human driven coastline changes in the adra river deltaic system southeast spain abstract the recent evolution of the adra river delta in southeastern spain has been reconstructed from historical maps aerial photographs and submarine multibeam bathymetric data we have distinguished three main evolutionary stages whose development took place as a direct response to the main anthropic and natural influences on the river system the first stage 4000 bc to 1872 ad represents the natural behavior of the deltaic system with negligible anthropic influence this long stage is characterized by coastline advance with the formation of a small asymmetric triangular delta in the natural river mouth and a typical prodeltaic deposit in contrast the second and third stages are characterized by anthropic interventions in the catchment and the river mouth which heavily modified the natural dynamics of the deltaic system the second stage 1872 ad to 1972 ad coincided with damming of the natural river channel very close to its mouth and the construction of two successive artificial channels to deviate the river flow the coastal dynamics changed during this second stage with erosion of the original delta and the formation of a new asymmetrical delta at the mouth of the artificial channels this younger eastern delta comprises two infralittoral wedges in the submarine realm which recorded changes of lateral redistribution processes and enhanced influence of energetic events and can only be explained if the sediment supply from the river source was reduced during this period the third stage 1972 ad to present day started with the damming of the trunk river in the central sector of the catchment thus drastically reducing sediment flow to the coastal realm and triggering general erosion and coastline retreat

groundwater flow conditions in a low angle fracture zone at finnsjon sweden abstract the performance and results of a series of hydraulic head measurements and differently designed tracer tests are described a combined interpretation of the results is utilized to estimate the natural groundwater flow conditions in a low angle major fracture zone zone 2 investigated at the finnsjon study site central eastern sweden the transport of tracer labelled flushing water used during drilling of a cored borehole was utilized to determine hydraulic connections and estimations of hydraulic parameters the breakthrough of tracer was monitored at a distance of 440 m from the injection point with a mean residence time of 37 days in order to determine transport parameters of the fracture zone a tracer test was performed in conjunction with an interference test the hydraulic fracture conductivity flow porosity equivalent fracture width and dispersivity were calculated for three different tracer routes tracer was also used to detect any bypass around the packers during the interference test a series of groundwater flow determinations are also described which used the point dilution technique in packed off borehole sections carried out under natural gradient conditions the groundwater head measurements indicated that a pressure gradient from high to low exists between the adjacent rocks and zone 2 where zone 2 is located closer to the ground surface the opposite situation prevails the upper highly conductive part of the zone was found to have high natural flow rates whereas in the lower highly conductive part the groundwater flow rates were very low close to the rate of molecular diffusion

hydrochemical investigations at finnsjon sweden abstract ground water collected from within and around a highly conductive low angle fracture zone in crystaline rock has been studied in relation to drilling and sampling methods water quality and hydrogeochemical interpretation air flush percussion drilling was demonstrated to be efficient down to 200 250 m at greater depths large amounts of drilling debris and increasing groundwater contamination from air dissolution become apparent a stepwise drilling sampling procedure using water flush rotary drilling in combination with water analysis carried out on site using a mobile laboratory is recommended for future studies the chemistry of the finnsjon ground waters shows a sharp contact between saline and non saline compositions this contact corresponding to a highly conductive low angle fracture zone zone 2 this zone is therefore a horizon along which ground waters of contrasting age and chemistry come into contact and partially mix this mixing has produced a highly supersaturated water resulting in the precipitation of calcite this is most evident in fractures within the more conductive upper part of zone 2 thus partly forming a seal between the two groundwater environments comparison of the finnsjon saline waters with other saline environments particularly in the fennoscandian shield has shown that the ground waters are dominantly marine in origin but with clear modifications resulting from water rock interaction apparent radiocarbon ages range from 9000 to 15000 years in those waters containing tritum levels below detection limits these ages are considered too young and are thought to have resulted from mainly carbon 14 dilution caused by groundwater mixing during the holocene when large quantities of glacial melt water were available this mixing process is also supported by the oxygen 18 data

