the effect of wind stress over the eastern mediterranean on deep water formation in the adriatic sea abstract we investigate the effect of interannual variability of the wind stress over the eastern mediterranean on adriatic deep water adw formation using an oceanic general circulation model of the mediterranean sea driven by monthly era interim wind stress of the years 1979 2014 this is done by using climatological annual cycle of the surface temperature and freshwater flux but interannually varying wind stress a connection between the wind stress magnitude over the rhodes gyre region and adw outflow is found in association with the formation of levantine intermediate water liw 720 years artificially generated wind stress fields were constructed based on the first 50 empirical orthogonal functions eofs of the wind stress monthly anomalies this simulation strengthen the connection that was found and also reveal a centennial internal variability of both the liw and the adw outflow it is also found that the intensity of the rhodes gyre is almost linearly related to the wind stress amplitude however the adw outflow is non monotonically related to the wind stress amplitude there is an optimal wind stress amplitude for which the adw formation is maximal when the wind stress amplitude is more than 50 the climatological mean wind stress amplitude the adw outflow is weakened this implies a different balance between the saline liw and the fresh atlantic water entering the eastern mediterranean from sicily strait under stronger than present wind stress amplitude

marked differences between van genuchten soil water retention parameters for temperate and tropical soils a new water retention pedo transfer functions developed for tropical soils all of the physical chemical and soil water retention data suitable for the derivation of a pedo transfer functions ptf for water retention for tropical soils 771 suitable horizons were extracted from the igbp dis soil database the parameters s r and n of the van genuchten vg soil sci soc am j 44 1980 892 equation were derived and compared with parameter values from two published data sets of temperate region soils thirty five percent of the soils in the tropical igbp t database were classified as clays compared with only 4 and 7 in the temperate databases the igbp t soil bulk densities were significantly lower p 0 001 for nine textural classes for the more clayey textural classes the value of was higher for the igbp t soils implying more large pores and more structure for kaolinitic soils in the igbp t database was typically around 0 4 kpa 1 compared with 0 04 kpa 1 for montmorillonitic soils mineralogy is clearly important and should be included in ptfs if available the value of n for clay soils in the igbp t data set was significantly higher than for temperate soils and s was significantly higher for nine textural classes p 0 001 reflecting their lower bulk density r was also significantly higher for all textural classes except sand for clay the mean value of r was 0 27 m3 m 3 compared to only 0 11 m3 m 3 for temperate soils for 17 of the igbp t data r exceeded 0 3 m3 m 3 a value often used as a fitting constraint a tropical soil ptf was developed using multiple regression techniques this predicted water retention curves more reliably than either class ptfs or soil class ptfs but was not reliable for low density soils such as andosols the igbp t data set includes some groups of soils e g andosols and ferralsols whose properties are extremely different from those of most temperate soils these differences emphasise the need to develop separate ptfs for tropical soils or perhaps for specific groups of soils there were few water retention data from below 1 5 m depth and a complete lack of hydraulic conductivity data in the igbp t database this is a major impediment to the modelling of water movement and uptake in deep rooted ecosystems for example tropical forest and savannah

the levantine intermediate water experiment liwex group levantine basin a laboratory for multiple water mass formation processes 1 in winter 1995 the last major field work of the physical oceanography of the eastern mediterranean poem program was carried out the levantine intermediate water experiment liwex in this study a thorough analysis is presented of the data set collected during three successive surveys in january february and march april 1995 the major overall result is that the levantine basin is shown to be the site for multiple and different water mass formation processes levantine deep water ldw was formed in the rhodes gyre with the preconditioning phase starting in december 1994 in late january the chimney was ventilating to the atmosphere in february the strong mixing phase is documented by the convective cell vertically homogeneous to 900 m depth in march april recapping has occurred in the upper 200 m ldw remained confined inside the rhodes gyre cyclonic circulation levantine intermediate water liw is instead deeply affected by the upper thermocline circulation shallow ventilating chimneys with the liw thermostads were found in the january survey inside the cyclonic region of the northern levantine the formation process of liw does not involve deep penetrative convection winter surface cooling and evaporation are sufficient to produce a surface mixed layer 100 m deep with liw characteristics at the mixed layer basis liw subducts and spreads along isopycnal surfaces along pathways determined by the cyclonic anticyclonic structures of the upper thermocline circulation

a mixed layer study of the formation of levantine intermediate water a mixed layer model is used to investigate the formation of levantine intermediate water liw over the eastern mediterranean the one dimensional model is initialized with climatological hydrography and integrated over the levantine basin with forcing by climatological surface fluxes realistic and repeated seasonal mixed layer cycles are obtained if the annual surface heat input and water loss are offset by a parameterized horizontal advection the model integrations show that liw is formed during winter in the mixed layer of the northwestern levantine the preferred formation region for liw is found through idealized experiments to be controlled by the preconditioning of the hydrography especially that of the cold cyclonic rhodes gyre rather than by the pattern of the climatological fluxes the annual mean formation rate of liw is estimated to be 1 0 sv using the climatological surface fluxes the magnitude of the annual surface fluxes alters the formation rate and modifies the formation region an additional annual heat flux reduces the formation rate of liw whereas an extra cooling enhances it as well as forming waters denser than liw in the center of the rhodes gyre

