long lived mesoscale eddies in the eastern mediterranean sea analysis of 20 years of aviso geostrophic velocities we analyzed 20 years of aviso data set to detect and characterize long lived eddies which stay coherent more than 6 months in the eastern mediterranean sea in order to process the coarse gridded 1 8 aviso geostrophic velocity fields we optimized a geometrical eddy detection algorithm our main contribution was to implement a new procedure based on the computation of the local and normalized angular momentum lnam to identify the positions of the eddy centers and to follow their lagrangian tra jectories we verify on two mesoscale anticyclones sampled during the egypt campaign in 2006 that our methodology provides a correct estimation of the eddy centers and their characteristic radius corresponding to the maximal tangential velocity our analysis reveals the dominance of anticyclones among the long lived eddies this cyclone anticyclone asymmetry appears to be much more pronounced in eastern mediter ranean sea than in the global ocean then we focus our study on the formation areas of long lived eddies we confirm that the generations of the ierapetra and the pelops anticyclones are recurrent and correlated to the etesian wind forcing we also provide some evidence that the smaller cyclonic eddies formed at the southwest of crete may also be induced by the same wind forcing on the other hand the generation of long lived eddies along the libyo egyptian coast are not correlated to the local wind stress curl but surprisingly their initial formation points follow the herodotus trough bathymetry moreover we identify a new formation area not discussed before along the curved shelf off benghazi

a view of the lower crustal component of hydrothermal systems at the mid atlantic ridge an extensive suite of hydrothermally altered gabbros was recovered by alvin and dredging from the mid atlantic ridge in the vicinity of the eastern ridge transform intersection rti of the kane fracture zone mark where tectonic extension has provided a window into the lower crustal component of hydrothermal cells four alteration types are distinguished on the basis of metamorphic assemblage mineral composition and deformation textures a conceptual model is presented that places temperature fluid rock ratio relationships in conjunction with styles of deformation into a spatial and temporal framework exsolution of late stage magmatic fluids in the vicinity of the magma hydrothermal interface at temperatures 700 c marks the onset of fluid rock interaction in the mark gabbros kelley et al this issue with subsequent alteration involving seawater derived fluids being strongly influenced by deformation mechanisms in zones of ductile shear hydration was initiated at temperatures between 550 and 700 c and moderate fluid rock ratios elsewhere in the lower crust the onset of seawater penetration occurred at temperatures of 400 550 c and was facilitated by brittle fracturing early vein networks indicate very low initial fluid rock ratios and are interpreted as being related to the solidification of plutons later fractures indicate higher water rock ratios and may be related to the downward propagation of shallow fault systems throughout the crust fluid rock interaction ceased at temperatures 180 300 c subsequent cataclastic deformation associated with the unroofing and emplacement of crustal blocks in the rti massif produced moderate fluid rock ratios within localized zones hydrothermal alteration in the crustal section exposed at mark was initiated at lower temperatures and water rock interaction proceeded to lower temperatures than many other plutonic suites these differences must reflect the temporal and spatial evolution of magmatic and tectonic extension that is particular to each section of sampled crust

water masses and hydrography during april and june 2016 in the cretan sea and cretan passage eastern mediterranean sea abstract two successive cruises in the cretan sea and cretan passage west levantine basin during april and june 2016 surveyed the physical characteristics of the water masses in these large eastern mediterranean basins data confirm that the hydrographical status is far different from that of the eastern mediterranean transient emt period however the basins have not yet returned to the pre emt status in the cretan sea intermediate water masses of both cretan and levantine origins are detected the stagnating bottom waters of this basin still hold high salinity density and dissolved oxygen values remnant of the emt deep water formation episodes characterised by low salinity and oxygen values transitional waters of mediterranean origin are present between intermediate and bottom layers throughout the cretan sea intermittent weak outflow of warm and saline masses of cretan origin towards the eastern mediterranean is observed at the bottom of both east and west cretan straits in the cretan passage there is no sign of the ierapetra anticyclonic gyre possibly related to the seasonality of the gyre or linked to larger scale eastern mediterranean circulation variability the observed surface circulation in this area is comprised of a series of smaller gyres between the cretan cyclone and the rhodes gyre the bottom waters of the cretan passage present a west to east gradient of increasing salinity and decreasing oxygen related to the propagation of new adriatic deep water from the ionian sea towards the levantine basin

