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A submerged elevation located off the coast of Le Castella, a small village on the Ionian Coast of Calabria (Italy) populated for thousands of years that features notable archaeological remains from the Great Greece (Magna Graecia) and the Middle Ages, was investigated through in-depth, multidisciplinary, geoarchaeological research. This submarine elevation, once aligned with the marine terrace MIS 3 of Le Castella and still completely emerged between 10 and 8 ka years ago, slowly sank due to erosion and local tectonic-structural subsidence and was also favoured by a submerged normal fault that cuts the terrace in two. The dismantling and sinking of this part of the marine terrace has significantly changed the Late Holocene shorelines, with notable consequences on a topographic and archaeological level. In fact, one of the consequences of the sinking of this ancient promontory was the disappearance of two small islands that were reported to be right in front of Le Castella by numerous historical and cartographic sources. In the last decades, there has been a scientific debate over the existence of these islets, but no convincing evidence has been found about their actual presence up until now. This research, funded by the Marine Protected Area “Capo Rizzuto”, was conducted by means of underwater archaeological and geological surveys, geophysical seabed mapping systems, and both direct and instrumental optical surveys made with an Autonomous Surface Vehicle. The outcomes allow us to confirm the presence of these two partially emerged rock bodies up to half a millennium ago. In addition, the presence of anthropogenic extrabasinal materials in a marine area corresponding to one of the highest points of the submerged elevation allows us to define the exact position of one of the two islets. These archaeological findings have been subject, for the first time ever, to a thorough topographical and architectural analysis, then compared with other near and very similar submerged structures. On the basis of these comparisons, the findings should be attributed to the Byzantine Age or, at most, to the Middle Ages. In-depth archival research on portolan charts and navigation maps, in many cases unpublished and dating from the Middle Ages to the early 18th century, supports the results of our marine investigations from a historical point of view.

A submerged elevation located off the coast of Le Castella, a small village on the Ionian Coast of Calabria (Italy) populated for thousands of years that features notable archaeological remains from the Great Greece (Magna Graecia) and the Middle Ages, was investigated through in-depth, multidisciplinary, geoarchaeological research. This submarine elevation, once aligned with the marine terrace MIS 3 of Le Castella and still completely emerged between 10 and 8 ka years ago, slowly sank due to erosion and local tectonic-structural subsidence and was also favoured by a submerged normal fault that cuts the terrace in two. The dismantling and sinking of this part of the marine terrace has significantly changed the Late Holocene shorelines, with notable consequences on a topographic and archaeological level. In fact, one of the consequences of the sinking of this ancient promontory was the disappearance of two small islands that were reported to be right in front of Le Castella by numerous historical and cartographic sources. In the last decades, there has been a scientific debate over the existence of these islets, but no convincing evidence has been found about their actual presence up until now. This research, funded by the Marine Protected Area "Capo Rizzuto", was conducted by means of underwater archaeological and geological surveys, geophysical seabed mapping systems, and both direct and instrumental optical surveys made with an Autonomous Surface Vehicle. The outcomes allow us to confirm the presence of these two partially emerged rock bodies up to half a millennium ago. In addition, the presence of anthropogenic extrabasinal materials in a marine area corresponding to one of the highest points of the submerged elevation allows us to define the exact position of one of the two islets. These archaeological findings have been subject, for the first time ever, to a thorough topographical and architectural analysis, then compared with other near and very similar submerged structures. On the basis of these comparisons, the findings should be attributed to the Byzantine Age or, at most, to the Middle Ages. In-depth archival research on portolan charts and navigation maps, in many cases unpublished and dating from the Middle Ages to the early 18th century, supports the results of our marine investigations from a historical point of view. [ABSTRACT FROM AUTHOR]

Most studies on solute transport in coastal aquifers affected by tides focus on the transport of instantaneous released solute, and there are few studies on continuously released solute affected by tides. In this study, the image monitoring method is used to establish the quantitative relationship between the concentration of the colored tracer and the hue value of the image, and the digital image is used to determine the tracer concentration distribution. Using image monitoring method laboratory experiments, quantitative analysis of the characteristics of continuously released solute transport in coastal unconfined aquifers under the tidal influence. Experiments show that the high tide inhibits the increase in the concentration of each point in the aquifer. Under the influence of tides, the solute plume retreats towards the land. During the low tide period, the solute plume migrates toward the sea again. And the solute plume will maintain a relatively stable shape after entering the aquifer for a long enough time. Ignoring the tidal effect seems to have little effect on the estimation of the position of the solute plume, but ignoring the tidal effect has a certain influence on the estimation of the dispersion range of the solute plume. No matter whether considering the tidal action, the final dispersion range of the solute plume is almost the same. But before the solute plume reaches a stable state, ignoring the tidal effect will lead to a smaller dispersion range of the solute plume. [ABSTRACT FROM AUTHOR]

