accessibilities of reactive minerals in consolidated sedimentary rock an imaging study of three sandstones abstract widespread implementation of geological storage of co 2 requires an understanding of dissolution reactions with formation minerals this will be aided by reactive transport modeling which relies on accurate estimates of the accessible surface areas of reactive minerals in consolidated sedimentary rocks for three viking sandstones alberta sedimentary basin canada we have employed backscattered electron microscopy and energy dispersive x ray spectroscopy to examine mineral content and to statistically characterize mineral contact with pore space porosities range from 20 in a lightly cemented sandstone with grains on the order of 100 m to 8 in a highly cemented shaly sandstone with a mix of primary pore space and fractures to 7 in a lightly cemented conglomerate sandstone with grain sizes between 500 m and 1 mm in all three specimens kaolinite is the primary authigenic clay mineral cementing quartz grains it accounts for only 5 to 31 of mineral content but 65 to 86 of pore mineral contact boundaries the sandstone specimen has 6 minerals in the reactive category which in this study includes minerals other than kaolinite and quartz such as k feldspar apatite and pyrite for this specimen only one third of the reactive minerals are accessible to pore fluids due to clay mineral grain coatings for the shaly sandstone only one fifth of its 5 reactive minerals are accessible to pore fluids due to regions of cementation of fine detrital matrix thus if a mineral volume fraction is used in reactive transport modeling as a proportional measure of accessible surface area in consolidated sandstones the reaction rates are likely to be overestimated by three to five times the conglomerate sandstone has only 1 of its mineral matter in this category and these are often found as inclusions rather than grains

distribution of anthropogenic co2 in the pacific ocean 1 this work presents an estimate of anthropogenic co2 in the pacific ocean based on measurements from the woce jgofs oaces global co2 survey these estimates used a modified version of the c technique modifications include a revised preformed alkalinity term a correction for denitrification and an evaluation of the disequilibrium terms using an optimum multiparameter analysis the total anthropogenic co2 inventory over an area from 120 e to 70 w and 70 s to 65 n excluding the south china sea the yellow sea the japan east sea and the sea of okhotsk was 44 5 5 pg c in 1994 approximately 28 pg c was located in the southern hemisphere and 16 5 pg c was located north of the equator the deepest penetration of anthropogenic co2 is found at about 50 s the shallowest penetration is found just north of the equator very shallow anthropogenic co2 penetration is also generally observed in the high latitude southern ocean one exception to this is found in the far southwestern pacific where there is evidence of anthropogenic co2 in the northward moving bottom waters in the north pacific a strong zonal gradient is observed in the anthropogenic co2 penetration depth with the deepest penetration in the western pacific the pacific has the largest total inventory in all of the southern latitudes despite the fact that it generally has the lowest average inventory when normalized to a unit area the lack of deep and bottom water formation in the north pacific means that the north pacific inventories are smaller than the north atlantic

advanced remote sensing of internal waves by spaceborne along track insar a demonstration with terrasar x since the seasat mission in 1978 satellite based synthetic aperture radar sar images have been used to study oceanic internal waves internal waves become visible in sar images because their orbital currents modulate the surface roughness while this leads to an accurate spatial representation of internal wave patterns the complexity of the imaging mechanism makes it difficult to derive actual currents and internal wave amplitudes from sar signatures we demonstrate in this paper how a more robust parameter retrieval is possible with along track interferometric sar insar data that resolve amplitudes and temporal phase changes of the backscattered signal together the latter of which are directly related to the scatterers line of sight velocities our example data set which was acquired by terrasar x in dual receive antenna mode at dongsha south china sea exhibits strong signatures of internal waves in the interferogram amplitude and phase we use a simple internal soliton parameterization and a numerical radar imaging model to find a plausible combination of internal wave parameters which leads to good agreement between simulated and observed signatures testing the sensitivity of radar amplitude and phase signatures to various parameters we show that along track insar data should generally permit more accurate and less ambiguous internal wave parameter retrievals than conventional sar images

seasonal variations in the aragonite saturation state in the upper open ocean waters of the north pacific ocean seasonal variability of the aragonite saturation state ar in the upper 50 m and 100 m depths north pacific ocean npo was investigated using multiple linear regression mlr the mlr algorithm derived from a high quality carbon data set accurately predicted the ar of evaluation data sets three time series stations and p02 section with acceptable uncertainty 0 1 ar the algorithm was combined with seasonal climatology data and the estimated ar varied in the range of 0 4 0 6 in the midlatitude western npo with the largest variation found for the tropical eastern npo these marked variations were largely controlled by seasonal changes in vertical mixing and thermocline depth both of which determine the degree of entrainment of co2 rich corrosive waters from deeper depths our mlr based subsurface ar climatology is complementary to surface climatology based on pco2 measurements

role of surface films in ers sar signatures of internal waves on the shelf 1 short period internal waves analysis of synthetic aperture radar sar images of internal waves iws on the iberian shelf and classification of the iw surface signatures is presented there are three types of iw signatures in the form of bright dark dark and bright bands that correspond to positive negative negative or positive variations of radar backscatter respectively strong positive sign iw signatures occur at very low wind velocities less than 2m s at winds higher than 2 m s both positive negative and negative signatures are observed for range propagating iws for azimuth propagating iws negative signatures prevail two groups of experiments carried out in the frame of the multidisciplinary oceanographic research in the eastern north atlantic morena project on the iberian shelf in august 1994 are described 1 iw measurements simultaneous with ers 1 sar overpasses and 2 iw measurements visual observations of the surface and sampling of films from the sea surface iw manifestations at low to moderate winds took the form of slicks locating over iw troughs at the near threshold wind velocity they were of the form of intensified decimeter scale waves antislicks located over iw crests measurements of wave damping due to films collected from the slick and nonslick areas showed the concentration of surfactants and retrieved film elasticity to be higher in the slicks than in the nonslick areas a theoretical model of the surface wave modulation by iws is developed to include surface wave straining by the iw current and surface wave damping due to surfactant films pressure area curves for real marine films are used in the model the relation between the film and the straining effects on the surface wave spectrum in the iw field is shown to depend on film parameters surface wave length and wind velocity the model predicts strong damping of centimeter scale waves over iw troughs mainly due to the film effect and intensification and depression of decimeter scale waves due to both straining and film effects dependencies of the model spectrum variations as a function of wind velocity for range and azimuth propagating iws are obtained the negative sign contrast being shown to predominate for azimuth propagating iws model variations of the spectrum of decimeter scale waves are shown to be significantly sensitive to surfactants film pressure the negative sign contrasts due to films being superimposed on the straining effects and these are eventually capable of suppressing the positive sign contrasts it is concluded that the occurrence of the different classes of iw signatures in the sar images can be explained by the action of surface active films