depositional versus ecological control on the conodont distribution in the lower frasnian fore reef facies holy cross mountains poland abstract lithofacies and conodont biofacies of reef slope deposits of the wietrznia beds lower frasnian palmatolepis transitans zone were studied in three measured sections at the wietrznia quarry holy cross mts poland the diverse reef derived grained deposits interrupted the background sedimentation that included lime mudstones deposited largely at 50 to 90 m depths in oxygen depleted middle slope to toe of slope settings the mainly storm controlled proximal gradient is laterally marked by gradual changes from coarse grained tempestites represented by flat pebble conglomerate fabric to diluted muddy tempestites the mostly sparse polygnathid and mesotaxid polygnathid biofacies characterize the hemipelagic facies whilst polygnathid ancyrodellid biofacies dominates in the event layers three step taphofacies scheme is proposed distinguishing settled parautochthonous residual winnowed and displaced settled from waning currents and or transported in sediment gravity flows conodont element accumulations the primary ecological signals are still partly preserved in most of the tempestite derived assemblages indicating scarcity of truly residual lag like taphofacies the hydraulic sorting was most effective in the middle slope setting affected by unidirectional and or oscillatory flows syndepositional mixing was strengthened upslope by an importation of off reef mesotaxid faunas due to storm surge onto the reef this reworking pattern as a key factor in biofacies interpretation may be applicable only on a local scale however similarly biased conodont signature is probably common in other hurricane affected carbonate complexes even if without a disrupting impact on major biofacies belts

surface circulation of the eastern mediterranean levantine basin insights from analyzing 14 years of satellite altimetry data 1 the complex multiscale system circulation of the levantine eastern mediterranean em basin is analyzed by applying various spatiotemporal statistical methods on the aviso 14 years 1993 2006 data set of satellite altimetry sea level anomalies the rossby deformation radius at the em is at the order of 10 km which is also the horizontal satellite resolution therefore the geostrophic currents derived from the satellite altimetry measurements represent well the basin and the mesoscale circulations the long term averaged mean dynamic topography mdt is found to capture the different eddy activity regions in the em however these regions are highly turbulent the instantaneous currents in these regions can be different from the mdt derived currents by the same order of magnitude furthermore the turbulence intensity appears to be nonperiodic despite of the seasonal and long term steric periodic variability because these eddies interact with the basin circulation flow they modify it continuously the major exception of this sporadic behavior is the ierapetra eddy southeast of crete it appears to be forced by shear of the summer etesian winds created when the crete mountain ridges block these winds and cause a funneling effect it has a persistent seasonal signature that dominates the variance of the entire levantine basin

compositions and phase relations of calcic amphiboles in epidote and clinopyroxene bearing rocks of the amphibolite and lower granulite facies central massachusetts usa calcic amphiboles coexisting with epidotegroup minerals zoisite clinozoisite epidote and or clinopyroxene plagioclase quartz garnet occur in amphibolites and calc silicate rocks that underwent amphibolite to lower granulite facies metamorphism in the acadian metamorphic high of central massachusetts usa across the region peak metamorphic conditions range from about 580 c and 6 2 kbar to 730 c and 6 3 kbar the coexistence of most ca amphiboles with fe3 rich epidote group minerals suggests the presence of fe3 in most of these amphiboles an empirical fe3 estimation for the microprobe analyses is based on two constraints the na ca content of the m4 sites of ca saturated gravimetrically analyzed hornblendes gives the relation ca m4 c 1 479 na m4 c 2 c corrected the second constraint is the stoichiometric equation ca m4 na m4 fm 15 where fm is the sum of all cations exclusive of ca na and k solving the two equations simultaneously gives 20 185 0 479 ca m4 1 479 fm starting with the uncorrected values of ca m4 u and fm m4 u u uncorrected of the all ferrous formula the normalization factor nf for calculating the corrected cations of the ferric formulas is 20 185 0 478 ca m4 u 1 479 fm u from the deficient oxygen the fe3 content which is equal to 2 23 ox can be calculated determinations of fe3 contents of four hornblende separates by mossbauer spectroscopy are in agreement with the calculated values the ca amphiboles show systematic changes in composition with increasing grade of metamorphism within the amphibolite and lower granulite facies zones increasing edenite and tschermakite substitution increasing ti content and increasing fe2 fe2 mg ratio in addition the coexisting clinopyroxenes are also characterized by an increase in fe2 fe2 mg ratio in quartz free rocks with coexisting ca amphibole and plagioclase there is an increase in the ratio x ab x ed where x ab na na ca in plagioclase and x ed na in the amphibole a site these chemical changes in mineral composition together with the disappearance of epidote at the transition to granulite facies metamorphic conditions are attributed to the continuous reaction albite epidote fe mg hornblende fe mg clinopyroxene anorthite naalsi 1 hbl h2o