Manned submersible dives in the northwest South China Sea encountered substantial amounts of plastic litter accumulated at the base of scours along the floor of a submarine canyon, which may associate with the depositional behaviors of turbidity currents. In this study, we conduct numerical simulations using field‐scale bathymetry to investigate the relationship between the canyon floor morphology, flow processes, and the locations and sizes of the plastic litter piles. The consistent deposition pattern caused by the numerical turbidity currents with different input parameters indicate that morphology of the canyon may exert a dominant influence on turbidite deposition. This is attributed to a significant reduction in shear velocity as simulated turbidity currents flowing through the scours on the canyon floor. Spatial correspondence between deposits of turbidity currents and plastic litter accumulation suggests that suspended sediments and plastic may undergo simultaneous dynamic processes during the transportation of turbidity currents. Plain Language Summary: The issue of marine plastic litter has attracted wide attention, particularly in terms of its transportation mechanisms and locations of accumulation on the ocean floor. Turbidity currents are subaqueous sediment‐gravity flows that can transport large amounts of sediment, nutrients and pollutants into the deep sea, yet there is sparse research on the dynamics of plastic litter transport under the control of turbidity currents, and its accumulation in the deep sea. Here, we present a series of numerical simulations of turbidity currents in a submarine canyon with various input parameters, when combined with observational data on topography and plastic litter distribution, confirm that turbidity currents constitute a plausible mechanism for the transport of plastic litter and for its accumulation in response to changes in flow associated with scours. In addition, we find that the concavity of the scours is also necessary for plastic litter accumulation, since it induces significant fluctuations in the shear velocity and the corresponding depositional process. Key Points: Numerical simulations were applied to investigate turbidity currents as a cause for plastic litter accumulations in a submarine canyonThe simulated turbidite deposits and observed plastic litter accumulations exhibit a strong spatial correspondenceThe morphology of the canyon floor may exert dominant influence on the plastic litter accumulations in submarine canyons [ABSTRACT FROM AUTHOR]

This paper shows an example of how to create morphological and geological maps of the seabed combining high-resolution bathymetric data and onshore geological information. The mapped area corresponds to the BIMEP offshore test site, located in the south-eastern part of the Bay of Biscay, in the northern part of the Iberian Peninsula. In the Morphological map, using semi-automatic methods, the seafloor is categorized in 10 classes, obtained by the combination of terrain variables and a decision table. In the Geological map, onshore-defined geological units are extended into the continental shelf, and bedding traces, folds, and fractures are depicted. These maps could serve as valuable tools for stakeholders involved in marine energy projects, enabling informed decision-making and promoting sustainable development practices.

