factors influencing recent benthic foraminifera distribution on the guadiana shelf southwestern iberia abstract benthic foraminiferal assemblages in 24 sediment surface samples collected at water depths ranging from 9 to 103 m on the continental shelf off guadiana river were analysed leading to the identification of a total of 270 species cluster analyses performed on species with a relative abundance higher than 5 led to the identification of four assemblages the shallowest assemblage down to 12 m water depth is represented by ammonia beccarii asterigerinata mamila eggerelloides scaber mississipina concentrica planorbulina mediterranensis elphidium crispum and quinqueloculina laevigata a second assemblage between 12 and 40 m water depth is characterised by bulimina elongata cribrononion gerthi and nonion fabum the assemblage between 40 and 95 m water depth is characterised by bolivina dilatata epistominella vitrea bulimina aculeata bolivina ordinaria spiroloxostoma croarae and nonionella iridea finally below a depth of 95 m on the upper outer shelf an assemblage exists characterised by brizalina spathulata bulimina marginata cassidulina minuta brizalina subaenariensis cassidulina laevigata and uvigerina peregrina the spatial distribution of assemblages is closely associated with sea bottom sedimentary environments and bathymetry the number of benthic foraminiferal tests and the distribution of several nearshore species within the two shallowest assemblages are clearly influenced by the outflow of the guadiana estuary and by local hydrodynamic conditions the deeper water assemblages on the other hand were found to be more related to low levels of tidal energy low oxygen environments associated to fine grained sediments and cold water filaments related to seasonal upwelling

boussinesq modeling of wave induced hydrodynamics in coastal wetlands in this paper an improved formulation of the vegetation drag force applicable for the fully non linear boussinesq equations and based on the use of the depth varying higher order expansion of the horizontal velocity in the quadratic vegetation drag law has been presented the model uses the same numerical schemes as funwave tvd but is based on the cactus framework the model is validated for wave height and setup against laboratory experiments with and without vegetation cover the wave attenuation results using the improved formulation were compared with those using the first order reference velocity as well as with analytical solutions using linear wave theory the analytical solution using the depth varying velocity predicted by the linear wave theory was shown to match the model results with the fully expanded velocity approach very well for all wave cases except under near emergent and emergent conditions when the ratio of stem height to water depth is greater than 0 75 and when the ursell ur number is less than 5 simulations during peak storm waves during hurricane isaac showed that vegetation is very effective in reducing setup on platforms and in reducing the wave energy within the first few hundred meters

boussinesq modeling of longshore currents 1 a time domain boussinesq model for nearshore hydrodynamics is improved to obtain the conservation of vertical vorticity correct to second order and extended for use on an open coast using longshore periodic boundary conditions the model is utilized to simulate surface waves and longshore currents under laboratory and field conditions satisfactory agreement is found between numerical results and measurements including root mean square wave height mean water level and longshore current one striking result of the simulations is the prediction of the strong longshore current in the trough shoreward of the bar as observed during the duck experiment on low frequency and incident band longshore and across shore hydrodynamics field campaign the model results give insight into the spatial and temporal variability of wave driven longshore currents and the associated vertical vorticity field under the phase resolving random wave forcing with wave current interaction numerical experiments are carried out to examine the response of the modeled longshore currents to the randomness of surface waves and the cross shore distributions of bed shear stress coefficient we find that both regular and irregular waves lead to very similar mean longshore currents while the input of monochromatic unidirectional waves results in much more energetic shear waves than does the input of random waves the model results favor whitford and thornton s 1996 finding that the bed shear stress coefficient for the area offshore the bar is larger than that in the trough as better agreement with the field data for both regular and irregular waves is found if such coefficients are used in the boussinesq model

damage quantification of built stone on dark gate belgrade serbia sample of damage index application for decay rate evaluation the dark gate is the monument of culture part of the cultural and historical complex of the belgrade fortress it is constructed of limestone blocks that after 270 years of exposure to environmental conditions and different anthropogenic influences show wide ranges of decay forms during 2007 detail registration of all built limestone microfacies and weathering forms was done using tools of monument mapping a correlation scheme intensity damage category was made according to the type intensity and distribution of damage forms for quantification of decay rate of the dark gate damage indices were calculated on the bases of mapping results calculated values of damage indices 3 reflected differences between separate zones of the gate south north facades east west oriented parts of the gate this approach allowed assessment and comparison of weathering rates according to the gate s position and the exposure of the stone to environmental influences the linear damage index showed that the moderate damage is the dominant category on the entire monument while the progressive damage index implies to the need of urgent intervention after 7 years re evaluation of these parameters was done new data of weathering mapping and recalculated values of damage indices reflected significant acceleration in decay rate by comparing weathering maps and values of damage indices from 2007 and 2014 the eastern part of the gate was separated as the zone of the monument that had suffered the heaviest damage differences among the values of damage indices showed that the position of the gate is one of the main causes of the present state of stone blocks built in the dark gate they also showed that a carefully made damage category scheme is a key diagnostic tool in each restoration project

run up from impact tsunami summary we report on calculations of the on shore run up of waves that might be generated by the impact of subkilometre asteroids into the deep ocean the calculations were done with the coulwave code which models the propagation and shore interaction of non linear moderate to long wavelength waves kh using the extended boussinesq approximation we carried out run up calculations for several different situations 1 laboratory scale monochromatic wave trains onto simple slopes 2 10 100 m monochromatic wave trains onto simple slopes 3 10 100 m monochromatic wave trains onto a compound slope representing a typical bathymetric profile of the pacific coast of north america 4 time variable scaled trains generated by the collapse of an impact cavity in deep water onto simple slopes and 5 full amplitude trains onto the pacific coast profile for the last case we also investigated the effects of bottom friction on the run up for all cases we compare our results with the so called irribaren scaling the relative run up r h0 s h0 l0 1 2 where the run up is r h0 is the deep water waveheight l0 is the deep water wavelength s is the slope and is a dimensionless quantity known as the irribaren number our results suggest that irribaren scaling breaks down for shallow slopes s 0 01 when 0 1 0 2 below which r h0 is approximately constant this regime corresponds to steep waves and very shallow slopes which are the most relevant for impact tsunami but also the most difficult to access experimentally

