closure of a seaway stratigraphic record and facies guadix basin southern spain during the late tortonian upper miocene the guadix basin in s spain formed one of the betic corridors that connected the mediterranean sea with the atlantic ocean the closure of this connection occurred in a series of steps documented by three sedimentary units a lower unit consisting of basinal marls shallow water calcarenites and sands records the formation of a wide seaway during deposition of the following unit this narrowed to a strait no more than 2 km in wide triggering an intensification of currents that caused migration of submarine dunes preserved as giant cross beds in bioclastic sands and conglomerates current flowed from the mediterranean to the atlantic the third unit constitutes the youngest marine episode of the filling of the guadix basin at this stage the connection between the mediterranean sea and the atlantic ocean was broken and a system of coastal coral reefs was established in the northern part of the basin

numerical assessment of infragravity swash response to offshore wave frequency spread variability this work has been funded under 1 the retos investigacion 2014 grant bia2014 59718 r program of the spanish ministry of economy and competitiveness and 2 the neptune 2 project l r 7 2007 by regione autonoma della sardegna

wave induced sediment transport and sandbar migration onshore sediment transport and sandbar migration are important to the morphological evolution of beaches but are not well understood here a model that accounts for fluid accelerations in waves predicts the onshore sandbar migration observed on an ocean beach in both the observations and the model the location of the maximum acceleration induced transport moves shoreward with the sandbar resulting in feedback between waves and morphology that drives the bar shoreward until conditions change a model that combines the effects of transport by waves and mean currents simulated both onshore and offshore bar migration observed over a 45 day period

paraglacial adjustment of alluvial fans to the last deglaciation in the snežnik mountain dinaric karst slovenia abstract glaciokarst depressions are major glacigenic depocenters in the dinaric mountain karst areas and often store important information about the timing and nature of glacial processes and paraglacial sediment reworking this study focuses on praprotna draga which is one of the largest glaciokarst depressions in the sne nik mountain dinaric karst with an area of 3 4 km2 and a maximum depth of 140 m the western slopes of the depression are characterized by undulated moraine morphology and alluvial fans are filling its entire floor we present the results on the thickness origin and age of the sediment infill using a complementary geomorphological sedimentological geophysical and dating approach distribution of moraines point to two glacial advances that were associated with two main alluvial fan aggradation phases recognized using the electrical resistivity tomography measurements the youngest alluvial deposits were sampled for cosmogenic 36cl analysis using amalgamated carbonate pebbles the depth profile of 36cl concentrations suggests an age of 12 3 1 7 ka when assuming a likely denudation rate of 20 mm ka 1 since the existence of the younger dryas glaciers in the study area is climatically difficult to explain we tentatively propose that the youngest alluvial deposition in praprotna draga took place after the glacier retreat during the paraglacial period our findings suggest that the time window of paraglacial adjustment in the sne nik mountain was brief and likely conditioned by quick recolonization with vegetation and inefficient surface runoff on deglaciated karst terrain

a review on natural and human induced geohazards and impacts in karst karst environments are characterized by distinctive landforms related to dissolution and a dominant subsurface drainage the direct connection between the surface and the underlying high permeability aquifers makes karst aquifers extremely vulnerable to pollution a high percentage of the world population depends on these water resources moreover karst terrains frequently underlain by cavernous carbonate and or evaporite rocks may be affected by severe ground instability problems impacts and hazards associated with karst are rapidly increasing as development expands upon these areas without proper planning taking into account the peculiarities of these environments this has led to an escalation of karst related environmental and engineering problems such as sinkholes floods involving highly transmissive aquifers and landslides developed on rocks weakened by karstification the environmental fragility of karst settings together with their endemic hazardous processes have received an increasing attention from the scientific community in the last decades concurrently the interest of planners and decision makers on a safe and sustainable management of karst lands is also growing this work reviews the main natural and human induced hazards characteristic of karst environments with specific focus on sinkholes floods and slope movements and summarizes the main outcomes reached by karst scientists regarding the assessment of environmental impacts and their mitigation

climate stability in central anatolia during the messinian salinity crisis abstract deposition of large amounts of evaporites and erosion of deep canyons within the mediterranean basin as a result of reduced basin connectivity with the atlantic ocean and the epicontinental paratethys sea characterized the messinian salinity crisis msc 5 97 5 33 ma the influence of the msc on mediterranean environmental conditions within the basin itself has been intensely studied from marine records but reconstructing the impact of the msc on circum mediterranean continental climate has been hampered by the absence of continuous sedimentary archives that span the duration of the event here we report results of a continental record of carbon 13c and oxygen 18o isotopes from lake carbonates framed by new magnetostratigraphic and 40ar 39ar dating as well as by existing mammal stratigraphy kangal basin central anatolia the sampled section records continuous fluvio lacustrine sedimentation from 6 6 ma to 4 9 ma which spans the msc and the miocene pliocene boundary this dataset so far represents the only continuous continental paleoenvironmental record of the msc in the circum mediterranean realm the kangal basin isotope record indicates a low degree of evaporation furthermore covariance between 13c and 18o suggests a coupling between lake water balance and biologic productivity variations in 13c and 18o therefore likely reflect changes in the amount of incoming precipitation rather than changes in 18o values of incoming precipitation the most prominent spike in 13c and 18o occurs during the acme of the msc and is therefore interpreted to have resulted from a decrease in the amount of incoming moisture correlative to a period of vigorous erosion and sea level lowering in the mediterranean basin major sea level lowering of mediterranean basin waters during the acme of the msc could have therefore led to slightly dryer conditions over anatolia which is also suggested by modeling studies overall changes in 13c and 18o values are small therefore we surmise that the msc had limited effects on the paleoenvironmental and paleoclimatic conditions in the anatolian interior

simulating wave setup and runup during storm conditions on a complex barred beach abstract the purpose of this study is to assess the ability of the swash model to reproduce wave setup and runup in highly dissipative stormy conditions to proceed we use data collected during the ecors truc vert 08 experiment especially during the johanna storm in the winter of 2007 008 wave setup under hs 8 2 m and tp 18 3 s and runup under 6 4 m and peak period up to 16 4 s we test different model settings 1d and 2d mode and model forcing spectral and parametric to reproduce sensor measured wave setup at several locations in the nearshore area and video measured runup on two beach profiles for the whole tested configurations the wave setup is reproduced accurately results considering all the sensor locations in the near shore area in 1d and 2d are significantly correlated to the observations with respectively 0 66 and 0 81 rmse 0 13 m and 0 08 m without any significant bias observations and simulations of runup are investigated in terms of spectra and statistic component 1d simulations produces an overall overestimation and no significant improvement is obtained by modifying the breaking parameters the results for 2d simulations are fairly satisfactory reproducing significant swash height s but are significantly improved with spectral forcing than parametric with respectively 0 73 and 0 71 rmse 0 19 m and 0 43 m generally the model reproduces accurately the infragravity component but tends to overestimate the incident component leading to an overestimation of the energy density for moderate wave conditions and more accurate results for higher energy wave conditions results in 2d with spectral forcing show a saturation of the infragravity component with a threshold around hs 4 to 5 m which is comparable to the observations collected at truc vert beach as regards the conventional statistical parameter for runup estimation r2 three methods are applied to derive the 2 exceedence value for runup from observed and simulated shoreline vertical elevation time series when r2 is based on the sum of wave setup and half of the significant swash height results provided by the model are close or even better than estimations provided by empirical formulas from the bibliography defining r2 as the exceeded 2 values of the time derived considering the cumulative distribution function of the entire water level time series also provide fairly good results results using only runup maxima time series are less satisfactory in the two last cases r2 is slightly underestimated for moderate wave conditions hs

submerged karst landforms observed by multibeam bathymetric survey in nagura bay ishigaki island southwestern japan abstract submerged tropical karst features were discovered in nagura bay on ishigaki island in the southern ryukyu islands japan the coastal seafloor at depths shallower than 130 m has been subjected to repeated and alternating subaerial erosion and sedimentation during periods of quaternary sea level lowstands we conducted a broadband multibeam survey in the central area of nagura bay 1 85 2 7 km and visualized the high resolution bathymetric results over a depth range of 1 6 58 5 m various types of humid tropical karst landforms were found to coexist within the bay including fluviokarst doline karst cockpit karst polygonal karst uvalas and mega dolines although these submerged karst landforms are covered by thick postglacial reef and reef sediments their shapes and sizes are distinct from those associated with coral reef geomorphology the submerged landscape of nagura bay likely formed during multiple glacial and interglacial periods according to our bathymetric results and the aerial photographs of the coastal area this submerged karst landscape appears to have developed throughout nagura bay i e over an area of approximately 6 5 km and represents the largest submerged karst in japan

