and associated with a station, a survey, a year and other metadata. Each object is described by a set of morphological and grey-level-based features (8 bit encoding, 0 = black, 255 = white), including size, that were automatically extracted from each individual image. Each object was taxonomically identified using the web-based application Ecotaxa with built-in random-forest and CNN-based semi-automatic sorting tools, which was followed by expert validation or correction. The objects were sorted into 172 taxonomic and morphological groups. Each dataset features a table combining metadata and data at individual-object granularity from which one can easily derive quantitative population and community descriptors such as abundances, mean sizes, biovolumes, biomasses and size structure. Each object's individual image is provided along with the data. These two datasets can be used in combination for ecological studies, as the two instruments are interoperable, or they can be used as training sets for ZooScan and ZooCAM users. The data presented here are available at the SEANOE dataportal: 10.17882/94052 (ZooScan dataset, Grandremy et al., 2023c) and 10.17882/94040 (ZooCAM dataset, Grandremy et al., 2023d). [ABSTRACT FROM AUTHOR]

The Malay states remain sovereign from the pre-Federation of Malaya in 1957 until today. They acquired external sovereignty through international recognition via membership of Malaya in the United Nations. International law recognises Malaysia's continental shelf, a federation comprising a few coastal states under UNCLOS 1982. A local issue close to this subject is the Malay states’ rights in the Federation of Malaysia over petroleum production within the continental shelf adjacent to their territorial waters. Hence, this paper examines a Malay state's rights over Malaysia's continental shelf. This study is a qualitative legal analysis using a case study design promoting the method of watanic jurisprudence. Therefore, the Federal Constitution, UNCLOS 1982, and various statutes are analysed to answer many related issues beforehand. This paper has found that the territorial waters of the Malay states cannot be limited to three nautical miles from the low tide line in pursuance of the Territorial Sea Act 2012 without strict compliance with Article 2 of the Federal Constitution. The legitimacy of the territorial limits of the Malay states' waters is essential as it determines their rights to the continental shelf and its petroleum production. [ABSTRACT FROM AUTHOR]

There are distinct bodies of cultural knowledge attached to the sea. In this paper we orient the focus towards the nature and extent of cultural framings of sea territories, as inclusive of submerged landscapes, for Indigenous maritime peoples in northern Australia. This approach is distinguished by a pluralist methodology and reorients the primal focus of a human geography and broader geographical scholarship concerning submerged landscapes to begin with an Indigenous perspective. Engaging ethnographic accounts of Indigenous Australian knowledges of Sea Country, as inclusive of ancient pre‐inundation landscapes that lie out‐of‐sight on Australia's continental shelves, highlights the potential for a more expansive vision of human connections to the past and present continental landmass of Australia. Indigenous oral traditions, Dreaming Ancestor narratives and songlines provide extensive detail to assist in understanding these parts of the greater Australian landmass and in this paper are brought into relation with recent sea floor mapping efforts which operate to draw back the water and reveal commensurable geographies upon which to envision possibilities for socialised realms of human emplacement. Both bodies of knowledge generate information of submerged landscapes that call for an expansion of thinking on where the land ends and the sea begins and how submerged terrestrial landscapes are understood across cultures as part of human geography. The approach outlined here calls for a habit of bringing principled systems of understanding to stand together as part of an explanatory schema for a world populated by and yet differentially known by people. [ABSTRACT FROM AUTHOR]

Simple Summary: This is the first study to investigate the spatial distribution and population structure of the tub gurnard (Chelidonichthys lucerna) in different regions of the northeast Atlantic. To analyze fish body shape, a morphometry-based method, which helps identify variations in fish body shape that may exist due to genetic factors or environmental adaptability, was used. This study relied on C. lucerna individuals captured in the following three fishing areas: Conwy Bay (United Kingdom), Biscay Bay (Spain) and Matosinhos (Portugal). The findings indicate the existence of significant regional differences in fish bodies, thus highlighting the existence of distinct fish populations in the three regions. Results also suggest that the Spanish and British populations may inhabit similar habitats, as some similarities in body shape were found. To confirm these findings, we recommend future research using a holistic approach with alternative and complimentary stock assessment tools. The study of geometric morphometrics among stocks has proven to be a valuable tool in delineating fish spatial distributions and discriminating distinct population units. Variations in fish body morphology can be linked to genetic factors or to phenotypic adaptability in response to environmental variables. The tub gurnard (Chelidonichthys lucerna) is a demersal species that usually lives in the bottom of the continental shelf, being widely distributed along the northeast Atlantic, Mediterranean and Black seas. Worldwide interest in the species has increased since 2006, when ICES recognized its potential for commercial exploitation. However, despite its broad geographic occurrence, to date, research on C. lucerna population structure at large spatial scales is still lacking. In this paper, body geometric morphometrics, using a landmark-based truss network, was applied in order to discriminate C. lucerna populations caught in three different fishery grounds areas along the northeast Atlantic: Conwy Bay (United Kingdom), Biscay Bay (Spain) and Matosinhos (Portugal). The results obtained in this study revealed a high overall relocation success (95%) of samples to their original locations, thus demonstrating the existence of significant regional differences and indicating that we are dealing with different fish population units. Moreover, the data revealed a partial overlap between individuals from Spain and United Kingdom, suggesting that in geographically distant areas these populations may inhabit similar environments. However, to corroborate these findings, future works using a holistic approach with alternative and complimentary stock assessment tools (e.g., genetic and phenotypic natural tags) are highly recommended. [ABSTRACT FROM AUTHOR]

This paper accompanies the Maps of Geohazard features of the Cilento and the Calabro- Tyrrhenian continental margin in the southern Tyrrhenian Sea (Italy). The main geohazardrelated features were derived from extensive seafloor mapping through the collection of high-resolution multibeam data acquired during several oceanographic cruises. They encompass many fluids seepage features, fault scarps, landslides scars, gullies, channels, and canyons. Hazards related to coastal landslides and shelf-indenting canyons are very high in these sectors (especially in southern Calabria) due to active seismicity coupled with rapid uplift, high sedimentation rates and narrow or totally absent continental shelf, thus promoting a direct connection between steep slopes and coastal areas. In this setting, masswasting features can directly impact coastal or submarine infrastructures or indirectly create local tsunami waves, as observed in historical times. Moreover, this physiographic setting of the margin facilitates the transfer of marine litter toward deep-sea areas. [ABSTRACT FROM AUTHOR]