geological setting and deformation history of a low angle fracture zone at finnsjon sweden abstract in 1984 the swedish nuclear fuel and waste management company skb initiated detailed investigations involving the geological geophysical hydrological and geochemical character of a fracture zone for this purpose a low angle ssw dipping fracture zone in a foliated granodiorite of svecokarelian age approximately 1 8 ga within the sub cambrian peneplain of northeastern uppland central eastern sweden was identified and investigated by extensive drilling the initial formation of this zone which is estimated to have taken place approximately 1 7 ga ago as a result of ductile deformation was followed by shearing during ductile brittle transitional conditions and subsequently by brittle deformation it formed as a thrust in a 20 30 km wnw ese trending strike slip fault zone the fracture zone is approximately 100m wide with an anastomosing shear pattern and is displaced by subvertical faults late reactivation of the zone has occurred preferentially in the upper part which is now open permitting water transport the palaeo flow paths indicated by bedrock alteration and fracture infillings show that the hydraulic flow system in the rock mass has become increasingly restricted during geologic time flow now occurs predominantly along discrete zones which were initiated more than 1 7 ga ago and since then have been repeatedly reactivated the most intense penetrative fracturing associated with hydrothermal activity occurred more than 1 0 ga ago fractures and fracture zones most likely to conduct water i e forming transport pathways between a repository and the biosphere tend to be those with a long and complex tectonic history

rapid coastal geomorphic change in the river murray estuary of australia abstract the river murray estuary a ramsar wetland site has experienced considerable rapid coastal change during the quaternary the interplay of aeolian processes river flows tidal oscillations wave action and variations in relative sea level due to global sea level changes and land subsidence provides the energy for the ongoing dynamism often accelerated by human impacts the estuary is the terminus of the murray darling catchment which covers 1 073 million km 2 of the australian continent terminal lakes alexandrina albert and the coorong lagoon are holocene features occupying tectonically subsiding quaternary interdune areas they formed in response to eustatic sea level rise following the last glacial maximum ca 20 ka the last interglacial shoreline 125 000 yr bp parallels the modern shoreline several kilometres inland dislocation of the last interglacial shoreline demonstrates ongoing tectonic subsidence as does historical seismic activity the northern half of hindmarsh island formed during last interglacial times when it was the sink for dominant longshore transport from the southeast which pushed the river murray westward partly explaining the large bend in the river murray at goolwa the modern coastal barriers of sir richard peninsula and younghusband peninsula formed from 7000 yr ago following glacier melt and sea level rise subsequently the barriers have migrated landward sporadically exposing lagoonal sediments on the ocean beaches differential loading of the soft lagoonal sediments by advancing dunes possibly in conjunction with seismic events has deformed and elevated them to up to 10 m above present sea level apsl during the mid holocene an extensive sand flat with associated dunes formed immediately inland of the coastal barrier at least six generations of late pleistocene dune systems occur in the region for example during last glacial times the climate was drier colder and windier than at present and a system of parallel west east trending yellow red desert dunes developed around the lakes aeolian processes remain important with occasionally up to 5000 tonnes of sand being in motion along 10 km of the modern shoreline during mouth migration dunes up to 2 m high have been formed and vegetated in 12 months directly inland from the mouth and replicating the formation of older dunes on hindmarsh island elsewhere sand blown directly from the barrier system infills channels barrage construction on the beach facies of the last interglacial shoreline transformed the estuary into freshwater lakes with permanently raised water levels and reduced the tidal prism by 90 increased deposition upstream and downstream accompanied barrage construction as have accelerated lakeshore erosion and the growth and consolidation of the flood tidal delta bird island these human accelerated changes provide rapidly formed analogues of older quaternary features and aid their interpretation the shape and location of the murray mouth is constantly changing migrating over 1 6 km since the 1830s migrations of up to 6 km over the past 3000 yr have influenced sedimentation on the landward shore of the back barrier lagoonal system

six thousand years of coastline evolution in the guadalfeo deltaic system southern iberian peninsula abstract the 4000 bc to present day coastal and shallow marine changes of the guadalfeo river deltaic system southeast spain are studied using historic maps aerial photographs diverse submarine data and hydrodynamic models the deltaic system evolved with little anthropic influence until the 1940s when the river mouth was diverted to the west during the pre diversion stage the system evolved from an estuary to a delta due to the enormous sediment yield in the catchment induced both by anomalously wet climate conditions and by deforestation practices accordingly the coastline advanced significantly up to 3 3 m year 1 during this period particularly during the 1500 to 1873 interval the estimate for volumetric changes in the deltaic system shows very high specific sediment yield values around 60 65 t ha 1 year 1 in the catchment the deltaic system mainly evolved by cannibalization of the older lobate outlet depocentre after the river diversion and the generation of a more elongated depocentre coincident with the current outlet due to enhanced lateral redistribution of sediments from east to west the construction of two major dams in the trunk river in the last 30 years has severely blocked sediment supply to the system although expected coastline erosion has been partially mitigated by longshore sediment redistribution