water fluxes through the cretan arc straits eastern mediterranean sea march 1994 to june 1995 abstract five research cruises were undertaken incorporating adcp sections along the cretan arc straits and ctd surveys covering the entire area of the straits and the cretan sea in addition six moorings with 15 current meters were deployed within the straits which monitored flows in the surface 50 m intermediate 250 m and deep 50 m from the bottom layers the adcp cm and ctd datasets enable the derivation of water transports through the cretan arc straits to be assessed flow structure through the cretan arc straits is not the typical flow regime with a surface inflow and deep outflow instead there is a persistent deep outflow of cretan deep water cdw 29 2 with an annual mean of 0 6 sv through the antikithira and kassos straits at depths below 400 m and 500 m respectively cdw outflowing transports are higher 0 8 sv in april june and lower 0 3 sv in october december within the upper water layer 0 400 m the transport and the water exchanges through the straits are controlled by local circulation features which weaken substantially below 200 m the asia minor current amc influences the rhodes and the karpathos straits resulting in a net inflow of water in contrast the mirtoan west cretan cyclone influences the antikithira and kithira straits where there is a net outflow in the kassos strait there is a complex interaction between the east cretan cyclone the ierapetra anticyclone and the westward extension of the rhodes gyre which results in a variable flow regime there is a net inflow in autumn and early winter and a switch to a net outflow in early spring and summer the total inflow and outflow throughout all of the straits ranged from 2 to 3 5 sv with higher values in autumn and early winter and lower in summer the amc carries 2 sv of inflow through the rhodes and karpathos straits and this accounts for 60 80 of the total inflow about 10 15 of the total outflow is of cdw and a further 45 70 occurs through the upper 400 m of the kithira and antikithira straits the kassos strait exhibits a net inflow of 0 7 sv in autumn and early winter with a net outflow of 0 5 sv in early spring and summer

recent changes in deep water formation and spreading in the eastern mediterranean sea a review abstract observations of the last decade testify that the characteristics of the deep thermohaline circulation in the eastern mediterranean sea have changed thoroughly the source of the most dense waters of the basin has moved from the adriatic to the aegean sea this new source has proved to be very efficient since the estimated formation rate for the period 1989 95 was more than 1 sv about three times more than the dense water formation rate of the adriatic sea these new waters with hydrological characteristics that are warmer and more saline have replaced almost 20 of the older deep waters of the basin and have uplifted the deep isopycnals by about 500 m this major event can be attributed to important meteorological anomalies in the eastern mediterranean and to changes of circulation patterns the extended dry period of 1988 93 and the exceptionally cold winters of 1987 and 1992 93 created favorable conditions for increased formation of dense water in the aegean furthermore changes in the circulation patterns in the intermediate water range levantine intermediate water liw and cretan intermediate water themselves possibly linked to meteorological anomalies appear to have played an important role in the redistribution of salt as a result of an interruption to exchanges between the ionian and levantine basin the salinities in the latter started to rise high salinity waters were diverted into the aegean malanotte rizzoli p manca b b ribera dacala m theocharis a 1998 the eastern mediterranean in the 80s and in the 90s the big transition emerged from the poem bc observational evidence rapport du commission international de la mer medittanee 35 174 175 and the westward transport of liw was reduced an additional effect of the deep water discharge from the aegean and the resulting uplifting of mid depth waters was to lower salinities in the liw layer this effect is most strongly felt in the ionian sea a 3 d primitive equation numerical model for the eastern mediterranean with a 20 km grid size is used to simulate the observed changes and understand the basic mechanisms which caused them under appropriate atmospheric forcing the model successfully reproduces the main characteristics of the transient these results indicate that the observed changes can be at least partially explained as a response of the eastern mediterranean and more specifically of the aegean to atmospheric forcing variability