The MaGIC project (Marine Geohazard along the Italian Coasts) had the aim of mapping the geohazard in the Italian seas and resulted in the production of numerous maps covering parts of the Italian Seas. In this paper, we present the maps: 'The submerged portions of the Aeolian volcanic islands and the north-eastern Sicilian margin', located in the south-eastern Tyrrhenian Sea. Both areas are affected by active geological processes, which represent important geohazards elements. Inthe submarine parts of the Stromboli volcanoremobilization of volcaniclastic deposits occur along the Sciara del Fuoco, where small-scale instabilities may represent a source of geohazard. Hydrothermal activity occurs on Enarete and Enaretino conical seamounts. The north-eastern Sicilian margin has a narrow continental shelf. Numerous canyon heads indent the shelf and, sometimes, reach close to the coast. Canyons have often a retrogradational trend and further eventual landward shift through sliding can iendangeri coastal or offshore infrastructures. Many of the canyons connect with leveed channels with widespread sediment instability. In the Gioia Basin, some of the channels connect to form the Stromboli slope Valley. Volcanic unrest or local and regional earthquakes are proven to have caused submarine landslides and tsunamis. [ABSTRACT FROM AUTHOR]

Canada ratified the United Nations Convention on the Law of the Sea (UNCLOS) in 2003. With that ratification is an obligation to submit data and information to the U.N. pertaining to the limits of the country's extended continental shelf (ECS); the portion of the juridical continental shelf that extends beyond 200 nautical miles. A team of Canadian scientists, managers, and legal experts that included representation from three Federal Departments (Natural Resources Canada, Fisheries and Oceans Canada, and Global Affairs Canada) with additional support from other departments, spent 13 years compiling and acquiring data to provide the scientific evidence to support delineation of Canada's seaward most maritime limit. The submission has the potential to provide Canada with 2.4 million km2 of additional submarine landmass in the Atlantic and the Arctic oceans over which Canada exercises sovereign rights for the purpose of exploring and exploiting its natural resources. Specific information such as the tectonic framework of the continental margin, the geomorphology of the margin and in particular the continental slope, the geologic nature of adjoined ridges, rises, and plateaux, and sediment thickness within adjacent basins are examples of fundamental pieces of geoscientific information needed to substantiate Canada's outermost maritime limits. This paper highlights a number of segments of Canada's continental margins to showcase this scientific evidence and how it is applied in the UNCLOS context. In doing so, the paper demonstrates the geologic complexity of Canada's margins as illustrated in scientific publications that have resulted from these new data collections, while at the same time presenting new scientific evidence and interpretations. This collection of data and information provides a wealth of new knowledge in Canada's offshore regions. The massive data compilation in the Atlantic led to conception of continental margins, in a source-to-sink scenario, as having an equilibrium base level or graded form, comparable to river systems. Departures from this shape relate to the interplay of sedimentary processes and in particular to those processes that do not fit the source-to-sink paradigm. For example, a significant part of the Atlantic margin is shown to be heavily influenced by along-slope geostrophic currents that generated massive contourite drift deposits. These deposits reflect lateral transport of sediment that had a significant impact on the morphology of the margin. The role of mass transport processes in shaping continental margins is also highlighted, and in particular the collapses of entire segments of the margin were observed. The prominent role mass failure processes play in delivering sediment to the adjacent abyssal plain is also critical in the ECS context. These observations challenge the entrenched notion of a continental margin comprising a shelf, slope, and rise and in particular the concept of the "continental rise". Prior to 2006, regions of the Arctic Ocean seaward of the Canadian landmass had fewer than 5000 km of seismic reflection data. The massive efforts of Arctic coastal States to map their margins for ECS purposes have led to a leap in technological advances to acquire data in ice-covered seas and have led to a wealth of new geoscientific knowledge. Perhaps foremost amongst this knowledge is demonstration that Canada Basin is indeed a fully developed ocean basin, albeit significantly infilled with sediment. Based on this knowledge and identification of related structures, new realistic tectonic scenarios for opening of the Amerasia Basin are proposed that include a significant component of transform or strike-slip motions. With seismic velocity and rock sample information, the continental nature of Alpha and Mendeleev ridges has been substantiated. Even bathymetric data were lacking in the Arctic and new editions of seafloor maps now support grids of 500 m spacing; although some regions remain sparse. Once thought to be relatively stagnant, sedimentary processes such as found in many ocean basins were discovered in the Arctic Ocean. Evidence of geostrophic currents, sediment mass failures, and deep-sea turbidity current channels were found to be ubiquitous, even in the deepest parts of the Arctic's basins. [ABSTRACT FROM AUTHOR]

The Rockall Trough (RT) accommodates the warmest and saltiest branch of the North Atlantic Current, which delivers water from the Gulf Stream into the marine environment around western Europe. In addition, the European Slope Current (ESC) carries warm water northward along the eastern boundary of the RT, and exchange between the ESC and the continental shelf is a dominant factor in determining the oceanographic conditions around the British Isles. However, the picture of the mean circulation and variability in the RT is still emerging, with a continuous observational campaign still in its relative infancy. The ESC, in particular, is poorly constrained by ship‐based, mooring, and satellite observations. In this paper, we examine the RT circulation and volume transport using a temporally extended and spatially expanded observing network. Six years of continuous mooring occupation reveal that a large‐amplitude, basin‐scale freshening event, previously detected south of Iceland around 2015, impacted the RT around 2017. Geostrophic transport was greatly reduced during this period, driven by a concurrent subsurface temperature increase at the western boundary. The circulation regained strength during the latter part of the record. We gathered 110 glider transects over 22 months which capture the ESC velocity field in unprecedented detail. The data are sufficient to characterize both the mean state and the emergent seasonal variability of the ESC, and reveal the year‐round presence of a southward countercurrent at depth. Variability in the strength and structure of this previously unstudied feature modulates net northward transport in the eastern boundary current system. Plain Language Summary: The Rockall Trough (RT) is a key pathway for warm and salty water flowing northward, a process which plays a key role in dictating the western European climate. However, the amount of water flowing northward, and how it changes over time, is still rather uncertain. In particular, the narrow boundary current in the eastern RT has previously proven difficult to measure. In this paper, we use 6 years of continuous oceanographic observations in the RT to monitor the flow. We also used underwater robots, called gliders, to focus on the narrow current in the eastern boundary. The data gathered give the best description of the ocean currents in the region to date. The study period coincided with a period of profound change across the subpolar North Atlantic, with a strong freshwater signal detected in the RT around 2017. The glider observations give a detailed view of the narrow eastern boundary current and how it varies seasonally, and also revealed the presence of a southward‐flowing current at depth. Key Points: Eastern boundary current system captured in unprecedented detail using 22 months of near‐continuous glider observationsLarge‐scale freshening event in subpolar North Atlantic impacted Rockall Trough (RT) around 2017Interannual variability in poleward transport driven by subsurface temperature anomalies at the western flank of the RT [ABSTRACT FROM AUTHOR]