overview of the fracture zone project at finnsjon sweden abstract at the finnsjon site central sweden a 100 m wide low angle fracture zone in granodiorite zone 2 has been studied by means of borehole investigations this has included core and geophysical logging as well as hydraulic tests and groundwater sampling zone 2 was developed at 1 7 1 6 ga as a ductile shear zone at a depth of approximately 10 15 km and repeated reactivation has occurred during precambrian time and later today the upper boundary of the zone is defined in nine boreholes at depths ranging from 100 to 295 m pumping tests have demonstrated that the upper part of the zone is highly water conductive with a transmissivity in excess of 10 3 m 2 s 1 from tracer tests the equivalent single fracture hydraulic conductivity was calculated to be 0 03 0 2 ms 1 this extremely high transmissivity and conductivity over such a large areal extent can be speculated to be the result of recent opening of zone 2 during the last inland ice period in situ measurements of the natural groundwater flow show that the flow is high 67 90 m 3 m 2 year 1 at the upper boundary of zone 2 whereas near stagnant conditions occur at the lower boundary and in the relict saline water beneath the zone isotope data suggest a complex origin for the saline water the hydraulic head measurements as well as the groundwater chemistry strongly suggest that the low angle zone 2 acts as a hydraulic barrier preventing ground water from percolating downward through the zone these studies have helped to focus on repository safety assessment problems which hitherto had been oversimplified for the benefit of performance models furthermore the results have shown that these low angle large scale fracture zones are likely to be even more important controls than steep zones when considering bedrock stability rock stress regimes and lateral groundwater flow patterns quantification of such phenomena should provide an invaluable input into the various safety assessment performance codes for model validation and siting criteria for a repository

geomorphology sedimentology and recent evolution of the anthropogenically modified simeto river delta system eastern sicily italy abstract the purpose of this paper is to present a complete stratigraphic framework for the modern simeto river delta eastern sicily italy by the description of its geomorphology and sedimentology which allow an analysis of its recent evolution the simeto river delta represents an asymmetric wave influenced delta which developed during the holocene by prograding into the catania gulf this delta represents a good example of a mediterranean type system characterized by a micro tidal regime and moderate wave energy the peculiar distribution of sedimentary facies both in the subaerial and in the subaqueous sectors is interpreted as the response of the system to the intimate interaction of geological and in recent times anthropogenic coastal activity the integration of a large amount of historical data allows the definition of prograding and retrograding pattern within the delta and the cyclical shifting of the river mouth over the last two centuries a hypothetical model is proposed to explain this phenomenon and it is suggested that this may be a characteristic of several mediterranean type deltas progradation of the delta ended during the early middle xix century after which it began to retreat the retreat of the coastline accelerated after the 1950s when owing to the construction of embankments on the delta plain and since 1970s increasing diversion of water resources in the upper part of the simeto river drainage basin the sediment input of the river to the ionian sea sharply decreased this caused a dramatic change of the deltaic morphology and significant coastal land loss the morphological and sedimentary features of the simeto river fully reflect the processes of its adaptation to the persistence of coastal human activity within an active geological setting

acoustic observations of internal tides and tidal currents in shallow water significant acoustic travel time variability and frequency shifts of acoustic intensity level curves in broadband signal spectrograms were measured in the east china sea during the summer of 2008 the broadband pulses 270 330 hz were transmitted from a fixed source and received at a bottomed horizontal array located at the 33 km range the acoustic intensity level curves of the received signals indicate regular frequency shifts that are well correlated with the measured internal tides similarly regular travel time shifts of the acoustic mode arrivals correlate well with the barotropic tides and can be explained by tidal currents along the acoustic propagation track these observations indicate the potential of monitoring internal tides and tidal currents using low frequency acoustic signals propagating at long ranges