the benthic foraminiferal record of the medieval warm period and the recent warming in the gullmar fjord swedish west coast a high resolution study of benthic foraminiferal assemblages was performed on a ca eight metre long sediment core from gullmar fjord on the west coast of sweden the results of pb 210 and ams c 14 datings show that the record includes the two warmest climatic episodes of the last 1500 years the medieval warm period mwp and the recent warming of the 20th century both periods are known to be anomalously warm and associated with positive nao winter indices benthic foraminiferal successions of both periods are compared in order to find faunal similarities and common denominators corresponding to past climate changes during the mwp adercotryma glomerata cassidulina laevigata and nonionella iridea dominated the assemblages judging from dominance of species sensitive to hypoxia and the highest faunal diversity for the last ca 2400 years the foraminiferal record of the mwp suggests an absence of severe low oxygen events at the same time faunas and delta c 13 values both point to high primary productivity and or increased input of terrestrial organic carbon into the fjord system during the medieval warm period comparison of the mwp and recent warming revealed different trends in the faunal record the thin shelled foraminifer n iridea was characteristic of the mwp but became absent during the second half of the 20th century the recent skagerrak kattegat fauna was rare or absent during the mwp but established in gullmar fjord at the end of the little ice age or in the early 1900s also there are striking differences in the faunal diversity and absolute abundances of foraminifera between both periods changes in primary productivity higher precipitation resulting in intensified land runoff different oxygen regimes or even changes in the fjord s trophic status are discussed as possible causes of these faunal differences c 2011 elsevier b v all rights reserved less

ecological zonation of benthic foraminifera in the lower guadiana estuary southeastern portugal abstract the present study analyzes the spatial distribution and seasonal distribution of live benthic foraminiferal communities in the estuary of guadiana the fourth largest river on the iberian peninsula and establishes through statistical analysis their relationships with a series of environmental parameters forty four superficial sediment samples were collected along distance to sea and elevation gradients in the winter and summer of 2010 fifty three foraminifera species were identified along the intertidal margins of the estuary foraminiferal distribution reflected seasonal variation of environmental factors whose relative importance varied according to species tolerances elevation in relation to mean sea level appeared to be the most important parameter controlling foraminiferal distribution probably because it combines the effects of a series of other variables i e organic matter sediment texture ph and temperature in the highest marsh areas where environmental conditions approach survival thresholds only some agglutinated species are able to survive in the lower intertidal zone where subaerial exposure is diminished and environmental conditions are generally less variable more diverse faunas mainly composed of calcareous species prevail during winter when fluvial discharge peaks agglutinated species represent more than 80 of the total individuals in summer when marine conditions prevail calcareous species become more competitive increase their densities and expand into higher marsh zones and estuarine upper reaches in the estuary three different foraminiferal assemblages are distinguished i miliammina fusca assemblage which dominates in unvegetated areas of the lower marsh and tidal flats of the mid upper estuary ii jadammina macrescens assemblage which dominates in the highest marsh areas in the lower estuary and iii ammonia aberdoveyensis assemblage which dominates the areas of low marsh and tidal flats of the lower estuary

recent coastal evolution and sea level rise setiu wetland peninsular malaysia abstract sea level reconstructions based on foraminiferal assemblage data are common for temperate salt marsh settings in comparison the widespread mangrove swamps of equatorial to subtropical settings have received considerably less attention due to enhanced taphonomic loss of specimens extensive bioturbation abundant infaunal foraminifera and irregular intertidal topography the tropics however provide the best possible estimate of eustatic function and thus are important for testing earth ice models in this paper we use foraminiferal data in a chronologic framework provided by optically stimulated luminescence radiocarbon and pb 210 age estimates to determine coastal evolution and rates of sea level rise in the setiu wetland of northeastern peninsular malaysia on the western margin of the southern south china sea over the past ca 200 years foraminiferal data from three surface transects across fringing mangrove swamps were used to interpret four cores from mid to high mangrove swamp settings patterns of foraminiferal distribution were determined by correspondence analysis canonical correspondence analysis and detrended canonical correspondence analysis of dead assemblage data we used weighted averaging as the transfer function model to reconstruct sea level curves for the cores and to provide a composite reconstruction for the last ca 200 years based on one c 14 estimate sea level rose during the 19th century at 1 26 mm yr 1 the rate increased to 3 2 0 6 mm yr 1 around 1900 ce roughly coincident with rate increases recorded globally however the 20th century rate in the setiu wetland is considerably greater than that of global estimates ca 1 8 mm yr 1 for this period rates of sea level rise in the gulf of thailand immediately to the north of the setiu wetland determined from gps corrected tide gauge data and multi satellite altimetry are geographically variable but also greater than the global rate the data from the setiu wetland provide the first foraminifera based sea level reconstruction of the past few hundred years from the southeastern south china sea scs and they represent the first time the early 20th century increase in rate of sea level rise has been identified using proxy foraminiferal data in an equatorial setting

contemporary foraminiferal distributions of a mangrove environment great barrier reef coastline australia implications for sea level reconstructions abstract contemporary foraminiferal samples and associated environmental information were collected from cocoa creek a mesotidal fringing mangrove environment on the great barrier reef gbr coastline australia to elucidate the relationship of the foraminiferal assemblages with elevation and environment there is a strong and highly significant relationship between elevation and the foraminiferal assemblages supporting the intertidal vertical zonation concept which suggests that the distribution of foraminifera in the intertidal zone is usually a direct function of elevation with the most important controlling factors being the duration and frequency of subaerial exposure multivariate analyses separate the intertidal foraminiferal assemblages into three elevational zones with zone i the highest and zone iii the lowest zones i and ii are dominated by agglutinated species trochammina inflata and miliammina fusca respectively and zone iii is dominated by calcareous species notably ammonia tepida and elphidium discoidale multiloculum these assemblage zones are similar to those found in both tropical and temperate intertidal environments a predictive transfer function has been developed to allow reconstruction of former sea levels for tropical environments based upon the relationship between foraminiferal assemblage and elevation results suggest that a precision of 0 07 m should be attainable superior to most similar studies from temperate mid latitude environments our work has produced the first foraminifera based transfer function for environmental interpretations for tropical australia and allows the potential development of a new generation of high resolution sea level reconstructions for the post glacial sequences of the gbr shelf