This paper provides first information about possible occurrence of the myxosporean genus Kudoa in fish of the World Ocean and, in some cases, in associated freshwater bodies at different depths. An analysis of the theoretically assumed site preference by Kudoa of different habitat depths of their fish hosts in the World Fauna is made for the first time. It is revealed that all species of the myxosporean genus Kudoa can be found in coastal shelf zones, of which 90 species (70.8% of the total) occur exclusively in the shelf zone, and the hosts of 50 Kudoa species (39.4%) live in its shallowest part (down to 50 m). 16 species (12.6%) and 14 species (11%) of this genus can be found at depths from the shelf to 500 meters and 1000 meters, respectively. From 1 to 3 species of Kudoa can be encountered theoretically at 1500 m to 3000 m, which is from 0.8 to 2.4% of all known representatives of these parasites. [ABSTRACT FROM AUTHOR]

Intense methane emission from permafrost soil into the atmosphere has long been observed in Arctic shelf and coastal zones. Due to the potential danger of this phenomenon for the environment and infrastructure, there is a need for periodic monitoring of gas pockets, including by means of land seismic exploration. In the present paper, this process is studied using numerical simulation methods. In order to reflect the main specific features of the region, a model of layered permafrost sandy soil with curved boundaries between the layers is constructed. Vertical and horizontal gas migration is represented by an increase in the number of methane reservoirs. The hyperbolic equations of linear elasticity are used as a governing system. The problem is solved by applying the grid-characteristic method in the two-dimensional case. The elastic parameters of the layers are specified in each grid cell. Wave structures exhibited by the resulting synthetic wave patterns and seismograms are analyzed in detail, allowing the direction of gas migration to be determined. The results can be used to interpret similar in situ measurements. [ABSTRACT FROM AUTHOR]

A brief account of the achievements of the AUSCAN cruise is presented together with an extensive list of published papers resulting from this cruise. Many of these papers provide considerable detail about the link between marine and continental records, many of which span the entire last glacial cycle (MIS 5e - MIS 1). The second part of the paper argues that a large estuary to the north of the River Murray mouth during the early Holocene, postulated by Helfensdorfer et al. (2019, 2020) requires scrutiny because their postulated sealevel reconstruction is flawed. In addition, the extensive deposition of sediments dammed near the mouth of the River Murray thought by these authors to have prevented the dispersal of fluvial sediments to the continental shelf and slope is unfounded. [ABSTRACT FROM AUTHOR]

In this paper we evaluate new data and those from previous studies in northwest Scotland and perform a modelling study to test the hypothesis that the Storegga tsunami (submarine slope failure off the continental shelf of Central Norway dated to 8120–8175 bp) impacted this region. The model used is a 2D non‐linear, non‐conservative, Shallow Water Equation solver incorporating inundation and realistic glacial isostatic adjustment‐corrected palaeobathymetry, with horizontal resolution down to 30 m at sites of interest. The 15 coastal study sites analysed range from south of the Isle of Skye to Assynt. We predict run‐up between 2.7 and 9.4 m above contemporaneous mean tide level across the region, with the highest on the west coast of the Outer Hebrides, the east coast of Skye and at the head of long sea lochs east of Skye. We re‐evaluate evidence from previously studied open coastal marshes, isolation basins and barrier locations for the tsunami and suggest that in many locations the Storegga tsunami is the most likely cause of erosion, deposition and changes in microfossil assemblages in the early Holocene. The predictions of wave height and inundation produced by the tsunami modelling fit well with the range of available field evidence in the region. We predict significant wave heights at least as far south as Mull on the west coast. [ABSTRACT FROM AUTHOR]

The internal structure and architecture of evaporite sequences is often overlooked, with attention frequently concentrating on the external geometries that salt bodies form. The availability of extensive 3D seismic data affords the opportunity to interpret the internal structures within these evaporite sequences and comprehensively characterise the different structural facies over large areas. This paper concentrates on the Zechstein Supergroup evaporite deposits within the Southern North Sea of the United Kingdom's Continental Shelf. This analysis of the internal structural complexity and stratigraphic heterogeneity utilises 26,000 km2 of 3D seismic data together with over 96 wells from the Southern North Sea. Characterisation of the different structural facies present was undertaken alongside mapping their spatial distribution to understand the relationship they have with one another and the structural evolution that may have been taken. This work has (1) characterised and mapped six different internal structural facies present within the Zechstein with increasing levels of deformation; (2) shown the internal lithological heterogeneity is indicative of variations in the vertical strength profile of layered evaporite sequences; (3) discontinuous high‐amplitude reflections within the Zechstein are as a result of the geometries being too steeply dipping for the seismic data to image; and (4) the ability to possibly predict the internal heterogeneity of areas of poorly imaged salt, such as within large diapiric salt structures, from surrounding structural facies. These findings suggest that there is significant internal complexity even within areas of the basin with minor mobilisation to the external salt geometry. [ABSTRACT FROM AUTHOR]

The paper is devoted to the assessment and forecast of the occurrence of submarine landslides on the shelf of southeastern Vietnam. The prediction is based on the analysis of the existence of slip tendency on known faults, studying the magnitude of possible relative vertical and horizontal displacements in the Earth's crust, considering the slope steepness of bottom relief and surface of landslide deposits, as well as assessing the probability of reactivation of faults and likely earthquake zones. The results of the study allow making decisions on combating submarine landslides, reducing damage to people and property in coastal areas. Based on the information obtained, not only submarine landslides but also other geological hazards in areas of the Vietnamese continental shelf can be predicted. [ABSTRACT FROM AUTHOR]