mid ir bands of synthetic calcic amphiboles of tremolite pargasite series and of natural calcic amphiboles mid ir spectra 4000 400 cm 1 of synthetic calcic amphiboles in the tremolite pargasite series and of various natural calcic amphiboles have been investigated the pargasite substitution a combination of the tschermak 4 al 6 al 6 mg 1 4 si 1 and edenite 4 al a na 4 si 1 a 1 substitutions causes the following features in the region 1200 600 cm 1 1 weak 4 al o stretching bands appear at 895 and 815 cm 1 that are distinct from the 955 and 925 cm 1 si o stretching bands in tremolite 2 there is a reduction in the intensity and frequency of the si o si symmetric bending band chain breathing mode at 750 cm 1 in tremolite and there is an appearance of medium strong composite bands having a weak shoulder on the high frequency side near 690 cm 1 these bands are assigned to si o al deformation bands 3 two oh libration bands at 690 and 650 cm 1 become weak and broad composite bands from 720 to 610 cm 1 and 4 because the intensity and frequency of the band at 640 cm 1 in tremolite is affected neither by deuteration nor by the pargasite substitution this band is ascribed to o t2 si o bending even in pargasite most t2 sites are occupied by si so that the o2 t2 si o4 bending mode will be dominant in this amphibole the same behavior occurs for the synthetic fluorogallian tremolite pargasite series but with larger downward frequency shifts ga o stretching bands appear at 880 and 780 cm 1 and an si o ga bending band appears at 605 cm 1 the major t o t and o t o deformation bands in synthetic amphiboles are readily apparent in natural calcic amphiboles whose compositions are near the tremolite pargasite join

planar defects as ar traps in trioctahedral micas a mechanism for increased ar retentivity in phlogopite abstract the effects of planar defects and composition on ar mobility in trioctahedral micas have been investigated in samples from a small marble outcrop 500 m2 in the frontenac terrane grenville province ontario these micas crystallized during amphibolite facies metamorphism at 1170 ma and experienced a thermal pulse 100 ma later at shallow crustal levels associated with the emplacement of plutons 87rb 86sr ages of the phlogopites range from 950 to 1050 ma consistent with resetting during the later thermal event the same phlogopites however give 40ar 39ar ages between 950 and 1160 ma spanning the age range of the two thermal events this result is intriguing because these micas have undergone the same thermal history and were not deformed after peak metamorphic conditions in order to understand this phenomenon the chemical crystallographical and microstructural nature of four mica samples has been characterized in detail using a wide range of analytical techniques the scanning electron microscope sem electron microprobe emp and laser ablation inductively coupled plasma mass spectrometry la icp ms data show that the micas are chemically homogeneous with the exception of ba and similar in composition the fourier transform infrared spectroscopy and mossbauer results show that the m sites for three of the micas are dominated by divalent cations and the fe3 fe2 fe3 ratio for all four phlogopites ranges from 0 10 to 0 25 the stable isotopic data for calcite indicate that this outcrop was not affected by hydrothermal fluids after peak metamorphism no correlation between chemical composition and 87rb 86sr and 40ar 39ar age or between crystal size and 40ar 39ar age is observed the only major difference among all of the micas was revealed through transmitted electron microscope tem which shows that the older 1m micas contain significantly more layer stacking defects associated with crystallization than the younger micas we propose that these defect structures which are enclosed entirely within the mineral grain may serve as ar traps and effectively increase the ar retentivity of the mineral as this phenomenon has not been previously documented in micas this may have significant implications for the interpretation of 40ar 39ar ages of minerals which have similar defect structures