The ocean carbon reservoir controls atmospheric carbon dioxide (CO2) on millennial timescales. Radiocarbon (14C) anomalies in eastern North Pacific sediments suggest a significant release of geologic 14C‐free carbon at the end of the last ice age but without evidence of ocean acidification. Using inverse carbon cycle modeling optimized with reconstructed atmospheric CO2 and 14C/C, we develop first‐order constraints on geologic carbon and alkalinity release over the last 17.5 thousand years. We construct scenarios allowing the release of 850–2,400 Pg C, with a maximum release rate of 1.3 Pg C yr−1, all of which require an approximate equimolar alkalinity release. These neutralized carbon addition scenarios have minimal impacts on the simulated marine carbon cycle and atmospheric CO2, thereby demonstrating safe and effective ocean carbon storage. This deglacial phenomenon could serve as a natural analog to the successful implementation of gigaton‐scale ocean alkalinity enhancement, a promising marine carbon dioxide removal method. Plain Language Summary: The ocean is the largest carbon reservoir on Earth's surface and, as such, it controls the concentration of the greenhouse gas carbon dioxide (CO2) in the atmosphere over long time periods. When CO2 was rising at the end of the last ice age, marine sediment evidence indicates a regional carbon release into the ocean, due to a distinct carbon isotope fingerprint left behind. Using a carbon cycle model and atmospheric data, we simulated different geologic carbon addition scenarios since the last ice age. We find that substantial carbon addition to the ocean could have occurred (up to 1.3 billion tons per year) without causing significant changes to the carbon cycle, but only if the carbon is neutralized by alkalinity in an approximate 1:1 ratio. This neutralized release is similar to an approach of carbon removal called ocean alkalinity enhancement (OAE), which aims to reduce atmospheric CO2 as a potential solution for climate change. These findings suggest that neutralized carbon addition—in the form of "neutralized" bicarbonate ion HCO3− $\left({\text{HCO}}_{3}^{-}\right)$ instead of "acidic" CO2—could explain the low levels of radiocarbon during the last deglaciation and shows that large‐scale OAE is feasible without causing major changes to the marine carbon cycle. Key Points: Observed deglacial changes in atmospheric CO2 and 14C/C allow for up to 2,396 Pg of neutralized geologic carbon (i.e., bicarbonate) releaseThe global carbon cycle is essentially "blind" to neutralized carbon release, only constrained by 14C budgetThis gigaton‐scale neutralized carbon release may be a natural analog to the marine CO2 removal method of ocean alkalinity enhancement [ABSTRACT FROM AUTHOR]

The H structure is located in the central and southern part of the Xihu Depression central depression structural belt, adjacent to the hydrocarbon-rich Shaoxing 36 depression and divided by multiple faults as a structural trap, which has good conditions for hydrocarbon accumulation. However, currently, the research on faults in this structure is relatively weak, which restricts the exploration of hydrocarbon potential. To clarify the development characteristics of faults and their control over hydrocarbon accumulation, this article starts from 3D seismic data interpretation and drilling data, analyzes the development characteristics and evolution process of H structural faults, conducts research on the control of faults on hydrocarbon accumulation within the structure, and divides hydrocarbon accumulation types. Research shows that the faults within the H structure mainly developed in the Paleogene, the dominant trend was NNE. The faults can be divided into two hierarchical class: source rocks-linking faults and regulative faults. Among them, F1 and F4 faults located on the east and west sides of the structure control the formation of the structure, and fault activity controls the ancient high point. The fault level and fault sand coupling degree can control the abundance of hydrocarbon. Based on the comprehensive analysis of fault activity, source-fault combination types, and transportation models, two hydrocarbon accumulation models were established, providing guidance for the next step of oil and gas exploration in this structure. [ABSTRACT FROM AUTHOR]

Marine geological studies of Naples Bay are discussed and reviewed, focusing on the application of the seismo-stratigraphic concepts to a Late Quaternary volcanic area. The Naples Bay represents an active volcanic area in which the interactions between volcanic and sedimentary processes controlled a complex stratigraphic architecture during the Late Quaternary period. While the volcanic processes took place in correspondence with the activity of the Somma–Vesuvius, Campi Flegrei Ischia, and Procida volcanic complexes, the sedimentary processes were controlled by the fluvial processes in the Sarno-Sebeto coastal plain and by the tectonic uplift in correspondence with the Sorrento Peninsula's structural high Key geophysical and stratigraphic studies of the three active volcanic complexes are revised and discussed. The seismo-stratigraphic concepts applied in the geological interpretation of seismic profiles of Naples Bay are reviewed and discussed: here, the classical concepts of seismic and sequence stratigraphy have been successfully applied, but only partly, due to the occurrence of several buried volcanoes and volcanic seismic units and tephra layers, calibrated by gravity cores. [ABSTRACT FROM AUTHOR]

This document is an editorial from the journal Frontiers in Marine Science that discusses the importance of studying marine geology and the hydrodynamics environment. It introduces a research topic that includes 18 original research papers covering a wide range of methodologies and topics. The editorial provides a summary of key findings from these papers, which include studies on submerged carbonate platforms, seismic response of seabed sites, resistivity structure beneath mid-ocean ridges, and more. The studies utilize various methods such as laboratory tests, numerical simulations, and in-situ observations. These findings contribute to our understanding of marine environments and have implications for future research and engineering applications. [Extracted from the article]