correlation of late miocene to early pliocene sequences between the mediterranean and north atlantic ocean drilling program odp site 982 in the north atlantic contains a complete latest miocene to early pliocene section that was tuned to the astronomical timescale by correlating the record of gamma ray attenuation gra bulk density to summer insolation at 65 n and the benthic 18o signal to orbital obliquity for the interval from 4 6 to 7 5 ma the astronomical tuning of the site 982 record permits a direct bed to bed correlation to the cyclostratigraphy of messinian sections in the mediterranean krijgsman et al 1999a 2001 the benthic 18o signal at site 982 records a latest miocene glacial period that lasted from 6 26 to 5 50 ma and consisted of 18 glacial to interglacial oscillations that were controlled by the 41 kyr cycle of obliquity although the intensification of glaciation at 6 26 ma may have contributed to the restriction of the mediterranean it preceded the depositional onset of the lower evaporite unit at 5 96 ma by some 300 kyr the transition from stage tg12 to tg11 at 5 5 ma marks the end of the latest miocene glacial period and precedes the miocene pliocene boundary by 170 kyr although benthic 18o values are relatively low and 18o of bulk carbonate reaches a minimum at the miocene pliocene boundary at 5 33 ma there is no single event that would indicate deglaciation and sea level rise as the cause of the reflooding of the mediterranean we conclude that glacioeustatic changes alone were not responsible for either the start or end of evaporite deposition during the messinian suggesting that tectonic or local climate changes in the mediterranean region were the dominant cause s

the messinian marine to nonmarine gypsums of jumilla northern betic cordillera se spain isotopic and sr concentration constraints on the origin of parent brines the origin of the messinian hoya de la sima hs gypsum betic foreland is constrained using 87sr 86sr 34s sr concentration and petrographic data the lower and middle hs units consist of subaqueous vertically aligned and stromatolitic selenites the latter containing unusual microbial depositional textures the upper unit consists of very shallow water bioturbated lenticular gypsum with paracamelus ichnites 87sr 86sr and 34s indicate precipitation from predominantly marine waters with upward increasing continental influence mixing models between messinian seawater and continental water that dissolved triassic evaporites show that the percentages of seawater required to explain the measured 87sr 86sr are analogous to the percentages obtained using 34s supporting precipitation from such mixtures 87sr 86sr and 34s of lower hs selenites resemble those of the primary lower gypsum plg of the messinian salinity crisis msc in both cases indicating precipitation from seawater continental water mixtures in which most sr and so4 were supplied by messinian seawater in the lower hs selenites sr concentrations indicate contributing continental waters with sr ca ratios similar to seawater however sr concentrations of plg selenites from other betic basins bajo segura sorbas indicate parent waters with sr ca ratios lower than seawater if the sr contents of the betic plg selenites are representative it is unlikely that the lower hs selenites represent the plg however we cannot completely discard that option since different lpg subbasins could have had variable sr ca the hs gypsums formed coevally to diapirism of triassic evaporites in a restricted lagoonal basin developed during or slightly after a phase of strike slip faulting in the betic cordillera more general implications of this work are that sr concentrations combined with 87sr 86sr and 34s data provide key constraints on the origin of parent brines and using sr concentrations as paleosalinity proxy in gypsum precipitated from seawater continental water mixtures is inconclusive because they largely depend on the initial sr ca ratio of the brine this study also illustrates that the electron microprobe is ideal to obtain reliable spatially resolved sr concentration data in selenitic gypsum these data in combination with fluorescence petrography provide valuable criteria to discriminate primary depositional from diagenetic gypsum a critical step in the interpretation of geochemical data

late miocene turnover in the spanish mammal record in relation to palaeoclimate and the messinian salinity crisis abstract the latest miocene and earliest pliocene is a period of marked changes in geography and climate in the circum mediterranean area its geographical situation gives spain a key position and its fossil mammal record reflects these important geographical and climatic changes particularly well the spanish mammal record shows a gradual change of composition towards the typical pleistocene and recent fauna marked by several extinction and dispersal events these events have the effect that northern eurasian elements increase while taxa that locally go extinct may live on in tropical areas superposed on this large scale trend there are some events of short lived incursions of animals of african or south asian origins which seem to reflect a short reversal of this tendency and temporary geographical changes related to the messinian crisis these latter incursions are detected very well in spain but also in other parts of southern europe the messinian salinity crisis is caused by interplay of tectonics and global sea level variations which in turn depend on climate while some of these changes were permanent causing the replacement of central italian insular faunas by mainland faunas others were temporary probably allowing the short lived incursions of african mammals into sw europe and certainly allowing for mammals to reach the balearics corsica and sardinia we document an important event around 6 1 ma of mammals adapted to dry or open environments dispersing from africa and se europe to sw europe during the messinian desiccation phase animals adapted to more humid environments reached some of the west mediterranean islands suggesting that at least during part of the desiccation phase a part of the former sea bottom was not desertic between 6 3 and 5 3 ma tectonics united the island of toscany to the european mainland thereby closing a seaway of some 10 km wide and 100 m deep

effects of wave rollers and bottom stress on wave setup 1 setup the increase in the mean water level associated with breaking waves observed between the shoreline and about 6 m water depth on an ocean beach is predicted well by a model that includes the effects of wave rollers and the bottom stress owing to the mean flow over the 90 day observational period the measured and modeled setups are correlated squared correlation above 0 59 and agree within about 30 although rollers may affect setup significantly on beaches with large amplitude several meters high sandbars and may be important in predicting the details of the cross shore profile of setup for the data discussed here rollers have only a small effect on the amount of setup conversely bottom stress calculated using eddy viscosity and undertow formulations based on the surface dissipation and assuming that the eddy viscosity is uniform throughout the water column significantly affects setup predictions neglecting bottom stress results in underprediction of the observed setup in all water depths with maximum underprediction near the shoreline where the observed setup is largest

magnetostratigraphic biostratigraphic and stable isotope stratigraphy of an upper miocene drill core from the sale briqueterie northwestern morocco a high resolution chronology for the messinian stage we report a high resolution stable isotope carbonate magnetostratigraphic and biostratigraphic record from a 175 m drill core from the sale briqueterie which is part of the bou regreg section in northwestern morocco the sale drill core spans the interval from paleomagnetic chron c4n partim to c3r earliest gilbert which represents the time leading up to and including the isolation and desiccation of the mediterranean i e the messinian salinity crisis during chrons c3an and c3ar 6 935 to 5 894 ma the isotope and carbonate signals display quasi periodic variations with estimated periods of 40 and 100 kyr respectively we interpret the 40 kyr 18o variations as reflecting changes in global ice volume caused by obliquity induced changes 41 kyr in solar insolation in polar regions the 100 kyr carbonate variations probably represent long term modulation of the amplitude of the precessional cycle 21 kyr which is not resolved by our sampling frequency the cyclic nature of the oxygen isotope signal permits us to extend the isotope nomenclature of shackleton et al 1994a from stage tg24 in chron c3r earliest gilbert to stage c3ar 18o 18 at the base of chron c3ar 6 935 ma a major change in paleoceanographic conditions is recorded across the tortonian messinian boundary which we correlate to chron c3bn at 7 04 ma benthic foraminiferal 18o values increased by an average of 0 4 in two steps at 7 17 ma and 6 8 ma and 13c values decreased by 0 7 0 8 between 7 1 and 6 8 ma representing the late miocene carbon shift the first step in 18o values coincides with an inferred reversal in deep water circulation through the rifian corridor and the second correlates with the base of the tripoli formation and onset of crisis conditions in the mediterranean we suggest that the increase in 18o values represents at least in part an increase in global ice volume that lowered sea level and contributed to the establishment of a negative water budget in the mediterranean average 18o values remained high throughout most of chrons c3ar and c3an reaching maximum 18o values during isotope stages tg20 and 22 in chron c3r earliest gilbert the glacio eustatic falls associated with these events may have resulted in the complete isolation of the mediterranean from the world ocean shackleton et al 1994a following stage tg12 in the sale record there exists a trend toward progressively lower 18o values that may represent a series of marine transgressions that eventually reflooded the mediterranean and ended the salinity crisis

karstic uvala revisited toward a redefinition of the term abstract uvalas are a particular type of karst closed depression while other types of closed depression dolines and poljes are regularly listed and relatively well defined in overviews of karst surface morphology uvalas are either excluded or their vague identification is stressed the leading idea of this paper is to obtain a clearer meaning of the term uvala and prevent its abandonment from karstology and general geomorphology within the study 43 examples of uvalas have been selected the studied uvalas are located in the dinaric karst and karst of the carpatho balkanides all the case examples have been digitally processed in the same way creation of high resolution digital elevation models enabled quantification of morphometric parameters generation of inclination maps and cross sections as well as application of statistical analyses formation of the geographical information system of the studied uvalas was done using raster based and vector based gis software packages in 12 studied uvalas detailed structural geological mapping has been carried out which revealed dominant development of uvalas along regional scale tectonically broken zones a revised definition of the term uvala is suggested leaving the opportunity for further discussion