a synthesis of the levantine basin circulation and hydrography 1985 1990 abstract the levantine basin circulation derived from recent data consists of a series of sub basin scale to mesoscale eddies interconnected by jets the basin scale circulation is masked by eddy variability that modulates and modifies it on seasonal and interannual time scales long term qualitative changes in the circulation are reflected in the bifurcation pattterns of ther mid basin jets relative strengths of eddies and the hydrographic properties at the core of these eddies confinement within the basin geometry strongly influences the co evolution of the circulation features surface measurements satellite images and the mass field indicate an entire range of scales of dynamical features in the region the complexity of the circulation is consistent with the basin wide and mesoscale heterogeneity of the hydrographic properties the interannual variability of liw levantine intermediate water formation in the region appears correlated with the changes in the circulation wintertime convective overturning of water masses reach intermediate depths and constitute a dominant mechanism of liw formation especially in anticyclonic eddies and along the coasts of the northern levantine basin

chemical and textural equilibration of garnet during amphibolite facies metamorphism the influence of coupled dissolution reprecipitation metamorphic equilibration requires chemical communication between minerals and may be inhibited through sluggish volume diffusion and or slow rates of dissolution in a fluid phase relatively slow diffusion and the perceived robust nature of chemical growth zoning may preclude garnet porphyroblasts from readily participating in low temperature amphibolite facies metamorphic reactions garnet is widely assumed to be a reactant in staurolite isograd reactions and the evidence for this has been assessed in the late proterozoic dalradian pelitic schists of the scottish highlands the 3d imaging of garnet porphyroblasts in staurolite bearing schists reveals a good crystal shape and little evidence of marginal dissolution however there is also lack of evidence for the involvement of either chlorite or chloritoid in the reaction staurolite forms directly adjacent to the garnet and its nucleation is strongly associated with deformation of the muscovite rich fabrics around the porphyroblasts cloudy fluid inclusion rich garnet forms in both marginal and internal parts of the garnet porphyroblast and is linked both to the production of staurolite and to the introduction of abundant quartz inclusions within the garnet such cloudy garnet typically has a mg rich mn poor composition and is interpreted to have formed during a coupled dissolution reprecipitation process triggered by a local influx of fluid all garnet in the muscovite bearing schists present in this area is potentially reactive irrespective of the garnet composition but very few of the schists contain staurolite the staurolite producing reaction appears to be substantially overstepped during the relatively high pressure barrovian regional metamorphism reflecting the limited permeability of the schists in peak metamorphic conditions fluid influx and hence reaction progress appear to be strongly controlled by subtle differences in deformation history the remaining garnet fails to achieve chemical equilibrium during the reaction creating distinctive patchy compositional zoning such zoning in metamorphic garnet created during coupled dissolution reprecipitation reactions may be difficult to recognize in higher grade pelites due to subsequent diffusive re equilibration fundamental assumptions about metamorphic processes are questioned by the lack of chemical equilibrium during this reaction and the restricted permeability of the regional metamorphic pelitic schists in addition the partial loss of prograde chemical and textural information from the garnet porphyroblasts cautions against their routine use as a reliable monitor of metamorphic history however the partial re equilibration of the porphyroblasts during coupled dissolution reprecipitation opens possibilities of mapping reaction progress in garnet as a means of assessing fluid access during peak metamorphic conditions

impact of leaky wells on nitrate cross contamination in a layered aquifer system methodology for and demonstration of quantitative assessment and prediction abstract poorly constructed wells can cause deterioration of groundwater quality by carrying surface contaminants into a deep subsurface aquifer system in this study the impact of leaky wells on groundwater contamination was quantitatively evaluated in a layered aquifer system of the gosan agricultural fields jeju island korea where degradation in groundwater quality by nitrate has been reported we introduce a leaky well module and a double domain integration method to compute nitrate cross contamination through a layered aquifer system the simulation results clearly revealed that the leaky wells rapidly degraded the water quality of the underlying aquifer by acting as a direct pathway for nitrate rich shallow groundwater the model results predicted that in order to decrease the no3 n concentration at the regional groundwater wells below the maximum contamination level mcl the maximum allowable fertilizer amount of gosan would be 45 65 of the currently applied fertilizer level whereas sealing of the regional groundwater wells would rapidly decrease the no3 n concentration below the mcl without reducing fertilizer usage our study demonstrated that the well conditions and hydrogeological system play major roles in the occurrence of nitrate in the underlying aquifer in gosan therefore a proper groundwater management plan against nitrate contamination should be established on the basis of a comprehensive understanding of the hydrogeologic system of the area

pressure temperature and time indicators in mafic schist their application to reconstructing the polymetamorphic history of vermont mineral chemistry and overgrowth relationships in mafic schist from vermont are shown to be sensitive indicators of pressure temperature and relative time and to be good chronicles of the paleozoic history of this polymetamorphic terrane within the common assemblage amphibole chlorite epidote plagioclase quartz ti phase carbonate k mica fe 3 oxide electron microprobe analyses show that increasing metamorphic grade as defined by intercalated pelitic schist is recorded by an increase in the edenite glaucophane and tschermakite contents of amphibole in the anorthite content of plagioclase and in the substitution of al vi f 2 ti al iv for fe 2 mg mn si in biotite chlorite and muscovite with increasing pressure the glaucophane component of amphibole increases for medium pressure metamorphism the albite oligoclase gap is in the garnet zone where amphibole has between 1 2 and 1 8 formula proportion al iv and al vi fe 3 ti cr this gap is below the garnet isograd in low pressure mafic schist where al iv and al vi fe 3 ti cr in the amphibole are both less than 0 6 mineral growth periods observed are characterized by metamorphic grade and facies series and are assigned to two ordovician taconic and two devonian acadian events silurian devonian mafic schist in northeastern vermont records two periods of low pressure devonian metamorphism these events are expressed by medium pressure and low pressure metamorphism in the cambrian and ordovician rocks to the west and south in the pre silurian rocks high pressure and medium pressure metamorphism is assigned to the ordovician the observed high pressure metamorphism is confined to a 110 by 40 km area along the green mountain anticlinorium axis in north central vermont