theory of radar imaging of internal waves radar images taken over ocean areas in particular those obtained by the synthetic aperture radar sar onboard the american seasat satellite in 19781 2 sometimes show features that seem to be surface manifestations of oceanic internal waves3 11 here i present a theory explaining the large radar signatures of internal waves in which the imaging is attributed to variations in the short scale surface roughness induced by current variations associated with internal waves

reservoir characterization of a co2 storage aquifer the upper triassic stuttgart formation in the northeast german basin abstract ketzin in the northeast german basin negb is the site for pilot injection of co 2 co 2 sink project into a saline aquifer the upper triassic stuttgart formation situated at a depth of about 630 700 m this paper reports the baseline characterization of the reservoir formation based on new core material and well logs obtained from one injection well and two observations wells drilled at a distance from 50 m to 100 m from each other the reservoir is lithologically heterogeneous and made up by fluvial sandstones and siltstones interbedded with mudstones showing remarkable differences in porosity the thickest sandstone units are associated with channel sandstone whose thickness varies over short lateral distances in depth petrographic mineralogical mineral chemical and whole rock geochemical analysis were performed focusing on the sandstone intervals which display the best reservoir properties for co 2 injection the dominantly fine grained and well to moderately well sorted immature sandstones classify as feldspathic litharenites and lithic arkoses quartz 22 43 wt plagioclase 19 32 wt and k feldspar 5 13 wt predominate mineralogically muscovite plus illite and mixed layer minerals are omnipresent 4 13 wt quartz feldspar as well as meta sedimentary and volcanic rock fragments comprise the most abundant detrital components which often are rimmed by thin early diagenetic coatings of ferric oxides and locally of clay minerals feldspar grains may be unaltered and optically clear partially to completely dissolved partially altered to sheet silicates mainly illite or albitized analcime and anhydrite constitute the most widespread often spatially associated pore filling cement minerals authigenic dolomite barite and coelestine is minor the percentage of cements ranges in total from about 5 vol to 32 vol except of samples intensely cemented by anhydrite and analcime total porosities of the sandstones range from 13 to 26 the fraction of intergranular porosity varies between 12 and 21 about 1 5 porosity has been generated by dissolution of detrital plagioclase k feldspar and volcanic rock fragments the comparatively large modal abundance of feldspars micas chlorite clay minerals fe ti oxides and analcime account for the richness in ti al fe mg na and k and the paucity in si of the stuttgart sandstones relative to mature sandstones altogether these sandstones are comparatively rich in minerals that may potentially react with the injected co 2

systematics of chlorite alteration at the phelps dodge massive sulfide deposit matagami quebec hydrothermal alteration at the phelps dodge archcan volcanogenic massive sulfide deposit has converted rhyodacite and rhyolite footwall rocks into the following mineral assemblages quartz chlorite albite epidote or sericite quartz chlorite or sericite chlorite or sericite and chlorite talc or stilpnomelane alteration at constant al was initiated by hydration addition of fe mg silicification and leaching of ca na which produced al saturated chlorites with a wide range of fe fe mg ratios within the assemblage quartz chlorite albite epidote or sericite with continued addition of fe and less mg combined with extensive leaching of quartz the chlorite became al undersaturated quartz chlorite talc assemblage and ultimately formed a rock composed essentially of chlorite the chlorite talc or stilpnomelane assemblage is stable in late crosscutting veinlets and in the ore zone chlorites in the si al mg fe system form a rectangular solid solution plane with limited substitution of al for si and extensive substitution of fe for mg in si al space the solid solution plane is outlined by al saturation presence of other al rich mineral and al undersaturation presence of al poor or al free mineral boundaries al iv substitution for si in the chlorites increases from 2 3 to 3 01 formula units based on 8 si al iv with fe fe mg whereas al iv occupancy decreases from 2 88 to 2 65 the valence charge balance is compensated by octahedral site vacancies or by the conversion of fe super 2 to fe super 3 the al iv content of chlorite also increases with temperature chlorites on the al saturated boundary of the solid solution field form a potentially useful geothermometer t degrees c 106 al iv 18 al iv is corrected for changes with the fe fe mg ratio as al iv corrected al iv 0 7 fe fe mg the fe fe mg ratios of bulk rock and contained chlorite correlate well birefringence colors of the chlorite change from green to brown violet and berlin blue as fe fe mg changes from 0 18 to 0 64 the fe fe mg variation apparently depends largely on the proportions of mg rich seawater and fe rich hydrothermal fluid in the altering brine

coupling primary production and terrestrial runoff to ocean acidification and carbonate mineral suppression in the eastern bering sea water column ph and carbonate mineral saturation states were calculated from dissolved inorganic carbon dic and total alkalinity data collected over the eastern bering sea shelf in the spring and summer of 2008 the saturation states of the two most important carbonate minerals calcite calcite and aragonite aragonite were strongly coupled to terrestrial runoff from the yukon and kuskokwim rivers primary production in the surface waters and remineralization of organic matter at depth over the shelf in spring before ice melt occurred ph over the shelf was largely confined to a range of 7 9 8 1 and calcite and aragonite ranged from 1 5 to 3 0 and 0 8 to 2 0 respectively at the stations closest to river outflows aragonite was undersaturated in the water column from the surface to the bottom during the summer sea ice retreat high rates of primary production consumed dic in the mixed layer which increased ph and calcite and aragonite however calcite and aragonite decreased by 0 3 in the bottom waters over the middle and outer shelf over the northern shelf where export production is highest aragonite decreased by 0 35 and became highly undersaturated the observed suppression and undersaturation of calcite and aragonite in the eastern bering sea are correlated with anthropogenic carbon dioxide uptake into the ocean and will likely be exacerbated under business as usual emission scenarios therefore ocean acidification could threaten some benthic and pelagic calcifying organisms across the bering sea shelf in the coming decades

