Regularities of the formation of the granulometric composition of the bottom and beach deposits of the Anapa bay bar

As a result of the field studies conducted in 2010 of the spatial and temporal variability of the granulometric composition of the bottom and beach deposits of the southern part of the Anapa bay bar, the tendency of a decrease in the average size of the particles under the southward flow of the deposits of the coastal zone was revealed. The comparison of the data obtained in 1949, 1979, and 2010 shows that the average diameter of the particles in the deposits of the underwater slope also gradually decreases over the time. It was established that, with the decreasing of the particle sizes down to 0.1 mm, their nonrecoverable deposition to a depth of more than 7 m increases. Since, in the southern edge of the Anapa bay bar, over 70% of the bottom and about 60% of the beach deposits are represented by fractions smaller 0.16 mm, at this site the mass deposition of the sand material to a depth occurs. Based on the data obtained, the particle size of the sandy material recommended for the restoration of the beaches of the southern part of the Anapa bay bar was determined.     

The carbohydrates in relation to mineralogic and granulometric composition of surface sediments in the karst estuary (River Krka estuary,Yugoslavia)

The investigation of mineral, granulometric and chemical composition of sediments of the River Krka estuary (Yugoslavia) were performed in order to elucidate the origin of the sediments and the pattern of sedimentation. Estuarine surface sediments were found to be fine-grained with a bimodal distribution. Environmental conditions in estuarine sediments favour conservation of the organic matter (anoxic conditions). The carbohydrates in the sediments were investigated to determine whether they are of terrigenous or authigenous origin. Glucose, galactose, mannose, xylose, rhamnose, glucosamine and glucuronic acid were detected in the sediments. Their mutual relationship indicates a preferentially terrigenous source of sedimented organic material in estuarine sediments.     

Interstitial water chemistry of villefranche bay sediments: Trace metal diagenesis

Pore water aliquots were taken with an in situ close interval sampler: the “Peeper”.We report here the pore water concentration profiles of TCO₂, SO₄, TH₂S, Ca and the trace metals Mn, Cu, Pb, Cd and Cr from sediments of a relatively polluted area, the Villefranche Bay, on the French Riviera (close to Nice).We investigated the major ion concentrations in order to establish geochemical mass balances of organic matter oxidation. ΔTCO₂/ΔSO₄ was <−2.0, reflecting the precipitation of calcite as confirmed by the calcium profile. Reduction of sulfate led to increasing sulfide concentrations with depth.Trace metal interstitial water concentrations decreased from 63 to 5 nM, 18 to 4 nM and 6.6 to less than 2 nM for Cu, Pb and Cr, respectively. Cd showed a different pattern with top and deep values of 0.7 nM and a minimum of 0.27 nM.Thermodynamic calculations were performed which suggest the potential formation of mineral phases such as sulfides.     

Observations on the hydrology of bay of Islands,New Zealand

Observations were made on several hydrological features of Bay of Islands during 1970 to 1971. The topography of Bay of Islands allows for a gradual change from estuarine to oceanic conditions within the harbour.

Monthly means of sea surface temperatures ranged between 15°c and 23°c, and some sea stratification was observed during summer. Salinities in the main basin were about 35.5‰; water transparency ranged from 2 m to 6 m by Secchi disc in the estuaries, to more than 15m in outer basin areas. Dissolved oxygen content was high, usually exceeding 100% saturation in surface waters. Water circulation within the bay appears to consist of an anti‐clockwise movement of at least the surface water, induced by a north‐west moving current, possibly derived from the East Auckland Current.

The observations suggest that, except; for the estuarine areas, Bay of Islands is hydrologically a fairly homogeneous, well‐mixed body of water.     

地磁日变改正中磁湾磁钩等磁扰对海洋磁力资料的影响

在海洋磁力测量过程中,磁扰形态变化复杂的特性致使地磁日变的改正仍存在着许多困难。本文根据黄海、东海和南海北部十余年采集的超过10⁴ km的海洋和陆地地磁资料,利用对比分析的方法,总结了3种磁扰现象对海洋磁力资料的影响规律:1)微扰的海陆日变值持续时间短,幅度比值接近1∶ 1,对海洋磁力资料影响很小,利用低通滤波可以完全消除其影响;2)磁钩海陆日变幅值比为1~2,持续时间在1 h以内,校正后的地磁异常值仍有较大的误差,利用最小曲率法可以基本消除其影响;3)磁湾的持续时间长,海陆日变幅值变化大,无法准确消除其影响,采用最小曲率法等插值方法处理后,仍残留假异常,需要额外关注。     

Modeling of Coastal Dynamics of the Anapa Bay-Bar

Oceanology - Abstract—The trend of the recent development of the Anapa bay-bar is considered based on modeling of sediment transport and morphodynamic processes. It is shown that longshore...     