The east coast of India is highly prone to devastating winds, torrential rainfall, and storm surges caused by tropical cyclones. The storm surge is affected by ocean basin characteristics involving the width and slope of the continental shelf. The bed roughness plays a major role in surge formation. The east coast of India is characterized by a broader shelf in the north and a narrow shelf in the south. This paper uses a hybrid Finite Volume Method–Finite Element Method based Shallow water equation (SWE) solver to predict the storm surges during different cyclone events, and the roughness parameter Manning's n is used in bed friction calculations. The bottom friction coefficient parameterization involving bed roughness is used to calibrate the resistance to flow in the numerical model. The calibration exercises are carried out with different values of n for each surge simulations for different cyclones to predict the surface elevation. Different statistical parameters against the measured values are used to analyze the impact of varying n values on predicted surge levels, and the most suitable n value is carefully chosen. The relationship between n and the bed slope is established as an expression, to replace the formulations involving Manning's n, thereby minimizing the usual computational efforts. The performance of the novel bed friction formulation involving the physical parameter in bed slope is demonstrated through statistical evaluations. [ABSTRACT FROM AUTHOR]

Antarctic coastal polynyas produce dense shelf water, a primary source of Antarctic Bottom Water that contributes to the global overturning circulation. This paper investigates Antarctic dense water formation in the high-resolution version of the Energy Exascale Earth System Model (E3SM-HR). The model is able to reproduce the main Antarctic coastal polynyas, although the polynyas are smaller in area compared to observations. E3SM-HR also simulates several occurrences of open-ocean polynyas (OOPs) in the Weddell Sea at a higher rate than what the last 50 years of the satellite sea ice observational record suggests, but similarly to other high-resolution Earth system model simulations. Furthermore, the densest water masses in the model are formed within the OOPs rather than on the continental shelf as is typically observed. Biases related to the lack of dense water formation on the continental shelf are associated with overly strong atmospheric polar easterlies, which lead to a strong Antarctic Slope Front and too little exchange between on- and off-continental shelf water masses. Strong polar easterlies also produce excessive southward Ekman transport, causing a build-up of sea ice over the continental shelf and enhanced ice melting in the summer season. This, in turn, produces water masses on the continental shelf that are overly fresh and less dense relative to observations. Our results indicate that high resolution alone is insufficient for models to properly reproduce Antarctic dense water; the large-scale polar atmospheric circulation around Antarctica must also be accurately simulated. [ABSTRACT FROM AUTHOR]

The lack of suitable indicators of changes in such as sea‐level and circulation has been a major limit to paleoenvironmental and paleoceanographic investigations in continental shelf regions. This paper presents an environmental magnetic study by comparing two late‐Quaternary sediment cores (DH02 and DH03) from the outer shelf of the East China Sea (ECS). Late and early Marine Isotope Stage (MIS) 3 sediments were deposited in a prodelta under cold coastal currents and an open‐shelf with the Taiwan Warm Current and upwelling. The dominant iron‐bearing minerals of the late and early MIS 3 sediments are authigenic greigite (Fe3S4) and pyrite (FeS2), respectively, which were assumed to be formed nearly syndepositionally. The overlying sediments, however, are magnetically dominated by detrital magnetite. This pattern corresponds well to the temporal changes in sea‐level over this period. The widespread occurrence of greigite in the late MIS 3 sediments can also be used for future stratigraphic division and correlation in the ECS. Additionally, compared to microfossil assemblages, rock magnetic parameters based on greigite may be more sensitive to environmental changes on continental shelves. Furthermore, the inter‐borehole spatial comparisons imply not only a sedimentary hiatus/erosion of at least 30‐m thickness in core DH02, most probably during the Last Glacial Maximum, but also that core DH02 was in a more reductive environment than core DH03 during late MIS 3. The findings highlight the potential of authigenic greigite as an indicator of spatiotemporal changes in paleoenvironmental and paleoceanographic conditions on the continental shelf at orbital or even suborbital timescales. Plain Language Summary: Environmental and oceanographic conditions on continental shelves are vital for sedimentation processes and human settlements, but the reconstruction of their evolution is hindered by the lack of effective indicators. Recent studies have indicated that syndepositional formation of greigite, a precursor to pyrite, is highly likely in shallow‐water environments with rapid sedimentation. Here, two sediment cores meridionally traversing the outer shelf of the East China Sea were investigated. The magnetic mineral assemblage and sedimentary environment exhibited almost identical change patterns, with pyrite, greigite, and magnetite as the major magnetic minerals of the early and late Marine Isotope Stage 3, and Last Glacial Maximum/last deglacial deposits, respectively. This agreeably reflects the temporal fluctuations in sea‐level and ocean circulation. By comparing the two cores, the spatial characteristics of stratigraphy and redox conditions could be determined clearly. This study thus provides a good reference for paleoenvironmental and paleoceanographic research based on authigenic greigite in continental shelf sediments. Key Points: Greigite was further confirmed as the major magnetic mineral of the late Marine Isotope Stage 3 deposits widespread on the outer shelf of the East China SeaSpatiotemporal changes in environmental and oceanographic conditions on the continental shelf are well revealed by greigite‐based parametersAuthigenic greigite can serve as a sensitive indicator for paleoenvironmental and paleoceanographic studies in continental shelf regions [ABSTRACT FROM AUTHOR]

In this paper, the physiography, geomorphological features, and sedimentary bedforms of the offshore Egadi Islands (Italy) have been illustrated and mapped through an integrated analysis of high-resolution bathymetric, seismo-acoustic, and sedimentological data. The study area is characterized by a wide, up to 25 km, continental shelf which is separated by a NNW-trending linear incision, the Marettimo Channel, along which several erosional and depositional features have been detected and mapped. Sedimentary prograding wedges were detected at water depths between 100–125 m along the shelf margin, which accumulated during the sea-level fall and lowstand stages of the last glacio-eustatic cycle (post- MIS 5.5). This study detected several slope breaks defining scarps across the continental shelf, which were interpreted as coastal cliffs that originated during the post-LGM eustatic sea-level rise. Several fields of different types of sedimentary bedforms, including 2-D and 3-D hydraulic dunes and sorted bedforms, were found across the continental shelf, providing evidence of a high hydrodynamic regime affecting the seafloor. Further on, this study recognized erosive and depositional features related to bottom currents (contourites) in the Marettimo Channel. These findings provide a better understanding of the morpho-sedimentary evolution of the Egadi Islands offshore in the latest Quaternary. Moreover, they offer essential scientific support for effectively managing the most valuable priority habitats for conservation, such as the Posidonia oceanica meadow and coralline algae bioconstructions (Coralligenous habitat). [ABSTRACT FROM AUTHOR]

