Marine Sand Research Articles

Experimental study on shear behavior of marine sands subjected to acidic conditions

Experimental study on shear behavior of marine sands subjected to acidic conditions

Electrodeposition of calcareous cement from seawater in marine silica sands

The erosion of marine sediments is a pressing issue for coastal areas worldwide. Established methods to mitigate coastal erosion fail to provide lasting and sustainable solutions to protect marine ecosystems. Here we demonstrate the application of mild electrical stimulations to precipitate calcareous mineral binders from seawater in the pores of marine soils via electrodeposition, an alternative approach to mitigating coastal erosion. Results of electrochemical laboratory experiments unveil that the polymorphs, precipitation sites, intrusion mechanisms, and effects of electrodeposited minerals in marine sands vary as a function of the magnitude and duration of applied voltage, soil relative density, and electrolyte ionic concentration. Surprisingly, in addition to the precipitation of calcium carbonate and magnesium hydroxide, the formation of hydromagnesite is also observed due to electrically driven fluctuations in the local pH\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${pH}$$\\end{document}. These electrodeposits lead to enhanced mechanical and hydraulic properties of the marine sands, indicating that electrodeposition routes could be developed to reinforce marine soils in coastal areas that more closely mimic natural systems.

Description and Assessment of an Antimicrobial Substance from Marine Actinobacteria

Streptomyces is thought to be the primary source of bacteria for the synthesis of bioactive substances, such as naturally occurring antibiotics. Finding and identifying the actinomycetes exhibiting antagonistic activity was the primary goal of the current investigation. A strain of actinomycetes that was isolated from marine sand samples that were collected off the Indian coast of Vedharanyam exhibited antimicrobial activity against a number of microbial pathogens. The nutritional requirements and cultural conditions for maximal growth and yield of bioactive compounds have been optimized under shake flask condition. Analyze the compound characterization of the sample such as UV, FT-IR, GC-MS and sequencing 16S rRNA for species identification. The actinomycetes isolates which are isolated from sediment sample can be further used as antimicrobial activity agents against bacterial and fungal pathogens and their compound characterization.

A novel three-part pharynx and its parallel evolution within symbiotic marine nematodes (Desmodoroidea, Stilbonematinae)

Stilbonematinae are nematodes commonly found in shallow marine sands. They are overgrown by a genus- and species-specific coat of chemoautotrophic sulphur-oxidizing ectosymbiotic bacteria which profit from the vertical migration of their hosts through the chemocline by alternately gaining access to oxidizing and reducing chemical species, while in return, the host feeds on its symbionts. The subfamily exhibits a large morphological variability; e.g. the anterior pharynx is cylindrical in genera possessing a voluminous coat, but species with a bacterial monolayer possess a distinctly swollen corpus and therefore a tripartite pharynx. Since 18S-based phylogenetic analyses do not show close relationships between corpus-bearing species, we investigated the pharynx morphology using phalloidin staining in combination with confocal laser scanning microscopy, transmission electron microscopy and light microscopy in order to assess an independent evolution. The class-wide stable position of the subventral pharynx ampullae was used as a morphological marker. Ampullae are positioned at the anterior-most end of the isthmus in Cyathorobbea, further posterior in Catanema and Robbea and inside the corpus in Laxus oneistus. We therefore conclude an independent evolution of corpus enlargements within Stilbonematinae. This further suggests that pharynx morphology is driven by the volume of the symbiotic bacterial coat rather than phylogeny. Based on an existing mathematical model, an enlarged corpus should enable its bearer to ingest food in smaller quantities, in gourmet style, whereas a cylindrical pharynx would restrict its bearer to ancestral gourmand feeding. A review of pharynx types of Nematoda showed that the Stilbonematinae pharynx is substantially different compared to other tripartite pharynges. The lack of pharyngeal tubes and valves, the undivided corpus and evenly distributed nuclei in the isthmus warrant the definition of the “stilbonematoid” three-part pharynx.