current structures and topographic rossby waves in the levantine basin south of crete revealed by snapshot and time series current measurements abstract the 1 5 lat x 3 5 lon levantine area south of crete was surveyed for the first time in april 2016 with a combination of direct current measurements comprised by ctd ladcp lowered acoustic doppler current profiler grid casts and ship track adcp measurements in the upper 500 m while a mooring was launched at the end of the continental slope and provided yearly current records at 700 m and 30 m off the bottom depth of 4300 m horizontal flow structures are mapped in the upper 1000 m via objective analysis of the direct current measurements depicting the cretan cyclone at the west the rhodes gyre at the east and anticyclonic circulation in the middle due to modified atlantic water in the upper 80 m and a thick saline warm mass extending from 100 m to 1500 m possibly of cretan origin the bottom kinetic energy spectra have higher density values than those at 700 m in the two month energetic period of end jan to end mar 2017 topographic rossby waves trw with wavelength of 42 km exist in the window of 34 19 days with significant coherence between the near bottom and the 700 m records at the trw spectral window the motions are transverse and the direction of maximum velocity variance veers from nearly along isobaths 20 north northeast to 45 northeast with decreasing period the presence of trws in the specific time period within 2017 appears to be related to the lateral shifts of the ierapetra anticyclone over the sloping bottom of the continental margin

evolution of dynamics in the eastern mediterranean affecting water mass structures and properties in the ionian and adriatic seas 1 basin wide hydrographic observations performed in the eastern mediterranean during the past 2 decades attest changes in the thermohaline circulation as well as new aspects concerning the onset and the follow up of the major transient event that occurred at the beginning of the 1990s i e the change of the dense water formation site from the adriatic to the aegean sea since 1999 the upper thermohaline circulation has indicated the restoring of the opposite flows of the atlantic water and the levantine intermediate water which were greatly reduced in the period 1987 1995 in the deep layer the comparison between water mass structures observed in 1995 during the mature status of the transient and those observed in 1999 shows a damping of the event and a regained role of the adriatic sea as a primary source of dense waters separate calculations of the salt content in the ionian and in the levantine seas show an overall salt redistribution during 1987 1995 a salt loss of about 25 1012 kg was computed for the upper 800 m constituting only 27 of the salt gain in the deep layer over most of the eastern mediterranean on the contrary during 1995 1999 the restored upper thermohaline circulation caused a salt redistribution between the two basins of about the same amount but in the opposite sense while an extra quantity of 12 1012 kg was deposited in the deep layer in addition calculations of the salt concentration in the convection region of the southern adriatic reveal a remarkable amount of the salt not yet totally transferred into the deep layers by its interior dynamics because of mild winters

influence of hydraulic properties on physically modelling slope stability and the definition of rainfall thresholds for shallow landslides abstract physically based models are recognized as a good tool for slope stability analysis and have been implemented for the definition of rainfall thresholds for landslides in this study a methodology for estimating rainfall intensity and duration thresholds for shallow sliding failure using the physical model trigrs was implemented in a tropical mountainous basin of the valle de aburra colombia the variation of pressure head and factor of safety during different rainfall events and hydraulic conditions is studied for specific grid cells steady state and a maximum pressure head were reached for each grid cell regardless of the different rainfall intensities and hydraulic conductivities simulated but the time in which this condition is reached depends on these variables and occurs faster for steeper slopes the influence of hydraulic properties on the stability results and the position of the rainfall intensity and duration thresholds were studied with parametric analysis very low values of saturated hydraulic conductivity do not allow rainfall intensity and duration thresholds to be developed the rainfall threshold position also has a greater variation with respect to the parameters of the soil water retention curve and the initial infiltration rate or long term background rainfall rate for low values of saturated hydraulic conductivity

high pressure metamorphism in mafic schist from northern vermont the only confirmed occurrence of glaucophane and omphacite in the appalachian mountains of new england is in mafic schist from tillotson peak 44 48 72 33 north central vermont mineral assemblages observed all with epidote sphene magnetite phengitic muscovite carbonate calcite or dolomite apatite sulfide are 1 actinolite glaucophane chlorite garnet quartz 2 actinolite glaucophane chlorite albite garnet 3 actinolite glaucophane omphacite garnet 4 glaucophane chlorite garnet quartz 5 glaucophane omphacite quartz 6 albite glaucophane chlorite quartz and 7 albite paragonite chlorite quartz electron microprobe investigations show that plagioclase chlorite sphene white mica carbonate and magnetite grains are relatively homogeneous however amphibole pyroxene epidote and garnet grains are zoned indicating incomplete equilibration and changing physical conditions during metamorphism glaucophane in assemblage 6 has the general formula rim composition na 1 9 m4 ca 0 1 mg 1 8fe 1 2 2 al 1 0 vi fe 0 3 3 si 7 9 al 0 1 iv o 22 oh 2 glaucophane in assemblages 1 to 5 is somewhat poorer in the glaucophane endmember and richer in actinolite ca rich amphibole grains are zoned extensively with barroisite cores and actinolite rims omphacite grains in assemblages 3 and 5 have the general formula rim composition na 0 5 ca 0 5 mg 0 4 fe 0 1 2 al 0 4 vi fe 0 1 3 si 2o 6 in spite of the significant zoning the partitioning of elements among the minerals at their grain margins suggests that all seven assemblages above may coexist at the same physical conditions of metamorphism in mafic rocks with a relatively small range in bulk composition correlation of mineral compositions and assemblages with mineral stability data suggests high pressure facies series metamorphism at about 9 2 kb and 450 100 c with p h2o p total it is proposed that the metamorphism occurred during the ordovician