swash an operational public domain code for simulating wave fields and rapidly varied flows in coastal waters abstract a computational procedure has been developed for simulating non hydrostatic free surface rotational flows in one and two horizontal dimensions its implementation in the publicly available swash an acronym of simulating waves till shore is intended to be used for predicting transformation of surface waves and rapidly varied shallow water flows in coastal waters this open source code http swash sourceforge net has been developed based on the work of stelling and zijlema 2003 stelling and duinmeijer 2003 zijlema and stelling 2005 zijlema and stelling 2008 the governing equations are the nonlinear shallow water equations including non hydrostatic pressure and provide a general basis for describing complex changes to rapidly varied flows typically found in coastal flooding resulting from e g dike breaks and tsunamis and wave transformation in both surf and swash zones due to nonlinear wave wave interactions interaction of waves with currents and wave breaking as well as runup at the shoreline the present paper provides a complete description of the numerical algorithms currently used in the code the code is benchmarked using some analytical problems moreover the numerical results are validated with various cases of laboratory data with the principal aim to convey the capabilities of the swash code in particular emphasis is put on an analysis of model performance and associated physical implications serial and parallel performance scalings are also presented

evaporitic sedimentation in the southeastern anatolian foreland basin new insights on the neotethys closure abstract we integrate stratigraphic petrographic and geochemical analysis of subsurface data wells together with field surveys to study the sedimentation of a marginal miocene sub basin of the southeastern anatolian foreland basin seafb se turkey this sub basin located in the batman siirt region is characterized by the existence of evaporites carbonates sulphates and chlorides and alluvial detritus which were divided in the following five lithostratigraphic members from older to younger lower and upper yapilar and lower middle and upper sulha these members deposited in an epicontinental mudflat during the early miocene both the bromine content and the sulphur and oxygen isotope composition 34 s v cdt and 18 o v smow of halite and sulphates samples respectively also suggest a marine origin of the precipitation brines however influence of geothermal fluids and dissolution and re precipitation of evaporites from uplifted areas in these brines such as the early miocene members and or triassic units is interpreted comparing and integrating our results with data documented in previous works it is here recognized that the depositional model of the studied sub basin differs from that which explain the coeval sedimentation of units situated in the western part of the seafb moreover our model shows some depositional and paleoenvironmental similarities with miocene evaporites located in the mesopotamian foreland basin this work provides valuable insights on the middle miocene salinity crisis which is related to the evolution of the neotethys closure

the european record of the gerbil myocricetodon rodentia mammalia and its bearing on the messinian salinity crisis abstract the gerbillid myocricetodon is mainly known from the miocene of africa and asia but some small samples of this genus have been identified in southwestern europe interpreted as immigrants driven by the messinian salinity crisis however the specific determination of these european populations and their relationships with african forms have proved controversial the population from negratin 1 guadix basin southern spain was attributed to the african species myocricetodon jaegeri but other european samples have still not been determined at the specific level here we describe the material of myocricetodon from almenara m eastern spain which represents the most abundant sample of the genus known from europe confirming its assignation to m jaegeri we also analyze material from salobrena pino mojon southern spain and castelnou 3 southern france concluding that these samples belong to the same species the presence of these coeval and conspecific populations of myocricetodon is explained by a single migratory event from northern africa the occurrence of myocricetodon interpreted as an indicator of warm and arid conditions is restricted to southern and eastern spain and the southeastermost extreme of france being mainly limited to the mediterranean coast it is absent in other iberian areas such as the granada cabriel and teruel basins despite their rich and well studied record of late miocene mammals this distribution suggests the existence of different environmental more humid conditions in those areas during the latest miocene as already proposed for the granada basin our data also indicate that the presence of myocricetodon in europe was limited to a short interval close to the miocene pliocene boundary contrarily to other gerbils namely debruijnimys which persisted during the pliocene this suggests that myocricetodon could be extremely sensitive to environmental factors and its occurrence in europe was linked to a specific moment of arid conditions

observations of wave energy fluxes and swash motions on a low sloping dissipative beach 1 field observations of swash and ocean waves show that runup saturation at infragravity frequencies 0 025 0 035 hz infragravity waves where typically less than 5 of the linear energy flux was reflected from the beach and where similar to the sea swell band the swash energy was independent of offshore wave energy the infragravity frequency range of saturation was determined by the tide with saturation extending to lower frequencies at low tide when the local beach face slope over the concave shaped profile was gentler runup was strongly dominated by infragravity frequencies which accounted on average for 96 of the runup variance and its energy levels were entirely consistent with strong infragravity wave dissipation observed in the surfzone particularly when including the nonlinear contributions to the wave energy fluxes the infragravity wave dissipation was strongly associated with breaking of sea swell waves which abruptly decreased nonlinear transfers to infragravity frequencies and made infragravity dissipation prevail over forcing within the breaking region our observations show evidence of nonlinear interactions involving infragravity and high frequency harmonic waves and suggest that these harmonics could play a role in the wave energy balance near the shoreline on low sloping dissipative beaches

the onset of the messinian salinity crisis in the eastern mediterranean pissouri basin cyprus the pissouri basin in cyprus contains one of the most suitable sedimentary successions with which to study the onset of the messinian salinity crisis in the eastern mediterranean exposures along the new paphos limassol motorway near pissouri exhibit distinct cyclic bedding which permits the construction of a chronology based on orbital tuning biostratigraphic results reveal 10 planktonic foraminifera events that have been astronomically dated in other mediterranean sections and as such provide an excellent first order age control magnetostratigraphic results are in good agreement with the biostratigraphic data and show that all magnetic chrons between c4n 1n and c3an 1n are present the pattern of sedimentary cycles generally fits well with the insolation curve astronomical tuning of the succession shows that the first gypsum bed at pissouri overlies a 40 60 kyr stromatolite bearing transitional interval and correlates with the amplitude increase in insolation at 5 96 ma as in the western mediterranean this indicates that the onset of evaporite precipitation was synchronous right across the entire mediterranean basin fl 2002 elsevier science b v all rights reserved

spatial analysis of a karst depression population clues to genesis a detailed analysis of depression spatial distribution on the parts of the western highland rim and pennyroyal plain underlain by the st louis and ste genevieve limestones indicates the presence of a depression infrastructure the major geomorphic elements of the infrastructure include depression density no km 2 doline swallet order and interdoline spacing a multigenerational diffusion and competition process model best explained 1 the presence of two lognormally distibuted depression density subpopulations 2 discrete clustered depression sets containing second order swallet dolines surrounded by first order swallet depressions 3 geomorphic competition between adjacent second order swallet dolines for runoff and catchment area and 4 a positive correlation between interdoline rim spacings of the small swallet order and the sum of their respective major axial lengths

geodynamic evolution of the central dinarides abstract the central part of the dinarides unlike the northwestern and southeastern dinarides shows a consistent pattern in the distribution of the large tectonostratigraphic units from southwest apulia to northeast the following five main units originating in different parts of the mesozoic tethys can be distinguished 1 adriatic dinaridic carbonate platform formations 2 carbonate clastic units flysch bosniaque of the passive continental margin 3 ophiolite bearing formations of the dinaridic ophiolite zone also containing radiolarites greywackes and shales including melange formations and overstepped late jurassic to cretaceous cover sequences 4 active continental margin units represented by upper cretaceous palaeogene trench sediments with blueschists tectonized ophiolite melange alpine medium pressure metamorphic rocks originated from upper cretaceous palaeogene sediments and alpine synkinematic granitoids 5 a nappe consisting of allochthonous palaeozoic triassic formations which is thrust onto the ophiolites and genetically related sedimentary formations the frontal parts of this nappe directly overlie the northeastern margin of the adriatic dinaridic carbonate platform i e the external dinarides the evolution of the central dinarides was controlled by a sequence of tectonic events which took place within the alpine cycle 1 rifting processes lasting some 40 50 ma which started in the late permian and ended in the norian 2 opening of the oceanic dinaridic tethys commenced in the late triassic and persisted for some 70 80 ma until the end of the jurassic 3 subduction processes and emplacement of ophiolites started in late jurassic early cretaceous times during the closing phase of the dinaridic ocean or dinaridic tethys the palaeozoic triassic nappe was emplaced on the ophiolites the thrusting was accompanied by alpine metamorphism 120 100 ma 4 the main alpine deformational event and medium pressure metamorphism with synkinematic granite plutonism took place in late eocene early oligocene times when the ophiolite and palaeozoic triassic nappes were emplaced on the adriatic dinaridic carbonate platform which at the same time was deformed resulting in the development of the external dinarides fold and thrust belt