tectonometamorphic evolution of the chuncheon amphibolite central gyeonggi massif south korea the chuncheon amphibolite part of the gubongsan group which overlies the yongduri gneiss complex is interlayered with calc silicate rock marble quartzite biotite schist and quartzofeldspathic gneiss in the central gyeonggi massif south korea metamorphic pressures and temperatures estimated from the amphibolite are 5 5 10 6 kbar and 615 714 c these p t conditions are close to those defined by the reaction curve between kyanite and sillimanite and suggest medium pressure type metamorphism of the chuncheon amphibolite for two metapelites intercalated with the amphibolite temperatures are estimated to be 607 699 c consistent with those obtained from the amphibolite on the other hand pressures estimated from these metapelites are significantly different 4 6 kbar and 9 13 kbar when rim and core compositions of garnet are respectively used these p t estimates obtained from the amphibolite and metapelite suggest a nearly isothermal decompression of 3 7 kbar during denudation rapid decompression is likely on the basis of the results of mineral chemistry phase equilibria and geothermobarometer moreover in conjunction with the occurrence of kyanite in the adjacent gyeonggi gneiss complex p t estimates of the chuncheon amphibolite and metapelite suggest a clockwise p t t path this evolutionary path may be related to the amalgamation of continents during the late proterozoic event which corresponds to the jinningian orogeny in the qinling belt of china

hydrothermal synthesis of amphiboles along the tremolite pargasite join and in the ternary system tremolite pargasite cummingtonite we report here an investigation of amphibole synthesis within the ternary system ca 2mg5si8o22 oh 2naca2mg4al3si6o22 oh 2 mg7si8o22 oh 2 tr pg mc to define better the limits of solid solution for amphiboles formed along and near the join tremolite pargasite hydrothermal syntheses were conducted in the range of 750 1000 c and 1 6 kbar syntheses at 10 mol compositional intervals along the tr pg join produced incomplete yields of amphibole and the resultant amphiboles were found to be associated with varying amounts of accessory clinopyroxene plagioclase and gehlenite syntheses of end member pargasite with progressively greater amounts of the mc component produced a very good amphibole yield for a pargasite composition containing 2 5 mol mc the persistence of clinopyroxene or gehlenite and the improved yield of pargasitic amphibole with minor addition of the mc component indicate a shift toward mc enrichment for amphiboles made from bulk compositions directly on the tr pg join syntheses within the tr pg mc ternary system suggest that the ca rich limit of solid solution is a slightly curved field in the tr pg mc field amphiboles made along this join showed a very systematic change in the 151 and 3 31 peak spacing with mol pg providing a simple technique for deducing the composition of amphiboles made near the tremolite pargasite join electron microprobe analysis confirms that the amphiboles for the most part conform to the pargasite substitution the one exception being amphiboles formed near 80 90 mol pg compositions which proved both difficult to synthesize 75 wt amphibole yield and displayed a small but significant excess of na in their structure high yields of amphibole could be formed from this same bulk composition with the use of a dilute naoh solution instead of pure water suggesting that there was insufficient na in the starting mixture to allow complete amphibole formation structural refinements using x ray diffraction xrd rietveld refinement confirmed the high na content for this sample and also revealed a non linear trend in the unit cell volume with composition with a maximum at the 80 mol pg bulk composition the difficulty in synthesizing amphiboles near this bulk composition and its unusually high volume suggest that immiscibility in natural hornblendes may initiate with increasing pressure for pargasite rich bulk compositions

a petrochemical study of calcic amphiboles from the east bull lake anorthosite gabbro layered complex district of algoma ontario calcic amphiboles are ubiquitous in the east bull lake anorthosite gabbro complex northeastern ontario the mode of occurrence suggests the amphiboles replaced clinopyroxene throughout the stratigraphic levels of the pluton but they are also prolific in the top younger units three types of amphiboles namely 1 tremolite actinolite 2 actinolitic hornblende and 3 hornblende were identified the composition of the amphiboles shows that they define a continuous series without any obvious compositional miscibility gap the analyses further indicated that the amphiboles evolved from actinolite to hornblende through coupled substitution involving edenite and tschermakite end members among the three coexisting amphiboles chlorine is concentrated in hornblende this is due to preferential location of hornblende along grain boundaries and or its favourable structure