on the effect of sea drops on the atmospheric boundary layer 1 one of the possible mechanisms responsible for the reduction of the sea surface drag at high winds is explored the mechanism is based on the direct effect of sea drops as heavy particles on the turbulent mixing if assumed that sea drops are ejected upward from the sea surface no significant effect can be found a more realistic picture presumes that the spume drops resulting from a mechanical tearing of wave crests are ejected horizontally at altitudes of breaking crests a model of the spume drops generation is proposed the spume drops being torn off from breaking crests and sprayed inside the airflow significantly affect the surface drag at highest model wind speeds 60 80 m s the model actually predicts an effect of the slippery surface when the drag coefficient is reduced in about 10 times a comparison with available observations is given

mediterranean sea large scale low frequency ocean variability and water mass formation rates from 1987 to 2007 a retrospective analysis abstract we describe a synthesis of the mediterranean sea circulation structure and dynamics from a 23 year long reanalysis of the ocean circulation carried out by adani et al 2011 this mesoscale permitting dynamical reconstruction of past ocean variability in the mediterranean sea allows the study of the time mean circulation and its low frequency decadal components it is found that the time mean circulation is composed of boundary and open ocean intensified jets at the border of cyclonic and anticyclonic gyres the large scale basin circulation is generally characterized in the northern regions by cyclonic gyres and in its southern parts by anticyclonic gyres and eddy dominated flow fields with the exception of the tyrrhenian and the northern ionian sea the time mean tyrrhenian sea circulation is dominated by cyclonic gyres of different intensity and intermittency the northern ionian sea circulation however reverses in sign in two ten year periods the first in 1987 1996 and the second in 1997 2006 which is here called the northern ionian reversal phenomenon this reversal is provoked by the excursion of the atlantic ionian stream from the middle to the northern parts of the basin the decadal variability of other parts of the basin is characterized by changes in strength of the basin scale structures the water mass formation rates and variability are dominated by event like periods where the intermediate and deep waters are formed for 2 3 years at higher rates the largest deep water formation events of the past 23 years occurred separately in the western and eastern mediterranean basin the first coincided with the eastern mediterranean transient roether et al 1996 and the second with the western mediterranean deep water formation event in 2005 2006 smith et al 2008 a new schematic of the basin scale circulation is formulated and commented

garnet and staurolite producing reactions in a chlorite chloritoid schist during prograde metamorphism garnet and in some higher grade samples staurolite were produced in a chlorite chloritoid schist part of the precambrian z to cambrian hoosac formation near jamaica vt garnet grew during two prograde events separated by a retrogression this sequence resulted in distinctive inclusion textures and zoning anomalies in garnet produced by diffusive alteration textures reaction space analysis and mineral compositional variations constrain the possible sequence of reactions in these rocks below the staurolite isograd and to some unknown extent above it garnet grew by the reaction chloritoid chlorite quartz garnet h2o with increasing grade the mineral compositions are displaced towards lower mn fe and higher mg fe ratios the data are compatible with equilibrium with respect to exchange reactions for the matrix assemblages on a thin section scale and with minerals having closely followed equilibrium paths during reaction the staurolite isograd coincides with the reaction chloritoid quartz garnet staurolite chlorite h2o this reaction is continuous and trivariant with zno becoming an additional component concentrated in staurolite during this reaction both the mn fe and mg fe ratios of the phases appear to have decreased this new chemical trend is recorded by garnet zoning profiles and is compatible with trends predicted from phase diagrams thus there are two distinct types of garnet zoning reversals in these samples one is near the textural unconformity and is best explained by diffusive alteration during partial resorption of first stage garnet the other occurs near the outer rim of garnet in staurolite zone samples and marks the onset of a new prograde garnet producing reaction

soil pore characteristics of evergreen and deciduous forests of the tropical monsoon region in cambodia both evergreen and deciduous forests efs and dfs are widely distributed under similar climatic conditions in tropical monsoon regions to clarify the hydraulic properties of the soil matrix in different forest types and their effects on soil water storage capacity the soil pore characteristics spc were investigated in ef and df stands in three provinces in cambodia soils in the ef group were characterized in common by large amounts of coarse pores with moderate pore size distribution and the absence of an extremely low ks at shallow depths compared to df group soils the mean available water capacity of the soil matrix awcsm for all horizons of the ef and df group soils was 0 107 and 0 146 m3 m 3 respectively the mean coarse pore volume of the soil matrix cpvsm in the ef and df groups was 0 231 and 0 115 m3 m 3 respectively a water flow simulation using a lognormal distribution model for rain events in the early dry season indicated that variation in spc resulted in a larger increase in available soil water in ef soils than in df soils further study on deeper soil layers in ef and each soil type in df is necessary for the deeper understanding of the environmental conditions and the hydrological modelling of each forest ecosystem copyright 2010 john wiley sons ltd

effect of basin morphometric parameters on physically based rainfall thresholds for shallow landslides abstract the morphometric characteristics of a basin have a significant effect on landslide occurrence and can provide valuable information related to rainfall induced shallow landslides basin morphometric parameters e g average slope relief and melton ratio can be correlated to landslide triggering factors such as rainfall intensity and duration in this study the physically based model trigrs was used to determine rainfall intensity and duration i d thresholds for shallow landslides in 93 small basins in the colombian andes the results show highly variable thresholds even for basins in the same region that are very close together different morphometric parameters were calculated for each basin and their effect on the threshold power law curves characteristics was analysed the morphometric parameters with greater effect on the threshold position in the i d graph are mainly related to the slope gradient but other elements e g soil properties and basin area that are important to consider in a physically based methodology for defining rainfall thresholds are also described this analysis is useful for a better understanding of the factors affecting the threshold variability it could be significant in the subsequent validation of rainfall thresholds defined using this methodology and its implementation in a landslide early warning system in areas for which landslide inventories are not available