mechanism of backarc opening in the japan sea role of asthenospheric injection abstract the process of backarc extension in the japan sea includes two modes of spreading the parallel and rotational or fan shape opening data from paleomagnetism for rocks on the northeast japan arc radiometric age determination for dredged volcanic rocks and heat flow in the basin have suggested that the parallel opening of the japan sea took place earlier than the rotational opening at 21 14 ma the mechanism of opening of the japan sea has been examined based on the secular change in the geometry of the subducted slab and in the volcanic activity on the northeast japan arc mechanisms of backarc rifting including mantle diapirism mantle flow induced by the slab subduction or interaction of the over and the underriding plates cannot reasonably explain the process of opening of the japan sea the most plausible mechanism operating in the spreading process of the japan sea is injection of the asthenosphere into the mantle wedge that forcefully pushed the subducted slab to cause both steepening of the slab and the backarc extension the asthenospheric current towards the northeast japan arc trench system may have been associated with the large scale upwelling of the asthenosphere beneath the northeastern china region that caused intra plate volcanism and produced continental rift systems in the region the present mechanism can also explain the active backarc rifting in the okinawa trough in the western pacific and the taupo depression in north island new zealand

physical oceanography of the western iberia ecosystem latest views and challenges the present review is focused on the mesoscale physical processes recognized in the western iberia ecosystem complementing earlier reviews dedicated to larger scales recent studies support the idea that the mesoscale processes superimposed on the larger scale variability are the major factor controlling the ecosystem functioning in the region a complex structure of interleaved alongshore slope shelf and coastal currents that interact with eddies buoyant plumes upwelling filaments and fronts surface layer expressions of the subsurface circulation and internal waves is revealed by the latest research all of these contribute in different ways to have an effect on the ecosystem the supposedly less variable winter circulation also exhibits significant mesoscale activity in the form of eddy shedding from the poleward slope current intermittent upwelling events and transient nearshore poleward flows the present incomplete knowledge of this complex system presents a number of challenges and questions that must be addressed if we are to arrive at a satisfactory understanding and predictive capability for the system as a whole 2007 elsevier ltd all rights reserved

decadal changes in the aragonite and calcite saturation state of the pacific ocean 1 based on measurements from the woce jgofs global co2 survey the clivar co2 repeat hydrography program and the canadian line p survey we have observed an average decrease of 0 34 yr 1 in the saturation state of surface seawater in the pacific ocean with respect to aragonite and calcite the upward migrations of the aragonite and calcite saturation horizons averaging about 1 to 2 m yr 1 are the direct result of the uptake of anthropogenic co2 by the oceans and regional changes in circulation and biogeochemical processes the shoaling of the saturation horizon is regionally variable with more rapid shoaling in the south pacific where there is a larger uptake of anthropogenic co2 in some locations particularly in the north pacific subtropical gyre and in the california current the decadal changes in circulation can be the dominant factor in controlling the migration of the saturation horizon if co2 emissions continue as projected over the rest of this century the resulting changes in the marine carbonate system would mean that many coral reef systems in the pacific would no longer be able to sustain a sufficiently high rate of calcification to maintain the viability of these ecosystems as a whole and these changes perhaps could seriously impact the thousands of marine species that depend on them for survival

distinct sedimentary processes reflected in the isotopic signatures of dolomitic concretions in the miocene pohang basin southwestern east sea abstract dolomitic concretions in diatomaceous hemipelagic sediments of the miocene pohang basin in the southwestern east sea sea of japan preserve distinct signals of two independent sedimentary processes which controlled the extents of isotopic compositions variable 18o 9 1 to 0 7 and high 13c 3 1 to 17 9 values suggest that the concretions formed in the methanogenic zone with alteration of the residual mid miocene seawater by volcanogenic sediments remarkable 18o and 13c values show a strong linear relationship indicating that distinctly independent depositional processes operated during the formation of the concretions the degree of methanogenesis was enhanced during rapid hemipelagic sedimentation of organic rich particles resulting in higher 13c values and the effect of volcaniclastics was diluted maintaining the original properties of ambient mid miocene seawater in contrast lower 18o and 87sr 86sr values characterize the effect of volcaniclastic sediments that were transported by intermittent gravity flows and interacted with mid miocene seawater the input of volcaniclastic sediment probably degraded the role of methanogenesis by lowering the contents of organic matter and thereby decreased the 13c values within the concretions isotopic signals recorded within the concretions highlight understanding of the depositional environment and evolution of the pore water chemistry

direct observations of basin wide acidification of the north pacific ocean 1 global ocean acidification is a prominent inexorable change associated with rising levels of atmospheric co 2 here we present the first basin wide direct observations of recently declining ph along with estimates of anthropogenic and non anthropogenic contributions to that signal along 152 w in the north pacific ocean 22 56 n ph changes between 1991 and 2006 were essentially zero below about 800 m depth however in the upper 500 m significant ph changes as large as 0 06 were observed anthropogenic and non anthropogenic contributions over the upper 800 m are estimated to be of similar magnitude in the surface mixed layer depths to 100 m the extent of ph change is consistent with that expected under conditions of seawater atmosphere equilibration with an average rate of change of 0 0017 yr future mixed layer changes can be expected to closely mirror changes in atmospheric co 2 with surface seawater ph continuing to fall as atmospheric co 2 rises