Kitasu Hill and MacGregor Cone formed along the Principe Laredo Fault on British Columbia's central coast as the Wisconsinan ice sheet withdrew from the Coast Mountains. These small-volume Milbanke Sound Volcanoes (MSV) provide remarkable evidence for the intimate relationship between volcanic and glacial facies. The lavas are within-plate, differentiated (low MgO < 7%) Ocean Island Basalts, hawaiites, and mugearites that formed from ∼1% decompression melting of asthenosphere with residual garnet. Kitasu Hill, on glaciated bedrock, formed between 18 and 15 cal ka BP. Dipping, poorly stratified, admixed hyaloclastite, and glacial diamicton with large plutonic clasts and pillow breccia comprise its basal tuya platform (0–43 masl). Subaerial nested cinder cones, with smaller capping lava flows, sit atop the tuya. New marine samples show McGregor Cone formed subaerially but now sits submerged at 43–200 mbsl on an eroded moraine at the mouth of Finlayson Channel. Seismic data and cores reveal glaciomarine sediments draping the cone's lower slopes and show beach terraces. Cores contain glaciomarine diamictons, ice-rafted debris, delicate glassy air fall tephra, and shallow, sublittoral, and deeper benthic foraminifera. Dates of 14.1–11.2 cal ka BP show volcanism spanned ∼2000 years during floating ice shelf conditions. The MSV have similar proximal positions to the retreating ice sheet, display mixed volcano-glacial facies, and experienced similar unloading stresses during deglaciation. The MSV may represent deglacially triggered volcanism. The dates, geomorphic and geological evidence, constrain a local relative sea level curve for Milbanke Sound and show how ice gave way to fire. [ABSTRACT FROM AUTHOR]

This paper shows an example of how to create morphological and geological maps of the seabed combining high-resolution bathymetric data and onshore geological information. The mapped area corresponds to the BIMEP offshore test site, located in the south-eastern part of the Bay of Biscay, in the northern part of the Iberian Peninsula. In the Morphological map, using semi-automatic methods, the seafloor is categorized in 10 classes, obtained by the combination of terrain variables and a decision table. In the Geological map, onshore-defined geological units are extended into the continental shelf, and bedding traces, folds, and fractures are depicted. These maps could serve as valuable tools for stakeholders involved in marine energy projects, enabling informed decision-making and promoting sustainable development practices. [ABSTRACT FROM AUTHOR]

The Chukchi Borderland is a tectonic unit of the eastern part of the Arctic continental margin of Eurasia that is part of the complex of the Central Arctic rises, along with the Lomonosov Ridge, the Alpha‒Mendeleev Rise, the Podvodnikov, Chukchi and Mendeleev basins. The study provides data on the structure of the Chukchi Borderland and the surrounding geological structures, morphology and geology, uses bathymetric materials, seismic materials from CDP and deep seismic survey, sampling and drilling data. A review of materials on the study region was carried out. The latest results of geomorphological analysis of bathymetric data and 3D modeling of the Earth's crust of the study region using geophysical data are presented. To explain the identified features of the morphology and deep structure of the Chukchi Borderland, a tectonic model is proposed that explains the deep mechanisms of its formation and adjacent structures, as well as a structural-tectonic scheme of the Arctic Alaska–Chukotka microplate, which presents the morphological and geological connection of the Chukchi Borderland with the continental shelf. [ABSTRACT FROM AUTHOR]

Wave cyclic loading in submarine sediments can lead to pore pressure accumulation, causing geohazards and compromising seabed stability. Accurate prediction of long-term wave-induced pore pressure is essential for disaster prevention. Although numerical simulations have contributed to understanding wave-induced pore pressure response, traditional methods lack the ability to simulate long-term and real oceanic conditions. This study proposes the use of recurrent neural network (RNN) models to predict wave-induced pore pressure based on in-situ monitoring data. Three RNN models (RNN, LSTM, and GRU) are compared, considering different seabed depths, and input parameters. The results demonstrate that all three RNN models can accurately predict wave-induced pore pressure data, with the GRU model exhibiting the highest accuracy (absolute error less than 2 kPa). Pore pressure at the previous time step and water depth are highly correlated with prediction, while wave height, wind speed, and wind direction show a secondary correlation. This study contributes to the development of wave-induced liquefaction early warning systems and offers insights for utilizing RNNs in geological time series analysis.