ecological evidence from live dead comparisons of benthic foraminiferal faunas off cape blanc northwest africa abstract a comparison of live and dead benthic foraminiferal faunas in a five station sample transect off cape blanc suggests that interspecific differences in living dead l d ratios are to a large extent determined by seasonal differences in reproduction it is proposed that many epifaunal and superficial infaunal species show a highly opportunistic behaviour with a majority of the foraminifera being produced in a relatively short period of the year the density of deeper infaunal taxa on the contrary would be much more stable over time sites with large contrasts in l d ratios between deep intermediate infaunal and epifaunal shallow infaunal taxa should be subject to important seasonal variations in the downward flux of organic matter this study suggests that important ecological information can be gained from live dead comparisons

atlantic paleobathymetry paleoproductivity and paleocirculation in the late albian the benthic foraminiferal record spatial distribution patterns of benthic foraminifers in upper albian sediments from 25 dsdp odp sites and 31 onshore sections of the north and south atlantic ocean are used to generate paleobathymetric reconstructions and to identify areas of high primary production such as coastal and equatorial upwelling zones new paleobathymetric estimates are provided for dsdp odp sites and onshore locations that are not situated on oceanic crust paleobathymetric reconstructions indicate shallow water exchange between the north and south atlantic but show the existence of a deep water connection between the western and eastern tethys 2500 m through the gibraltar gateway strikingly there is no evidence for a strong latitudinal gradient in deep water benthic foraminiferal distribution during the late albian south atlantic assemblages show close affinity to north atlantic and tethyan assemblages exhibiting only a minor degree of provincialism biogeographic patterns reveal a distinct asymmetry in late albian paleoproductivity for the north atlantic as for the present day the eastern margins of the atlantic were generally more productive than the western margins and a belt of enhanced carbon aux export to the seafloor can be traced around the north african coast which probably corresponded to a zone of vigorous coastal upwelling by contrast assemblage composition in the south atlantic generally reflects mesotrophic to oligotrophic conditions benthic foraminiferal distribution patterns thus provide robust proxy data to test predictions from paleocirculation and paleobathymetric models for the mid cretaceous atlantic ocean and adjacent margins c 2001 elsevier science b v all rights reserved

recent benthic foraminifera from the continental margin of northwest africa community structure and distribution abstract sediment grab samples were collected at 107 locations along the continental margin of northwest africa these samples form a series of depth transects between the straits of gibraltar and dakar senegal the greater than 250 m size fraction was retained for a census of both the live and dead foraminifera after deleting trace occurrences jaccard and correlation coefficient based cluster analyses were performed to decipher the community structure for this margin the geographic distribution of the four major faunal provinces recognized is conventional in that for both the live and dead assemblages three are related to depth upper slope and shelf middle slope and lower slope and continental rise the biotopes and thanatotopes within these provinces are strongly restricted along vertical or latitudinal boundaries when the data are analysed using jaccard coefficients dendrograms constructed from correlation coefficients emphasize depth related faunal communities dominant species such as cibicides lobatulus trifarina fornasinii planulina ariminensis uvigerina finisterrensis and c wuellerstorfi are generally distributed within a definite depth range along this margin and strongly influence the correlation coefficient based dendrograms other distributions are clearly not depth related but correspond to various environmental variables for example cancris auriculus coarse substrate bolivina subaenariensis oxygen minimum cibicidoides kullenbergi and hoeglundina elegans low organic carbon uvigerina peregrina is also a notable exception to depth dependence in that this dominant species and the province it represents are generally confined to the continental slope south of cape blanc its preference for that region may arise from the high organic carbon and fine grain size of the sediment there from low salinity of the bottom water or from other unknown variables the most important vertical faunal boundary occurs between cape barbas and cape blanc between 22 and 21 n latitude in contrast the canary island ridge intersects the continental margin at a saddle depth of about 1500 m but that physiographic barrier has little effect on provincialism of the deep water benthic foraminifera

numerical study of turbulence and wave damping induced by vegetation canopies article i nfo vegetation canopies control mean and turbulent flow structure as well as surface wave processes in coastal regions a non hydrostatic rans model based on nhwave ma et al 2012 is developed to study turbulent mixing surface wave attenuation and nearshore circulation induced by vegetation a nonlinear k e model accounting for vegetation induced turbulence production is implemented to study turbulent flow within the vegetation field the model is calibrated and validated using experimental data from vegetated open channel flow as well as nonbreaking and breaking random wave propagation in vegetation fields it is found that the drag related coefficients in the k e model cfk and cf can greatly affect turbulent flow structure but seldom change the wave attenuation rate the bulk drag coefficient cd is the major parameter controlling surface wave damping by vegetation canopies using the empirical formula of mendez and losada 2004 the present model provides accurate predictions of vegetation induced wave energy dissipation wave propagation through a finite patch of vegetation in the surf zone is investigated as well it isfound that the presenceof a finite patch of vegetation may generate strong pressure driven nearshore currents with an onshore mean flow in the unvegetated zone and an offshore return flow in the vegetated zone published by elsevier b v

hydrodynamic modeling of tsunamis from the currituck landslide article i nfo article history accepted 24 september 2008 tsunami generation fromthe currituck landslide offshore northcarolina and propagation of waves towardthe u s coastline are modeled based on recent geotechnical analysis of slide movement a long and intermediate wave modeling package coulwave based on the non linear boussinesq equations are used to simulate the tsunami this model includes procedures to incorporate bottom friction wave breaking and overland flow during runup potential tsunamis generated from the currituck landslide are analyzed using four approaches 1 tsunami wave history is calculated from several different scenarios indicated by geotechnical stability and mobility analyses 2 a sensitivity analysis is conducted to determine the effects of both landslide failure duration during generation and bottom friction along the continental shelf during propagation 3 wave history is calculated over a regional area to determine the propagation of energy oblique to the slide axis and 4 a high resolution 1d model isdeveloped to accuratelymodel wavebreakingand the combined influence of nonlinearity and dispersion during nearshore propagation and runup the primary source parameter that affects tsunami severity for this case study is landslide volume with failure duration having a secondary influence bottom friction during propagation across the continental shelf has a strong influence on the attenuation of the tsunami during propagation the high resolution 1d model also indicates that the tsunami undergoes nonlinear fission prior to wave breaking generating independent short period waves wave breaking occurs approximately 40 50 km offshore where a tsunami bore is formed that persists during runup these analyses illustrate the complex nature of landslide tsunamis necessitating the use of detailed landslide stability mobility models and higher order hydrodynamic models to determine their hazard published by elsevier b v