obtaining equilibrium oxygen isotope fractionations from rocks theory and examples a generalized approach for retrieving equilibrium isotope fractionations from natural rocks is proposed in which models of prograde reaction histories and retrograde diffusional exchange are used to identify coexisting minerals with similar isotope closure temperatures examples using literature data and new analyses from 32 natural amphibolite facies schists demonstrate both the feasibility and limitations of obtaining equilibrium oxygen isotope fractionations from minerals in natural rocks by screening samples according to the theoretical models natural data are shown to have highly consistent mineral fractionations 2 reproducibilities of 0 16 to 0 54 that within uncertainty reproduce experimental determinations among the minerals quartz biotite muscovite and calcic amphibole this correspondence indicates that the proposed theoretically based selection criteria improve the likelihood of measuring equilibrium fractionations the new data further corroborate the expected progressive enrichment of 18o in the orthosilicates with increasing al si relative to fe mg ky grt 1 05 st grt 0 6 and st cld 0 3 at 525 575 c in contrast typical samples that fail to satisfy screening criteria exhibit fractionations involving quartz biotite and amphibole that are strongly disequilibrium because of exchange during cooling theoretical screening of samples prior to isotope analysis allows robust independent assessment of theoretical and experimental determinations of equilibrium isotope fractionations

a synthesis of the ionian sea hydrography circulation and water mass pathways during poem phase i abstract in this paper we revisit with a thorough in depth analysis the dataset collected in the hydrographic surveys of the international collaborative programme poem physical oceanography of the eastern mediterranean in the period 1986 1987 the work has two major objectives the first is to refine the dynamic picture of the ionian upper thermocline sub basin scale circulation rather less definitive than the dynamic picture of the levantine sea circulation the second is to identify the pathways of the major water masses of the basin not only in the near surface but also in the intermediate and deep layers to our knowledge this is the first work defining the pathways of the levantine intermediate water liw and of the adriatic deep water adw eastern mediterranean deep water emdw that characterize the intermediate and deep circulations the major novel results can be summarized as follows in the upper thermocline 1 the atlantic ionian stream ais jet entering the sicily straits bifurcates into two main branches at 37 n 17 e it advects the modified atlantic water maw into the ionian sea interior the first branch turning directly southward encloses an overall anticyclonic area comprising multiple centers around which the maw is advected 2 the second ais branch extends further into the northeastern ionian where it too turns southward before crossing the entire ionian sea meridionally advecting maw on its left side and ionian surface water isw on its right this branch of the jet is confined to the ionian margin and does not pass around the pelops gyre 3 a new water mass the lsw is formed in the levantine basin and enters the cretan passage then is first veered cyclonically south of crete by the cretan gyre and successively is entrained anticyclonically around the pelops gyre and then enters the aegean sea 4 a permanent cyclone located in the northeastern ionian determines the pathway of mixed adriatic surface water ionian surface water asw isw 5 a permanent cyclone is found in all the surveys near the tip of the italian boot this novel analysis of the liw pathways shows that 1 the major source of intermediate liw during the period 1986 1987 was actually in the levantine sea liw formed there entered the cretan passage was veered cyclonically by the cretan gyre south of crete and then entered the southern ionian sea the major liw pathway was westward directly to the sicilian straits 2 secondary important liw pathways were determined by the interior structures the strong pelops anticyclone was entraining liw around its periphery and was determining the liw northward pathway that closely followed the eastern greek coastline it was along this pathway that liw entered the otranto strait a further branch of liw was entrained and recirculated around the multiple ionian anticyclones ia of the western ionian sea 3 the cretan cyclone is a feature confined to the upper thermocline intermediate layer it disappears at 400 dbar while the pelops anticyclone is strongly barotropic below the upper 100 dbar and penetrates quite intense down to 800 dbar 4 a further completely novel result concerns the new water mass found in the deep layer that spreads on the 29 15 kg m3 isopycnal surface this water mass characterized by high salinity and high oxygen content is formed inside the aegean sea and is observed to spread out all around the cretan arc straits the final fully novel result is the demonstration of a second pathway for the adw exiting from the otranto strait that is transformed into emdw and occupies the abyssal layers of the ionian sea interior the traditional pathway for emdw is along the isobaths along the western side of italy but adw was observed to be exiting from the otranto strait in the eastern hellenic trench at 39 5 n both during poem on86 and poem as87 this second pathway for emdw follows isobath contours along the western side of greece the two emdw routes converge and merge between 36 n and 35 n so producing a deep layer of emdw that occupies uniformly the abyssal plain of the interior of the ionian sea

distribution of ordovician and devonian metamorphism in mafic and pelitic schists from northern vermont 40 ar 39 ar range from 471 to 439 my and confirm that ordovician metamorphism is recorded from the canadian border south to the precambrian core of the green mountain anticlinorium gma medium high pressure p facies series metamorphism in the north and medium p metamorphism to the south similar metamorphic ages and compatible estimates of t and p indicate mafic and pelitic rocks were metamorphosed together medium p devonian metamorphism has overprinted the ordovician metamorphism in northern vermont east and probably west of the gma axis resulting in conventional k ar 40 ar 39 ar total fusion and plateau ages of 386 to 355 my on muscovite biotite and amphibole modified journal abstract