Increasing awareness of the importance of effective communication of scientific results and concepts, and the need for more accurate mapping and increased feature visibility led to the development of novel approaches to visualization of high-resolution elevation data. While new approaches have routinely been adopted for land elevation data, this does not seem to be the case for the offshore and submerged terrestrial realms. We test the suitability of algorithms provided by the freely-available and user-friendly Relief Visualization Toolbox (RVT) software package for visualizing bathymetric data. We examine the algorithms optimal for visualizing the general bathymetry of a study area, as well as for highlighting specific morphological shapes that are common on the sea-, lake- and riverbed. We show that these algorithms surpass the more conventional analytical hillshading in providing visualizations of bathymetric data richer in details, and foremost, providing a better overview of the morphological features of the studied areas. We demonstrate that the algorithms are efficient regardless of the source data type, depth range, resolution, geographic, and geological setting. The summary of our results and observations can serve as a reference for future users of RVT for displaying bathymetric data.

The Xihu Sag is a key area for gas exploration in the East China Sea. With the gradual development and utilization of oil and gas in the Eocene Pinghu and Oligocene Huagang Formations, the Baoshi Formation has gradually become a hot field for oil and gas exploration in the East China Sea. Research on the Baoshi Formation is limited by the lack of drilling data and deep burial depths. Based on the comprehensive utilization of drilling, core, paleontology, and three-dimensional seismic data, the Baoshi Formation is in a warm and humid subtropical climate and belongs to a shallow sea sedimentary environment. Tidal deltas, tidal flats, and limited shallow sea sedimentary systems are mainly developed in the western slope zone. These results indicate a favorable direction for exploration of the Baoshi Formation in the western slope zone [ABSTRACT FROM AUTHOR]

Geology is a core component of two major multidisciplinary seabed-mapping initiatives in Norway (MAREANO, Marine Base Maps for the Coastal Zone). Helped by Norway’s Nature Diversity Act, which acknowledges geological and landscape diversity alongside biodiversity, geological information has gained recognition nationally as part of an essential foundation for knowledge-based management, both in the coastal zone and offshore. Recently, international focus on the United Nations Sustainable Development Goals has led to the proposal of Essential Geodiversity Variables, a framework for geological (geodiversity) information, intended to stand alongside Essential Variables already defined for climate, biodiversity and oceans (limited to ocean physics, biochemistry, biology and ecosystems). Here, we examine to what extent map products from the Geological Survey of Norway generated under these multidisciplinary mapping initiatives fit within this framework of Essential Geodiversity Variables, and how well it is suited to information on marine geodiversity. Although we conclude that the framework is generally a good fit for the marine-relevant Essential Geodiversity Variable classes (geology and geomorphology), we examine opportunities for further highlighting quantitative geodiversity information. We present preliminary examples of substrate diversity and morphological diversity and discuss our experience of geological mapping as part of multidisciplinary initiatives. We highlight many benefits, which far outweigh any perceived or real compromises of this approach in monetary, practical and scientific terms.

The evolution of alluvial megafans has mainly been investigated in unconfined settings; however, at the boundary of these large depositional systems, the development of fluvial channels can be affected by structural constraints with regional extent. Here we present the study of the eastern sector of the megafan of Isonzo River, in the Gulf of Trieste, where this system fed through the southern Alps is constrained by the Karst and Istria cliffs. Although this area is now submerged under the northern Adriatic Sea, stratigraphy from seismo-acoustic profiles, drill cores and multi-beam bathymetry allows us to reconstruct the paleochannel system of the Isonzo River in detail, which was likely active within the period of 21–17.5 ka cal BP, at the end of LGM. This was reconstructed for over 50 km and currently represents the longest abandoned fluvial channel in the Mediterranean seabed. The occurrence of the mountain fringe and competition with nearby alluvial systems forced the paleochannel to follow the present coastline and conditioned the slope of its thalweg to decrease almost to null, resulting the transformation from the megafan to the undifferentiated alluvial plain. [ABSTRACT FROM AUTHOR]

Recent advances in basin and petroleum system modelling have allowed for the investigation of gas hydrate systems, including modelling of the generation, migration, and accumulation of biogenic and thermogenic gas within gas hydrate deposits. In this brief survey paper, the treatment of sediment organic properties (organic content and richness, expressed as total organic carbon and the hydrogen index) within previously published basin and petroleum system models of marine gas hydrate systems is reviewed. Eight studies (published between 2015 and 2020) are described and discussed. This review contributes to the state of knowledge in the field by reviewing existing modelling studies of gas hydrates and concludes with brief takeaways on important considerations and knowledge gaps in the state of basin and hydrocarbon system modelling of gas hydrate systems.