Design criteria, and risk evaluation for marine structures, over continental shelf and slope might be affected by currents associated with internal waves. The derivation of design criteria requires long time series of currents at very high sampling rates commonly not available. Therefore, methodologies to derive those time series are required. In this paper, an approach based on numerical modelling is proposed as a proof-of-concept. The Sulu Sea was selected to test the capability of the model to simulate those currents. Model results were compared to data available in the literature. The currents and other properties such as travelling time, wavelength, period and number of waves per packet are within the range of observations. [ABSTRACT FROM AUTHOR]

(Series Information) European Papers - A Journal on Law and Integration, 2020 5(3), 1511-1530 | European Forum Insight of 4 November 2020 | (Table of Contents) I. Introduzione. - II. La divisione dell’Isola di Cipro e il non riconoscimento della Repubblica turca di Cipro del nord. - III. Gli accordi di delimitazione della piattaforma continentale e/o della ZEE conclusi da Cipro, Turchia e Grecia e le attività illecite condotte dalla Turchia. - IV. La reazione coesa dell’Unione europea alle attività illecite turche. - V. Le particolarità delle misure restrittive dell’Unione contro uno Stato candidato all’adesione all’UE ma distante da essa. - VI. Quale ruolo diplomatico per l’Unione europea nel contesto della crisi del Mediterraneo orientale? | (Abstract) This Insight examines the EU’s reaction to the breaches of the territorial sovereignty of Cyprus and Greece by Turkey in the context of the crisis of the Eastern Mediterranean sea which developed between 2019 and 2020. The EU has reacted by adopting restrictive measures against two Turkish nationals responsible for drilling operations authorised by Turkey in the territorial sea and in the exclusive economic zone of the Republic of Cyprus. The individual restrictive measures examined in this paper are adopted for the first time against a candidate to the EU membership and a NATO member in order to protect the sovereign rights of one its Members, namely the Republic of Cyprus. The territorial dispute between the latter and Turkey, on the exercise of sovereignty over the marine areas around the island of Cyprus has extended to Greece due to the sismic activities carried out by Turkey vessels in waters included in the Greek continental shelf. Turkey, which is not part of the UNCLOS, has also delimited the continental shelf with Libya and has an interest in exploiting the natural resources on the continental shelf of both Greece and Cyprus. This contribution illustrates the various diplomatic initiatives taken to solve the territorial disputes and reflects on the diplomatic role that the EU may play in order to settle the dispute between the Parties.

The role of the short-lived 134Cs radionuclide in the formation of the radioecological background in the marine environment of the Arctic is studied. This paper analyzes the data collected during long-term observations of the Murmansk Marine Biological Institute, Russian Academy of Sciences, on the levels of the 134Cs radioisotope in the marine and coastal environments of the Barents and Kara seas, including the high-latitude archipelagos: soils, lichens, algae, fish, seawater, and bottom sediments. The geography of the 134Cs distribution in marine and coastal environments is also examined, and the acting and potential sources of transport of this radioisotope into marine ecosystems of arctic seas are identified. 134Cs is rarely included among radioactive contaminants nowadays, and its specific radioactivity is insignificant. Its short half-life makes it a marker of the contamination that happened recently, such as the emissions from the Fukushima-1 nuclear power plant and local sources in the region studied. The possile local sources in the Barents and Kara seas are nuclear-powered fleet facilities and glaciers of high-latitude archipelagos. Findings of 134Cs in some samples of modern bottom sediments for fjords of the Svalbard Archipelago and its outer continental shelf suggest 134Cs transport with meltwater from the Svalbard glaciers. This paper provides data on the modern background of the 134Cs specific radioactivity in the Barents and Kara seas. In the case when an increase in these background levels is detected, an immediate search for the sources of 134Cs entry into the environment must be undertaken. [ABSTRACT FROM AUTHOR]

A comprehensive review of state of the art numerical modeling in the field of sea bed morphology during cyclonic events is of vital importance. In this study a high impact and devastating cyclone, Vardah (2016) is considered to understand the hydrodynamic conditions, whereas, the recent cyclone, Nivar (2020) is considered for investigating the morphodynamic changes along the continental shelf region off the state of Tamilnadu, India. Three different models are coupled intrinsically to simulate hydrodynamics of tides and surges, waves and morphodynamic conditions. Initially, the hydrodynamic and wave models are established and validated with field measurements for an extreme event. Then, morphodynamic model is coupled with validated wave and tide model. Furthermore, the validation of bed evolution is performed for two cases viz., currents only and combination of waves and currents. The combined effect of tides, waves and surges improves the morphodynamic predictions. The present paper emphasizes the spatial and temporal morphological changes along the radius of cyclone pertaining to the shelf region. It is observed that the impact of cyclone on morphodynamics is predominant upto half the radius of the cyclone along the coast and upto 25 m contour from the coast across the shelf region. In this study, the bed evolution and its rate of change at various locations along the coast and across the shelf are extensively discussed. [ABSTRACT FROM AUTHOR]

Nepheloid layers are widely distributed in the marine environment, and their formation and evolution pose many challenges to the current understanding of ocean dynamics and marine sedimentology. In sediment transport processes, nepheloid layers significantly contribute to the exchange of sediment between the continental shelf and the slope. In this paper, we summarize the global research trends on nepheloid layers. In total, 689 publications from 1990 to 2022 were collected from the Web of Science and analyzed using bibliographic software, including Bibliometrix, VOSviewer, CiteSpace, and CorText. Based on these publications, past and present popular research on nepheloid layers is examined and evaluated. The trends in nepheloid layer research are summarized by analyzing keywords, article references, countries, institutions, and authors. Finally, prospects and several key questions related to nepheloid layers are concluded, which can potentially guide future studies. The bibliographic analysis can provide new insights into the history of nepheloid layers. The results also provide valuable information for other researchers and programs investigating geological, geophysical, and biogeochemical processes. [ABSTRACT FROM AUTHOR]