regional climate and glacial control on high resolution oxygen isotope records from ain el beida latest miocene northwest morocco a cyclostratigraphic analysis in the depth and time domain 1 high resolution benthic and planktonic stable oxygen isotope records are presented for the upper miocene ain el beida aeb section in northwestern morocco and reveal the clear imprint of the climatic precession obliquity and eccentricity cycles in the interval between 6 5 and 5 5 ma the 18o depth series were transformed into time series using astronomical tuning of the sedimentary color cycles to the 65 n summer insolation curve of the la93 solution with present day values for tidal dissipation and dynamical ellipticity spectral analysis and band pass filtering show that the ratios of the astronomically related spectral peaks are not consistent in the depth and time domain the inconsistencies are mainly due to variations in sedimentation rate that are positively correlated with precession amplitude i e modulated by eccentricity in addition they result from a long term trend in sedimentation rate a simple model of nonlinear response of the sedimentation rate to the eccentricity modulation of precession was used to simulate the observed shifts in the relative position of the spectral peaks in the depth domain cross spectral analysis was carried out on the 18o time series and a combined eccentricity tilt obliquity and precession etp curve the precession controlled 18o signal varies in phase with etp partly as a result of the tuning procedure while the obliquity related signal reveals a small lag of 2 3 kyr relative to obliquity this lag is slightly reduced at the time of the messinian salinity crisis msc and increases to 5 6 kyr if the tidal dissipation term in the astronomical solution is reduced to half its present day value the obliquity related lag is most likely associated with the slow buildup of ice caps whereas the precession signal is interpreted as to dominantly reflect regional climate changes comparable to those associated with mediterranean sapropels finally the benthic 18o record is compared with open ocean records and discussed in terms of an astronomically tuned oxygen isotope stratigraphic framework

morphometric properties of dolines in matarsko podolje sw slovenia matarsko podolje in sw slovenia is a karstic surface with many dolines which appear between the flysch composed brkini hills in the ne and mt slavnik in the sw we have analyzed dolines to find the morphometric parameters of the depth area volume and circularity index and also calculated the doline density and pitting index all parameters were also calculated separately for individual lithological units to explain the variations of the calculated values among these groups morphometry was performed in gis environment on a 1 1 m digital elevation model with bare earth obtained by lidar the results show a high density of dolines 94 dolines km2 and also a high pitting index rp 8 27 compared to other studies there are some significant differences between the measured values in individual lithologies as the depths areas and volumes are largest in dolomitic beds other beds include various types of limestones and carbonate breccia the median values of depth area and volume are 2 98 m 541 m2 and 690 m3 the circularity index is also lowest in dolomite beds and kozina limestones however the differences are not so pronounced as for areas and volumes dolines longer axes are parallel to the directions of major structural elements however more detailed mapping should be done to confirm the influence of faults and fracture zones on the doline geometry

evolution of the late miocene mediterranean atlantic gateways and their impact on regional and global environmental change marine gateways play a critical role in the exchange of water heat salt and nutrients between oceans and seas as a result changes in gateway geometry can significantly alter both the pattern of global ocean circulation and associated heat transport and climate as well as having a profound impact on local environmental conditions mediterranean atlantic marine corridors that pre date the modern gibraltar strait closed during the late miocene and are now exposed on land in northern morocco and southern spain the restriction and closure of these miocene connections resulted in extreme salinity fluctuations in the mediterranean leading to the precipitation of thick evaporites this event is known as the messinian salinity crisis msc the evolution and closure of the mediterranean atlantic gateways are a critical control on the msc but at present the location geometry and age of these gateways are still highly controversial as is the impact of changing mediterranean outflow on northern hemisphere circulation here we present a comprehensive overview of the evolution of the late miocene gateways and the nature of mediterranean atlantic exchange as deduced from published studies focussed both on the sediments preserved within the fossil corridors and inferences that can be derived from data in the adjacent basins we also consider the possible impact of evolving exchange on both the mediterranean and global climate and highlight the main enduring challenges for reconstructing past mediterranean atlantic exchange

directional spreading of waves in the nearshore observations of surface gravity waves shoaling between 8 m water depth and the shoreline on a barred beach indicate that breaking results in an increase in the directional spread of wave energy in contrast to the directional narrowing with decreasing depth predicted by refraction theory snell s law during low energy wave conditions when breaking induced wave energy losses over the instrumented transect are small the observed mean propagation direction and spread about the mean both decrease with decreasing depth consistent with the expected effects of refraction nonlinearity causes high frequency components of the spectrum to become directionally aligned with the dominant incident waves during high energy wave conditions with significant wave breaking on the sand bar the observed mean directions still decrease with decreasing depth however the observed directional spreads increase sharply nominally a factor of 2 for values integrated over the swell sea frequency range between the outer edge of the surf zone and the crest of the sand bar followed by a decrease toward the shoreline observations on a nonbarred beach also show directional broadening with spreads increasing monotonically from the outer edge of the surf zone to a maximum value near the shoreline although the mechanism is not understood these spatial patterns of directional broadening suggest that wave breaking causes significant scattering of incident wave energy into obliquely propagating components

late miocene stratigraphy and palaeogeographic evolution of the intramontane guadix basin central betic cordillera spain implications for an atlantic mediterranean connection abstract the guadix basin is an intramontane basin located in the central sector of the betic cordillera its late miocene stratigraphic record is divided into three depositional sequences limited by unconformities representing tectonic and or eustatic events depositional sequence i late tortonian is composed by two systems tracts the lower marks the beginning of marine sedimentation in the basin and comprises three retrograding lithological complexes or depositional systems coastal shallow platform and pelagic basin and is interpreted as a transgressive systems tract the upper systems tract consists of a shallow shelf prograding into a pelagic basin this systems tract exhibits a typically regressive pattern and was deposited during high sea level and is therefore interpreted as a highstand systems tract depositional sequence ii late tortonian is composed of both continental alluvial cones and shallow marine gilbert type delta shallow shelf and reef depositional systems the deposits of this sequence record a significant fall in sea level and are interpreted as a lowstand systems tract depositional sequence iii late turolian ventian or late tortonian messinian was formed of solely retrograding continental depositional systems alluvial fan lacustrine fan delta mud flat and lacustrine with this sequence begins the continental sedimentation in guadix basin in an endorheic context the palaeogeographic evolution of the guadix basin during the late miocene can thus be divided into three stages the first corresponds to depositional sequence i and is characterised by the development of shallow marine environments on the basin margins and deep water deposits in its centre during this stage the basin was connected to the west with the atlantic ocean via the granada and guadalquivir basins and toward the east with the mediterranean sea through the almanzora and campo coy basins in the second stage represented by depositional sequence ii most of the basin was occupied by shallow marine environments during this stage the connection with the atlantic and mediterranean was only open through the guadalquivir and campo coy basins respectively finally the third and last stage corresponding to depositional sequence iii is characterised by the development of continental environments throughout the basin this stage records the definitive closing of the connections with the atlantic ocean and the mediterranean sea

paleoenvironmental evolution of the eastern mediterranean during the messinian constraints from integrated microfossil data of the pissouri basin cyprus abstract integrated data of calcareous nannofossils as well as planktonic and benthic foraminifera from the pissouri motorway section on cyprus allow the reconstruction of surface and bottom water paleoenvironments of the eastern mediterranean during the interval preceding the messinian salinity crisis msc contrary to deeper water locations where benthic foraminifera faunas are suppressed or absent just after the tortonian messinian boundary sediments deposited at intermediate water depths do contain benthic assemblages from the earliest messinian onwards a development towards increasingly unfavourable paleoenvironments is reflected in the planktonic and benthic microfossil records of the pissouri section and proceeds with rather discrete time steps that can be correlated to sequences throughout the mediterranean shortly after the tortonian messinian boundary a transition is recorded in the sedimentology and the open marine deeper water taxa disappear from the benthic foraminifera assemblages subsequently the diversity of all fauna groups diminishes the changes recorded at species level in both surface water and sea floor dwelling taxa suggest decreasing circulation of the bottom waters associated with changes in the surface waters most likely due to increasing stratification from 6 73 ma onwards our data indicate a prominent change to more restricted conditions and increasing salinity at the sea floor together with intermittently rising surface water salinity the dominance of oligotypic and monospecific assemblages and the frequent shifts in assemblage compositions of all microfossil groups indicate severely stressed environments after 6 4 ma probably related to increased salinity the major changes in paleoenvironmental conditions including oxygen deprivation due to stagnation and hypersalinity can be explained by hydrographical changes in the mediterranean basin which are probably caused by tectonic movements in the rif corridor acting in concert with astronomical cyclicity evaluation of the paleodepth proxies indicates that the depth of the pissouri basin remained rather constant at 300 500 m with a minimum of 200 m until deposition of the barre jaune the transitional interval towards the evaporites and that early shallowing to neritic depths as was proposed before is highly unlikely

karst rivers particularity an example from dinaric karst croatia bosnia and herzegovina the very complex system of sinking losing and underground transboundary karst rivers lakes and aquifers in the central part of the deep and bare dinaric karst in croatia and bosnia and herzegovina is analysed the groundwater and surface water are hydraulically connected through numerous karst forms which facilitate the exchange of water between the surface and subsurface a complex underground conduit system is an inherent characteristic karst system analysed groundwater and surface water exchange with both adjacent and distant aquifers through underground routes or inflows from surface streams and artificial reservoirs because of a complex surface and underground karst features which strongly influenced its hydrological and hydrogeological regime the main open stream flow with a longitude of about 106 km undergoes eight name changes in this paper it is noted as the eight name river in fact it represents one river with losing sinking and underground stream sections different surface and underground karst forms play crucial roles in the way the water flowing over the surface and on the underground sections of its catchment the analysed area is full of varied and often spectacular surface landforms including for example the blue and red lakes and the kravice waterfall the analyses made in the paper show the existence of a decreasing trend of mean annual discharges on the eight name river which can cause numerous problems in the regional water resource management of this transboundary river and catchment