Chemical composition of Aegean Sea sediments

The partial composition of 241 sediment samples from the Aegean Sea, determined for Ca, Mg, Al, Ti, Fe, Mn, Ni, Cr, Pb, Cu, and Zn, can be largely explained by admixture of terrigenous components of variable composition and biogenic components poor in minor elements. Cr and Pb appear to be enriched owing to the occurrence of mafic rocks and minor Pb mineralisation onshore. Variations in elemental abundances within the Aegean Sea can generally be accounted for by differences in depositional environment, except at Sounion where anomalous concentrations of Pb and Zn are probably associated with onshore mining activity.     

Morpholithodynamic processes in the coastal zone of the Anapa spit barrier

The results of field studies of the beach dynamics and the continental slope (over the depth range from 0 to 5 m) of the Anapa spit barrier that were carried out in 2002–2005 using ten lateral profiles are presented. The analysis of the location of the submarine ridges based on the data of 1992 up to a depth of 11 m has shown that the configuration thereof facilitates the transport of sediments to the southeast, thus bypassing Cape Anapa. No resultant accumulation of beach-forming sediments on the southeastern flank of the spit barrier occurs within the submarine slope bordering the high coast, thus provoking the active erosion of the town beach over the last 25–30 years. The main reasons for this are the tectonic deformation of the coastal region and the submarine slope between the harbor and the central part of the town beach, as well as the change in the azimuth orientation of the resultant waves from 135° in the 1960s–1970s to 210° over the past decade. The relatively stable coast and the regions of intense erosion of the accumulative body of the Anapa spit barrier were revealed on the basis of the measurements and the analysis of the topographic data.     

Effects of oilfield brine effluent on sediments and benthic organisms in trinity bay,Texas

Field studies have established the concentrations of naphthalenes in bay sediments and water in the vicinity of an oil separator platform and their effects on the benthic fauna. Fifteen stations were occupied monthly, from July, 1974 to December, 1975, along three transects extending from the separator platform outfall outwards for a distance of 4·0 to 5·6 km. A lesser number of stations were occupied from April, 1974 to June, 1974. Bottom sediments at each station were analysed for total naphthalenes content and for number of species and individuals. All stations were located in 2 to 3 m of water. The outfall was located 1 m off the bay bottom.There was a definite correlation between sediment naphthalenes concentration and number of species and individuals. As expected, the first station, located 15 m from the outfall, had the highest concentration of naphthalenes of all stations sampled. The naphthalenes levels dropped sharply from the outfall to the stations located 75 m from the platform where levels were about 20–50% of those found 15 m from the outfall. Naphthalenes concentrations then decreased gradually to near background levels at stations farther out. Hydrocarbon concentrations in bottom water 15 m from the outfall were three orders of magnitude lower than those in the full strength effluent, but sediments 15 m from the outfall had hydrocarbon concentrations four times as great as in the full strength effluent. There were approximately four orders of magnitude more hydrocarbons in the sediment than in the overlying water.The bay bottom was almost completely devoid of organisms within 15 m of the effluent outfall. Stations located 150 m from the outfall had severely depressed benthic faunas but not to the extent of stations nearer the outfall. Stations located 455 m from the platform were unaffected. Both numbers of species and individuals increased with distance from the platform and reached a peak at the first station medial to the control on each transect (685 to 1675 m from the platform) and then dropped at the control station. Physical environmental factors such as temperature, salinity, water depth and sediment type were essentially the same at all stations.The temporary use of a second outfall located 275 m from the main platform outfall resulted in a rapid build up of naphthalenes in surrounding sediments which persisted for at least six months following the termination of use of the second outfall. The benthic fauna was also severely depressed in the vicinity of the second outfall. The use of multiple outfalls, located some distance apart, appears to be more harmful than the use of a single outfall.Trinity Bay, Texas, the site of this investigation, has a mean depth of 2·5 m. The bay water is highly turbid due to the presence of a high concentration of clay-sized particulate material. The brine outfall was located approximately 1 m above the bay bottom. These special conditions undoubtedly contributed significantly to the observed impact of the brine. Therefore, extrapolations from the results of this study to offshore oil production and brine disposal should be made with extreme caution.     