Most of the continental shelf area is a weakly range-dependent shallow-water environment. Compared with range-independent Bayesian geoacoustic inversion, range-dependent inversion usually has problems with the complex forward model and low efficiency for posterior analysis. According to the adiabatic normal-mode theory, the weakly range-dependent shallow-water environment can be divided into a series of range-independent segments; thus, this paper proposes a dual-source modal dispersion inversion method for local geoacoustic parameters of a segment based on a range-independent forward model. In addition, considering that the computational cost of the forward model limits the application of sampling-based methods for posterior analysis, a novel approximate variational inference, namely variational Bayesian Monte Carlo, is applied in this study. It has superior efficiency and shows similar accuracy compared with Markov Chain Monte Carlo sampling. This work is demonstrated in the shallow-water experiment in the continental shelf area of the East China Sea, and the results indicate that the local and range-dependent geoacoustic parameters are well-estimated. [ABSTRACT FROM AUTHOR]

Downstream of Cape Hatteras, the Gulf Stream (GS) is bounded to the north by a sharp temperature front known as the North Wall (NW). Previous studies have generally assumed that variations of the NW and GS are equivalent. Using satellite sea surface height to identify the GS and the 15 °C isotherm at 200‐m depth to represent the NW, this paper examines their similarities and differences during 1993–2016. The NW and GS are geographically close and vary similarly only to the west of 71°W. Downstream of that, they rapidly diverge—and the variances of their latitudes increase by more than a factor of 2—as the GS flows past the New England Seamounts. Evidence is presented to show that the difference in properties of the NW and the GS is related to the presence of mesoscale eddies in the region separating them. Plain‐Language Summary: To the east of Cape Hatteras where the Gulf Stream leaves the continental shelf, a sharp gradient in ocean temperature, known as the North Wall, is seen just north of the current. Fluctuations in the position of the North Wall have large impacts in the distribution of heat in the North Atlantic and on plankton populations. There is a widespread assumption in the literature that variations of the North Wall and the Gulf Stream are similar. Results presented in this paper show that variations of these two features become increasingly different as the current proceeds eastward and the divergence in their properties is due to the presence of turbulent eddies, which arise after the Gulf Stream interacts with the New England Seamounts. These results suggest that recognition of distinct behaviors of the Gulf Stream and the North Wall is needed for a better understanding of their dynamics and their impact on climate. Key Points: The Gulf Stream and its North Wall are close to each other west of 71°W but depart sharply in their properties farther downstreamDifferences in the behaviors of the Gulf Stream and the North Wall are related to mesoscale eddies between themRecognition of distinct properties of Gulf Stream and the North Wall is necessary for understanding their dynamics and impact on climate [ABSTRACT FROM AUTHOR]

Oilfield production is controlled by a wide range of geological and engineering parameters, many of which are at least partially interrelated. This paper uses multivariate statistical methods (principal component analysis, regression analysis and analysis of variance) to determine how these parameters are related, and which of them are most significant in controlling and predicting oilfield performance. The analysis is based on a database of publicly available oilfield data from the United Kingdom Continental Shelf (UKCS), from which a series of geological, engineering and fluid‐related control variables from 136 fields were pre‐processed and analyzed. This dataset is a subset of a much wider project database for UKCS oil, gas and condensate fields. For this study, the project database was divided into two datasets: a first dataset with 10 parameters from 136 fields, and a second, more detailed dataset with 27 parameters from 38 fields. Both datasets were analysed using principal component analysis in order to investigate possible correlations between numerically/statistically interrogable predictor variables such as porosity, permeability, number of production wells, gas‐oil ratio and reservoir temperature. A regression analysis was then carried out on the predictor variables in order to obtain a ranking of predictability (i.e. how indicative a predictor is of a particular outcome) and sensitivity (how sensitive an outcome is to slight changes in a predictor) in relation to recovery factor based on R‐squared and regression coefficient values. The results showed that key variables from the principal component analysis included field size, number of production wells, PVT, gross depositional environment and reservoir quality. High‐ranking parameters of predictability and sensitivity from the regression analysis were found to include API, net‐to‐gross, porosity and reservoir depth. These results are consistent with previous studies and suggest that it should be possible to forecast oilfield recovery based on only a few selected input variables. As a preliminary test of forecasting ability of the variable permutations put forward, a best‐subsets multiple regression was carried out using a statistical software package and yielded results which corroborated the main findings. [ABSTRACT FROM AUTHOR]

Copyright of Journal of China University of Petroleum is the property of China University of Petroleum and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Quaternary sediment in the Labrador Sea was derived from many proglacial sources in Greenland and eastern Canada. Understanding the spatial and temporal changes in sediment provenance provides information on ice extent and sediment dispersal patterns. Variations in mineral composition of sediment from late Quaternary cores has been determined by a whole pattern of quantitative X-ray diffraction procedure. Mineral facies were extracted statistically by a supervised analysis of 90 samples from bedrock and ice-rafted clasts, which were then used to predict the most probable mineral facies in 1443 marine sediment samples. We used a non-parametric Classification Decision Tree (CDT) to validate that decision. Only 26% of the samples were misclassified in the CDT. The six facies identified consisted of four facies reflecting differences in the composition of Canadian and Greenland Precambrian igneous and metamorphic bedrock, a set of samples dominated by high weight percentages of calcite and dolomite (detrital carbonate (DC) and Hudson Strait Heinrich (HS-H) events), and a "shale" facies. We isolated 284 sediments from the HS-H DC facies and determined that they could be divided into four categories based on differences in their mineral proportions. These categories vary geographically, based on non-carbonate sediment supply during these events from Greenland, the Canadian Shield, the Appalachians, and the outer continental shelf. In the Holocene of the Labrador Sea, dolomite is derived from Baffin Bay and abundance of calcite is influenced by both biogenic productivity and dissolution. [ABSTRACT FROM AUTHOR]