distribution of modern salt marsh foraminifera in the albemarle pamlico estuarine system of north carolina usa implications for sea level research abstract we described the distributions of foraminifera from ten physiographically distinct salt marshes in the albemarle pamlico estuarine system north carolina using 193 surface samples we defined elevation dependent ecological zones at individual sites using cluster analysis and detrended correspondence analysis additionally seven principal biozones of salt marsh foraminifera were identified that have distinctive spatial distributions reflecting a pattern of salinity regimes caused by the current configuration of barrier island inlets high salinity sites along the southern outer banks are associated with sub tidal calcareous assemblages low marshes dominated by miliammina fusca and high marsh environments defined by haplophragmoides wilberti trochammina inflata and arenoparrella mexicana in contrast lower salinity marshes have ammobaculites spp in sub tidal settings miliammina fusca dominated low marshes and high marsh settings characterized by jadammina macrescens spatial variation of foraminiferal populations and the potential for biozones to migrate in response to changing inlet configuration and salinity suggests that datasets of modern salt marsh foraminifera from multiple environments would be appropriate for reconstructing holocene relative sea level in north carolina

generation of the benthic foraminiferal assemblage theory and preliminary data abstract the production of benthic foraminiferal communities is filtered through taphonomic mainly destructive processes within the sediments to generate the fossil assemblage both the production and the taphonomy depend on bottom water oxygen content and flux of organic carbon to the seabed an examination of the relationships of processes generating the fossil assemblage to oxygen and organic carbon supply is made using pore water geochemical measurements to estimate carbon flux for locations in the gulf of mexico and the central california margin the locations are plotted in a three dimensional field with bottom water oxygen content organic carbon flux and sediment depth as the axes then the response of foraminiferal standing stock taphonomic processes and the developing fossil assemblage to the field is investigated variation in the vertical stratification of foraminiferal standing stock and test production species stratification taphonomic process intensity and stratification and sediment bioturbation lead to marked differences in the way the fossil assemblage is generated across the oxygen content organic carbon flux field the result is that the oxygen carbon flux field has a significant impact on the fossil assemblage through the interaction of biological and biogeochemical processes in the sediments a model of this interaction is investigated to show how its elements change across the oxygen carbon flux field and how these affect the generation of the fossil assemblage

differential rates of benthic foraminiferal test production in surface and subsurface sediment habitats in the southern adriatic sea abstract live communities and corresponding dead assemblages of benthic foraminifera recovered in box cores from the southern adriatic sea differ significantly with respect to the relative abundances of species and higher order groups of foraminifera taphonomic destruction of disintegration prone arenaceous species is held responsible for the observed strong reduction in relative abundance of arenaceous foraminifera in the dead assemblage systematic differences in live and dead relative abundances of calcareous and calcite cemented arenaceous species may be due to differential rates of test production rather than selective taphonomic destruction we observed that epifaunal or shallow infaunal foraminifera are often overrepresented in the dead assemblage compared to their relative number in the live community whereas deeper infaunal species tend to be underrepresented on this basis we hypothesize that test production rate of benthic foraminiferal species may be related to their living depth in the sediment

techniques for estimation of tidal elevation and con nement salinity histories of sheltered harbours and estuaries using benthic foraminifera examples from new zealand techniques for estimating tidal elevation and con nement proxy for salinity using modern benthic foraminiferal census data from new zealand harbours and lower salinity estuaries are described and assessed for their utility for reconstructing the depositional settings of late holocene sequences we describe a simple modern analogue technique for estimating tidal or subtidal elevation of holocene fossil faunas utilizing the modern data set most applicable to the holocene setting sheltered tidal harbours and inlets or lower salinity estuaries canonical correspondence analysis was used to extract a synthetic con nement gradient from for aminiferal census data in transects down ve new zealand estuaries this gradient was used to develop a new zealand con nement index that can be computed for new zealand modern and holocene estuarine and harbour samples based on their foraminiferal composition the value of the method for estimating holocene elevational and con nement palaeosalinity histories was

hurricane gustav 2008 waves and storm surge hindcast synoptic analysis and validation in southern louisiana abstracthurricane gustav 2008 made landfall in southern louisiana on 1 september 2008 with its eye never closer than 75 km to new orleans but its waves and storm surge threatened to flood the city easterly tropical storm strength winds impacted the region east of the mississippi river for 12 15 h allowing for early surge to develop up to 3 5 m there and enter the river and the city s navigation canals during landfall winds shifted from easterly to southerly resulting in late surge development and propagation over more than 70 km of marshes on the river s west bank over more than 40 km of caernarvon marsh on the east bank and into lake pontchartrain to the north wind waves with estimated significant heights of 15 m developed in the deep gulf of mexico but were reduced in size once they reached the continental shelf the barrier islands further dissipated the waves and locally generated seas existed behind these effective breaking zones the hardening and innovative deployment of gauges since hur

the distribution of living benthic foraminifera on the continental slope and rise off southwest norway abstract surface sediment samples taken by corer from 45 stations on the norwegian continental margin and in the norway basin have been investigated for their benthic foraminiferal content unlike previous studies the living benthic foraminiferal fauna was differentiated from empty tests comprising the foraminiferal death assemblage factor analysis of both the living and dead faunal data reveals six living species assemblages and five corresponding dead assemblages the additional living assemblage is characterized by the arenaceous speciescribrostomoides subglobosum that dominates between 1400 and 2000 m water depth but is rare in the dead faunal data trifarina angulosa and to a lesser extent cibicides lobatulus characterize the shallowest foraminiferal assemblage from 200 to 600 m water depth where it is associated with strong bottom currents and warm saline atlantic water of the north atlantic drift on the slope between 600 and 1200 m water depth themelonis zaandami species assemblage dominates particularly in areas characterized today by rapid sedimentation of terrigeneous material between 1000 and 1400 m depth where the slope is covered by fine grained organic rich terrigeneous mud the living foraminiferal assemblage is characterized bycassidulina teretis andpullenia bulloides below 1400 m three foraminiferal assemblages are found c subglobosum is found from 1400 to 2000 m cibicidoides wuellerstorfi andepistominella exigua predominantly live from 2000 to 3000 m water depth and below 3000 m oridorsalis umbonatus andtriloculina frigida dominate the fauna all of theelphidium excavatum tests found in this study and thecassidulina reniforme tests found above 500 m water depth were found to be reworked analysis of the sediment grain size distribution and the organic carbon content in surface samples from the deepest stations suggest that the abundance ofc wuellerstorfi ande exigua is positively correlated to relatively coarse caused by planktic foraminifera and organic rich sediments whereas high frequencies ofo umbonatus andt frigida coincide with low organic carbon content we suggest thatc wuellerstorfi is adapted to deep sea environments with relatively high food supply tolerating relatively low interstitial water oxygen content whereaso umbonatus may tolerate lower food supply prefering well oxygenated interstitial waters