hydraulic testing and modelling of a low angle fracture zone at finnsjon sweden abstract the hydraulic characteristics of a gently dipping fracture zone in crystalline rock at the finnsjon test site in sweden are described the information is derived from single hole injection tests of different packer spacings including very detailed tests in 0 11 m sections in a few borehole segments in addition detailed hydraulic interference tests were performed by pumping in different parts of the zone and monitoring pressure changes in multiple section observation boreholes the results of the hydraulic testing show that the fracture zone is composed of two to five thin highly conductive subzones in the boreholes the uppermost subzone is consistently located close to the upper boundary of the major zone and can be correlated over several hundreds of metres there is evidence of both lateral and vertical hydraulic anisotropy along the zone the interference tests show that the fracture zone is delimited by semi permeable boundaries probably constituted by steeply dipping fracture zones the results of the hydraulic testing are used to simulate the pressure responses obtained in the observation boreholes by numerical modelling

hydrogeological behaviour of some fault zones in a carbonate aquifer of southern italy an experimentally based model complex flow circulation patterns are likely to be present in fault controlled groundwater flow systems such as carbonate aquifers nevertheless not much information is available for faults in carbonates and their hydrogeological behaviour is often neglected in conceptual and numerical models the understanding of this aspect of subsurface fluid flow has been improved in a carbonate aquifer where hydrogeological investigations at site scale demonstrated the existence of fault zones that act as barriers the hydraulic conductivity of the fault core is as low as that of siliciclastic rocks that represent the regional aquitard of the carbonate aquifer despite the lower permeability the fault zones allow a significant groundwater flowthrough and a good interdependence of piezometric heads upgradient and downgradient of the faults because of this discontinuous heterogeneity the aquifer looks like a basins in series system where seasonal springs can be detected along some fault zones as a function of groundwater level fluctuations

the subsidence history of the northern hyblean plateau margin southeastern sicily abstract the southeastern corner of sicily is dominated by the hyblean plateau which is composed of carbonate rocks of triassic to miocene age the plateau forms part of the african foreland which collided during tertiary times with the calabrian arc giving rise to the maghrebian thrust belt the present study attempts to reconstruct the subsidence history of the northern hyblean plateau during the neogene climax of the plate collision this area has been a centre for widespread basaltic volcanic activity 8 1 ma and uplift at the close of the collisional events pliocene early pleistocene the area under consideration has been affected by subsidence and the progressive consumption of the northern margin of the hyblean plateau led to the development of the modern foredeep a quantitative analysis was done by one dimensional airy backstripping of seven deep wells located on this crucial part of the hyblean plateau the results of the analysis show that the subsidence history of the northern hyblean plateau area is characterized by four main phases similar to other domains in the central and eastern mediterranean basins these phases are a neotethyan rifting during late triassic early jurassic time b a slow thermal subsidence from early jurassic until late cretaceous time leading to the formation of a widespread mesozoic carbonate platform c compressional phase during late cretaceous palaeogene time which resulted in the formation of fold systems and d uplift and subsidence events during the middle tertiary which are probably the result of the continued collision of the european african plates after the early pleistocene unlike other terranes within the mediterranean an uplift occurred in the northern hyblean plateau following the upper miocene lower pleistocene massive volcanic activity this uplift is probably associated with the latest stages of thrusting along the frontal part of the maghrebian thrust belt

plio quaternary tectonic evolution and structure of the catania foredeep the northern hyblean plateau and the ionian shelf se sicily abstract available multi and single channel seismic reflection profiles calibrated by onshore borehole data have been used for defining the structural styles in the shelf and slope of the ionian sea between catania and augusta se sicily the geological and geophysical data suggest that this area represents a segment of the foredeep foreland system which collapsed after late pliocene times the foundering was controlled by normal faults trending ne sw which flank the southern margin of the catania foredeep onland in outcrop these faults appear largely to be post dated by lower pleistocene sediments nearshore carbonates passing laterally into basinal clays which lie unconformably upon older substrata offshore close to the southern edge of the foredeep seismic lines allow recognition of two distinct units a syn rift wedge upper pliocene submarine tholeiites and sediments and a post rift sequence which can be correlated with lower pleistocene carbonates sands and clays recognisable on land both in outcrop and by borehole data the true frontal part of the thrust belt as detected by the seismic lines occupies the inner part of the area investigated and is buried by upper pliocene and lower pleistocene sediments however the compressive deformation seems to propagate toward the south southeast by means of growing detachment levels developing at depth within pleistocene marine clays for a length of about 10 km ahead of the present day thrust front offshore the faults trending ne sw are dissected towards the east by faults trending nnw sse subparallel to the malta escarpment which flank the edge of the submerged messina rise these faults originating in a steep scarp which drops eastwards to the deep ionian basin have triggered submarine slides and affected the present day seafloor sediments as shown by seismic lines and as stressed by the modern seismicity of the area some of the faults along the malta escarpment could be still active