late cenozoic base level variations of the caspian sea a review of its history and proposed driving mechanisms abstract the caspian sea is characterized by significant variations in its base level during the late cenozoic and provides an important repository for long term records of both regional climate and tectonics due to its position within the interior of the eurasian continent and at the northern margin of the ongoing arabia eurasia collision zone the caspian also serves as an important moisture source for eastern eurasia including the northern tibetan plateau and thus the history of caspian base level variations represents an important and poorly understood constraint on paleoclimate reconstructions throughout eurasia prior work in the caspian region has largely focused on developing biostratigraphic age divisions and investigating the history of connection between the caspian black and mediterranean seas as well as the global ocean recent geochronologic work in the caspian and related basins has questioned previous correlations of hydrologic events in these different basins as a result prior estimates of the chronology and magnitude of caspian sea level variations may be incorrect here we synthesize previous work to develop a new caspian base level curve starting at the beginning of the meotian regional stage 7 ma we also present a new synthesis of potential driving mechanisms for the large variations in caspian base level and speculate on a possible cause for the enigmatic akchagyl transgression this synthesis highlights the dynamic range of caspian sea level which varied from 200 m above to in excess of 1000 m below its current level during the late cenozoic and provides a basis for future work investigating the tectonic and climatic drivers behind variations in caspian base level

the messinian diatomite deposition in the mediterranean region and its relationships to the global silica cycle abstract diatomites constitute a widely represented lithology in the messinian sections of the circum mediterranean neogene marginal basins although traditionally interpreted as genuine evidence of the gradually restricted conditions that characterized the mediterranean just before the messinian salinity crisis their coeval occurrence with a global intensification of the opaline production in the world oceans late miocene early pliocene biogenic bloom suggests that an integrative analysis of the origins of these sediments is necessary a comprehensive analysis of the geological and paleontological records suggests that the synergistic intervention of abiotic tectonic and climate reconfigurations and biotic expansion of grass dominated opal rich biomes controlling factors may have promoted a remarkable enhancement of silica flux from continents to oceans which in turn can explain the opaline burst that occurred during the late miocene at both the global and mediterranean scale the finely laminated pattern and the rich fossil content of diatomaceous deposits that are usually considered to be byproducts of anoxic conditions are briefly discussed some studies seem to indicate that instead of anoxia the aggregation and sedimentation of diatom tests may play a critical role in these processes the lower messinian diatomites of the mediterranean region are generally interbedded with organic rich sediments sapropels clearly attesting prolonged precessionally controlled periods of basin stratification and bottom water anoxia or hypoxia a causal relationship between sapropel and diatomite deposition in the mediterranean is proposed considering the possible interplay between stratification adapted diatoms and anaerobic bacteria and their respective role in influencing the marine silica cycle

modelling storm hydrodynamics on gravel beaches with xbeach g abstract in this paper we present a process based numerical model for the prediction of storm hydrodynamics and hydrology on gravel beaches the model comprises an extension of an existing open source storm impact model for sandy coasts xbeach through the application of 1 a non hydrostatic pressure correction term that allows wave by wave modelling of the surface elevation and depth averaged flow and 2 a groundwater model that allows infiltration and exfiltration through the permeable gravel bed to be simulated and is referred to as xbeach g although the model contains validated sediment transport relations for sandy environments transport relations for gravel in the model are currently under development and unvalidated consequently all simulations in this paper are carried out without morphodynamic feedback modelled hydrodynamics are validated using data collected during a large scale physical model experiment and detailed in situ field data collected at loe bar cornwall uk as well as remote sensed data collected at four gravel beach locations along the uk coast during the 2012 2013 storm season validation results show that the model has good skill in predicting wave transformation overall sci 0 14 0 21 run up levels sci

chronology causes and progression of the messinian salinity crisis the messinian salinity crisis is widely regarded as one of the most dramatic episodes of oceanic change of the past 20 or so million years 1 3 earliest explanations were that extremely thick evaporites were deposited in a deep and desiccated mediterranean basin that had been repeatedly isolated from the atlantic ocean1 2 but elucidation of the causes of the isolation whether driven largely by glacio eustatic or tectonic processes have been hampered by the absence of an accurate time frame here we present an astronomically calibrated chronology for the mediterranean messinian age based on an integrated high resolution stratigraphy and tuning of sedimentary cycle patterns to variations in the earth s orbital parameters we show that the onset of the messinian salinity crisis is synchronous over the entire mediterranean basin dated at 5 96 0 02 million years ago isolation from the atlantic ocean was established between 5 59 and 5 33 million years ago causing a large fall in mediterranean water level followed by erosion 5 59 5 50 million years ago and deposition 5 50 5 33 million years ago of non marine sediments in a large lago mare lake sea basin cyclic evaporite deposition is almost entirely related to circum mediterranean climate changes driven by changes in the earth s precession and not to obliquity induced glacio eustatic sea level changes we argue in favour of a dominantly tectonic origin for the messinian salinity crisis although its exact timing may well have been controlled by the 400 kyr component of the earth s eccentricity cycle

numerical modelling of short and long wave transformation on a barred beach abstract this work aims to demonstrate an advancement towards the integrated modelling of surf zone hydrodynamics by means of a vof type numerical model cobras uc based on the reynolds averaged navier stokes equations in this paper the numerical model is adapted and validated for the study of nearshore processes on a mildly sloping beach the model prediction of wave energy transformation and higher order statistics skewness and asymmetry are in good agreement with detailed laboratory observations from a barred beach boers m 1996 simulation of a surf zone with a barred beach report 1 wave heights and wave breaking tech rep 96 5 comm on hydrol and geol eng dept of civil engineering delft university of technology moreover the numerical model allows us to study the low frequency motions inside the surf zone it is found that in order to achieve a satisfactory simulation of both short and long wave transformation the numerical model must achieve i the simultaneous second order wave generation and absorption ii the energy transfer between triad of components iii the short and long wave energy dissipation inside the surf zone and iv the wave reflection at the shoreline comparisons between numerical and experimental results demonstrate the model capability to satisfactorily simulate all the aforementioned processes

modeling the effect of wave vegetation interaction on wave setup aquatic vegetation in the coastal zone attenuates wave energy and reduces the risk of coastal hazards e g flooding besides the attenuation of sea swell waves vegetation may also affect infragravity band ig waves and wave setup to date knowledge on the effect of vegetation on ig waves and wave setup is lacking while they are potentially important parameters for coastal risk assessment in this study the storm impact model xbeach is extended with formulations for attenuation of sea swell and ig waves and wave setup effects in two modes the sea swell wave phase resolving nonhydrostatic and the phase averaged surfbeat mode in surfbeat mode a wave shape model is implemented to capture the effect of nonlinear wave vegetation interaction processes on wave setup both modeling modes are verified using data from two flume experiments with mimic vegetation and show good skill in computing the sea swell and ig wave transformation and wave setup in surfbeat mode the wave setup prediction greatly improves when using the wave shape model while in nonhydrostatic mode nonlinear intrawave effects are directly accounted for subsequently the model is used for a range of coastal geomorphological configurations by varying bed slope and vegetation extent the results indicate that the effect of wave vegetation interaction on wave setup may be relevant for a range of typical coastal geomorphological configurations e g relatively steep to gentle slope coasts fronted by vegetation

reconstructing the internal structure and long term evolution of hazardous sinkholes combining trenching electrical resistivity imaging eri and ground penetrating radar gpr abstract the approaches aimed at characterising specific damaging sinkholes have received limited attention compared with other ground instability phenomena e g landslides moreover the practicality of the trenching technique in combination with numerical dating and retro deformation analysis for sinkhole site investigations has been barely explored this work illustrates the advantages of combining geomorphic mapping electrical resistivity imaging eri ground penetrating radar gpr and trenching for sinkhole characterisation and shows how the trenching technique contributes to fill significant gaps that neither geomorphic nor geophysical methods can address two large sinkholes 200 m long related to the interstratal karstification of evaporites and generated by contrasting subsidence mechanisms sagging collapse were investigated in the fluvia valley ne spain although gpr data may provide high resolution information on subsidence related stratigraphic and structural features at shallow depth the profiles acquired in the investigated sites with 100 mhz shielded and 40 mhz unshielded antennae provided limited insight into the internal geometry of the sinkholes due to reduced signal penetration related to the presence of conductive clayey material the eri sections satisfactorily imaged the general geometry of the sagging and collapse subsidence structures up to depths higher than 100 m and clearly captured the basal contact of the low resistivity sinkhole fill in the sections with adequate layout and resolution the trenches despite their limited depth ca 5 m allowed us to obtain valuable objective information on several key aspects of the subsidence phenomenon 1 mechanisms deformation style and kinematics progressive versus episodic 2 limits of ground deformation 3 temporal evolution expansion versus contraction 4 chronology and timing of most recent deformation phase 5 rates of subsidence and sedimentation and 6 the role played by subsidence in the development of lacustrine environments and the associated sedimentation patterns