decadal changes in the caco3 saturation state along 179 e in the pacific ocean 1 to assess degrees of ocean acidification we mainly investigated decadal changes in the saturation state of seawater with respect to aragonite arg which is a more vulnerable mineral form of caco3 along the 179 e meridian woce p14n in the pacific ocean we found a maximum decrease of arg of 0 48 0 034 a 1 at 200 300 dbar isopycnal surfaces of 24 0 25 8 kg m 3 at 20 n between 1993 and 2007 the saturation horizon rose by 17 dbar 1 2 dbar a 1 at latitudes 10 n 50 n although arg mostly reflected changes in normalized dissolved inorganic carbon nct it was larger than could be explained by anthropogenic co2 storage alone decomposition of nct revealed that argwas enhanced by approximately 50 by a non anthropogenic co2 contribution represented by changes in apparent oxygen utilization our results suggest that ocean acidification can be temporarily accelerated by temporal changes in oceanic conditions

the rhine outflow plume studied by the analysis of synthetic aperture radar data and numerical simulations the dynamics of the rhine outflow plume in the proximity of the river mouth is investigated by using remote sensing data and numerical simulations the remote sensing data consist of 41 synthetic aperture radar sar images acquired by the first and second european remote sensing satellites ers 1 and ers 2 over the outflow region of the river rhine most of them show sea surface signatures of oceanic phenomena for example surface current and wind variations ship wakes and oil slicks in particular in 36 of these images pronounced frontal features are visible as narrow zones of mainly enhanced sometimes enhanced reduced radar backscatter that can be associated with the rhine surface front within the area enclosed by the frontal line large zones characterized by a lower radar backscatter than in the outer area are often visible the analysis of the ers sar images suggests that the form and the location of the frontal features are mainly linked to the semidiurnal tidal phase in the outflow region although their variability suggests also that they weakly depend on river discharge residual currents and neap spring tidal cycle in order to test this observational hypothesis the results obtained from the analysis of the ers sar images are compared with the results obtained from the numerical simulation of the hydrodynamics of the rhine outflow region carried out using a two layer frontal model which is based on the nonlinear hydrostatic shallow water equations on an f plane the model is forced by prescribing tidal and residual currents and river discharge at the open boundaries several simulations are performed by varying the values of these forcing parameters the numerical results corroborate the observational conjecture it is found that the form and the location of the simulated interface outcropping lines in the proximity of the river mouth are mainly determined by the semidiurnal tidal phase in the outflow region and that river discharge residual currents and neap spring tidal cycle contribute only secondarily to their determination inserting the simulated surface velocity field into a simple radar imaging model that relates the modulation of the backscattered radar power to the surface velocity convergence in radar look direction narrow elongated bands of enhanced radar backscatter emerge near the model frontal line while patches of low radar backscatter appear within the simulated rhine plume area the consistency of the model results with the results obtained from the analysis of the sar images enables one to infer a mean spatial and temporal evolution of the rhine outflow plume over a semidiurnal tidal cycle from the analysis of spaceborne sar images acquired during different tidal cycles over the rhine outflow area and suggests the possibility of using numerical modeling in conjunction with the analysis of spaceborne measurements for monitoring the oceanic variability in the rhine outflow area

detecting the progression of ocean acidification from the saturation state of caco3 in the subtropical south pacific progression of ocean acidification in the subtropical south pacific was investigated by using high quality data from trans pacific zonal section at 17 s world ocean circulation experiment section p21 collected in 1994 and 2009 during this 15 year period the caco3 saturation state of seawater with respect to calcite cal and aragonite arg in the upper water column 400 dbar decreased at rates of 0 037 a 1 and 0 025 a 1 respectively east of 145 w longitude these rates are among the fastest in the world s oceans in contrast at longitudes 170 e 145 w cal and arg decreased relatively slowly at 0 008 a 1 and 0 005 a 1 respectively the arg saturation horizon occurred at a depth of about 1200 dbar at the westernmost end of the section and shoaled eastward to about 20 dbar from 1994 to 2009 it migrated upward at a rate of 5 2 dbar a 1 west of 145 w decomposition of the temporal changes of showed that the accumulation of anthropogenic co2 in the ocean accounted for more than half of the more rapid rate of decline of in the eastern section was attributable to a relatively large contribution of organic matter remineralization whereas the slower rate in the central section was attributed to a decrease of anthropogenic co2 uptake caused by rising water temperatures an important finding of this study was that acidification of the upper water column was enhanced by processes related to the oxygen minimum zone in the eastern subtropical south pacific ocean

persistently declining oxygen levels in the interior waters of the eastern subarctic pacific abstract fifty years of measurements at ocean station papa osp 50 n 145 w show trends in the interior waters of the subarctic pacific that are both impacted by short term few years to bi decadal atmospheric or ocean circulation oscillations and by persistent climate trends between 1956 and 2006 waters below the ocean mixed layer to a depth of at least 1000 m have been warming and losing oxygen on density surfaces found in the depth range 100 400 m 26 3 27 0 the ocean is warming at 0 005 0 012 c y 1 whereas oxygen is declining at 0 39 0 70 mol kg 1 y 1 or at an integrated rate of 123 mmol m 2 y 1 decrease of 22 over 50 years during this time the hypoxic boundary defined as 60 mol o 2 kg 1 has shoaled from 400 to 300 m in the alaska gyre the 26 2 isopycnal occasionally ventilates whereas at osp 26 0 has not been seen at the ocean surface since 1971 as the upper ocean continues to stratify to interpret the 50 year record at osp the isopycnal transport of oxygenated waters within the interior of the subarctic pacific is assessed by using a slightly modified no parameter broecker w 1974 no a conservative water mass tracer earth and planetary science letters 23 100 107 the highest nitrate oxygen signature in interior waters of the north pacific is found in the bering sea gyre western subarctic gyre and east kamchatka current region as a consequence of winter mixing to the 26 6 isopycnal by mixing with low no waters found in the subtropics and okhotsk sea this signature is diluted as waters flow eastward across the pacific evidence of low no waters flowing north from california is seen along the coasts of british columbia and se alaska oxygen in the subsurface waters of the alaskan gyre was supplied 60 by subarctic and 40 by subtropical waters during woce surveys whereas such estimates are shown to periodically vary by 20 at osp other features discernable in the osp data include periods of increased ventilation of deeper isopycnals on an 18 year cycle and strong short term few month variability caused by passing mesoscale eddies the potential impacts of declining oxygen on coastal ecosystems are discussed