The South China Sea disputes are becoming increasingly tense with more and more countries expressing their views on legal issues and actions of claimant Statess in the South China Sea. In December 2019, Malaysia deposited a partial submission to the United Nations Commission on the Limits of the Continental Shelf to establish the limits of its extended continental shelf beyond 200 nautical miles in the northern part of the South China Sea. The submission sparked a new legal battle of diplomatic notes with the participation of South China Sea coastal States which can also be regarded as claimant States in the contet of the South China Sea disputes (Brunei, China, Malaysia, the Philippines and Viet Nam) as well as non-claimant States (Australia, France, Germany, Indonesia, Japan, New Zealand, the United Kingdom and the United States). Following the article "South China Sea: New Battle of the Diplomatic Notes among claimants in 2019–2021" published in the Asia-Pacific Journal of Ocean Law and Policy 6 (2021), this paper provides an analysis of the exchange of diplomatic notes between China and non-claimant States with the aim of understanding the impact of these exchanges on the prospect for the peaceful settlement of the maritime disputes in the South China Sea. [ABSTRACT FROM AUTHOR]

Copyright of Revista de Direito Internacional is the property of Revista de Direito Internacional and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Offshore wind energy resources far exceed those on land. However, the increase in water depth of the continental shelf in China's sea area slows down as the distance from the shore increases. In view of the characteristics of China's sea, how to optimize the design of mooring systems to adapt to the water depth conditions in China's waters and to resist the harsh sea conditions is one of the major problems encountered in the development of floating wind turbines. In this paper, the 5MW-OC4 semi-submersible floating wind turbine is taken as the research object, and the frequency domain and time domain calculation of the floating wind turbine are carried out by using SESAM software under the water depth of 40 m in the Bohai Sea. By comparing the motion response and tension of catenary and tension mooring floating wind turbine. The mooring system is optimized by combining the buoy and clump weight. The results show that the catenary mooring mode is more suitable for the floating wind turbine under shallow water conditions. Mooring accessories used in combination have the same effect on the overall response of the floating wind turbine as changing the same mooring parameters when used alone, but the effect of changing the mooring parameters on the performance optimization of the mooring system is more obvious when used in combination, and a reasonable combination of accessories can significantly change the overall characteristics of the floating system and affect the safety and cost of the system. [ABSTRACT FROM AUTHOR]

At present, the study of accretionary orogenic belts and collisional orogenic belts has achieved numerous insights and improvements. However, continental subduction, which often occurs during the oceanic and continental transition, has not received enough attention for a long time, such as what kind of structural deformation characteristics it has and how it affects the evolution of the orogenic belt. This paper studied two Cenozoic orogenic belts (the Taiwan orogenic belt and the Yarlung Zangbo River orogenic belt) and one Mesozoic orogenic belt (the Qiangtang orogenic belt) in order to clarify the unique structural deformation characteristics of continental subduction and its interaction with orogenic processes. It is found that the subduction of continental crust often forms a double-layer structure in the orogenic belt. The upper part is a set of thrust imbricate composed of Smith strata, and the lower part is a set of subduction complexes with a " blocks in the matrix" structure. The upper and lower parts of the double-layer structure are similar, mainly slope facies -submarine fan facies rocks and little shelf facies rocks. Due to the similar deformation time, the double-layer structure should be a structural system formed in different depths by the subduction of the same passive continental margin. We suppose that the subduction of the slope -submarine fan is the main factor for the formation of the double-layer structure. The subsequent continental shelf subduction could induce the collision and thus lead to strain's gradual propagation to the craton's interior, resulting in the foreland fold-thrust. Also, the double-layer structure is often destroyed during the collision, so the deeply underplated continental subduction complex can be exhumed to the shallow level. Therefore, this study also emphasizes the importance of continental subduction and the exhumation of subducted crustal rocks in the evolution of orogenic belts. [ABSTRACT FROM AUTHOR]

Previous studies have demonstrated that tides are subject to considerable changes on secular time scales. However, these studies rely on sea level observations from tide gauges that are predominantly located in coastal and shelf regions and therefore, the large‐scale patterns remain uncertain. Now, for the first time, satellite radar altimetry (TOPEX/Poseidon & Jason series) has been used to study worldwide linear trends in tidal harmonic constants of four major tides (M2, S2, O1, and K1). This study demonstrates both the potential and challenges of using satellite data for the quantification of such long‐term changes. Two alternative methods were implemented. In the first method, tidal harmonic constants were estimated for consecutive 4‐year periods, from which the linear change was then estimated. In the second method, the estimation of linear trends in the tidal constants of the four tides was integrated in the harmonic analysis. First, both methods were assessed by application to tide gauge data that were sub‐sampled to the sampling scheme of the satellites. Thereafter the methods were applied to the real satellite data. Results show both statistically significant decreases and increases in amplitude up to 1 mm/year and significant phase changes up to ∼0.1 deg/year. The level of agreement between altimeter‐derived trends and estimates from tide gauge data differs per region and per tide. Plain Language Summary: Tidal predictions are valuable for many purposes, ranging from processing satellite data to coastal engineering. Although tidal constants are often perceived to be stationary in time, earlier studies have shown that tides are subject to changes both on seasonal and long‐term time scales. However, these studies mainly concern coastal data and therefore, the processes at open ocean remain unclear. The study behind this paper is the first that uses global satellite data to quantify secular trends in tides, thereby filling in the gaps of earlier work. Results show the changes in tides to be significant, with both decreases and increases in tidal amplitude of the order of several centimeters and phase changes of several degrees over the past decades. Key Points: Satellite altimetry has for the first time been used to assess large scale secular trends in global tidesSecular trends in the M2, S2, O1, and K1 tides are observed across the globe, with amplitude changes up to ±1 mm/yearGlobal altimetry‐derived trends have magnitudes and spatial variability comparable to estimates at tide gauges [ABSTRACT FROM AUTHOR]

Future energy scenarios include both green and blue hydrogen, as both are needed to scale up decarbonized energy supply. A transition to renewable energy is predicted over time, but the urgency we are facing cannot be met by renewable energy alone. For blue hydrogen production, the overall greenhouse gas (GHG) emissions are primarily affected by emissions from natural gas production, processing, and transport (CO2 and methane), as well as process efficiency and carbon capture ratio. Few complete and updated analyses are available that cover the entire blue hydrogen value chain with the best available technology for process facilities, as well as the proper design, operation, and maintenance of all relevant systems and infrastructure. This paper analyses the GHG intensity of blue hydrogen, using recent data as well as input from technology providers on state‐of‐the‐art gas reforming technologies. Data are primarily based on natural gas production and transport in the North Sea Basin, with gas export from the Norwegian continental shelf to continental Europe or the United Kingdom, and with blue hydrogen production either in Norway or near pipeline landfall in the European Union or United Kingdom. Some data related to potential blue hydrogen production in the US Appalachian region are also given. The data show that the properly designed and operated value chains for blue hydrogen supply, with minimal emissions from natural gas supply and high carbon capture in hydrogen production, will give a major reduction in GHG emissions from energy end‐use. GHG footprint for end‐users based on blue hydrogen will typically be 80%–90% lower than for direct supply and use of natural gas. [ABSTRACT FROM AUTHOR]