the metamorphic behaviour and petrogenetic significance of zinc in amphibolite facies staurolite bearing mica schists puolankajarvi formation central finland abstract whole rock analyses and mineral analyses were performed on 24 samples of mica schists from the early proterozoic puolankajarvi formation pjf the whole rock zn content 36 127 ppm mean 77 ppm was at the normal level for pelitic and crustal rocks staurolite being the only mineral phase to contain zinc in measurable amounts 0 0 1 33 wt zno mean 0 28 wt when staurolite was present it contained nearly all of the zinc of the rock the zn content does not vary between the rocks in which staurolite has never been generated those in which staurolite is present and those from which staurolite has been destroyed this suggests that despite the fact that staurolite is a very strong acceptor of zn the generation of staurolite under reducing conditions log f o 2 22 5 t 545 c p 3 7 kbar did not increase the content of zn in the whole rock neither did the destruction of staurolite under more oxidizing conditions log f o 2 22 2 21 0 t 500 520 c p 2 1 3 5 kbar reduce it because there is evidence of considerable fluid flow through the rock during certain stages of the metamorphism of the pjf it is concluded that zn is an immobile element in amphibolite facies metamorphism in petites zinc should be treated as an additional component in metamorphic reactions of staurolite which increases the degrees of freedom of these reactions because of the immobility of zn and the increase in degrees of freedom these reactions will become dependent upon the concentration of zn in the rock

transient eastern mediterranean deep waters in response to the massive dense water output of the aegean sea in the 1990s abstract we present a detailed account of the changing hydrography and the large scale circulation of the deep waters of the eastern mediterranean emed that resulted from the unique high volume influx of dense waters from the aegean sea during the 1990s and of the changes within the aegean that initiated the event the so called eastern mediterranean transient emt the analysis uses repeated hydrographic and transient tracer surveys of the emed in 1987 1991 1995 1999 and 2001 2002 hydrographic time series in the southern aegean and southern adriatic seas and further scattered data aegean outflow averaged nearly 3 10 6 m 3 s 1 between mid 1992 and late 1994 and was largest during 1993 when south and west of crete aegean influenced deep waters extended upwards to 400 m depth emt related aegean outflow prior to 1992 confined to the region around crete and to 1800 m depth wise amounted to about 3 of the total outflow outflow after 1994 up to 2001 2002 derived from the increasing inventory of the tracer cfc 12 contributed 20 to the total of 2 8 10 14 m 3 densities in the southern aegean sea deep waters rose by 0 2 kg m 3 between 1987 and 1993 and decreased more slowly thereafter the aegean waters delivered via the principal exit pathway in kasos strait east of crete propagated westward along the cretan slope such that in 1995 the highest densities were observed in the hellenic trench west of crete aegean influenced waters also crossed the east mediterranean ridge south of crete and from there expanded eastward into the southeastern levantine sea transfer into the ionian mostly followed the hellenic trench largely up to the trench s northern end at about 37 n from there the waters spread further west while mixing with the resident waters additional transfer occurred through the herodotus trough in the south levantine waters after 1994 consistently showed temperature salinity t s inversions in roughly 1000 1700 m depth with amplitudes decreasing in time the t s distributions in the ionian sea were more diverse one cause being added aegean outflow of relatively lower density through the antikithira strait west of crete spreading of the aegean influenced waters was quite swift such that by early 1995 the entire emed was affected and strong mixing is indicated by near linear t s relationships observed in various places referenced to 2000 and 3000 dbar the highest aegean generated densities observed during the event equaled those generated by adriatic sea outflow in the northern ionian sea prior to the emt a precarious balance between the two dense water source areas is thus indicated a feedback is proposed which helped triggering the change from a dominating adriatic source to the aegean source but at the same time supported the previous long year dominance of the adriatic the emed deep waters will remain transient for decades to come

prograde reactions and garnet zoning reversals in staurolite schist british columbia significance for thermobarometric interpretations an outcrop of staurolite bearing pelitic schist from the solitude range in the south western rocky mountains british columbia was examined in order to determine the nature of prograde garnet and staurolite producing reactions using information from garnet zoning and inclusion mineralogy although not present as a matrix phase chloritoid is present as inclusions in garnet and is interpreted to have participated in the simultaneous growth of garnet and staurolite by a reaction such as chloritoid quartz garnet staurolite h2o a garnet zoning trend reversal which is most pronounced with respect to almandine and grossular components is present in the outer core of garnets the location of the zoning reversal corresponds to the outer limit of chloritoid inclusions in garnet as there is no evidence for polymetamorphism the zoning reversal is interpreted to indicate continued garnet growth by prograde reaction s during a single metamorphic event after the exhaustion of chloritoid as a matrix phase metamorphic conditions recorded by mineral rim compositions are 550 600 c at 6 7 kbar because there is no evidence for partial resorption of garnet during production of staurolite we interpret these results to represent peak conditions

garnet chloritoid equilibria in eclogitic pelitic rocks from the sesia zone western alps their bearing on phase relations in high pressure metapelites abstract a detailed study of garnet chloritoid micaschists fom the sesia zone western alps is used to constrain phase relations in high pressure hp metapelitic rocks in addition to quartz phengite paragonite and rutile the micaschists display two distinct parageneses namely garnet chloritoid chlorite and garnet chloritoid kyanite talc has never been observed garnet and chloritoid are more magnesian when chlorite is present instead of kyanite the distinction of the two equilibria results from different bulk rock chemistries not from p t conditions or redox state estimated p t conditions for the eclogitic metamorphism are 550 600 c 15 18 kbar the presence of primary chlorite in association with garnet and chloritoid leads us to construct two possible afm topologies for the sesia metapelites the paper describes a kfmash multisystem for hp pelitic rocks which extends the grid of harte hudson 1979 towards higher pressures and adds the phase talc observed parageneses in hp metapelites are consistent with predicted phase relations critical associations are gt ctd chl and gt ctd ky at relatively low temperatures and gl chl ky and gt tc ky at relatively high temperatures