the role of ocean acidification in systemic carbonate mineral suppression in the bering sea ocean acidification driven by absorption of anthropogenic carbon dioxide co2 from the atmosphere is now recognized as a systemic global process that could threaten diverse marine ecosystems and a number of commercially important species the change in calcium carbonate caco3 mineral saturation states brought on by the reduction of seawater ph is most pronounced in high latitude regions where unique biogeochemical processes create an environment more susceptible to the suppression of values for aragonite and calcite which are critical to shell building organisms new observations from the eastern bering sea shelf show that remineralization of organic matter exported from surface waters rapidly increases bottom water co2 concentrations over the shelf in summer and fall suppressing values the removal of co2 from surface waters by high rates of phytoplankton primary production increases values between spring and summer but these increases are partly counteracted by mixing with sea ice melt water and terrestrial river runoff that have low values while these environmental processes play an important role in creating seasonally low saturation states ocean uptake of anthropogenic co2 has shifted values for aragonite to below the saturation horizon in broad regions across the shelf for at least several months each year furthermore we also report that calcite became undersaturated in september of 2009 in the bottom waters over the shelf the reduction in caco3 mineral saturation states could have profound implications for several keystone calcifying species in the bering sea particularly the commercially important crab fisheries

diagenetic study on the neogene sedimentary basin as paleoenvironmental proxy data for an offshore co2 storage project in pohang basin south korea abstract as the importance of reducing greenhouse gas emissions has attracted much attention pohang basin has been identified as a co2 geological sequestration test site in korea this study aims to provide a better understanding of the diagenetic history of pohang basin through mineralogical and microstructural analyses with a focus on tectonic evolution in the reservoirs offshore of the pohang basin during the east sea sea of japan opening in the miocene we focused on two sections in the core that are considered to be target layers for co2 storage samples were analyzed for texture observation and chemical analysis the major mineral components include quartz feldspar illite chlorite kaolinite and calcite and the minor mineral components include pyrite siderite iron oxide and titanium oxide the detrital grains are composed of quartz and feldspar and the primary pore is cemented with kaolinite i calcite pyrite and chlorite the analyzed chlorites are differentiated into five types by their textural characteristics such as pore filling pf pore filling with kaolinite pf k pore lining pl replaced rd and detrital da chlorites and they were all categorized as either brunsvigite diabantite or ripidolite generally the dissolution of feldspar is observed for all samples the diagenetic temperature is estimated by chlorite geothermometry to be 170 c on average which is higher than the present temperature of pohang basin 55 60 c considering all results together the target layers have undergone diagenetic processes from early diagenesis eogenesis to late diagenesis mesogenesis and uplift related diagenesis telogenesis after sedimentation of the pohang basin kaolinite i calcite and pyrite were cemented in the pore and detrital mica was replaced with chlorite as the burial depth increased the dissolution of feldspar advanced the high temperature resulting from the chlorite geothermometry could be influenced by the burial heat as source also the neogene volcanism and related tectonics known as eoil orogeny could become a heat source capable of high temperatures and a high geothermal gradient and tectonically compressional environment may have influenced fluid flow after the uplift kaolinite ii was precipitated in both an intergranular pore and intragranular pore as a result of dissolution the effects of diagenesis such as cementation and dissolution in co2 reservoir rocks could be an important factor in assessing the appropriacy of predicting potential charge after injection in carbon capture and storage project

revised stratigraphy and reinterpretation of the miocene pohang basinfill se korea sequence development in response to tectonism and eustasy in a back arc basin margin abstract the miocene pohang basin is a pull apart basin formed along the eastern continental margin of korea ecmk during the back arc opening of the east sea sea of japan the basin is filled by more than 1 km thick nonmarine to deep marine strata these strata show extreme vertical and lateral lithofacies changes and have caused decades long controversies on their nature and stratigraphy previous sedimentological studies suggest that the basinfill was deposited by a series of contemporaneously developed depositional systems including fan delta prodelta slope apron and basin plain detailed mapping and magnetotelluric surveying show however that the basinfill is composed of several packages of strata sequences that are bounded by distinct and laterally persistent stratigraphic discontinuities sequence boundaries this suggests that the depositional systems in the pohang basin developed sequentially rather than contemporaneously six packages of strata are identified in the basin a nonmarine to shallow marine transgressive sequence sequence 1 a gilbert type delta conglomerate sequence 2 and alternations of submarine conglomerates and hemipelagic mudstones sequences 3 6 the conglomerates and hemipelagic mudstones of the latter four sequences are interpreted to represent lowstand depositional systems slope apron submarine fan and high gradient delta and condensed intervals respectively compilation of geochronologic paleomagnetic and biostratigraphic data suggests that sequence 1 formed during the gradual subsidence of the ecmk prior to 17 ma whereas sequence 2 formed in response to abrupt downfaulting of the pohang basin at about 17 ma both sequences are interpreted to have developed in response to the early miocene back arc opening tectonism of the east sea on the other hand sequences 3 6 formed between 17 and about 10 5 ma the pohang basin was subject to only minor tectonism during this period and could record global sea level fluctuations we suggest that the four alternations of conglomerates lowstand systems and hemipelagic mudstones condensed intervals resulted most probably from the 3rd order glacioeustatic cycles during the middle miocene this finding implies that the signatures of global sea level fluctuations can be deciphered from a tectonically active sedimentary basin if the timing of regional tectonic development is well constrained and the global sea level chart of haq et al haq b w hardenbol j vail p r 1987 chronology of fluctuating sea levels since the triassic science 235 1156 1167 haq b u hardenbol j vail p r 1988 mesozoic and cenozoic chronostratigraphy and eustatic cycles in wilgus c k hastings b s posamentier h van wagoner j ross c a kendall c g s c eds sea level changes an integrated approach soc econ paleont mineral spec publ 42 pp 71 108 may serve as a guide to basinfill interpretation even in tectonically active sedimentary basins