dense intermediate water outflow from the cretan sea a salinity driven recurrent phenomenon connected to thermohaline circulation changes data collected from different platforms in the cretan sea during the 2000s decade present evidence of gradually increasing salinity in the intermediate and deep intermediate layers after the middle of the decade the observed gradual salt transport toward the deeper layers indicates contributions of dense water masses formed in various aegean sea subbasins the accumulation of these saline and dense water masses in the cretan sea finally led to outflow from both cretan straits with density greater than typical levantine cretan intermediate water but not dense enough to penetrate into the deep layers of the eastern mediterranean we name this outflowing water mass as dense cretan intermediate water dciw a retrospective analysis of in situ data and literature references during the last four decades shows that similar events have occurred in the past in two occasions a in the 1970s and b during the eastern mediterranean transient emt onset 1987 1991 we argue that these salinity driven aegean outflows are mostly attributed to recurrent changes of the eastern mediterranean upper thermohaline circulation that create favorable dense water formation conditions in the aegean sea through salinity preconditioning we identify these phenomena as emt like events and argue that in these cases internal thermohaline mechanisms dominate over atmospheric forcing in dense water production however intense atmospheric forcing over an already salinity preconditioned basin is indispensable for creating massive deep water outflow from the cretan sea such as the emt event

pervasive exsolution within the calcic amphibole series tem evidence for a miscibility gap between actinolite and hornblende in natural samples

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

water mass properties and dynamic conditions of the eastern mediterranean in june 2007 abstract five locations in the eastern mediterranean situated in the ionian sea cretan passage and levantine basin were characterized for their physical and biogeochemical properties on the basis of the data collected during an oceanographic cruise in june 2007 basinwide subbasin and mesoscale surface dynamic features are described in terms of absolute dynamic topography of the sea surface sea surface temperature and chlorophyll a distribution additional information along the ship s track was acquired via the vessel mounted thermosalinograph and the acoustic doppler current profiler providing data on temperature salinity and marine current the latter helped identify the depth penetration

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

a large abrupt change in the abyssal water masses of the eastern mediterranean 1 in this letter we report observations showing for the first time the occurrence of a new major transformation in the thermohaline cell of the eastern mediterranean sea after 2 decades during which waters of aegean origin dominated the abyssal layers of that basin the adriatic sea has returned to represent a major source of eastern mediterranean deep water emdw the observed characteristics of such water however profoundly differ from those observed previously in the abyssal layers of the ionian basin in fact the newly formed emdw we observed there is saltier warmer and denser than emdw observed before and during the eastern mediterranean transient emt thus during the past 2 decades the thermohaline cell of the eastern mediterranean once considered steady showed two large abrupt somehow opposite fluctuations as in the case of the first one origins climatic implications and fate of this second fluctuation have to be clarified

recurrent intrusions of transitional waters of eastern mediterranean origin in the cretan sea as a tracer of aegean sea dense water formation events abstract available temperature and salinity data in the cretan sea from 1955 up to 2014 as well as literature sources were revisited in order to trace the appearance of low salinity temperature oxygen and nutrient rich waters inside the basin at depths below the intermediate layer first appearing as far back as 1961 in literature these waters were found originating in the layers that separate intermediate and deep waters of the eastern mediterranean sea emed and were named transitional mediterranean water tmw in the 1990s data analysis showed that the appearance of tmw in the cretan sea is a recurrent phenomenon connected to water mass exchanges between the aegean sea and the emed in particular the inflow of tmw in the cretan basin acts as compensation for the outflow of equally dense or denser masses from the aegean this export is a result of dense water formation dwf events taking place inside the aegean sea triggering tmw compensatory inflow into the cretan sea through the cretan straits in this context tmw intrusions in the cretan basin can be used as a tracer of dwf in the aegean sea while the depth of the intrusion can provide valuable information about the intensity of the dwf event the importance of tmw intrusions is not solely restricted to the tracing and evaluation of dwf events but could additionally expand to the impact on local ecological processes as tmw is a nutrient carrier for the oligotrophic cretan sea