Dampak Aktivitas Penambangan Pasir Laut Terhadap Lingkungan di Desa Sathean Kabupaten Maluku Tenggara

The purpose of this study was to evaluate the environmental impact of sea sand mining in Sathean village, Kei Kecil sub-district, Southeast Maluku district. This study focuses on the state of the environment around marine sand mining and the impacts of these activities. Qualitative research is the chosen research method. The results show that marine sand mining damages the biological quality of marine and coastal waters through increased abrasion. Economic income for miners and mining workers increases as a result of social conditions caused by sea sand mining, but decreases for fishing communities due to reduced fish catches and pearl cultivators because pearl growth is not optimal due to damage to the aquatic environment.

Effect of Mean Particle Size and Uniformity on Modulus Degradation of Nonlinearly Graded Marine Sands

Effect of Mean Particle Size and Uniformity on Modulus Degradation of Nonlinearly Graded Marine Sands

Feasibility studies on marine sand from off-shore dredging for plastering applications

Feasibility studies on marine sand from off-shore dredging for plastering applications

Living root contributions dominate vertical accretion, but not carbon burial, in two SE Australian tidal wetlands

Organic matter derived from allochthonous and autochthonous sources makes an important contribution to the accumulation and burial of “blue carbon” in tidal wetlands. Organic matter accretion is also a mechanism by which tidal marshes and mangroves adjust vertically to the pressure of sea-level rise, through feedbacks between marsh autotrophic productivity and hydroperiod. However, the separate contributions of inorganic matter, detrital organic matter and living roots to marsh accretion have rarely been documented. We used a network of Surface Elevation Table-Marker Horizon (SET-MH) stations SE Australia as a benchmark against which the accumulation of inorganic, organic and living root material was measured. Established in 2000–2002, the SET-MH stations allowed for sampling accretion and elevation gain in mangrove and saltmarsh in fluvial and marine sand geomorphic settings. We found living root material to be the dominant contributor to the volume of accretion above feldspar marker horizons and elevation gain over the 20-year experimental period. However, detrital organic matter, being of lower bulk density than living roots, contributed most to carbon burial. Higher rates of accretion and elevation gain were associated with higher contributions of pore volume, and lower contributions of inorganic matter. The rate of subsidence increased with accretion and was lower where inorganic matter contributions to mass were higher. The results highlight the importance of biological and hydrological contributions to accretion and elevation gain in a region subject to riverine minerogenic inputs.

In-situ and laboratory characterisation of stiff and dense geomaterials for driven pile analysis and design

Integrated field and laboratory characterisation of geomaterial behaviour is critical to foundation analysis and design for a wide range of offshore and onshore infrastructure. Challenges include the need for high-quality sampling, addressing natural and induced micro-to-macro structures, and applying soil and stress states that represent both in-situ and in-service conditions. This paper draws on the Authors’ recent research with stiff glacial till, dense marine sand and low-to-medium density chalk, and focuses particularly on these geomaterials’ mechanical behaviour, from small strains to failure, their anisotropy and response to cyclic loading. It considers a range of in-situ techniques as well as highly instrumented monotonic and cyclic stress-path triaxial experiments and hollow cylinder apparatus tests. The outcomes are shown to have important implications for the analysis of large driven piles under monotonic-and-cyclic, axial-and-lateral loading, and the development of practical design methods. Also highlighted are the needs for approaches that integrate field observations, advanced sampling and laboratory testing, numerical and theoretical modelling.

Investigation on the properties of sustainable alkali-activated GGBS mortar with nano silica and dredged marine sand: Mechanical, microstructural and durability aspects