the application of foraminifera to reconstruct the rate of 20th century sea level rise morbihan golfe brittany france abstract foraminiferal assemblages preserved within salt marsh sediment can provide an accurate and precise means to reconstruct relative sea level due to a strong relationship with elevation which can be quantified using a transfer function we collected a set of surface samples from two salt marshes in the morbihan golfe france to determine foraminiferal distribution patterns dominant taxa included jadammina macrescens trochammina inflata haplophragmoides spp and miliammina fusca we developed a foraminifera based transfer function using a modern training set of 36 samples and 23 species the strong relationship between observed and predicted values r 2 jack 0 7 indicated that foraminiferal distribution is primarily controlled by elevation with respect to the tidal frame and precise reconstructions of former sea level are possible rmsep jack 0 07 m the application of the transfer function to a short salt marsh core 0 32 m allowed the reconstruction of former sea levels which were placed in a chronological framework using short lived radionuclides 210 pb and 137 cs the agreement between the foraminifera based sea level curve and the brest tide gauge record confirms the reliability of transfer function estimates and the validity of this methodology to extend sea level reconstructions back into the pre instrumental period both instrumental and microfossil records suggest an acceleration of sea level rise during the 20th century

an equilibrium profile model for retreating marsh shorelines in southeast louisiana abstract louisiana s coastal marshes are experiencing the highest wetland loss rates in the u s in part due to subsidence driven relative sea level rise these marshes are also vulnerable to the erosive power of wave attack 1 on the marsh edge adjacent to open water bodies and 2 after the marsh platform is submerged marsh shorelines in barataria bay breton sound and the active balize delta of southeastern louisiana were examined in areas where the subaerial marsh platform had disappeared since 1932 vibracore transects of marsh and adjacent bay surface sediments to 2 m depth were analyzed using geotechnical stratigraphic and radiochemical 137 cs and 210 pb methods and the subaerial to subaqueous transition of the marsh was mapped for elevation using standard stadia rod transit and fathometer measurements results indicate that marsh edge erosion of the platform takes place subaqueously until water depths of 1 5 m are reached this is observed even in interior pond regions but the shoreface elevation profiles are a function of fetch exposed open bay sites display greater incision depth and rate of the marsh platform than protected interior bay or pond sites core stratigraphy reveals that the outer part of the subaqueous platform switches from erosional to depositional as retreat proceeds covering the incised marsh deposits unconformably with estuarine shelly muds 137 cs and excess 210 pb activity indicates that these muds are deposited within a few decades of subaerial marsh loss the consistency of the cross shore profile results suggests that a single profile of equilibrium can approximate the morphology of eroding marsh edges in southeast louisiana platform stratigraphy and resistance to erosion have a limited effect on profile shape this equilibrium profile and remote sensing images of shoreline change are used to estimate the sediment yield to adjacent estuarine areas by this process on average 1 5 m3 of sediment are yielded per m shoreline length annually from both barataria bay and breton sound due to the highly organic nature of the eroded sediment 30 this supply of organic rich material could significantly impact estuarine productivity and hypoxia on the louisiana continental shelf

sediment retention by a mediterranean posidonia oceanica meadow the balance between deposition and resuspension the role of posidonia oceanica in promoting sediment stability and accretion was studied in a 15 m deep meadow at fanals point nw mediterranean spain by comparing particle deposition within the meadow and adjacent bare sediment small sediment traps were used to measure deposition within and above the meadow and over bare sand a model based on measurements of particle deposition at increasing distances from the bottom was used to partition the total depositional flux between primary sediment particles deposited for the first time at the measuring site and resuspended deposition sediment particles that have been previously deposited at the measuring site measurements were conducted monthly over a year to establish the magnitude and seasonality of deposition and to form a balance of particle transport at the annual time scale significant differences in total deposition were found over time ranging from 1 5 to 500 g dw m 2 d 1 including those between bare and vegetated sediments the effect of p oceanica in increasing primary deposition at an annual scale was modest however p oceanica significantly buffered sediment resuspension which was reduced more than three fold compared to the unvegetated bottom the annual flux of deposition was dominated by settling of resuspended materials which represented 85 of the total flux within the meadow but 95 of the total deposition on bare sand thus seagrass meadows reduce resuspension in the nw mediterranean littoral thereby contributing to increased sediment retention and therefore reducing erosion in the coastal zone

marginal marine environments of the skagerrak and kattegat a baseline study of living stained benthic foraminiferal ecology this is the first detailed investigation of the distribution and ecology of living stained shallow water 0 6 m foraminifera along the skagerrak kattegat coast eastern north sea a total of 25 species 13 agglutinated 12 calcareous are common in the 169 sediment surface samples which were collected from 27 geographic areas the sediment grain size and total organic carbon toc content are strongly variable and the salinity and temperature ranges were 10 31 and 9 30 c respectively at the time of sampling july to october but temperatures down to freezing occur during the winter the species are divided into six environmental categories of which the first five comprise euryhaline and the sixth essentially stenohaline taxa 1 species associated only with marsh plants 2 species basically but not entirely associated with marsh plants 3 species basically but not entirely restricted to non marsh areas 4 species solely recorded in non marsh intertidal to subtidal environments 5 species restricted to subtidal areas 6 species basically living in the most open marine areas in this region marshes have a patchy distribution and they are small and compressed due to low tidal ranges 80 mud ammoscalaria runiana is common only in coarse grained sediments 20 mud with low toc 0 7 there are no marked biogeographic boundaries within the skagerrak kattegat area but 10 of the 25 commonly occurring species have not been reported from the adjacent baltic sea probably partly due to the brackish character of the water there the southern limits of distribution of the northern species elphidium albiumbilicatum ammotium cassis and ophthalmina kilianensis are in the kattegat baltic sea