40ar 39ar and k ar data bearing on the metamorphic and tectonic history of western new england 40ar 39ar ages of coexisting biotite and hornblende from proterozoic y gneisses of the berkshire and green mountain massifs as well as 40ar 39ar and k ar mineral and whole rock ages from paleozoic metamorphic rocks suggest that the thermal peak for the dominant metamorphic recrystallization in western new england occurred 465 5 m y ago taconian although textural data indicate a complex metamorphic tectonic history for paleozoic rocks no evidence in rocks at least as high as kyanite grade dictates an acadian age for the barrovian metamorphism available 40ar 39ar and k ar data suggest that the low grade metamorphism and cleavage formation in taconic allochthons and the higher grade metamorphism and emplacement of the berkshire massif allochthon are taconian 40ar 39ar age data from a poorly defined terrane beginning near the east margin of the green mountain massif and extending along the eastern one third of the berkshire massif as far south as otis massachusetts suggest that the area has been retrograded during a metamorphism that peaked at least 376 5 m y ago acadian available age and petrologic data from western new england indicate the presence of at least three separate metamorphic structural domains of taconian age 1 a small area of relict high pressure and low temperature metamorphism in northern vermont t 1 domain 2 a broad area in vermont and eastern new york of normal barrovian metamorphism from chlorite to garnet grade and characterized by a gentle metamorphic gradient t 2 domain and 3 a rather narrow belt of steep gradient barrovian series metamorphic rocks extending from near the cortlandt complex northeastward through dutchess county new york to the berkshire massif in western massachusetts t 3 domain areas of maximum metamorphic intensity within the t 3 domain coincide with areas of maximum crustal thickening resulting from imbricate thrusting berkshire massif or from recumbent folding manhattan prong of remobilized north american continental crust in the later stages of the taconic orogeny

a 130 000 year record of levantine intermediate water flow variability in the corsica trough western mediterranean sea abstract sortable silt particle size data and stable isotope analyses from the corsica trough western mediterranean sea provide a continuous palaeoceanographic record of the inflow ventilation and vertical fluctuations of the levantine intermediate water liw in the northern tyrrhenian sea for the last 130 000 years the results presented herein reveal that climate changes drive the mediterranean intermediate circulation on milankovitch to millennial time scales intensified intermediate inflow and ventilation in the corsica trough occurred throughout the last glacial interval with a cold faster warm slower pattern existing between the dansgaard oeschger climatic oscillations including heinrich events and the liw variability by contrast a weak intermediate ventilation characterised the holocene and the last interglacial period especially during insolation maxima and the sapropel deposition in the eastern mediterranean this variability probably reflects the changes of the eastern mediterranean net evaporation as well as the propagation to the western mediterranean of the profound hydrographic adjustments of the levantine sea and adjacent areas to climate forcing the implications for the formation and ventilation of the western mediterranean deep water wmdw in the northwestern mediterranean basin as well as for mediterranean atlantic exchange through the strait of gibraltar are discussed

a thermal tectonic model for high pressure metamorphism and deformation in the sesia zone western alps the sesia zone western alps is a slice of austroalpine continental crust that was once metamorphosed at t 500 560 c and p 14 16 kbar at 130 100 ma b p pervasive blueschist eclogite facies assemblages record this event and a later greenschist facies overprint is only well developed in the nw part of the zone on the basis of thermal calculations it is difficult to explain the preservation of high pressure assemblages in a simple model of underthrusting and subsequent uplift erosion an alternative model is proposed in which the sesia zone was emplaced by underthrusting of the austroalpine continental margin prior to subduction of oceanic lithosphere of the piemonte basin subduction of relatively cool oceanic lithosphere below the underthrust sesia zone then continued for a period of time e g 20 ma thus suppressing thermal recovery of this latter unit exhumation of sesia zone rocks began during this subduction episode by uplift on the insubric line erosion and by underplating of oceanic

deformation and metamorphism on the east side of the green mountain massif in southern vermont an early deformation in the jamaica vermont area on the east side of the green mountain massif produced kilometre scale north plunging f1 folds overturned to the west with an axial planar foliation s1 motion on two major thrust faults juxtaposed three similar but distinctive cover rock sequences after or late in f1 folding smaller scale f2 folds deformed f1 fold limbs and the thrust faults and have an axial planar crenulation cleavage s2 in the structurally higher central and eastern cover rock sequences an early stage of garnet growth began late in s1 development or after it a retrogression partially resorbed first stage garnet and was followed by a second prograde stage of garnet growth late in or after s2 development this metamorphic history resulted in distinctive textural unconformities and zoning anomalies in garnet the western cover rock sequence lacks evidence for a major retrogression f1 folding and f2 folding approximately bracket both the motion on the thrust faults and the retrogression the second prograde metamorphism and the younger deformation are acadian tentative correlation of the first garnet growth stage with ordovician metamorphism recognized in western new england and of motion on the thrust faults with taconian synmetamorphic thrusts in the region suggests that these early thermal and tectonic events occurred in the ordovician the retrogression recorded in the central and eastern cover sequences furthermore may reflect thrusting of these rocks to a structurally higher colder environment followed by reburial and later prograde metamorphism

variability in the vertical structure of the water column and paleoproductivity reconstruction in the central western mediterranean during the late pleistocene abstract a sedimentary sequence spanning marine isotope stage mis 6 to mis 2 in core lc07 recovered in the central mediterranean has been investigated in order to produce a high resolution paleoceanographic reconstruction the changes in productivity deduced from calcareous plankton relative abundances and independently confirmed by the ba xs fluctuations are linked to the stability of the water column which is mainly controlled by the water mass temperature during glacial intervals productivity was generally enhanced oligotrophic and warmer water masses with a deepened seasonal thermocline can be inferred for most of mis5 the magnetic properties of the sediment show increased occurrences of north africa dust in the central mediterranean during cold phases likely as a consequence of a more efficient erosive process triggered by southward displacement of the intertropical convergence zone although increases in both productivity and saharan dust occurred during cold periods the atmospheric inputs do not seem to contribute significantly to the fertilization of primary producers a shannon index curve has been used to tentatively synthesize the variations of calcareous nannofossil assemblages through the last 150 kyr the assemblage diversity sharply increased coincident with the transition from the penultimate glacial to the last interglacial subsequently low diversity was gradually reached again in the last glacial