the messinian guadalhorce corridor the last northern atlantic mediterranean gateway miocene tectonics with the last survi ving gateway occurring during the early messinian north west of malaga in the region of the guadalhorce river valley the guadalhorce gateway pro vided a significant control on messin ian pre evaporitic oceanic circulation in the mediterranean sea it acted as a major outflow channel of mediterra nean water into the atlantic and its closure induced water mass restriction and stratification in the western medi terranean immediately prior to the messinian salinity crisis abstract messinian marine deposits of the guadalhorce river valley in southern spain record evidence of the last northern gateway that existed between the mediterranean and the atlantic they comprise sandstones and conglomerates with unidirectional cross bed sets up to nearly 1 km long in their down sedimen tary dip direction these cross bed sets relate to extremely fast 1 0 1 5 m s 1 bottom currents flowing from the mediterra nean into the atlantic the guadalhorce gateway which had a maximum width of 5 km and a maximum water depth of 120 m was an important element controlling the messinian pre evaporitic oceanic circulation in the mediterranean sea as it acted as a major outflow channel its closure limited the exchange of water between the atlantic and the mediterranean to the rifian corridors of morocco inducing water mass restriction and stratification in the western mediterranean immediately prior to the messinian salinity crisis

numerical modeling of wave runup on steep and mildly sloping natural beaches abstract runup on ocean beaches includes steady wave setup and oscillating swash often decomposed into wind generated sea swell ss and lower frequency infragravity ig waves we show that the numerically fast open source numerical model 1d swash predicts accurately the bulk properties of runup observed on two natural beaches one steep and one shallow sloped for a range of incident wave conditions the runup tongue shape was measured with a scanning lidar and the waterline location was defined in both the observations and model with a 10 cm depth threshold runup is reasonably accurately predicted with energetic e g 5 m significant height incident waves even though the assumption of 1d bound waves significantly overpredicts infragravity energy at the offshore boundary in 10 m depth the model data comparisons are limited by statistical chatter often larger in runup than offshore because runup energy is concentrated in the relatively narrow infragravity ig band with low effective degrees of freedom

an energetics bedload model for a plane sloping beach local transport bagnold s energetics based sediment transport model for streams is used as a basis for the development of a model for the time varying transport of bedload over a plane sloping bed the sediment transport vector is found to consist of two components the velocity induced transport directed parallel to the instantaneous velocity vector and the gravity induced transport vector directed downslope the model is applied to the case of sediment transport within the surf zone for the separate cases of weak and strong longshore currents relative to the wave bore oscillatory water velocity the results suggest the bagnold s oscillatory sediment transport model which forms the basis for a number of longshore sediment transport models is only correct for the special case of weak longshore currents and near normal incident waves for an artibrary strength longshore current v and a local incident wave angle a the longshore transport rate is found to be proportional to sina v 1 sin sup 2 a v sup 3 where u is the wave induced oscillatory water velocity the model also predicts the onshore offshore sediment rate for weak longshore currents and near normal incident waves the predicted equilibrium beach slope is equal to tanf strong longshore currents and or significant local wave angle conditions however cause amore change in this equilibrium beach slope less authors bailard j a inman d l publication date 1981 03 20 osti identifier 6767919 resource type journal article resource relation journal name j geophys res united states journal volume 86 c3 research org scripps institution of oceanography university of california la jolla california 92093 country of publication united states language english subject 58 geosciences shores sedimentation coastal waters gravitation sediments silt velocity water currents currents surface waters 580500 oceanography 1980 1989

numerical simulation of extreme wave runup during storm events in tramandai beach rio grande do sul brazil abstract we present a high resolution analysis of the interaction of irregular waves with natural and urban structures leading to extreme wave runup horizontal runup data instantaneous flooding maps and wave propagation beyond the coastline are numerically predicted the novel methodology combining the wave watch iii swan and swash models to achieve accurate and computationally feasible simulation of waves at different time and spatial scales from the formation process at deep water up to the total energy dissipation in the swash zone is proposed an access to the lidar database has provided a high resolution 15 cm 25 cm of the subaerial surface which is essential for accurate representation of the hydrodynamic interactions with the beach profile the suggested approach has been applied for evaluation of wave runup related to six storm events in tramandai beach in southern brazil this allowed for an identification of critical vulnerable overwashing areas as well as critical information on flooding zones the results are in agreement with the runup measurements performed in january 2014 the numerical methodology employed in this work has been also compared with the survey and conventional empirical model data it was discovered that the empirical models lead to the systematic overestimation of the runup results

evidence for african iberian exchanges during the messinian in the spanish mammalian record abstract the thick continental record in the fortuna basin enables the to establishment of an accurate chronology for the main mammalian events in the western mediterranean between 7 6 and 4 5 my thus covering the whole messinian interval a first mammalian event at about 7 2 my records a significant turnover in the muroid rodent associations a second mammalian event is characterized by the dispersal of the murid paraethomys and a number of large mammals which indicates a first african iberian exchange at about 6 2 my finally a third mammalian event dated between 5 9 and 5 3 my involved the dispersal from northern africa of the gerbil rodents this event is clearly associated with the mediterranean sea level drop following the messinian salinity crisis

simulating coastal engineering processes with openfoam abstract in the present work the openfoam newly developed wave generation and active absorption boundary condition presented in the companion paper higuera et al submitted for publication is validated in order to do so the simulation of some of the most interesting physical processes in coastal engineering is carried out and comparisons with relevant experimental benchmark cases presented water waves are found to be generated realistically and agreement between laboratory and numerical data is very high regarding wave breaking run up and undertow currents

evidence for an african iberian mammal dispersal during the pre evaporitic messinian the accurate timing of biogeographic dispersal can be determined by examining the age of fossiliferous strata on either side of a physical barrier here we show that african mammals migrated to iberia and european mammals migrated to north africa at the same time before isolation of the mediterranean sea during the messinian the fossil site of venta del moro spain exhibits western europe s most complete vertebrate fauna for the latest miocene its uniquely cosmopolitan assemblage is evidence of faunal dispersals from africa and asia to europe during the latest miocene glaciation a preliminary paleomagnetic study suggested an age of 5 8 ma for this site but our expanded magnetostratigraphy dates the site at 6 23 ma in addition we recalibrated the paleomagnetic age of the librilla site spain and the north africa site of afoud 1 morocco using the astronomical tuned neogene time scale our results show a two way african iberian mammal dispersal just before 6 2 ma these new ages indicate that an ephemeral land corridor existed between the two continents 250 k y before the onset of the messinian salinity crisis reflecting a tentative initial isolation of the mediterranean sea this corridor developed after tectonics closed the betic seaway at 6 3 ma and during the intensification of the latest miocene glaciation at 6 26 ma when water circulation in the mediterranean became very restricted

bar generating cross shore flow mechanisms on a beach random waves normally incident on a dissipative beach induce a variety of cross shore flows such as asymmetric oscillatory flow wave grouping induced long wave flow breaking induced turbulent flow and momentum decay induced undertow these flows are identified analyzed and hindcasted in a set of laboratory experiments with the aim of revealing the role of each of the flow mechanisms in the two dimensional case of bar generation on a beach

the offshore boundary condition in surf zone modeling abstract numerical models predicting surfzone waves and shoreline runup in field situations are often initialized with shoreward propagating sea swell and infragravity waves at an offshore boundary in 10 30 m water depth we develop an offshore boundary condition based on fourier analysis of observations with co located current and pressure sensors that accounts for reflection and includes nonlinear phase coupling the performance of additional boundary conditions derived with limited or no infragravity observations are explored with the wave resolving nonlinear model swash 1d in some cases errors in the reduced boundary conditions applied in 11 m depth propagate shoreward whereas in other cases errors are localized near the offshore boundary boundary conditions that can be implemented without infragravity observations e g bound waves do not accurately simulate infragravity waves across the surfzone and could corrupt predictions of morphologic change however the bulk properties of infragravity waves in the inner surfzone and runup are predicted to be largely independent of ig offshore boundary conditions and dominated by ig generation and dissipation

energy transfer between wind waves and low frequency oscillations on a fringing reef ipan guam field observations from a guam fringing reef are used to examine the cross reef energy exchange between high frequency sea and swell ss and low frequency infragravity ig and far infragravity fig waves energetic ss waves significant wave heights 2 4 m break at the outer reef leading to weak 1 m conditions on the shallow reef flat as ss waves shoal on the reef face before breaking ig and fig energy fluxes both increase through nonlinear energy transfer from the ss waves in contrast through the surf zone the ig energy flux decreases whereas fig flux increases the decrease in ig energy flux through the surf zone is attributed to breaking ss waves working against the incident bound ig wave energy which dominates breakpoint forced ig waves yielding a net flux decrease in contrast fig energy flux increases through the surf zone consistent with breakpoint forcing and the absence of an energetic bound fig component on the reef face ig and fig energy fluxes decay on the shallow reef flat due primarily to frictional dissipation with tidal modulations attributed to nonlinear conversion and friction forcing at fig frequencies may lead to a normal mode response on the reef with comparable incoming and outgoing fig energy fluxes at the outer reef flat depending on water level over the reef flat and the degree of frictional dissipation