sedimentation in the yellow river delta part ii suspended sediment dispersal and deposition on the subaqueous delta abstract rapid deposition and suspended sediment dispersal off the modern yellow river mouth has been examined from the data of topographic maps 1 25 000 suspension and bed sediments current and salinity which were measured in the field the results show that the sedimentation rate of the mouth bar is the highest of all the environments of deposition in the modern yellow river delta about 30 40 of the sediment that the river transports into the sea has been deposited within the mouth bar area rapid deposition of the mouth bar results mainly from kinetic energy dissipation of the river under the influence of three ambient mechanisms these three mechanisms occur simultaneously as shear front movement which obstructs the river s jet like flow small scale circulations where large velocity gradients occur and the bulldozer effect of the tide sensitive zone in the estuary at ebb based on the analysis of morphologic changes the mouth bar can be divided into two morphologic types one is the double lobe and single channel type and the other double channel and single lobe type weak hyperpycnal plumes with small density differences between the river flow and ambient water dissipate rapidly and deposit about 20 of the river sediments on the delta front slope while hyperpycnal underflows from the river mouth can go through the steep delta front slope to form a rise apron along the upper part of the prodelta grain size analysis of suspended sediment shows that the flow can be divided into three layers a tide layer in the upper part and a hyperpycnal layer in the lower part these two layers are normally graded and a transition layer with inverse grading in the mid part the fine suspended sediments have been transported in the hypopycnal plume layer into the prodelta and deep sea such as the north huanghai sea north yellow sea this study indicates that the tidal current field has dominated the distribution of deposition of sediment on the subaqueous delta and the movements of the river effluent and hyperpycnal underflows

acoustic travel time perturbations due to shallow water internal waves and internal tides in the barents sea polar front theory and experiment during august 1992 a combined acoustics physical oceanography experiment was performed to study both the acoustical properties and the ocean dynamics of the barents sea polar front in the region near bear island oceanographic observations from shipboard hydrography and moored sensors allowed the construction of the internal wave frequency spectrum for the area a rapidly sampled tomographic section from a 224 hz 16 hz bandwidth acoustic source to a 16 element vertical receiving array enabled the monitoring of travel time fluctuations over the internal wave frequency band to describe the measured acoustic fluctuations theoretical expressions have been developed for the travel time variances which are functions of the internal wave oceanographic field the local acoustic propagation characteristics and the acoustical system s properties both ray and mode theory expressions are generated as the experiment was performed in shallow water and both ray and mode arrivals were resolvable comparison of the

morphosedimentary evolution of a delta sourced drift aligned sand barrier lagoon complex western bight of benin the coast of eastern ghana and togo is bounded by a major holocene sand barrier complex hinged on the volta delta to the west and subject to high rates of longshore sand drift 1 1 5 106 m3 yr in spite of its proximity to this major deltaic sediment source this barrier system shows marked longshore variations in progradation following the middle holocene eustatic stillstand it is a hybrid system in terms of internal facies composition and plan view morphology in that it has evolved from an essentially regressive to a stationary synonymous with cessation of progradation system both transgressive and barrier inlet facies have also developed through time and space these temporal and spatial changes in patterns of development reflect variations in longshore sand transport and deposition over the last 5000 years such variations have been controlled by sediment supply from the volta by antecedent topography by lagoonal and river drainage by sediment cell development and maturation and in the very recent past by anthropogenic perturbation barrier progradation in the western bight of benin diminished considerably or ceased probably as early as 3400 yr b p as a single major equilibrium drift aligned bight cell matured permitting transport of volta sand toward the rest of the eastern bight in benin and nigeria the eastward longshore supply from the volta has involved both direct inputs of upland derived sand by the volta river channel and reworking of nearshore deltaic deposits a recent reduction in direct fluvial supply exacerbated by the akosombo dam completed in 1961 has induced a wave of erosion of the downdrift delta mouth barrier and shoreface deposits to fulfil the strong drift requirements in togo construction of a deepwater port in 1967 has also affected the barrier system both of these changes have had considerable impacts on longshore sediment dynamics the most significant impact has been segmentation of the former unique sediment cell characterising the 400 km long bight of benin coast resulting in differential longshore erosion progradation or equilibrium these changes have also induced new patterns of barrier behaviour that include transgressive and regressive dynamics at various locations alongshore