Carbon-isotope composition of sediments from the Gulf of Papua

Rivers draining into the Gulf of Papua (GOP) from the Papua New Guinea mainland deliver approximately 340 × 10⁶ t yr^–1 of sediment to the marine environment. The terrestrially derived sediment contains 1.1 ± 0.2% particulate organic carbon with a carbon-isotope composition of –26.5 ± 0.2, and amounts to 3.7 ± 0.7 × 10⁶ t yr^–1. The carbon-isotope composition of sediments in the Gulf of Papua indicates that 40% of the sediment cover contains 75% or more terrestrially derived carbon. Suspended sediments that are transported beyond the delta complex of the Fly River are transported north and northwest, augmented by sediments from other rivers along the coast of the GOP. The carbon-isotope results suggest that a significant quantity of terrestrially derived sediment escapes from the GOP, either along the coastlines to east and west or into the deep ocean via the Moresby and Pandora troughs. Little sediment travels south onto the Great Barrier Reef shelf. Extrapolating the results from this study to the region of Oceania suggests a total flux of particulate organic carbon to the world's oceans from the islands of Oceania of ~ 90 × 10⁶ t yr^–1 or twice the flux of riverine POC from the major rivers of North America, South America, and Africa combined. While such a calculation must be considered illustrative only, the similar tectonic, geomorphologic, and climatic features of the islands of Oceania suggest that the calculation is unlikely to be grossly in error and that the rivers of Oceania therefore represent a major but poorly documented source of sediment and organic carbon to the global ocean.     

Influence of infrequent floods on the trace metal composition of estuarine sediments

By use of iron variation diagrams, it is shown that the concentrations of Mn, Ni, Cu and Zn in sediments of upper Chesapeake Bay are 50–75% lower than expected if they were simple mixtures of their apparent source materials: eroding Atlantic Coastal Plain deposits and material delivered by the Susquehanna River under ordinary discharge conditions. The Fe concentrations in the sediments, on the other hand, are consistent with derivation from these sources. Evidence is presented that the ratios of total Mn, Ni, Cu and Zn to Fe in the Susquehanna River decline during high discharge events. Because such events are responsible for removal of a major fraction of the total material carried out of the river basin, it is likely that the upper bay sediments simply reflect the long-term average composition of material from the basin. Averaging over a period much greater than one year is necessary to obtain a meaningful estimate of the trace element composition of material being removed from this river basin.     

Geology and geotechnical characteristics of sediments in east bay area,Mississippi delta

Abstract

Deltaic sedimentation has produced an accumulation of clay and silt with a maximum thickness of 90 m in East Bay area. Sediments in the upper 50 m grade from interbedded sand, silt, and clay near South Pass and Southwest Pass to predominantly clay in the central part of the area. The variation in the types of sediments and rates of deposition greatly affected the engineering properties of these deposits. Sediments from boreholes in the central part of the area have shear strengths of less than 10 kPa to a depth of at least 50 m. Near the distributaries, shear strength increases with depth; values as high as 43 kPa were measured in sediments in the upper 50 m. These sediments are generally stronger and coarser, and have a lower water content and liquid limit than do sediments at comparable depths in the central part of the area.     

Structure and chemistry of sediments in Belfast Lough,a semi-enclosed marine bay

In a study of the benthic environment of Belfast Lough the structure of the subtidal sediment was examined along with its content of organic matter and selected metals (Cr, Mn, Ni, Cu, Zn, Pb). A wide range of sediment types occurred within the lough but the mean grain sizes for individual sites lay predominantly within the size classes of fine sand, very fine sand and silt. The content of organic matter and metals in the sediments showed strong positive correlations with each other and with the content of silt/clay. Both organic matter and metals decreased in concentration in a seawards direction. The content of organic matter lay generally within the range of 1–5% which is normally associated with shelf sediments, but constituted up to 12% of the sediment in the docks area. Likewise, metals were usually within the range reported within other nearshore coastal waters of the U.K., but sediments in the docks area and inner lough were enriched with several metals. Cluster analysis identified four major subdivisions in the lough which were distinctly different in their contents of silt/clay, organic matter and metals.     

Mineral composition of the modern bottom sediments of the White Sea

The mineral composition of the modern bottom sediments were studied in the White Sea. The single terrigenous-mineralogical province is defined; it is characterized by the mineral association of amphibole, epidote, garnet, and pyroxene. Five regions are assigned in the White Sea in accordance with the mineral composition of the surface bottom sediments. We argue that the granite-metamorphic rock complexes of the Baltic Shield are the main source of the modern sediments in the White Sea, while the East European Craton (Russian Platform) plays a secondary role.     

Meteorological effects on the surface circulation and hydrology of Tasman bay,New Zealand

Analyses of trajectories of drift cards, released over a 2‐year period April 1969‐Aprit 1971, and hydrological observations at nine stations all occupied in and near Tasman Bay within 19 hours on 4–5 March 1970, show variable surface flows, which are strongly influenced by wind. Water characteristics are altered by insolation and coastal run‐off. The exchange times for the water in Tasman Bay were calculated for differing wind speeds.     