immiscibility in ca amphiboles the literature data of nine different occurrences of coexisting mineral pairs of ca amphibole have been studied and the bulk vectors spanning the miscibiuty gap derived the additive component is always impure mg tremolite accompanied by some glaucophane and cummingtonite component the four major exchange components required to describe the compositional variation in coexisting mineral pairs are the edenite ed tschermaki ts femg j and f tschermaks fets vector trivalent iron is postulated on the basis of excess charges in the bulk vector the size of which coincides with residuals in al si fe and mg the four cations have equal sizes forming the vector ft al mg jsi j this distribution scheme is consistent for all the different occurrences and sets the basis for a comparison deviations from the scheme would radically complicate the proposed exchange pattern the ratio t ed in most mineral samples fluctuates between one and two projection of the data points in the vector space ts ed onto the line 1ed 2ts tr hbl or 1ed 1ts tr prg provides the projected tremolite content x y 7 x w or 1x j this parameter applied to coexisting pairs and plotted against the ratio mg mg fe shows some characteristic features about the miscibiuty gap in the mg pure system the solvus is almost symmetric and located in the temperature range between 800 and 870 c small amounts 0 10pfu offe in the m 4 sites and replacing ca have a dramatic effect forcing the solvus to much lower temperatures of 650 c an increase in the ratio fe fc mg causes a shift of the solvus towards more tremolitic compositions with temperatures 500 650 c the maximum asymmetry of the solvus is reached where the al poor member tremolite has a composition of x y 10 and mg mg fe 0 6 the corresponding al rich member has x 0 5 and mg mg fe 0 4 an anomaly of the solvus is observed at mg mg fe 0 8 it manifests as a kind of highly asymmetric sub gap in the tremolite rich composition range this is explained by the partitioning of fe into the single m 3 site and is characterized by a thermal hump to 650 700 c

can internal processes sustain reversals of the ocean upper circulation the ionian sea example 1 in 1997 an inversion in the ionian upper layer circulation was documented and ascribed to a massive inflow of aegean dense waters associated with the eastern mediterranean transient emt and not to the wind stress borzelli et al 2009 here we generalize the concept hypothesizing that such inversions are possible even in the absence of the aegean influence indeed salinity and density data collected in the southern adriatic the main source of the eastern mediterranean deep water show decadal variations coherent with changes in the sea level height in the northern ionian scaling considerations suggest that the redistribution of ionian water masses resulting from changes in the thermohaline properties of waters entering the basin can sustain inversions of the upper layer circulation therefore we propose a feedback mechanism named the adriatic ionian bimodal oscillating system bios between variations in the thermohaline properties of waters formed in the southern adriatic and the ionian circulation

a synthesis of the circulation and hydrography of the south aegean sea and the straits of the cretan arc march 1994 january 1995 abstract four seasonal oceanographic cruises were carried out in the eastern mediterranean sea within the framework of the cec mast mtp project pelagos during 1994 1995 the surveys covered the south aegean sea and the adjacent open sea regions southeastern ionian northwestern levantine analysis of ctd data revealed that a multiscaled circulation pattern prevails in the area it differs from the circulations detected during the 1986 87 thus indicating interannual variability cyclonic and anticyclonic gyres and eddies are interconnected by currents and jets variable in space and time most of the features are persistent others seem transitional or recurrent the hydrological structure is also complex and apart from the upper layer does not present basinwide any significant seasonality dynamical and hydrological regimes are variable in the upper and intermediate layers at the straits of the cretan arc while the deep regime seems rather constant topographic control is evident on the flows through the straits the new very dense deep water mass namely the cretan deep water cdw and a well defined intermediate layer of minimum temperature and salinity the so called transition mediterranean water tmw consists the new important structural elements of the south aegean sea the cdw outflows towards the deep and bottom layers of the eastern mediterranean thus considerably contributing to the formation of the new denser deep and bottom water of the eastern mediterranean which sinks and displaces the eastern mediterranean deep water of adriatic origin in the adjacent sea regions outside the aegean sea