sedimentation in the yellow river delta part i flow and suspended sediment structure in the upper distributary and the estuary abstract a 44 year data record measured by lijin hydraulic station on the yellow river shows that sediment concentration has been increasing while river discharge has been decreasing into the delta since the 1970s these changes are important because flood waters of the yellow river which are heavily laden with sediment must be used to supply dongying city and shengli oil company which are located on the delta based on the analyses of data of velocity sediment concentration salinity and sediment grain size from four cross section measurements at lijin station and one 8 vessel simultaneous measurement cruise in the estuary structural characteristics of the river flow and suspended sediments throughout the upper distributary and the estuary have been studied and discussed results show that when sediment concentrations of the yellow river exceed 100 kg m 3 in the lower layer of the river flow during the flood period the river flow structure does not coincide with the logarithmic law of wall and becomes vertically layered and the vertical distributions of suspended sediment do not coincide with the diffusion law the channel length influenced by the tide wave is less than 15 km and there is no tidal intrusion flow only weak osmosis of salinity occurs inside the river mouth during the flood period of the yellow river simultaneous 8 vessel measurements and simulation using the method of preissman show that there is a tidal sensitive zone inside the river mouth bar with a length of 6 7 km when the discharge is as large as 1100 m 3 s and an area of very active sedimentation the tidal sensitive region near the river mouth becomes a low velocity zone that traps a large amount of river sediment which rapidly forms a plastic bed at flood tide and a high velocity zone with a strong hydrodynamic action to erode the new bed and transport the sediments into the sea at ebb tide

asymmetry in holocene river deltas patterns controls and stratigraphic effects abstract understanding controls on sediment distribution in river deltas is paramount to predicting facies relationships and stratal architecture most classifications of deltas have focused on subaerial plan morphology as a simplistic function of river tide and wave energy new work however is revealing the importance of subaqueous deposits and in particular shore parallel sediment redistribution in the shaping of delta planform delta asymmetry has emerged as an important characteristic reflective of patterns of alongshore sediment dispersal asymmetry has been described from onshore and offshore environments from several different types of modern deltas but aspects of asymmetry have not been fully documented and the degree to which these patterns are recorded in deltaic strata is not yet known this study is a comprehensive literature review of sediment distributions in modern deltas focusing on studies with high resolution geomorphic geophysical and geochronological datasets we reviewed 27 deltas using over 100 papers primarily from the past 15 20 years morphological facies and stratigraphic aspects were analyzed across the entire spectrum of deposits from the delta apex to the most distal muds of the prodelta we define quantifiable indices of asymmetry describing upcurrent vs downcurrent distribution of sediment volume sediment area sediment caliber and distributary channels most deltas are asymmetrical to some degree with respect to one or more of these parameters many deltas are increasingly skewed toward the downcurrent side from proximal to distal sub environments i e delta plain delta front prodelta some deltas are skewed toward the upcurrent side in one sub environment and toward the downcurrent side in another sub environment sand is preferentially deposited on the downcurrent side of most deltas but distributary channels tend to develop toward the upcurrent side the highest sand mud ratios are often on the upcurrent side in the lower delta plain but in the delta front these ratios are highest on the downcurrent side these complex patterns of asymmetry reflect different combinations of controls including discharge partitioning lobe abandonment and localized transgression plume deflection by coastal currents dominance of longshore current direction variable subsidence and other factors these processes may result in upcurrent downcurrent variations in clinoform geometry rates of progradation and stratal lapping relationships asymmetry has multiple aspects manifestations and controls even within a single delta but the long term preservation potential of these patterns likely varies depending on depositional setting and shoreline trajectory studies of ancient deltas will be better informed by recognizing the wide variety of controls on sediment distribution and avoiding the tendency toward a single model of delta asymmetry