breaking wave induced cross shore tracer dispersion in the surf zone model results and scalings 1 the dispersion of surf zone tracers including pollutants and bacteria is determined by many processes acting over a range of timescales and space scales breaking waves bores are clearly important to cross shore tracer dispersion in the surf zone but little is known about the dispersal effects of bores here a simple model for bore induced cross shore dispersion are developed based upon the diffusion equation with an eddy diffusivity that propagates with the bores depth uniform tracer and bore induced mixing along with alongshore uniformity are assumed the bores are assumed well developed and the dispersion results are for a self similar constant wave height to water depth ratio surf zone four nondimensional parameters are identified and solution space is explored the tracer center of mass is approximately constant and tracer width grows with the square root of time tracer distribution becomes initially skewed after the passage of the first bore but becomes symmetric after multiple bores have passed the nondimensional tracer patch growth and dilution rates depend strongly upon the nondimensional phase speed and wave period the simple model results are consistent with the a boussinesq wave model where the breaking wave eddy viscosity is used for the bore eddy diffusivity the scaling of the dimensional parameters regarding the bore eddy diffusivity and the ranges of the nondimensional parameters are examined covariation of the nondimensional phase speed and wave period suggest that nondimensional tracer dispersion is largely cross shore independent

benthic foraminiferal thanatocoenoses from the cap ferret canyon area ne atlantic a complex interplay between hydro sedimentary and biological processes abstract benthic foraminiferal thanatocoenoses from the cap ferret canyon area were studied in the 150 m fraction of 4 5 cm deep sediment levels at 13 stations the shallowest station 151 m depth is located at the shelf break close to the canyon head all other stations are located along two bathymetric transects seven stations along the canyon axis between 300 and 3000 m depth and five stations from 300 m to 2000 m depth along the southern flank of the canyon the comparison between the live rose bengal stained and dead assemblages shows that biological i e population dynamic and taphonomic processes i e test destruction transport generate important discrepancies between live and dead assemblages an important question is to what degree post mortem transport and redeposition of foraminiferal tests contribute to the difference between living and dead assemblages the composition of the thanatocoenoses 150 m from the inner continental shelf to the cap ferret canyon axis however transport of tests from outer shelf or upper canyon axis towards deeper sites occurs as indicated by an increase of diversity indices of the dead fauna along the canyon axis moreover some species e g cassidulina carinata are observed in the living fauna restricted to the shallow sites but occur in important amounts in the dead fauna at deeper stations suggesting that these taxa have been transported from upper canyon stations toward deeper sites since cap ferret canyon is inactive in terms of massive sediment transport i e gravity events downslope transport of foraminiferal tests probably takes place in nepheloid layers downslope transports of foraminiferal tests may create important biases for the utilisation of paleoceanographic proxies using the assemblage characteristics and or the geochemical composition of selected species however the study of dead assemblages along a canyon axis can give important clues about the sedimentary dynamics especially an idea of the quantity of reworked foraminifera transported through the canyon axis along the adjacent flank such evidence of downslope transport was not observed despite taphonomic test destruction and biological processes population dynamics the live fauna closely resembles the distribution and the composition of the dead assemblage therefore ecological information obtained from the fossil flank samples can be more reliably used to reconstruct paleoenvironmental conditions

numerical investigation of wave induced flow in mound channel wetland systems abstract coastal wetlands are an important ecosystem in nearshore regions but they are also significant in affecting the flow patterns within these areas wave induced flow in wetlands has complex circulation characteristics because of the interaction between waves and plants especially in discontinuous vegetation here a numerical investigation is performed to analyze the wave averaged flow in vegetated mound channel systems different water levels vegetated conditions and mound configurations are studied with the coulwave cornell university long and intermediate wave boussinesq model model simulations show rip currents in the mound channel systems whose strength varies with different mound separation distances the relative influence of vegetation depends on both mound configuration and water level approximately a 15 change in significant wave height results as waves propagate over the vegetated mounds while up to a 75 decrease in the mean shoreward flow speed through vegetation is observed in addition vegetation influences the spatial distribution of mean water level within the wetlands dimensional analysis shows that rip current strength and primary circulation size depend on mound spacing water depth wave height and vegetation cover

benthic foraminiferal assemblages from the eastern weddell sea between 68 and 73 s distribution ecology and fossilization potential surface sediment samples taken with a vented box corer from the eastern weddell sea on four profiles perpendicular to the continental margin have been investigated for their benthic foraminiferal content the live fauna was differentiated from empty tests comprising the foraminiferal death assemblage based on the dead assemblages potential fossil assemblages were calculated to facilitate the analogy with late neogene core material five distinct live assemblages inhabit the continental margin today six dead assemblages and five potential fossil assemblages respectively correspond to these biocoenoses a predominantly calcareous live fauna dominated by trifarina angulosa is correlated with strong bottom currents and sandy sediments at the shelf break and on the uppermost continental slope below this on the upper slope down to 2000 m water depth the predominantly calcareous bulimina aculeata assemblage coincides with the core of warm 0 c weddell deep water and with fine and more organic rich sediments these calcareous live assemblages completely change composition during early diagenesis because of calcite dissolution within the uppermost sediment which depends largely on the grain size distribution of the sediment and the fluxes of organic matter therefore a still calcareous t angulosa dominated fossil assemblage indicates the sandy substrates on the shelf break and the upper slope whereas the deeper slope with hemipelagic calm sedimentation and with high fluxes of organic matter is indicated by martinottiella nodulosa the characteristic arenaceous fossil remnant of the former predominantly calcareous live b aculeata fauna on a continental terrace between 2500 and 3500 m water depth cribrostomoides subglobosus dominates the live fauna but because of rapid disintegration of the empty tests of this agglutinated species a predominantly calcareous fauna characterized by oridorsalis umbonatus and epistominella exigua comprises the dead assemblage and the potential fossil assemblage respectively on the lower continental slope between the carbonate lysocline 3500 m and the carbonate compensation depth 4000 m tests of nuttallides umbonifer are the characteristic dead and potential fossil remnants of a former predominantly arenaceous live fauna which is associated with the lower part of the antarctic bottom water aabw this corroborates earlier investigations suggesting a relationship between the carbonate corrosiveness of water masses and the distribution of n umbonifer this is important for inferring paleo routes and estimates of paleo production rates of aabw during the neogene