non hydrostatic modelling of infragravity waves under laboratory conditions the non hydrostatic wave model swash is compared to flume observations of infragravity waves propagating over a plane slope and barred beach the experiments cover a range of infragravity wave conditions including forcing by bichromatic and irregular waves varying from strongly dissipative to strongly reflective so that model performance can be assessed for a wide range of conditions the predicted bulk wave parameters such as wave height and mean wave period are found to be in good agreement with the observations moreover the model captures the observed breaking of infragravity waves these results demonstrate that swash can be used to model the nearshore evolution of infragravity waves including nonlinear interactions dissipation and shoreline reflections

early pliocene continental vertebrate fauna at puerto de la cadena se spain and its bearing on the marine continental correlation of the late neogene of eastern betics in this paper we synthesize sedimentological magnetostratigraphic and paleontological data from the continental vertebrate site of puerto de la cadena murcia se spain in order to clarify its age the study site is located on the northern edge of the carrascoy mountain range in the upper part of the cigarron unit the end messinian discontinuity has been detected at the base of this unit which indicates it has an early pliocene age abundant remains of small and large vertebrates including rodents lagomorphs primates carnivorans perissodactyls artiodactyls proboscideans testudines squamats and crocodiles have been found in this area some of these elements are of african origin such as debruijnimys sp macaca sp and sivatherium cf hendeyi and their presence is related to the messinian salinity crisis in addition remains found at this site verify the persistence of crocodylia in the european record beyond the late miocene the association includes typical elements of the early ruscinian terrestrial record mn14 like apocricetus cf barrierei sivatherium gazella aff baturra and hipparion fissurae the puerto de la cadena site is located in a reversed geomagnetic chron that has been correlated with c3n 3r from 4 997 to 4 896 ma according to this correlation the mn13 mn14 boundary has a minimum age of 4 9 ma

late cenozoic micromammal biochronology of northwestern africa abstract this synthesis aims to integrate former recent and unpublished data on fossil micromammals rodentia erinaceomorpha soricomorpha chiroptera from moroccan algerian and tunisian archeological and paleontological sites an updated biochronology of these taxa is established from the middle miocene to the holocene ten main biozones are defined they are characterized by specific faunal assemblages whose evolution and migrations were influenced by geologic and climatic events throughout the studied period during the miocene myocricetodontinae were dominant this period was followed by a progressive diversification among murinae gerbillinae and crocidurinae from the plio pleistocene onwards along with sporadic occurrences of european asian and sub saharan taxa before a decrease in small mammal diversity at the beginning of the late pleistocene while modern faunas stabilized overall the new biochronology matches well with the former ones however some slight discrepancies emerge notably because the former biochronologies were based on more sporadic data and often did not consider the whole small mammal faunas the present work represents the first complete biochronological synthesis of north african small faunas for the whole late cenozoic which should be useful for paleontologists and archeologists in providing an up to date framework into which future discoveries will easily find their place

evolution of the adriatic carbonate platform palaeogeography main events and depositional dynamics abstract the adriatic carbonate platform adcp is one of the largest mesozoic carbonate platforms of the perimediterranean region its deposits comprise a major part of the entire carbonate succession of the croatian karst external or outer dinarides which is very thick in places more than 8000 m and ranges in age from the middle permian or even upper carboniferous to the eocene however only deposits ranging from the top of the lower jurassic toarcian to the top of the cretaceous can be attributed to the adcp defined as an isolated palaeogeographical entity although the entire carbonate succession of the karst dinarides was deposited within carbonate platform environments there were different types of carbonate platforms located in different palaeogeographical settings carboniferous to middle triassic mixed siliciclastic carbonate deposits were accumulated along the gondwanian margin on a spacious epeiric carbonate platform after tectonic activity culminating by regional middle triassic volcanism recorded throughout adria the african promontory a huge isolated carbonate southern tethyan megaplatform abbreviated as stm was formed with the area of the future adcp located in its inner part tectonic disintegration of the megaplatform during the middle to late early jurassic resulted in the establishment of several carbonate platforms including the adriatic apenninic and apulian separated by newly drowned deeper marine areas including the adriatic basin as a connection between the ionian and belluno basins lagonero basin and the area of the slovenian and bosnian troughs the adcp was characterised by predominantly shallow marine deposition although short or long periods of emergence were numerous as a consequence of the interaction of synsedimentary tectonics and eustatic changes also several events of temporary platform drowning were recorded especially in the late cretaceous when synsedimentary tectonics became stronger leading up to the final disintegration of the adcp the thickness of deposits formed during the 125 my of the adcp s existence is variable between 3500 and 5000 m the end of adcp deposition was marked by regional emergence between the cretaceous and the palaeogene deposition during the palaeogene was mainly controlled by intense synsedimentary tectonic deformation of the former platform area some carbonates mostly eocene in age were deposited on irregular ramp type carbonate platforms surrounding newly formed flysch basins and the final uplift of the dinarides reached its maximum in the oligocene miocene the adriatic carbonate platform represents a part although a relatively large and well preserved one of the broader shallow water carbonate platform that extended from ne italy to turkey although its continuity is somewhat debatable in the area near albanian greece boundary this large carbonate body which was deformed mostly in the cenozoic including a significant reduction of its width needs a specific name and the central mediterranean carbonate platform is proposed abbreviated to cmcp although the local names such as adcp for its nw part should be kept to enable easier communication and to facilitate description of local differences in platform evolution

the adriatic region an independent microplate within the africa eurasia collision zone 1 we use gps measurements and block modeling to investigate the present day deformation of the adriatic region whose kinematics within the nubia eurasia plate boundary zone is not well constrained and remains controversial block modeling allows us to compute rigid plate angular velocities while accounting for elastic strain accumulation along block bounding faults results suggest that the adriatic is a microplate adria and that the southern boundary with the nubia plate and the aegean domain may be located along the apulia escarpment and the kefallinia fault geodetic data alone cannot discriminate between a single block ap or a two blocks gdap description of adria but the gdap model predicts boundary slip rates that are in better agreement with observations from previous studies

validated coastal flood modeling at imperial beach california comparing total water level empirical and numerical overtopping methodologies abstract flood extent field observations collected during a winter storm h s 1 8 m t p 14 s coinciding with a spring high tide are used to evaluate the accuracy of static bathtub and hydrodynamic coastal flood modeling methodologies static models rely on empirically calculated wave setup or runup and simply compare total water level twl to land elevation the dynamic model resolves temporally variable overtopping rates overland flow urban features and storm system drainage swan a numerical wave model transformed deep water buoy spectra to the nearshore static twls were calculated using swan output and an empirical runup model numerical xbeach and empirical eurotop overtopping models parameterized with survey data and swan bulk wave statistics estimated temporally variable overflow rates along representative transects for overland flow model input xbeach model mode hydrostatic nonhydrostatic boundary depth and random realizations significantly affected overtopping rates nonhydrostatic mode estimated order of magnitude larger overflow volumes suggesting the importance of incident waves particularly in near threshold conditions boundary depth and random realizations varied overflow rates approximately fourfold field observations showed static twl models performed poorly maximum runup substantially overestimated flood extent and setup predicted no flooding all dynamic models reasonably predicted flood extent despite significant overflow volume differences backshore topography and flow dynamics are important flood extent controls accurate near threshold coastal flood predictions require dynamic overland flow modeling parameterized with temporally variable overtopping estimates and site specific beach and backshore topography

bathymetric control on the spatial distribution of wave breaking in the surf zone of a natural beach abstract a non hydrostatic wave model swash that phase resolves the free surface and fluid motions in the water column is applied to investigate wave transformation and the spatial distribution of wave breaking over different morphological features the model is forced using observed directional energy spectra and results are compared to wave observations collected outside the surf zone using acoustic wave sensors and over a 100 m nearshore transect using high frequency measurements of the sea surface from a lidar sensor mounted on the beach dune at the field research facility in duck nc the model is applied to four cases with different wave conditions and bathymetry tested for sensitivity of model parameters to these different natural conditions and used to predict the spatial variability in wave breaking and correlation between energy dissipation and morphologic features model results compare very well with observations of spectral evolution outside the surf zone and generally well with the remotely sensed observations of wave transformation inside the surf zone with r 0 85 0 93 for h s along the cross shore transect in particular the model is able to spatially resolve wave shoaling and dissipation at the shore break at the same location as observed in the lidar data the results indicate that nearshore morphology has a significant effect on the spatial distribution of wave energy dissipation alongshore variability in bathymetry due to bars rip channels and larger morphological features such as the scour depression under the pier causes large alongshore changes in cross shore wave energy flux that influence the location and intensity of wave breaking