Marine geological studies of Naples Bay are discussed and reviewed, focusing on the application of the seismo-stratigraphic concepts to a Late Quaternary volcanic area. The Naples Bay represents an active volcanic area in which the interactions between volcanic and sedimentary processes controlled a complex stratigraphic architecture during the Late Quaternary period. While the volcanic processes took place in correspondence with the activity of the Somma–Vesuvius, Campi Flegrei Ischia, and Procida volcanic complexes, the sedimentary processes were controlled by the fluvial processes in the Sarno-Sebeto coastal plain and by the tectonic uplift in correspondence with the Sorrento Peninsula’s structural high Key geophysical and stratigraphic studies of the three active volcanic complexes are revised and discussed. The seismo-stratigraphic concepts applied in the geological interpretation of seismic profiles of Naples Bay are reviewed and discussed: here, the classical concepts of seismic and sequence stratigraphy have been successfully applied, but only partly, due to the occurrence of several buried volcanoes and volcanic seismic units and tephra layers, calibrated by gravity cores.

The Geological Survey of Israel (GSI) was founded in 1948 with the establishment of the State of Israel. Over the years, changes of the research directions were dictated by national needs as the population grew from less than 1 million to more than 9 million in 2020 in a small country of only 22,000 km2 with highly diverse geological features. This was associated with a change in the structure of the survey and establishing it as a key player in sustainable development and effective utilization of natural resources. It became possible by the upgrade of the staff levels and the research facilities after the survey was recognized as an independent research institute by the government. The achievement of the GSI as an applied science organization in response to the country's ever-developing challenges is going hand in hand with becoming an international geo-scientific recognized organization. [ABSTRACT FROM AUTHOR]

Ischia shows intriguing and complex geology, which has been deeply investigated. In this paper, a reappraisal of the Quaternary geologic evolution of Ischia based on literature data is advised, concentrating on the volcanology of the island, based on field data and geochemistry, due to the happening of active fumarolic systems on the island and the marine geology and geophysics, which are intensively studied in the frame of the CARG Project. The literature studies have been incorporated with the geological interpretation of high-resolution seismic profiles, partly previously published and herein reorganized with the aim to highlight the geologic evolution of the different sectors of the island (northern Ischia, southern Ischia). The outcrop data have shown the deposits of ten explosive eruptions: among them, we focused on the S. Angelo Tephra. The laccolith model has been described in order to explain the resurgence of Ischia starting from 55 ky B.P. Geochemical information has been synthesized to reconstruct the volcano-tectonic development of Ischia during the last 55 ky B.P. Different models of block resurgence of Ischia have been discussed, based on literature studies. These aspects have supplemented the Quaternary geologic evolution of Ischia. While the northern Ischia offshore shows complex stratigraphic relationships between buried volcanic edifices, the southern Ischia offshore has been mainly commanded by erosional activities, progressive next to a dense system of submarine channels, and by the volcano-tectonic activities, which have triggered off the location of the Ischia Debris Avalanche. [ABSTRACT FROM AUTHOR]

The Southeastern portion of the East African Rift System reactivates Mesozoic transform faults marking the separation of Madagascar from Africa in the Western Indian Ocean. Earlier studies noted the reactivation of the Davie Fracture Zone in oceanic lithosphere as a seismically active extensional fault, and new 3D seismic reflection data and exploration wells provide unprecedented detail on the kinematics of the sub‐parallel Seagap fault zone in continental/transitional crust landward of the ocean‐continent transition. We reconstruct the evolution of the seismically active Seagap fault zone, a 400‐km‐long crustal structure affecting the Tanzania margin, from the late Eocene to the present day. The Seagap fault zone is represented by large‐scale localized structures affecting the seafloor and displaying growth geometries across most of the Miocene sediments. The continuous tectonic activity evident by our seismic mapping, as well as 2D deep seismic data from literature, suggests that from the Middle‐Late Jurassic until 125 Ma, the Seagap fault acted as a regional structure parallel to, and coeval with, the dextral Davie Fracture Zone. The Seagap fault then remained active after the cessation of both seafloor spreading in the Somali basin and strike‐slip activity on the Davie Fracture Zone, till nowaday. Its architecture is structurally expressed through the sequence of releasing and restraining bends dating back at least to the early Neogene. Seismic sections and horizon maps indicate that those restraining bends are generated by strike‐slip reactivation of Cretaceous structures till the Miocene. Finally based on the interpretation of edge‐enhanced reflection seismic surfaces and seafloor data, we shows that, by the late Neogene, the Seagap fault zone switched to normal fault behaviour. We discuss the Seagap fault's geological and kinematic significance through time and its current role within the microplate system in the framework of the East African rift, as well as implications for the evolution and re‐activation of structures along sheared margins. The newly integrated datasets reveal the polyphase deformation of this margin, highlighting its complex evolution and the implications for depositional fairways and structural trap and seal changes through time, as well as potential hazards. [ABSTRACT FROM AUTHOR]