Copyright of Estudios Internacionales is the property of Instituto de Estudios Internacionales de la Universidad de Chile and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The paper in question by Van Camp and co-authors [MVC] challenges previous work showing that ground gravity data arising from hydrology can provide a consistent signal for the comparison with satellite gravity data. The data sets used are similar to those used previously, that is, the gravity field as measured by the GRACE satellites versus ground-based data from superconducting gravimeters (SGs) over the same continental area, in this case Central Europe. One of the main impediments in this paper is the presentation that is frequently confusing and misleading as to what the data analysis really shows, for example, the irregular treatment of annual components that are first subtracted then reappear in the analysis. More importantly, we disagree on specific points. Two calculations are included in our comment to illustrate where we believe that the processing in [MVC] paper is deficient. The first deals with their erroneous treatment of the global hydrology using a truncated spherical harmonic approach which explains almost a factor 2 error in their computation of the loading. The second shows the effect of making the wrong assumption in the GRACE/hydrology/surface gravity comparison by inverting the whole of the hydrology loading for underground stations. We also challenge their claims that empirical orthogonal function techniques cannot be done in the presence of periodic components, and that SG data cannot be corrected for comparisons with GRACE data. The main conclusion of their paper, that there is little coherence between ground gravity stations and this invalidates GRACE comparisons, is therefore questionable. There is nothing in [MVC] that contradicts any of the previous papers that have shown clearly a strong relation between seasonal signals obtained from both ground gravity and GRACE satellite data. [ABSTRACT FROM AUTHOR]

This paper provides a new deglacial chronology for retreat of the Irish Ice Sheet from the continental shelf of western Ireland to the adjoining coastline, a region where the timing and drivers of ice recession have never been fully constrained. Previous work suggests maximum ice‐sheet extent on the outer western continental shelf occurred at ~26–24 cal. ka BP with the initial retreat of the ice marked by the production of grounding‐zone wedges between 23–21.1 cal. ka BP. However, the timing and rate of ice‐sheet retreat from the inner continental shelf to the present coast are largely unknown. This paper reports 31 new terrestrial cosmogenic nuclide (TCN) ages from erratics and ice‐moulded bedrock and three new optically stimulated luminescence (OSL) ages on deglacial outwash. The TCN data constrain deglaciation of the near coast (Aran Islands) to ~19.5–18.5 ka. This infers ice retreated rapidly from the mid‐shelf after 21 ka, but the combined effects of bathymetric shallowing and pinning acted to stabilize the ice at the Aran Islands. However, marginal stability was short‐lived, with multiple coastal sites along the Connemara/Galway coasts demonstrating ice recession under terrestrial conditions by 18.2–17. ka. This pattern of retreat continued as ice retreated eastward through inner Galway Bay by 16.5 ka. South of Galway, the Kilkee–Kilrush Moraine Complex and Scattery Island moraines point to late stage re‐advances of the ice sheet into southern County Clare ~14.1–13.3 ka, but the large errors associated with the OSL ages make correlation with other regional re‐advances difficult. It seems more likely that these moraines are the product of regional ice lobes adjusting to internal ice‐sheet dynamics during deglaciation in the time window 17–16 ka. [ABSTRACT FROM AUTHOR]

The evaluation of seal in conventional stratigraphic and structural traps requires the characterization of the capillary top seal to assess the capacity to hold a hydrocarbon column. Typically, this seal analysis addresses the static seal and does not consider the role that hydrodynamics (the flow of water into or out of the reservoir) may play in influencing the seal capacity. Although possessing extremely low permeability, shale seals are not perfect seals and water can seep through them under an imposed hydraulic gradient. Likewise, water can move vertically through trapped hydrocarbon columns even though relative permeabilities are very low. The impact of this flow on the capillary seal capacity can, in theory, be quite profound and should be considered in seal analysis workflows. This paper revisits the Manzocchi & Childs model for hydrodynamic effects on capillary seals and employs it directly in real-world trap analysis. The implementation of this model is described, and a workflow developed to incorporate the impact of hydrodynamics into column height prediction. The technique is applied to several known over-pressured fields from the Norwegian continental shelf to evaluate its applicability. Preliminary results from Monte Carlo modelling are promising and with some agreement between the observed column heights and the predicted hydrodynamic seal-controlled columns, dependant on the parameterization used. Further testing is ongoing, but the methodology should be considered in exploration prospect evaluation. The impact of hydrodynamics on seal capacities should not be discounted. Thematic collection: This article is part of the Fault and top seals 2022 collection available at: https://www.lyellcollection.org/topic/collections/fault-and-top-seals-2022 [ABSTRACT FROM AUTHOR]

This paper aims to conduct a preliminary re-evaluation of the claim made by the Government of Sarawak regarding its jurisdiction over oil and gas on the continental shelf. The basis of Sarawak's claim is rooted in the pre-Malaysia status quo of state territory, which was established through the Alteration of Boundaries of 1954. This proclamation extended the borders of the state to include the continental shelf adjacent to its coast, ensuring the state's rights to natural resources, including oil and natural gas. However, this research questions the legality of the 1954 law based on the context of legal history. It appears to be incompatible with the 1958 Geneva Convention on the High Seas and the 1982 United Nations Convention on the Law of the Sea. These conventions provide the statutory basis for incorporating sea territorial waters beyond three nautical miles and designating Exclusive Economic Zones for specific nations. As such, obtaining jurisdiction over sea territorial waters was the responsibility of the federal government of Malaysia, which acted as the deemed signatory. The research will employ content analysis of relevant secondary sources, as well as selected historical and legal documents. By doing so, it hopes to bring clarity to the legal complexities in the historical context surrounding Sarawak's claim. The ultimate goal is to redefine the current dimension of the issue and seek an amicable solution to address the jurisdictional matter. [ABSTRACT FROM AUTHOR]