structure and variability of the abyssal water masses in the ionian sea in the period 2003 2010 1 this study presents aspects of the spatial and temporal variability of abyssal water masses in the ionian sea as derived from recent temperature salinity dissolved oxygen and velocity observations and from comparisons between these and former observations previous studies showed how in the southern adriatic sea the adriatic deep water addw became fresher s 0 08 and colder t 0 1 c after experiencing warming and salinification between 2003 and 2007 our data collected from october 2009 to july 2010 from two bottom moorings one within the strait of otranto and the other in the northern ionian confirm this tendency a bottom vein of southward flowing addw whose temperature and salinity continuously decreased during the observation time was detected there typically the vein travel time between the two stations ranged between 45 and 50 days this gave us a temporal estimate for addw anomaly propagation towards the ionian abyss from their adriatic generation region the density excess of the observed vein was always enough to enable its existence as a bottom arrested current this evidence confirms that at that time 2009 and 2010 the adriatic sea was greatly contributing to the formation of eastern mediterranean deep water emdw the bottom water of the eastern mediterranean hence based on these results and on the evidence that from 2003 to 2009 abyssal ionian waters became saltier and warmer under the time lagged influence of addw possible future changes in the emdw characteristics as a response to adriatic variability are discussed

textural and compositional relationships of ca amphiboles in metabasites of the cape smith belt northern quebec implications for a miscibility gap at medium pressure

water masses and circulation in the central region of the eastern mediterranean eastern ionian south aegean and northwest levantine 1986 1987 in the framework of the major multinational coordinated poem ii 86 march april 1986 and poem v 87 september october 1987 cruises in the eastern mediterranean high resolution hydrographic ctd data were collected by r v aegaio in the eastern ionian sea south aegean sea and northwest levantine basin the intercalibrated data sets were analyzed objectively for an optimal estimation of the basin s circulation in two different seasons the analysis reveals a rather complex general circulation pattern consisting of basin sub basin and mesoscale features during both study periods the major results concern the advection of the modified atlantic water maw along its eastward route the spreading of the levantine intermediate water liw and its trapping by the eddy fields the interaction between the south aegean sea and the eastern mediterranean and the reverse circulation in the cretan sea during winter and summer from the hydrography and the dynamic height maps synthetic schemes show the main circulation features in the two seasons

synthesis and characterization of amphiboles along the tremolite glaucophane join actinolite and glaucophane are the principal amphiboles in greenschist and blueschist facies metamafic rocks respectively and constitute an important mineral pair for deducing the conditions of medium and high pressure metamorphism here we present the crystal chemical properties of amphiboles synthesized along the tremolite glaucophane join as an important starting point for the more chemically complex samples occurring in nature amphiboles were synthesized in 10 mol increments at conditions ranging from 840 c and 0 6 gpa for tremolite rich to 750 c and 2 5 gpa for glaucophane rich amphiboles the amphibole yields were generally high 95 wt though minor quartz pyroxene and amorphous material either glass or quenched solute were often present electron microprobe analysis of the amphibole showed that deviations from the nominal or intended compositions occurred with the observed compositions showing solid solution primarily toward the katophorite component and reaching a maximum near the middle of the join unit cell dimensions showed a pronounced positive deviation from ideality even after linear correction for the non join components suggesting a strong tendency toward exsolution single crystal refinements of a couple of selected amphiboles confirmed the deviation from nominal composition and confirmed the presence of ana tal and cal the latter disordered between the m 2 and m 3 sites infrared spectra in the oh stretching region were measured on samples that were heated to 250 350 c to remove absorbed moisture the spectra consist of a main band centered in the 3675 3660 cm 1 region and two minor absorptions on both sides of the dominant central peak which are centered at 3720 and 3640 cm 1 and can be attributed to oh next to ana and cal respectively the main band is evidently composed of several overlapping components due to local arrangements of b cations typical of tremolite caca glaucophane nana and cummingtonite mgmg examination of several intermediate amphiboles by both single crystal xrd and by high resolution tem analysis could not identify evidence of reflections or ordered domains that would violate the c 2 m symmetry of the end member amphiboles comparing the compositions of the synthetic amphiboles from this study with winchite rich amphiboles in nature shows that deviations from the tremolite glaucophane join are common the inability to make pure winchite or even winchite rich amphiboles on the tremolite glaucophane join suggests that this structure is unstable