In recent years, alkali-activated mortar (AAM) has emerged as a promising alternative to ordinary Portland cement (OPC) due to concerns regarding the environmental impact resulting from cement production, which releases carbon dioxide and degrades the quality of the environment. To address these concerns, researchers have explored the addition of supplementary binder materials to enhance cement properties and mitigate pollution. The effectiveness of these binder materials depends heavily on their chemical composition and fineness. Notably, ground granulated blast furnace slag (GGBS) enhances the strength and durability of the cement. In response to the scarcity of river sand (RS), dredged marine sand (DMS) has gained popularity as a potential substitute within the civil engineering field. Furthermore, the integration of nanomaterials has shown promising improvements in the mechanical and microstructural properties of mortar. Therefore, this study aims to investigate the properties of mortar by incorporating nano silica (NS) within the range of 1% to 7%, varying the molarity from 2 M to 8 M, and substituting RS with DMS. The tests carried out encompass a range of evaluations, including compressive strength, flexural strength, SEM-EDS, XRD, UPV, RCPT, and carbonation analysis, to comprehensively assess the properties of the mortar. The study reveals that the AAM demonstrates optimal performance when 50% of RS is replaced by DMS in the absence of NS. Once this optimal point is determined, further analyses are conducted at this value while varying the concentrations of NS from 1–7%. The experimental results indicate that replacing 50% of RS with DMS and incorporating 6% NS leads to maximum compressive strength (49.2 MPa) and flexural strength (9.36 MPa) in the assessed properties. Furthermore, the incorporation of NS in GGBS-based AAM mixes enhances durability by improving resistance against chloride penetration, reducing water absorption, and minimizing carbonation diffusion. Additionally, the microstructural and mineralogical characterization of GGBS-NS-based AAM specimens demonstrates the formation of C-S-H and C-A-S-H gels as the end products of the reactions.

Closure of Khor Al Balid and Khor Rori harbours/estuaries with coastal uplift and aridity in the 12th – 15th c. CE and evidence for an extreme overwash event in the 18th – 19th c. CE: Implications for ancient port sites in southern Oman

Ancient maritime trading ports along the southern coast of Oman have been the target of archaeological excavations for several decades. Though historical chronologies are well-researched, information from a paleoenvironmental perspective is lacking and can provide a more complete understanding of site development. This study investigates the timing of coastal sand barrier accumulation in the natural harbours at Khor Al Balid and Khor Rori, which had considerable effects on the populations at the ancient cities of al–Balīd and Sumhuram, respectively. Six cores from Khor Al Balid and four cores from Khor Rori were analyzed using sedimentological, microfossil (foraminifera and testate amoebae), geochemical (μXRF), and radiocarbon dating methods. Marine proxies (e.g., Amphistegina spp., C. pseudolobatulus, E. limbatum, Sr, Ca/Si) and lagoon proxies (e.g., T. macrescens, T. inflata, C. constricta and C. aculeata, Ti/Ca, Fe/Ca) were used to identify Marine Sand, Brackish Lagoon/Marsh, and Freshwater facies. Results indicate that the eastern arm of Khor Al Balid closed off from the sea around the 12th century CE and that the western arm closed around the 15th century CE. Siltation of harbours and the formation of sand barriers may have contributed towards site abandonment. Previous archaeological findings suggest that al-Balīd was able to continue with maritime trade activities along the southern seaside edge of the city for several centuries after siltation of Khor Al Balid, possibly with the help of dredging. An extreme overwash event was recorded in almost all cores across both sampling sites, suggesting that a very large cyclone or a tsunami hit the southern Oman coast sometime around the 18th–19th century CE. This event, as well as continuous coastal sand accumulation, may have contributed to the decline and abandonment of Khor Al Balid and highlights the impacts that large storm/wave events have on archaeological site preservation.

Effect of stage amplitude ratio on dynamic behaviors of sand under wind turbine loading

Offshore wind turbines are subjected to more significant wave and wind environmental loads at extreme weather conditions, making subsoil experience various loading stages with different amplitudes. To investigate the coupling effect of both cyclic shear stress ratio (CSR) and stage amplitude ratio (Ar) between normal and extreme weather conditions, a series of bi-directional simple shear tests with five different Ar and three CSR values were conducted on marine sand using the variable-direction dynamic cyclic simple shear (VDDCSS) apparatus. In the tests, soil samples were compacted under vertical stress and then sheared in undrained conditions by applying two shear stresses acting in different horizontal directions. Test results indicated that the cyclic strain, pore water pressure ratio, and cyclic strength were significantly determined by the value of stage amplitude ratios and the CSRs: at the same CSR, cyclic strains, and pore water pressure increased while cyclic strength decreased with the Ar. Comparing the test data between various cyclic stress ratios found that the CSRs can accelerate shear strains, pore pressure accumulation, and cyclic strength attenuation.