chemical and biological impacts of ocean acidification along the west coast of north america abstract the continental shelf region off the west coast of north america is seasonally exposed to water with a low aragonite saturation state by coastal upwelling of co2 rich waters to date the spatial and temporal distribution of anthropogenic co2 canth within the co2 rich waters is largely unknown here we adapt the multiple linear regression approach to utilize the go ship repeat hydrography data from the northeast pacific to establish an annually updated relationship between canth and potential density this relationship was then used with the noaa ocean acidification program west coast ocean acidification wcoa cruise data sets from 2007 2011 2012 and 2013 to determine the spatial variations of canth in the upwelled water our results show large spatial differences in canth in surface waters along the coast with the lowest values 37 55 mol kg 1 in strong upwelling regions off southern oregon and northern california and higher values 51 63 mol kg 1 to the north and south of this region coastal dissolved inorganic carbon concentrations are also elevated due to a natural remineralized component cbio which represents carbon accumulated through net respiration in the seawater that has not yet degassed to the atmosphere average surface canth is almost twice the surface remineralized component in contrast canth is only about one third and one fifth of the remineralized component at 50 m and 100 m depth respectively uptake of canth has caused the aragonite saturation horizon to shoal by approximately 30 50 m since the preindustrial period so that undersaturated waters are well within the regions of the continental shelf that affect the shell dissolution of living pteropods our data show that the most severe biological impacts occur in the nearshore waters where corrosive waters are closest to the surface since the pre industrial times pteropod shell dissolution has on average increased approximately 19 26 in both nearshore and offshore waters

mode shift in the indian ocean climate under global warming stress 1 a 115 year coral record from kenya has been found to preserve the history of rainfall anomalies in east africa in relation to global warming induced indian ocean dipole iod variability the coral iod index demonstrates a dominantly decadal periodicity in the early part of the 20th century this low frequency iod occurred more frequently before 1924 with mostly quasi biennial ranging from 18 months to 3 years events since 1960 the mode shift has also coincided with an intensified coupling with indian summer monsoon rainfall we suggest that a warming of the western indian ocean which has attenuated and replaced the el nino southern oscillation effect over the indian ocean has driven the observed shift

role of surface films in ers sar signatures of internal waves on the shelf 2 internal tidal waves analysis of ers 1 synthetic aperture radar sar images over the iberian shelf shows that they contain the signatures of large scale banded structures with characteristic wavelengths of 10 20 km parallel to the shelf break their consistency with the structure of internal tides leads to the conclusion that they are the surface manifestations of internal tidal waves the effect of imaging of such large scale phenomena by sar operating in l c and x bands cannot be explained by conventional hydrodynamic modulation models based on the effect of straining of surface wind waves due to the internal tidal currents an alternative explanation is described by an analysis of modulation of centimeter and decimeter scale surface waves caused by the redistribution of surface active substances by internal tidal currents model calculations of variations of the wind wave spectrum across the internal tide profile are presented an empirical film pressure area equation and the results of thermistor chain measurements of internal tidal waves in the study area were used in the modeling the effect of additional modulation of short surface waves due to variations of wind velocity relative to the internal tidal current is also estimated it is demonstrated that modulation of centimeter decimeter wind waves in the presence of surfactant films is the dominant factor and can explain the effect of internal tidal wave imaging by sar

p t deformation fe3 fe2 mapping at the thin section scale and comparison with xanes mapping application to a garnet bearing metapelite from the sambagawa metamorphic belt japan quantitative x ray maps of composition from a chlorite k white mica albite quartz and garnet bearing thin section from a sambagawa blueschist facies metapelite were combined with a multiequilibrium calculation method to calculate a p t fe3 fe2 deformation map at the millimetre scale the studied sample was chosen because elongated chlorite crystallization tails pressure shadows rimmed by phengite are present which is an appropriate assemblage for the quantification of the p t evolution chlorite temperature and fe3 content maps were calculated by successive iterations for each pixel analysis of fe3 until convergence of the four chlorite quartz h2o equilibria that can be written using the fe and mg amesite clinchlore daphnite and sudoite chlorite end members the calculated map of fe2 fe3 in chlorite is in good qualitative agreement with the in situ mapping of this ratio using xanes x ray absorption near edge structure techniques the temperature map indicates that high temperature chlorite zones with low fe3 contents alternate with lower temperature zones and higher fe3 contents in the crystallization tail late fractures perpendicular to the elongation axis of the tail are filled by very low temperature chlorite 250 c showing fe3 fetotal up to 0 4 groups of chlorite and mica pixels were then identified based on compositional and structural criteria and a p tdeformation map was calculated using representative analyses of these groups the calculated p tdeformation map suggests that in contrast to chlorite the composition of most mica did not change significantly during exhumation mica reequilibrated in late ew shear bands only ew shearing was already active at 0 1 gpa 500 c which corresponds to the peak temperature and probably pressure conditions at reduced redox conditions the intensity of deformation probably decreased with decrease in temperature to 350 400 c at this temperature a second main deformation event corresponding to a further ew stretching occurred and was still active below 250 c and more oxidizing conditions these results indicate that the scale at which p t data can be obtained is now close to the scale of observation of structural geologists a close link between deformation and mineral reaction is therefore possible at the microscopic scale which provides information about the relationship between deformation and mineral reactivity the modalities of deformation with time and the p t conditions at which it occurred

opening mode of the japan sea inferred from the palaeomagnetism of the japan arc the western edge of the pacific plate is marked by a chain of back arc basins stretching from the aleutians through japan and the philippines to new zealand most of the basins lie behind volcanic island arcs far from continents and are the result of extension of the oceanic lithosphere1 but the japan sea is bounded on one side by continental crust the sikhote alin and korean peninsula of the asian continent and on the other by an active arc with continental fragments it can thus be said to be associated more with continental rifting1 4 than with oceanic processes we report here palaeomagnetic data from the japan arc which indicate that since the early miocene north east japan has rotated counter clockwise through 47 around a vertical axis while south west japan has rotated clockwise through 56 refs 5 8 we attribute this differential rotation which took place concurrently between 21 and 11 myr ago to the back arc opening of the japan sea8 with a double door mode that is there are two fan shaped spreading basins facing each other such a fan shaped opening is probably peculiar to the geological phenomenon of rifting of a continental fragment from thick continental lithosphere