li rich zincostaurolite and its decompression related breakdown products in a diaspore bearing metabauxite from east samos greece an emp and sims study li h rich zincostaurolite locally formed at a metabauxite marble contact along the eastern coast of samos during early alpine high p low t metamorphism the staurolite which probably grew from gahnite cookeite kaolinite pyrophyllite diaspore and minor fe oxide occurs as prismatic crystals up to several mm long in a calcite matrix it has an unusual composition with 7 5 12 9 wt zno 1 0 4 9 wt feo 0 66 0 82 wt li 2 o up to 2 6 wt nio and 0 59 wt coo and 0 32 wt mgo calculated structural formulae point to high h 2 o contents 4 14 h atoms per 48 oxygen atoms during late alpine uplift of the samos rocks the staurolite was at greenschist facies conditions variably replaced by bluish cobaltoan gahnite x zn 0 82 white na ca li mica ni rich chlorite x ni 0 42 0 59 zincohogbomite x zn 0 68 0 80 diaspore and fe hydr oxide detailed emp work and determination of li in staurolite and mica by sims indicates systematic zn fe mg ni co li partitioning between staurolite and its decomposition products implying local scale chemical equilibrium balanced reaction equations based on mineral chemical data indicate that the breakdown of staurolite occurred largely isochemically with only introduction of water na and ca into the reacting system the breakdown of high p staurolite during uplift and decompression is thought to be related to the sensitivity of its complex crystal chemistry to changes in physico chemical conditions

coastal sea level trends from topex poseidon satellite altimetry and tide gauge data in the mediterranean sea during the 1990s a joint analysis of topex poseidon satellite altimetry and tide gauge data is used to estimate sea level trends along the mediterranean sea coast from 1993 january to 2002 february a generalized least squares gls method allows us to take into account the space time distribution of the data and their respective error budgets nearly optimal parameters of the covariance functions involved in the gls method are estimated at different scales of analysis using a trial and error method combined data time series are then reconstructed at 153 locations along the coast the basin wide averaged linear trend for the coastal area shows a sea level rise of 4 54 0 30 mm yr 1 compared to 4 28 0 30 mm yr 1 for the open ocean only i e a 0 26 0 16 mm yr 1 difference the error is smaller because the systematic error does not take part in the error budget which is quite significant at local scales the coastal linear trends ranges from 8 5 to 13 5 mm yr 1 which is much narrower than ranges found by other open sea studies 24 0 to 10 0 16 0 to 29 0 mm yr 1 however a detailed error budget shows that the largest estimation errors come from the spatial extrapolation of the sea level signal required when tide gauge and altimeter data are merged the second error source is the instrumental noise and the random noise generated by the littoral contamination on altimeter measurements and from the crustal motions that are contaminating the tide gauge signal at local scale it is estimated that 85 percent of the error on linear trends does not exceed 2 mm yr 1

impact of the spatial distribution of the atmospheric forcing on water mass formation in the mediterranean sea the impact of the atmospheric forcing on the winter ocean convection in the mediterranean sea was studied with a high resolution ocean general circulation model the major areas of focus are the levantine basin the aegean cretan sea the adriatic sea and the gulf of lion two companion simulations differing by the horizontal resolution of the atmospheric forcing were compared the first simulation med16 era40 was forced by air sea fields from era40 which is the ecmwf reanalysis the second simulation med16 ecmwf was forced by the ecmwf analyzed surface fields that have a horizontal resolution twice as high as those of era40 the analysis of the standard deviations of the atmospheric fields shows that increasing the resolution of the atmospheric forcing leads in all regions to a better channeling of the winds by mountains and to the generation of atmospheric mesoscale patterns comparing the companion ocean simulation results with available observations in the adriatic sea and in the gulf of lion shows that med16 ecmwf is more realistic than med16 era40 in the eastern mediterranean although deep water formation occurs in the two experiments the depth reached by the convection is deeper in med16 ecmwf in the gulf of lion deep water formation occurs only in med16 ecmwf this larger sensitivity of the western mediterranean convection to the forcing resolution is investigated by running a set of sensitivity experiments to analyze the impact of different time space resolutions of the forcing on the intense winter convection event in winter 1998 1999 the sensitivity to the forcing appears to be mainly related to the effect of wind channeling by the land orography which can only be reproduced in atmospheric models of sufficient resolution thus well positioned patterns of enhanced wind stress and ocean surface heat loss are able to maintain a vigorous gyre circulation favoring efficient preconditioning of the area at the beginning of winter and to drive realistic buoyancy loss and mixing responsible for strong convection at the end of winter

climatic changes in the aegean sea influence the eastern mediterranean thermohaline circulation 1986 1997 recent changes of water mass characteristics in the south aegean sea have considerably influenced the eastern mediterranean thermohaline circulation a combination of salinity increase 1987 92 and temperature drop 1992 94 caused massive dense water formation and strong outflow towards the deep and bottom parts of the eastern mediterranean this climatic shift the most important since the existence of observations in the basin is a combined effect of extreme meteorological events superimposed on large scale trends it has initiated a series of modifications in the hydrology and dynamics of the entire eastern mediterranean with possible influence on the mediterranean outflow in the north atlantic ocean