An integrated geological characterization of the Mid‐Pleistocene to Holocene geology of the Sørlige Nordsjø II offshore wind site, southern North Sea

Subsurface deposits in recently glaciated marine areas are highly heterogeneous, representing a range of glacial and postglacial environments and processes including glacitectonism, overconsolidation, fluvial and lacustrine deposition, and transgression. These heterogeneities are often linked to variations in engineering properties, with important implications for the design and installation of offshore wind infrastructure. In this study we present an integrated geological characterization of the Sørlige Nordsjø II offshore wind site, located in waters of 50–70 m depth along the southern border of the Norwegian North Sea, focusing on the evolution of the area's depositional setting during the late Quaternary period and its implications for offshore wind development. We integrate interpretations from a marine geological data set acquired in 2022 with legacy 3D seismic data and a review of the current understanding of the southern North Sea's complex glacial history. A preliminary ground model and accompanying risk map for the site is presented with five main geological units: (i) homogeneous and layered marine sands covering most of the site, with patchy distribution and coarser‐grained deposits in the east; (ii) buried, layered channel deposits containing organic material and possible associated shallow gas; (iii) buried, stiff glacilacustrine clay deposits; (iv) a buried, layered, glacitectonized unit incised by tunnel valleys, with a sandy marine infill; and (v) mounded tills and glacitectonized deposits containing boulders, exposed to shallowly buried in the east. Salt diapirism and gas migration were also found to be important potential geohazards at the site. Three‐dimensional seismic attribute maps were found to be a powerful aid to understanding the distribution and genesis of seismic facies identified on 2D high‐resolution sub‐bottom profiles. This type of data integration is an under‐utilized methodology for generating detailed preliminary ground models, which can inform more cost‐effective site survey and early foundation concept planning at geologically complex offshore wind sites.

Authigenic‐cemented pebbles formed during Pleisto–Holocene transgression of gently inclined coastal plains

ABSTRACTFrom numerous modern gently inclined coastal areas and deltas around the world carbonate‐cemented sandstone slabs and pebbles have been reported. Such sandstones collected at the coast of the German North Sea and the Mediterranean Sea (Rhône Delta) are cemented by calcite derived from the anaerobic oxidation of methane, as evidenced by biomarkers and δ13C isotope values <−35‰ typical of anaerobic oxidation of methane. The methane originated from peat, which formed in coastal lowlands, deltas and channels during the Pleisto–Holocene transgression due to the concomitant rise of the groundwater level. During ongoing transgression, the peat became overlain by marginal‐marine mud, acting as a seal, and finally by marine sand. In shallow‐marine settings, wave‐pumping effects during storms led to seal failure and methane could migrate upward. This scenario matches recent observations in the German North Sea where a pockmark field formed during the winter storm season. The emanating methane was eventually oxidized aerobically or anaerobically by anaerobic oxidation of methane in the sand cover. The CH4 generated in the peat underneath contains ‘old’ carbon that becomes, in the case of anaerobic oxidation of methane, incorporated into bicarbonate, which in turn facilitates cementation of sand and, thus, causes the peculiar situation that the C‐14 age of the cement is older than the bioclasts embedded in the sandstone. Such authigenically cemented sandstones have environmental significance for flooding of gently inclined coastal plains.