effect of obliteration on crater count chronologies for martian surfaces 1 the density of impact craters calibrated against lunar data is currently the only quantitative measure of surface age for terrestrial planetary surfaces unlike the moon however mars has been weathered and eroded obliterating some small 10 km diameter craters a phenomenon addressed in the mariner viking days of mars exploration but commonly overlooked in recent studies we present a quantitative model that extends this earlier work to assess the effect of erosion and infilling on surface ages inferred from crater frequency distributions our work affirms that small cratersizedistributionscanbeinterpretedquantitatively in terms of effects of erosion and crater infilling at rates comparable to those reported for mars a reanalysis of prior studies indicates that low to moderate long term rates of erosion and crater infilling can mask an ancient age and result in small crater populations similar to those offered as evidence for young and geologically significant surface activity citation smith m r a r gillespie and d r montgomery 2008 effect of obliteration on crater count chronologies for martian surfaces geophys res lett 35 l10202 doi 10 1029 2008gl033538

climate variability in the north pacific thermocline diagnosed from oxygen measurements an update based on the u s clivar co2 repeat hydrography cruises 1 new observations of oxygen variability in the north pacific ocean are reported on the basis of comparison of the u s climate variability and predictability and carbon clivar co2 repeat hydrography sections conducted along 30 n 2004 and 152 w 2006 with the earlier world ocean circulation experiment woce data and other cruises along these sections the largest changes in apparent oxygen utilization aou continue to occur as found in earlier north pacific repeat section analyses within the thermocline on 26 6 kg m 3 which is the densest isopycnal to outcrop in the open north pacific in climatological data in the northeastern north pacific along 152 w where a total of five cruises 1980 1984 1991 1997 and 2006 spanning a period of 26 years are available the aou changes correspond to an overall increase in aou on 26 6 kg m 3 from the 1980s early 1990s to 2006 however from 1997 to 2006 a decrease in aou is observed within the boundary region between the subtropical and subpolar gyres at 40 45 n along the center axis of the subtropical gyre at 30 n where two cruises are available 1994 and 2004 aou has also substantially increased on 26 6 kg m 3 from 1994 to 2004 in the eastern part of the section the repeat section data along 152 w and 30 n are consistent with a pattern of decadal scale ventilation anomalies that originate in the northwestern pacific possibly through variability including cessation of the 26 6 kg m 3 outcrop travel eastward along the subtropical subpolar gyre boundary and enter the northern portion of the subtropical gyre along the way for the 152 w aou data within the gyre boundary region 40 45 n good agreement exists with the close by time series data from ocean station p 50 n 145 w where a bidecadal cycle in aou has been observed in contrast a sensible correlation with the pacific decadal oscillation could not be found

optimal estimation of hydrographic station data and derived fields abstract optimal estimation is applied to contouring and analysis of hydrographic sections measured fields such as temperature and salinity and derived fields such as geostrophic velocity are decomposed into large scale and small scale components first a heavily sampled basin scale field is estimated and subtracted from the data a small scale field barely resolved by the hydrography is then found from the residuals the power and utility of the technique are illustrated by means of examples using a short section from the straits of florida and a transatlantic section along 24 n

drivers of the carbonate system seasonal variations in a mediterranean gulf abstract the effects of different physical and biogeochemical drivers on the carbonate system were investigated in a semi enclosed coastal area characterized by high alkalinity riverine discharge gulf of trieste northern adriatic sea mediterranean sea our 2 year time series showed that a large part of the seasonal carbonate chemistry variation was controlled by the large seasonal change of seawater temperature though air sea co 2 exchange biological activity primary production respiration and riverine inputs also exerted a significant influence with the exception of summer the gulf of trieste was a sink of atmospheric carbon dioxide showing a very strong co 2 fluxes from atmosphere into the sea 16 10 mmol m 2 day 1 during high wind speed event of north easterly bora wind the co 2 influx was particularly evident in winter when the biological activity was at minimum and the low seawater temperature enhanced co 2 solubility during spring the drawdown of co 2 by primary production overwhelmed the co 2 physical pump driving a significant decrease of dissolved inorganic carbon dic co 2 and increase of ph t25 c in summer the primary production in surface waters occurred with the same intensity as respiration in the bottom layer so the net biological effect on the carbonate system was very low and the further reduction of seawater co 2 concentration observed was mainly due to carbon dioxide degassing induced by high seawater temperature finally during autumn the respiration was the predominant process which determined an overall increase of dic co 2 and decrease of ph t25 c this was particularly evident when the breakdown of summer stratification occurred and a large amount of co 2 generated by respiration and segregated below the pycnocline was released back to the whole water column local rivers also significantly affected the carbonate system by direct input of total alkalinity a t coming from the chemical weathering of carbonate rocks which dominate the river watershed our finding clearly demonstrates a high a t concentration in low salinity surface waters a t max 2742 8 mol kg 1 and a negative a t salinity correlation as a result the gulf of trieste revealed a low revelle factor 10 1 and one of the highest buffer capacities of the mediterranean sea s dic 0 31 mmol kg 1 which allows the system to store a significant amount of atmospheric co 2 with a small decrease of seawater ph

mechanism of internal waves in the luzon strait 1 this study suggests a western boundary current instability generation mechanism for the ocean internal waves a linear model describing this instability is developed and an analytical solution is derived from a zero order complex frequency wavenumber relation the real part of the relation represents a dispersion relation of the generated internal waves and the imaginary part is an exponential growth rate the dispersion relation describes the wave propagation characteristics while the growth rate represents the instability properties the theoretical results are used for the case of the kuroshio east of the luzon strait based on the analysis it is found that for the westward propagating disturbance the kuroshio west wing is unstable and the east wing is stable while the reverse is true for the eastern propagating disturbance the results are used to interpret satellite sar images of the ocean internal waves which were generated in the luzon strait and propagated westward reasonable estimates for the growth rate and propagation velocity are derived from a scale analysis of the kuroshio east of the luzon strait