benthic foraminifera off west africa 1 n to 32 s do live assemblages from the topmost sediment reliably record environmental variability abstract recent benthic foraminifera 125 m were investigated from multicorer samples on a latitudinal transect of 20 stations between 1 n and 32 s along the upper slope off west africa samples were selected from a narrow water depth interval between 1200 and 1500 m so that changes in water masses are minimized but changes in surface productivity are important and the only significant environmental variable live rose bengal stained benthic foraminifera were counted from the surface sediment down to a maximum of 12 cm dead foraminifera were investigated in the top 5 cm of the sediment only five live and five dead benthic foraminiferal assemblages were identified using q mode principal component analysis matching distinct primary productivity provinces characterized by different systems of seasonal and permanent upwelling differences in seasonality quantity and quality of food supply are the main controlling parameters on species composition and distribution of the benthic foraminiferal faunas to test the sensitivity of foraminiferal studies based on the uppermost centimeter of sediment only a comparative q mode principal component analysis was conducted on live and dead foraminiferal data from the top 1 cm of sediment it has been demonstrated that on the upper slope off west africa most of the environmental signals as recorded by species composition and distribution of the total live and dead assemblages i e including live and dead foraminifera from the surface sediment down to 12 cm and 5 cm respectively can be extracted from the assemblages in the top centimeter of sediment only on the contrary subsurface abundance maxima of live foraminifera and dissolution of empty tests strongly bias quantitative approaches based on the calculation of standing stocks and foraminiferal numbers in the topmost centimeter

comparison between the dead and living benthic foraminiferal assemblages in aveiro lagoon portugal abstract this work provides a comparison between living las and dead das benthic foraminiferal assemblages in 53 sampled sites located in intertidal and subtidal areas of ria de aveiro portugal the results of multivariate statistical analysis provide evidence for the main factors that control the distribution of das and las which seems to correspond to different gradients of marine continental influence conditioned by differences in the hydrodynamics of tidal currents in addition to these factors the las are clearly influenced by the total organic carbon biopolymers and pollutants the main factor that however drives the high level of agreement or the degree of disorder between the das and the las seems to be the hydrodynamics the highest level of agreement between the das and the las is found in sheltered inner lagoon areas out of the tidal currents strongest influence this study shows an interesting application of advanced statistical analysis to study the similarity between las and das aiming to identify the zones or conditions of a coastal system in which the das can potentially be a better record of las through similar studies conducted in coastal systems it is possible to select the most suitable sites to collect cores in view of the development of paleoenvironmental studies

spectral wave flow attenuation within submerged canopies implications for wave energy dissipation 1 communities of benthic organisms can form very rough surfaces canopies on the seafloor previous studies have shown that an oscillatory flow induced by monochromatic surface waves will drive more flow inside a canopy than a comparable unidirectional current this paper builds on these previous studies by investigating how wave energy is attenuated within canopies under spectral wave conditions or random wave fields defined by many frequencies a theoretical model is first developed to predict how flow attenuation within a canopy varies among the different wave components and predicts that shorter period components will generally be more effective at driving flow within a canopy than longer period components to investigate the model performance a field experiment was conducted on a shallow reef flat in which flow was measured both inside and above a model canopy array results confirm that longer period components in the spectrum are significantly more attenuated than shorter period components in good agreement with the model prediction this paper concludes by showing that the rate at which wave energy is dissipated by a canopy is closely linked to the flow structure within the canopy under spectral wave conditions wave energy within a model canopy array is dissipated at a greater rate among the shorter period wave components these observations are consistent with previous observations of how wave energy is dissipated by the bottom roughness of a coral reef

lateral and vertical distributions of living benthic foraminifera off the douro river western iberian margin impact of the organic matter quality abstract in this study we assess the impact of the quantity and quality of the organic matter on the distribution of live benthic foraminifera on a cross margin transect off the douro river western iberian margin surface sediments from five stations ranging from 50 to 2000 m water depth were collected in march 2011 at the end of the period of maximal river runoff in order to better evaluate the importance of terrestrial input living stained benthic foraminiferal assemblages 150 m and environmental parameters grain size total organic carbon toc total nitrogen tn c n ratio 13 c toc pigments and amino acids were investigated organic matter amounts follow the sediment grain size pattern with higher concentration in fine sediments and seem to control faunal density except at the shallowest station where toc is low and faunal density high at this coastal site a massive sandy deposit is identified and associated with very low faunal diversity labile organic matter is richest at the shelf stations where benthic foraminifera standing stocks are high this is particularly evident on the douro mud patch where both density and diversity are high foraminiferal faunas living at the shelf stations are dominated by species e g nonion scaphum ammonia beccari i bulimina aculeata and eggerella scabra characteristic of the rich trophic conditions with organic matter of mixed estuarine and marine origin very low total standing stocks on the upper slope are associated with coarse sediments probably resulting from intense bottom currents at this depth resulting in poor trophic conditions deeper environments are characterized by species e g hoeglundina elegans uvigerina mediterranea and reophax scorpiurus indicative of fairly abundant but low quality organic matter finally the faunal differences between the shelf stations may reflect different successional stages an early stage at 50 m water depth where unstable conditions are observed with faunas dominated by opportunistic species and a more mature fauna in the mud patch where more stable conditions prevail

hydrodynamics induced by wind waves in a vegetation field the wave induced kinematics and dynamics of a submerged or emerged vegetation field is analyzed using potential flow and an eigenfunction expansion the problem is solved considering regular as well as irregular incident waves the model takes into account the vegetation motion and solves for the complete wave system on the vegetation field and in its vicinity the model is validated against experimental laboratory data obtained by other authors showing a much better agreement than previous theoretical models in this paper the model is used to evaluate wave height evolution damping vegetation and fluid motion and forces and moments on the vegetation furthermore the inclusion of irregular waves provides force and moment distributions on the vegetation field depending on the wave climate statistics