processes reshaping the ebro delta abstract due to the limited supply of sediment from the ebro river its delta is mainly subject to reshaping processes in the form of alongshore alternation of erosive and accretive coastal stretches without a significant change in the overall subaerial surface of the delta the main agents presently forcing these processes waves and mean water level oscillations are analysed in detail as a function of their contribution to coastal processes in this manner waves are characterised in terms of short term seasonal changes longshore sediment transport pattern long term cross shore transport at the shoreface and storm impacts although the study area is a microtidal one and waves are the main agent forcing coastal evolution at yearly scales mean water level oscillations meteorological tides and long term relative mean sea level variations play a non negligible role additionally a joint analysis of waves and storm surges has been done in order to characterise conditions inducing an impulsive type of coastal response at last the classical ternary classification of deltas has been applied in a dynamical way by considering the river vertex in terms of the variation in sediment supply moreover the effects of considering mean water level variations other than tides on the deltaic classification has also been tested the inclusion of rslr influence becomes relevant for river independent deltas since it indicates the inability of the delta to withstand it the main problem to include this agent in the ternary classification is that rslr is more of a passive factor whereas the other considered agents are active in the sense that they induce more perceivable morphological processes

the effect of low permeability fault zones on groundwater flow in a compartmentalized system experimental evidence from a carbonate aquifer southern italy the hydrogeological behaviour of fault zones in carbonate aquifers is often neglected in conceptual and numerical models furthermore no information is available regarding the relationships between piezometric levels when significant compartmentalization occurs due to the occurrence of low flow fault zones the aim of this study was to refine the conceptualization of subsurface flow in faulted carbonate aquifers and to analyse relationships between sub basins within a compartmentalized aquifer system in southern italy the interactions between compartments that straddle low flow faults were investigated over four hydrologic years using a statistical approach to compare i the hydraulic heads within two wells located up and down gradient of tectonic discontinuities as well as ii the rainfall and piezometric levels the results of this study suggest that a set of barriers exists between the wells and therefore the total head loss observed between the wells approximately 80 m should be distributed across several aquitards with one aquitard exhibiting a relatively high permeability or low degree of integrity due to slight differences in permeability transient conditions in aquitards can occur over relatively short periods which is in agreement with the results of the statistical data analysis consequently rather than being caused by pure aquitards aquifer system compartmentalization likely results from slight differences in the permeability between lower permeability fault zones and adjacent higher permeability protoliths copyright 2014 john wiley sons ltd

updrift river mouth migration on cuspate deltas two examples from the coast of tuscany italy the configuration of the arno and ombrone deltas italy is evaluated the terminal courses of the rivers forming these deltas face the dominant wave orthogonal this configuration came about during rapid delta progradation as a consequence of increased river sediment input due to widespread deforestation within the catchment area a prevailing phenomenon from the early middle ages to the xviii century the rivers attained and maintained their directions as the result of the increased accretion rate on the less exposed downdrift side of the delta on the more exposed updrift side delta growth caused the shoreline to gradually rotate so that it directly faced the waves approaching the coast here due to the lower refraction wave energy per shore unit increased whilst accretion rate decreased this rotation of the shoreline induced longshore inversion on the updrift side whereas today cusp erosion is restoring the original drift direction

acoustic monitoring of the tide height and slope water intrusion at the new jersey shelf in winter conditions waveguide invariant theory is used to describe the frequency shifts of constant acoustic intensity level curves in broadband signal spectrograms measured at the new jersey shelf during the winter of 2003 the broadband signals 270 330hz were transmitted from a fixed source and received at three fixed receivers located at 10 20 and 30km range along a cross shelf propagation track the constant acoustic intensity level curves of the received signals indicate regular frequency shifts that can be well predicted by the change in water depth observed through tens of tidal cycles a second pattern of frequency shifts is observed at only 30km range where significant variability of slope water intrusion was measured an excellent agreement between observed frequency shifts of the constant acoustic intensity levels and those predicted by the change in tide height and slope water elevations suggests the capability of long term acoustic monitoring of tide and slope water intrusions in winter conditions