wave run up on a high energy dissipative beach 1 because of highly dissipative conditions and strong alongshore gradients in foreshore beach morphology wave run up data collected along the central oregon coast during february 1996 stand in contrast to run up data currently available in the literature during a single data run lasting approximately 90 min the significant vertical run up elevation varied by a factor of 2 along the 1 6 km study site ranging from 26 to 61 of the offshore significant wave height and was found to be linearly dependent on the local foreshore beach slope that varied by a factor of 5 run up motions on this high energy dissipative beach were dominated by infragravity low frequency energy with peak periods of approximately 230 s incident band energy levels were 2 5 to 3 orders of magnitude lower than the low frequency spectral peaks and typically 96 of the run up variance was in the infragravity band a broad region of the run up spectra exhibited an f 4 roll off typical of saturation extending to frequencies lower than observed in previous studies the run up spectra were dependent on beach slope with spectra for steeper foreshore slopes shifted toward higher frequencies than spectra for shallower foreshore slopes at infragravity frequencies run up motions were coherent over alongshore length scales in excess of 1 km significantly greater than decorrelation length scales on moderate to reflective beaches

magnetostratigraphy and paleontology of ait kandoula basin high atlas morocco and the african european late miocene terrestrial fauna exchanges abstract a magnetostratigraphic study has been carried out on a middle miocene to upper pliocene lacustrine sedimentary deposit in the central part of the ait kandoula basin which contains micromammal faunas and is situated in the southern high atlas morocco in total 113 samples were subjected to paleomagnetic analysis 60 out of the 113 studied samples representing 52 different stratigraphic levels yielded a paleomagnetic direction and at least the polarity could be recognized in 42 specimens eleven specimens were submitted to af demagnetization the mean direction for normal polarity samples was d 349 4 i 50 7 n 36 95 4 5 k 27 and for reversed polarity samples d 191 2 i 53 4 n 16 95 12 32 k 9 these results yielded a polarity sequence which we interpret as spanning from chron c5n 2n to the beginning of chron c3n 4n this interpretation relies on biostratigraphic data previously proposed for a part of the continental fauna found in the basin this result is in agreement with the 40ar 39ar dating previously carried out on a volcanic ash layer which provided an age of 5 9 0 5 ma 1 and which is shown here to be reversely magnetized this layer is correlated here with the reverse polarity zone corresponding to chron c3r biostratigraphic studies on the same section have shown that the micromammal levels extend here only from middle vallesian to upper turolian upper miocene four localities have yielded western european species of micromammals indicating trans mediterranean terrestrial faunal exchanges between these two continents during the late miocene the european murid rodent occitanomys is recorded for the first time in north africa in level 8 of the afoud section an age younger than 5 32 ma being assigned to this level by the present study level 1 of the same section yields the lagomorph prolagus cf michauxi with an age of 6 1 ma the magnetostratigraphic data suggest therefore that the beginning of terrestrial faunal exchanges between north africa and western europe took place in subchron c3an 1n at about 6 1 ma some 0 4 myr before the beginning of the messinian salinity crisis

chronology of the late turolian deposits of the fortuna basin se spain implications for the messinian evolution of the eastern betics the magnetostratigraphy of the mammal bearing alluvial fan fan delta sequences of the fortuna basin se spain has yielded an accurate chronology for the late turolian messinian basin infill from early to late messinian at least between 6 8 and 5 7 ma the fortuna basin records the sedimentation of alluvial palustrine deposits over a confined shallow basin changing environmental conditions in the latest messinian are illustrated by the retreat of palustrine facies a rapid progradation of the marginal clastic wedges and the initiation of an efficient basin drainage at5 8 ma lower part of chron c3r most likely represents the onshore response to the drastic drop of base level taking place during the messinian salinity crisis this study further provides improved age estimates for the late turolian land mammal events in southern spain the oldest mn 13 locality in the studied sections is correlated to chron c3ar at an age of 6 8 ma the entry of camels and the murid paraethomys in southern spain occurs in chron c3an 1n at 6 1 ma and gives further support for land mammal exchange between africa and the iberian peninsula prior to the salinity crisis in good agreement with

geologic evolution of the betic cordilleras in the western mediterranean miocene to the present abstract the betic cordilleras were formed during the eo meso and neo alpine evolution of the western mediterranean area during the neo alpine stage the northward subduction of the african plate took place and the algerian provencal basin opened with the creation of oceanic floor associated space problems produced the expulsion and extensive stretching of the internal zones to the west which in turn disrupted and deformed the external zones of the betic and rif cordilleras these occurrences essentially took place in the burdigalian and continued with diminished intensity into the middle miocene following the suturing of the transcurrent contact between the internal and external zones important n60 90 e and nw se faults occurred the betic cordilleras are characterized as having been deformed by regional horizontal shortening compression oriented wnw ese or nw se which gradually rotated to the nnw sse in the late miocene when its most important intramontane neogene basins were formed the alboran basin with a thinned continental crust was formed as a western prolongation of the opening of the algerian provencal basin with its basic features already apparent in the burdigalian the volcanism present in the southeast of the betic cordilleras and in northeast morocco crossing the alboran basin is mainly late miocene in age it is linked to fracturing and exhibits chemistry related to the different thickness of the crust

cross shore sand transport by infragravity waves as a function of beach steepness two field data sets of near bed velocity pressure and sediment concentration are analyzed to study the influence of infragravity waves on sand suspension and cross shore transport on the moderately sloping sand motor beach 1 35 the local ratio of infragravity wave height to sea swell wave height is relatively small hig hsw 0 4 most sand is suspended during negative infragravity velocities and qig is offshore directed the infragravity contribution to the total sand flux is considerably larger and reaches up to 60 during energetic conditions on the whole hig hsw is a good indicator for the infragravity related sand suspension mechanism and the resulting infragravity sand transport direction and relative importance

observations of runup and energy flux on a low slope beach with high energy long period ocean swell the transformation of surface gravity waves from 11 m depth to runup was observed on the low sloped 1 80 agate beach oregon with a cross shore transect of current meters pressure sensors and a scanning lidar offshore wave heights h0 ranged from calm 0 5 m to energetic 7 m runup measured with pressure sensors and a scanning lidar increases linearly with h0l0 1 2 with l0 the deep water wavelength of the spectral peak runup saturation in which runup oscillations plateau despite further increases in h0l0 1 2 is not observed infragravity wave shoaling and nonlinear energy exchanges with short waves are included in an infragravity wave energy balance this balance closes for high infragravity frequencies 0 025 0 04 hz but not lower frequencies 0 003 0 025 hz possibly owing to unmodeled infragravity energy losses of wave breaking and or bottom friction dissipative processes limit but do not entirely damp increases in runup excursions in response to increased incident wave forcing

importance of second order wave generation for focused wave group run up and overtopping focused wave groups o er a means for coastal engineers to determine extreme run up and overtopping events numerical predictions and laboratory measurements are presented of newwave type focused wave groups generated by a pistontype paddle generator and interacting with a plane beach and a seawall in a wave basin the numerical wave tank is based on the boussinesq equations for non breaking waves and the non linear shallow water equations for broken waves good agreement is achieved between the numerical predictions and laboratory measurements of free surface elevation run up distances and overtopping volumes for the test cases driven by linear paddle signals errors in run up distance and overtopping volume are then assessed by repeating the test cases using second order accurate wave generation signals focused wave groups generated using rst order wave maker theory are found to be substantially contaminated by a preceding long error wave resulting in erroneously enhanced run up distances and overtopping volumes the use of second order wave maker theory for wave group run up and overtopping experiments is instead recommended

late neogene evolution of the taza guercif basin rifian corridor morocco and implications for the messinian salinity crisis abstract magnetostratigraphic and biostratigraphic results are presented from neogene deposits in the taza guercif basin located at the southern margin of the rifian corridor in morocco this corridor was the main marine passageway which connected the mediterranean with the atlantic during messinian times correlation of the biostratigraphy and polarity sequence of the taza guercif composite section to the astronomical time scale allows an accurate dating of three subsequent events in the rifian corridor 1 the oldest marine sediments marking the opening of the rifian corridor were deposited at 8 ma at this age a deep 600 m marine basin developed in the taza guercif area marked by deposition of precession controlled turbidite marl cycles 2 paleodepth reconstructions indicate that a rapid 5 m ka shallowing of the marine corridor took place at the tortonian messinian boundary at an age of 7 2 ma this shallowing phase is primarily related to active tectonics although a small glacio eustatic sea level lowering also took place 3 the taza guercif basin was emergent at an age of 6 0 ma and subsequently continental sedimentation continued well into the early pliocene we suggest that shallowing and restricting the marine passageway through the rifian corridor actually initiated the messinian salinity crisis well before the deposition of the messinian evaporites in the mediterranean