Morphological evolution of a complex drift‐aligned prograded barrier

AbstractPrograded barriers are coastal landforms with a worldwide distribution that provide a paleoenvironmental record within a sequence of successive ridges and intervening swales. Most barriers with variable terrestrial morphologies, also known as complex barriers, have been poorly studied. At the main entrance of Western Port, a bay in southeastern Australia, a morphologically complex barrier was formed as a function of its somewhat sheltered position and orientation in relation to sporadic swells and tidal circulation. LiDAR‐derived topography shows highly truncated and asymmetrical ridges both across and along the Somers–Sandy Point barrier plain. These uncommon morphologies are associated with an intricate hydrodynamic circulation subject to sporadic storms approaching at a sharp angle to the shoreline that eliminate a significant part of the sedimentary record but also redistribute vast quantities of sand to the downdrift shoreline, and a large and variable sandy bank that undergoes intense sediment movement. Optically stimulated luminescence (OSL) dating within a limited area on the western side revealed an age of ~2600 years for the innermost dated ridge, located about halfway across the plain. Significant erosion of the ridges' record occurred on the western side of the barrier between 2600 and 700 years ago and between 600 and 240 years ago, whereas undated ridges on the eastern side were preserved. This creates an opportunity for future research on past erosional events that would be of great value for coastal management and adaptation. Textural and elemental (XRF) sediment characteristics suggest that the type of material provided for barrier accretion remained the same throughout the late Holocene. Given the sustained growth of the barrier and other sandy parts of the bay, a net supply of marine sand from Bass Strait must have occurred. The proposed evolutionary model contributes to the understanding of the sediment budget for the bay as a whole.

Sediment texture and geochemistry as predictors of sub-depositional environment in a modern estuary using machine learning: A framework for investigating clay-coated sand grains

Sedimentary cores from the Ravenglass Estuary lack some of the sedimentary structures which can be seen in other estuarine sands due to their unconsolidated nature, making it difficult to meaningfully interpret depositional environments using standard sedimentological facies analysis. Here we explore how sediment texture, obtained from laser particle size analysis, and geochemistry, obtained from portable X-ray fluorescence, can be used independently, or in combination, to automatically classify sub-depositional environment and estuarine zone in a modern estuary. We have adapted an established Extreme Gradient Boosting workflow to select the most informative geochemical elements to be included in a training set to automatically classify sub-depositional environment at the surface of the Ravenglass Estuary, NW England, UK. Models that are trained exclusively on textural data significantly outperform those that use geochemical data when classifying sub-depositional environment but are comparable when classifying estuarine zone. However, the combination of textural and geochemical data in training sets improves model performance in all but one class when compared to separate textural and geochemical models. We have applied surface-calibrated combined textural and geochemical models to classify palaeo sub-depositional environment in three cores obtained from a tidal flat in the Ravenglass Estuary that are interpreted to record initial outer estuary deposition which transitioned to an inner estuary setting dominated by deposition from suspension. The subsurface classifications provide a framework to investigate the occurrence of reservoir quality-preserving detrital grain coats which vary in abundance as a function of sub-depositional environment at the surface. A review of literature suggests that the mixed flat sub-depositional environment is an ideal target for optimum clay grain coat occurrence, and we show that this sub-depositional environment is reliably identified by all models. We also discuss the implications of the modelling, how it compares to other machine learning approaches to understand reservoir quality in ancient systems, and how the workflow may be adapted for application to reservoir core. This study demonstrates value in utilising textural and geochemical data in conjunction with machine learning methods to help reveal the environmental evolution of marginal marine sands.

Investigating the management of marine sand mining: A case of West Sea Exclusive Economic Zone in South Korea

Due to marine sand being classified as a common resource, the environmental cost resulting from its mining has not been reflected in the market prices of marine sand and aggregates, leading to overexploitation. Thus, it is crucial to consider the environmental cost of sustainable management. This study employed the contingent valuation method (CVM) to estimate people’s willingness to pay (WTP) for the conservation of marine sand, specifically focusing on the West Sea Exclusive Economic Zone (EEZ) in South Korea through a nationwide survey. As a result, although many of them revealed zero WTP for the issue, South Korean people are nonetheless concerned about the environmental damages caused by marine sand mining and support the strengthening of related policies. The annual environmental cost is estimated at KRW 45.8 billion (USD 41.6 million), and the unit environmental cost based on this is KRW 1390.1 (USD 1.3) per m3.