On May 7, 2018, Xiamen Island was hit by extraordinary rainstorm (once in more than 100 years), which had a serious impact on the beaches in the southeast of the island. In this study, RTK GPS, leather ruler, ruler, drone and other equipment were used to investigate and estimate the degree of damage. A total of 10 shore sections including 22 beaches were washed out along the 10.78 kilometers beach in the southeast of Xiamen Island. The total length of the damaged shore line was 6.1 kilometers, accounting for 57% of the investigated beach. A total of 28 gullies were found and the damaged area was estimated to be 20, 286 m2. This extraordinary rainstorm was estimated to result in more than 40, 000 m3 sand being carried away. The damage could be due to the pavement of impermeable surface along the coastal zone which formed strong surface runoff on the sloping terrain when the extraordinary rainstorm occurred. The current was strong enough to erode the sand and stone steps and lawn, and even form gully. Based on the degree of damage and damage cause of individual beach, several remediation and restoration plans were suggested to recovery the beach. This study can provide some references for the future beach maintenance.

A high-resolution multibeam survey from a portion of the San Simeon Channel (offshore Morro Bay, California) captured a zone of recurring troughs and ridges adjacent to prominent submarine meander bends. Through an integrated study using surveying data, sediment core analysis, radiocarbon dating, and stable isotope measurements, we hypothesize that turbidity current event frequency was higher during the late Pleistocene than at present conditions. We speculate that the rise in sea-level following the Last Glacial Maximum sequestered sedimentation largely to the shelf during the Holocene. This work suggests that the occurrence of sediment gravity flows in this region, particularly away from any submarine channels, is appreciably lower than at times of continental shelf subaerial exposure.

Recent advances in basin and petroleum system modelling have allowed for the investigation of gas hydrate systems, including modelling of the generation, migration, and accumulation of biogenic and thermogenic gas within gas hydrate deposits. In this brief survey paper, the treatment of sediment organic properties (organic content and richness, expressed as total organic carbon and the hydrogen index) within previously published basin and petroleum system models of marine gas hydrate systems is reviewed. Eight studies (published between 2015 and 2020) are described and discussed. This review contributes to the state of knowledge in the field by reviewing existing modelling studies of gas hydrates and concludes with brief takeaways on important considerations and knowledge gaps in the state of basin and hydrocarbon system modelling of gas hydrate systems. [ABSTRACT FROM AUTHOR]

The assessment of the vulnerability of a site to tsunami events should take into consideration the geomorphological setting, which is strongly determined by the stratigraphic framework of the area. Lampedusa island is located in the central portion of the Sicilian Channel (Mediterranean Sea, Italy), where a significant incidence of tsunamis (with wave runup above 15 m) caused by earthquakes and submarine landslides has been historically documented. This work shows the geomorphological and stratigraphic differences between the western and south-eastern sectors of Lampedusa island. This update to the geological characterization of the island was used to create 3D flooding maps according to runup steps of 5 m, 10 m, and 15 m, thus showing a homogeneous involvement of the south-eastern sector of Lampedusa. Furthermore, our study aims to provide a geomorphological-stratigraphic base for a mathematical-statistical model to create coastal flooding maps due to tsunami waves. As such, this tool is useful for evaluation of strategic infrastructure for the security of the island and the improvement of risk management in civil protection. [ABSTRACT FROM AUTHOR]