relationship of foraminifera and thecamoebian distributions to sediments contaminated by pulp mill effluent saguenay fiord quebec canada gravity cores and grab samples collected in the saguenay fiord between 1976 and 1988 contain the record of a 20th century benthic marine environment contaminated primarily by organic matter discharges from several local pulp and paper mills spiroplectammina biformis is the dominant arenaceous species its living percent abundance decreases between 1982 and 1988 as a consequence of the apparent recolonization of the upper reaches of the fiord by several arenaceous taxa the most important beingtextularia earlandi cassidulina reniforme the dominant living calcareous species shows about a three fold increase in relative abundance over the six year interval grab sample observations also suggest a recolonization of some formerly barren benthic environments near the head of the fiord by foraminiferal species between 1982 and 1988 this recolonization may reflect the combined effect of government regulations imposed on local industrial polluters in the early 1970 s and the capping of a large area of contaminated sediment by a layer of clay that was transported to the basin at the head of the fiord as the result of a catastrophic landslide in 1971 x radiographs of core sections from a basin at the head of the fiord show sharp laminations that reflect both the absence of bioturbators and the seasonal variation of fluvial depositional processes organic waste deposition from pulp and paper mill outfalls first increased around 1910 and shows a first order inverse relationship to benthonic foraminiferal assemblage diversity the presence of only allochthonous thecamoebian and reworked planktonic foraminifera tests in many benthonic foraminifera barren core intervals supports the idea that common indigenous estuarine species such asspiroplectammina biformis were excluded from these areas at certain times as a consequence of pollution stress rather than having been removed from the sediment record as a result of post depositional diagenetic effects however future studies of estuarine pollution history based on proxy foraminiferal data from cores must give greater emphasis to distinguishing ecological stress responses from diagenetic process i e test dissolution effects since both mechanisms can be reflected in the proxy pollution signal in a similar way

variability of intertidal foraminiferal assemblages in a salt marsh oregon usa we studied 18 sampling stations along a transect to investigate the similarity between live rose bengal stained foraminiferal populations and dead assemblages their small scale spatial variations and the distribution of infaunal foraminifera in a salt marsh toms creek marsh at the upper end of the south slough arm of the coos bay estuary oregon usa we aimed to test to what extent taphonomic processes small scale variability and infaunal distribution influence the accuracy of sea level reconstructions based on intertidal foraminifera cluster analyses have shown that dead assemblages occur in distinct zones with respect to elevation a prerequisite for using foraminifera as sea level indicators our nonparametric multivariate analysis of variance showed that small scale spatial variability has only a small influence on live rose bengal stained populations and dead assemblages the dissimilarity was higher however between live rose bengal stained populations in the middle marsh we observed early diagenetic dissolution of calcareous tests in the dead assemblages if comparable post depositional processes and similar minor spatial variability also characterize fossil assemblages then dead assemblage are the best modern analogs for paleoenvironmental reconstructions the toms creek tidal flat and low marsh vascular plant zones are dominated by miliammina fusca the middle marsh is dominated by balticammina pseudomacrescens and trochammina inflata and the high marsh and upland marsh transition zone are dominated by trochamminita irregularis analysis of infaunal foraminifera showed that most living specimens are found in the surface sediments and the majority of live rose bengal stained infaunal specimens are restricted to the upper 10 cm but living individuals are found to depths of 50 cm the dominant infaunal specimens are similar to those in the corresponding surface samples and no species have been found living solely infaunally the total numbers of infaunal foraminifera are small compared to the total numbers of dead specimens in the surface samples this suggests that surface samples adequately represent the modern intertidal environment in toms creek

the taphonomy of deep sea benthic foraminifera comparisons of living and dead assemblages from and gravity cores taken in the sulu sea abstract comparisons between soutar core faunal data and gravity core top data from about 500 m to 4000 m in the sulu sea show that living stained benthic foraminiferal assemblages have similar faunal patterns to those observed in living dead assemblages for both assemblages faunal abundances and diversities decrease with increasing water depth to 4000 m and core samples and gravity core top sediments taken from the same water depth yield similar dominant taxa the similarity of living and living dead assemblage data indicates that at least most of these faunal patterns are independent of seasonal variations and that neither seasonality nor post depositional effects can account for the absence of significant numbers of bolivina bulimina globobulimina chilostomella and uvigerina below about 1500 m in the sulu sea the distribution of these taxa are similar in both cores and gravity core top sediments reconfirming the conclusion that the distributions of living representatives of these taxa are not due to bottom water oxygen concentrations differences which exist between living assemblages and combined living and dead assemblages of deep sea benthic foraminifera from about 500 m to 4000 m in the sulu sea result primarily from surficial material loss in gravity core samples mixing of older material from subsurface sediments and postdepositional destruction of some taxa based on the additional examination of the living dead assemblages found in 0 5 and 1 cm intervals of the top 10 cm in two cores 1980 m and 3000 m differences in abundance and percentage patterns for fauna found at 2000 and 3000 m in the sulu sea are not correlated with sedimentation rate but appear to be more strongly influenced by mixing from older material and postdepositional processes in the sediments increasing the interval of sediments examined does not necessarily improve the similarity between living assemblage faunal patterns and those of the dead or combined living and dead assemblage

the distribution of contemporary intertidal foraminifera at cowpen marsh tees estuary uk implications for studies of holocene sea level changes abstract foraminiferal assemblages were collected at 2 weekly intervals over a period of 12 months from the intertidal zone of cowpen marsh statistical analyses indicate that the foraminiferal distributions for this site are controlled predominantly by altitude furthermore the contemporary foraminiferal assemblages from cowpen marsh broadly reflect vertical floral zones based on vascular plants cluster analysis separates foraminiferal assemblages into four zones two high and middle marsh zones consisting of differing abundances of jadammina macrescens and trochammina inflata a low marsh zone dominated by jadammina macrescens and miliammina fusca and a mudflat zone dominated by calcareous foraminiferal species notably elphidium williamsoni haynesina germanica and quinqueloculina spp the altitudinal ranges of the faunal zones are employed to identify the vertical relationship of the local environment in which the assemblage accumulated to a reference tide level

probability distribution of wave heights attenuated by salt marsh vegetation during tropical cyclone abstract zero crossing wave heights obtained from the field measurement of random waves propagating through salt marsh vegetation spartina alterniflora during a tropical storm were analyzed to examine their probability distribution wave data significant wave heights up to 0 4 m in 0 8 m depth were collected over a two day period along a 28 m transect using three pressure transducers sampling at 10 hz wave height distribution was observed to deviate from the rayleigh distribution the observed probability densities of the larger wave heights were reduced significantly by vegetation producing wave heights lower than those predicted by the rayleigh distribution assuming rayleigh distributed wave heights for the incident waves to the vegetation patch existing vegetation induced wave attenuation formulations are used to derive a special form of two parameter weibull distribution for wave heights in the inundated wetland the scale parameter of the distribution is theoretically shown to be a function of the shape parameter which agrees with the measurements effectively reducing the proposed distribution to a one parameter type the derived distribution depends on the local parameters only and fits well to the observed distribution of wave heights attenuated by vegetation empirical relationships are developed to estimate the shape parameter from the local wave parameters