Mesoscale eddies in the area of peter the great bay according to satellite data

We have studied the characteristics of mesoscale eddies in the Peter the Great Bay and the adjacent area of the northwestern Sea of Japan. The characteristics were determined using infrared images (NOAA/AVHRR satellite data) for July–October periods of 2000–2004. It is established that anticyclonic eddies are always present in the indicated area, since they have been identified on 85% of the available cloudfree images. Characteristics of 43 anticyclonic eddies have been determined. Their diameters vary from 20 to 110 km, with the most probable sizes within 20–60 km. The typical eddy lifetime varies from 3 to 30 days. However, some medium-sized eddies (40–60 km) have been observed for a longer time (up to 40–60 days) and large eddies (60–110 km in diameter) remained for up to 1–2 months. Eddies drift southwestward and southward along the continental slope at a typical speed of 3–6 cm/s. There are interannual variations in the vortex structure of water flows in the area studied, which are manifested by the presence of a single large eddy occupying a large part of the bay in some years (2000, 2002, and 2003) or by the formation of several smaller eddies (2001 and 2004). The eddies contain warmer and less saline shelf waters (compared to the surrounding water) and transport it in their cores over quite a long distance. Thus, eddies are an essential element of the process of the intermediate low-salinity water-mass formation in the Sea of Japan. In addition, eddies play important role in the cross-shelf water exchange, providing rapid ventilation of the coastal zone and determining the variability of the biological processes.     

Deformation of the Submerged Slope of the Anapa Bay-Bar From 2012 to 2018

Oceanology - Abstract—The article considers the long-term relief dynamics of the submerged slope of the Anapa bay-bar. The Anapa bay-bar consists of five morphological elements—Solenoe...     

沉积环境对雅浦海沟沉积颗粒物组成和分布的影响

通过对西太平洋雅浦海沟不同水深沉积物中总有机碳（TOC）、总氮（TN）、碳稳定同位素（δ13C）、粒度组成和比表面积（SSA）等参数的分析,探讨了雅浦海沟不同水深沉积颗粒物来源、分布及其影响因素的异同。结果表明,雅浦海沟沉积物TOC含量和δ13C平均值分别为（0.34%±0.14%）和（-20.8‰±0.7‰）,其中海洋浮游植物、陆源土壤和维管植物来源有机碳（OC）的贡献分别为（70%±3%）、（22%±3%）和（8%±2%）,且不同水深差异不大,海沟内沉积物的横向输运可能是深部沉积OC的重要输入途径。由于水深更深站位沉积颗粒物中具有更强的微生物活动和在水柱中更长的保留时间,导致其TOC和TN含量较低,但δ13C无明显差异。水深较浅站位TN含量、SSA、粒径组成和中值粒径等参数垂向变化波动较更深站位更为显著,表明海沟沟壁水深较浅处物源输入和沉积环境的不稳定。同时,由于低OC含量、低SSA以及高密度的海底火山喷出岩在海沟水深较浅的沟壁坡折处的广泛分布,导致该区域粒径组成与TOC含量无显著相关性,而较深站位中TOC含量与粉砂呈正相关,与砂和黏土含量呈负相关。整体而言,雅浦海沟沉积物中粉砂粒级颗粒物是OC的主要载体,而SSA是影响海沟沉积OC剖面分布的最重要因素。     

Amino acid composition of sediments from a deltaic environment

Nineteen amino acids in sediments from the Ebro Delta (Spain) have been determined by HPLC. According to quantitative and qualitative data it is suggested that the distributions reflect organic autochthonous contributions and are constrained by environmental conditions of deposition.In the more reducing areas (8.7–11.6 mg total amino acids/g of dry sediment) hydroxyproline, threonine, glycine and glutamic acid are the major amino acids, while in the off-shore stations (1.0–2.7 mg total amino acids/g of dry sediment) ornithine, lysine, phenylalanine, serine and valine are dominant. In these samples absolute concentrations decrease with water depth.The analysis of two cores has shown that sulfur-containing and neutral branched-chain amino acids are the least resistant to geochemical degradation. Within the basic fraction, which appeared to be the most stable, ornithine is produced geochemically and preferentially in the more oxic sediments.     

On the hydrodynamic correction of SEASAT altimeter data (Hudson bay area of Canada)

Abstract

The SEASAT Geophysical Data Record (GDR) file includes a number of corrections for instruments, atmospheric effects, coastal effects, and geophysical effects. However, the transient sea surface variation due to the ocean circulation and wind surge is not implemented. In this research an interactive numerical scheme, based on the vertically integrated hydrodynamic equations, is developed to make this correction. Since the exactness of the transient sea surface depends upon the exactness of the input meteorological data, a method is also developed for extracting surface wind speed and direction from weather charts for the interactive hydrodynamic numerical algorithm.

The application of the algorithm over the Hudson Bay of Canada demonstrates that this technique can easily be applied to any regional altimeter data over a water‐covered area. The resulting transient sea surface profiles and the comparisons between wind fields derived from the weather charts and altimeter inferred wind fields over Hudson Bay for revolution numbers 559, 564, and 574 are presented.