The article is dedicated to the memory of Academician of the National Academy of Sciences of Ukraine Yevhen Fedorovych Shnyukov, an outstanding scientist-geologist, one of the world leaders in fundamental and applied areas of research in marine geology and geophysics, metallogeny, lithology and mineralogy of the World Ocean. [ABSTRACT FROM AUTHOR]

The Pinghu slope belt is the main oil and gas exploration area in the Xihu Sag of the East China Sea Basin, and the exploration field is gradually changing from structural oil and gas reservoirs to structural-lithologic oil and gas reservoirs. However, the control effect of faults on tectonic-lithologic reservoirs is unclear, which seriously restricts the understanding of the accumulation law and the analysis of sand body distribution characteristics in the Pinghu slope belt. Based on the fine interpretation of 3D seismic data, this paper systematically analyzes the planar and profile evolution characteristics of faults in different tectonic periods and their control on tectonic-lithologic reservoirs. The analysis shows that the control of fault on the reservoir in the Pinghu slope belt is mainly reflected in the sand body distribution and oil & gas migration and accumulation. Sand body distribution is controlled by syn-sedimentary faults, mainly distributed under the faulted slope break formed by syn-sedimentary faults. The rifted fault has a dual role in the process of oil & gas migration and accumulation, which can be used as a channel for vertical migration of oil & gas, and as an occlusion for preventing lateral migration of oil & gas. According to the fault distribution characteristics of the Pinghu slope belt, combined with the exploration and research of tectonic-lithologic reservoirs in the study area, the tectonic-lithologic reservoir types in this area are divided into three categories. The fault slope type structural-lithologic reservoirs are mainly developed in the descending wall of the Tuanjianting steep-slope fault; the Structural-lithologic reservoirs of consequent fault terrace type are mainly developed in Kongqueting, Tuanjiting and Pinghu area; the antithetic fault terrace type structural-lithologic reservoirs are mainly developed in the descending wall of the Baoyunting-Wuyunting antithetic fault. [ABSTRACT FROM AUTHOR]

The study details geological analysis of the South China Sea region. South China Sea is a marginal sea located in unique geographical region of west Pacific Ocean. It has a complex tectonics history being developed at subduction zone of three tectonic plates: Eurasian, Pacific and Indian. Geologically, South China Sea is rich in mineral resources and has high geological prospects. Within the scope of the study, the review of the general settings of the study area (bathymetry, geology, tectonics and sedimentation) is accomplished by the report on the current activities, methods and research clusters. Current directions in the marine geological research in the South China Sea area are presented. Research methods of the seafloor surveying and mapping currently undertaken in the South China Sea region are described: systematic measurement by multi-beam echo-sounders, altimetric measurements, GPS positioning, application of the unmanned underwater vehicles, GIS mapping, data analysis, dredging and drilling. The results include maps visualized by means of Generic Mapping Tools (GMT) showing geological and geophysical settings in the South China Sea region, bathymetry and model of the marine free-air gravity. Research development and recent progress in marine geologic investigations are reported with focus on current activities in the coastal area of the South China Sea region.

Ischia shows intriguing and complex geology, which has been deeply investigated. In this paper, a reappraisal of the Quaternary geologic evolution of Ischia based on literature data is advised, concentrating on the volcanology of the island, based on field data and geochemistry, due to the happening of active fumarolic systems on the island and the marine geology and geophysics, which are intensively studied in the frame of the CARG Project. The literature studies have been incorporated with the geological interpretation of high-resolution seismic profiles, partly previously published and herein reorganized with the aim to highlight the geologic evolution of the different sectors of the island (northern Ischia, southern Ischia). The outcrop data have shown the deposits of ten explosive eruptions: among them, we focused on the S. Angelo Tephra. The laccolith model has been described in order to explain the resurgence of Ischia starting from 55 ky B.P. Geochemical information has been synthesized to reconstruct the volcano-tectonic development of Ischia during the last 55 ky B.P. Different models of block resurgence of Ischia have been discussed, based on literature studies. These aspects have supplemented the Quaternary geologic evolution of Ischia. While the northern Ischia offshore shows complex stratigraphic relationships between buried volcanic edifices, the southern Ischia offshore has been mainly commanded by erosional activities, progressive next to a dense system of submarine channels, and by the volcano-tectonic activities, which have triggered off the location of the Ischia Debris Avalanche.