analysis of internal wave signatures in marine radar data satellite images have long been used to study surface manifestations of internal waves iws more recently marine x band radar data have been employed to retrieve iw packet parameters marine radars have the advantage over satellite systems that their high temporal resolution enables the study of the iw evolution until today no method to automatically detect iw surface signatures in marine radar data has been suggested in this paper we present a new fully automated tool to retrieve iw signatures from marine radar image sequences first after various preprocessing steps the iw packet velocity is determined using a combination of localized radon transform and cross correlation techniques temporal averaging of the marine radar data significantly enhances the iw signatures the knowledge of the iw packet velocity is used to correct for the iw motion enabling us to extend the averaging period which further enhances the iw signal an iw motion correction is necessary because otherwise the iw signal would become smeared if the averaging period were much longer than the time it takes the iw to propagate between radar resolution cells the iw enhanced images are then utilized for the iw signature analysis here we identify local backscatter peaks and exploit the marine radar s high temporal resolution to distinguish signal from noise the resulting series of iw soliton maps provides information on changes in soliton wavelength velocity and backscatter intensity our marine radar iw signature analysis tool therefore offers a great opportunity of studying the spatiotemporal evolution of iws as they grow and decay

sequence stratigraphic distribution of diagenetic alterations in coal bearing paralic sandstones evidence from the rio bonito formation early permian southern brazil linking siliciclastic diagenesis to sequence stratigraphy allows a better understanding of the parameters controlling the spatial and temporal distribution of diagenetic alterations and hence of reservoir quality a study of the coal bearing alluvial deltaic estuarine and shallow marine sandstones of the rio bonito formation early permian parana basin southern brazil reveals that the distribution of diagenetic alterations and of related reservoir quality evolution can be constrained within a sequence stratigraphic framework calcite dolomite siderite kaolinite and pyrite cementation is consistently linked to sequence and parasequence boundaries transgressive and maximum flooding surfaces and is systematically distributed within lowstand transgressive and highstand systems tracts diagenesis of coal layers at parasequence boundaries has promoted the formation of stratabound calcite detectable in resistivity wire line logs concretionary pyrite and kaolinite and of silicate grain dissolution in sandstones located above and below these boundaries particularly in the transgressive systems tract meteoric water diagenesis caused grain dissolution and the formation of kaolinite in sandstones below sequence boundaries and in lowstand systems tract sandstones carbonate bioclasts and low sedimentation rates in lag deposits at parasequence boundaries transgressive and maximum flooding surfaces favoured the formation of grain rimming siderite the results of this study are relevant to the exploration of coal bed methane and other coal bearing reservoirs where it is crucial to unravel and predict the distribution and quality of reservoirs and compartments

on the determination of characteristics of the interior ocean dynamics from radar signatures of internal solitary waves in this paper we discuss two different methods of inferring characteristics of the interior ocean dynamics from radar signatures of internal solitary waves visible on synthetic aperture radar sar images the first one consists in the recognition and the interpretation of sea surface patterns of internal solitary waves the second one consists in the analysis of the modulation depth of the normalized radar backscattering cross section nrcs associated with internal solitary waves for this purpose we consider a data set composed of sar and in situ measurements carried out from 1991 to 1997 in the region of the strait of messina the recognition and the interpretation of sea surface patterns of internal solitary waves in the strait of messina can be used to study characteristics of the density distribution in the area the internal wave field varies with seasonal variations in the vertical density stratification and with remotely induced variations i e variations induced by the larger scale circulation in the horizontal density distribution in order to inquire into the possibility of inferring parameters of the interior ocean dynamics by analyzing the modulation of the nrcs associated with internal solitary waves several numerical simulations are carried out using a radar imaging model these simulations are performed by assuming different wind conditions and internal wave parameters it is shown that an accurate knowledge of wind conditions is crucial for deriving internal wave parameters and hence parameters of the interior ocean dynamics from the modulation of measured nrcs associated with internal solitary waves

can near inertial internal waves in the east sea be observed by synthetic aperture radar 1 near inertial 18 hours internal waves were observed in the mid western part of the east sea on may 18 and 19 2004 using c band synthetic aperture radar sar images current and temperature measurements obtained during the field experiment from 10 may to 9 june 2004 iwxes2004 internal wave experiment in the east sea were analyzed to investigate the processes by which near inertial internal waves can be seen in sar images and how they progress the spatial distributions of horizontal wavelength and phase speed estimated from two successively acquired sar images are consistent with those inferred from water temperature and current measurements carried out during the field experiment based on these two independent observations sar and iwxes2004 we report a strong possibility that the observed wave patterns in the sar images during iwxes2004 are near inertial internal waves propagating westward off the east coast of the korean peninsula with a phase speed of about 0 3 m s

evidence of prolonged aragonite undersaturations in the bottom waters of the southern bering sea shelf from autonomous sensors abstract the southeastern shelf of the bering sea is a dynamic area that experiences seasonal variability in primary production and remineralization of organic matter both of which control the carbon biogeochemistry of the water column surface water partial pressure of carbon dioxide p co 2 is greatly reduced in summer by biological production which increases carbonate mineral saturation states in contrast the export of large quantities of organic matter from surface blooms drives an active remineralization loop that sharply increases p co 2 near the bottom lowering ph and suppressing new observations from moored biogeochemical sensors in 2011 showed that seasonal net community production lowers surface water p co 2 causing large gradients between the ocean and atmosphere that are sustained throughout the summer confirming that these waters likely remain supersaturated with respect to aragonite throughout the open water season on the other hand moored sensors deployed near the bottom showed that p co 2 levels exceed 500 atm by early june and remain at these high levels well into the autumn months indicating that the bottom waters are likely continuously undersaturated in aragonite for at least several months during each year only a small fraction of the increased p co 2 can currently be attributed to the intrusion of anthropogenic co 2 from the atmosphere while the majority is due to natural respiration processes the biological impacts along with the timing and duration of these undersaturation events could play a role in the development of larval and juvenile calcifiers in the region and will change as anthropogenic co 2 concentrations continue to rise