Application of corrosion resistance of FRP composites rebar in sea water sea sand concrete

In recent years, Fiber Reinforced Polymer(FRP) has been widely used as a reinforcement material to improve the flexural capacity of beams and slabs, and FRP has good corrosion resistance. And because of the wide variety of fiber materials, so more than the role of ordinary steel.This paper will discuss whether it can replace steel to improve building durability in alkaline environment such as seawater sea sand concrete.Due to the lack of natural river sand and water resources, people have been trying to use sea sand seawater instead in recent years. But there are many safety accidents because of the corrosion of steel bars. Due to the good corrosion resistance of FRP, this paper discusses the feasibility of its service as a steel bar in marine sand concrete, including its failure characteristics after corrosion and the problems and improvement strategies when working with Seawater-Sea Sand Concrete(SWSSC). The research object of this paper is Glass Fiber Reinforced Polymer(GFRP) steel bar and Carbon Fiber Reinforced Polymer(CFRP) steel bar. Glass fiber and carbon fiber are widely used materials in current production activities, mostly in the field of mechanical manufacturing. Although engineering materials have been used in recent years, the time is short. In this paper, it is discussed that in the simulated pore solution of concrete stirred by seawater and sea sand and exposed in the environment of seawater immersion, by increasing the temperature to accelerate the reaction rate, it is found that the corrosion resistance of the two kinds of steel bars is very different, but the corrosion mechanism is similar, both of them are caused by the dissolution of the resin matrix. The fiber is bare, and the internal fiber actually has the bearing capacity, but the ability of the material to bear the force is still reduced due to the loss of the bonding of the resin matrix. Therefore, this paper proposes that it is possible to find a more corrosion-resistant resin matrix or add a layer of medium at the interface between the fiber and the matrix to maximize the role of the fiber.

Submarine lateglacial lake deposits from jutland bank, the north sea

Little is known about Lateglacial environments in the North Sea, the so-called Doggerland. Here we report on submerged lake sediments from the north-eastern part of the North Sea, found in sediment core JR-14. The core contained Holocene marine sand underlain by clay and clay-gyttja with plant and invertebrate remains and sand without plant remains, interpreted as glaciofluvial sand. Radiocarbon dating of terrestrial plant remains from the Lateglacial sediments gave ages between 12 300 and 14 100 cal a BP, corresponding to the early part of the Younger Dryas stadial and the Bølling-Allerød interstadial. The Lateglacial sediments contained remains of Betula nana, Salix and Dryas plants indicating a tundra-like open landscape with dwarf shrub heaths, which is typical for the region. The sediments contained a diverse assemblage of bryophytes that throws light on the Lateglacial bryoflora of the region. Remains of macrolimnophytes indicate shallow carbonate-rich, cool lake waters. Remains of larvae of Trichoptera and Chironomidae dominated the invertebrate fauna and indicate a fairly species-rich fauna. The presence of lake sediments at ∼32.9–34.5 m below sea level shows that this part of the North Sea had not been transgressed by the sea during the Lateglacial.

Late Quaternary eolian dune-field mobilization and stabilization near the Laurentide Ice Sheet limit, New Jersey Pine Barrens, eastern USA

Well-preserved stabilized dune fields are widespread in the New Jersey Pine Barrens, northern Atlantic Coastal Plain, USA. In this area, which was unglaciated throughout the Quaternary, quartz-rich Miocene–Pleistocene age fluvial and marginal marine sands provided source sediments for eolian mobilization. Parabolic and transverse dunes within fluvial source-bordering dune fields in small-river watersheds migrated to the east-southeast (110–125°) over unconsolidated sands and gravels. The short eolian transport distance of most dune-field sand in the presence of moderately to sub-rounded quartz grains with low sphericity indicates eolian abrasion and dune-sand fashioning occurred within a short duration of transport. Although the absolute duration of eolian transport remains unknown, dune stabilization occurred about 23–17.5 ka, with a weighted mean of 19.5 ± 0.5 ka from six dated dunes. Dune stabilization coincided with northward retreat of the Laurentide Ice Sheet from its maximum position at ∼41.500° N (∼100 km north of the study area), to ∼41.375°N (∼200 km north). The well-preserved dune morphology and narrowly constrained ages suggest rapid dune stabilization. Dune-forming katabatic winds from the WNW declined abruptly with northward migration of the ice sheet, accompanied by climatic amelioration and stabilization by vegetation. A short-lived period of eolian mobilization may have been associated with a temporary increase in sand availability from adjacent fluvially derived sediments. Post-depositional processes included soil eluviation, with dissolution features and breakage blocks on quartz grains signifying long-term in-situ soil weathering.