physical properties of tuffs from a scientific borehole at alban hills volcanic district central italy recent seismic swarms and hydrothermal activity suggest that the quaternary volcanic complex of the alban hills may pose a threat to the city of rome a 350 m scientific borehole was therefore drilled into this volcanic area to elucidate its inner structure for the first time wire line logs were run in the borehole in order to characterize the physical properties of the rocks and their variations with depth in particular a detailed sonic log was run to measure the p wave velocity from the well head down to 110 m to further investigate velocity changes we carried out laboratory measurements of p and s elastic wave velocities and fluid permeability at effective pressures up to 70 mpa during both increasing and decreasing pressure cycles on selected core samples representative of the main volcanic units specifically we studied samples from two pyroclastic units representative of two classes of volcanic deposits that are representative of the whole succession i a coarse grained well lithified facies pozzolane rosse unit containing abundant mm to cm lava clasts and crystals and ii a fine grained matrix supported pyroclastic deposit tufo pisolitico di trigoria unit with rare lithic lava clasts and sparse pumice elastic wave velocities reveal significant differences between units and indicate how within the same lithology the different degree of lithification and presence of clasts can affect significantly physical property values the mean laboratory value of the p wave velocity for pozzolane rosse and tufo pisolitico di trigoria units is respectively of 3 75 and 3 2 km s at an effective pressure equivalent to that at the depth at which the sonic velocity was measured under increasing effective pressure a profound influence on the transport properties is observed permeability ranges from the order of 10 18 m 2 for the pozzolane rosse unit to the order of 10 15 m 2 for the tufo pisolitico di trigoria unit in good agreement with the shallow aquifer circulating in the shallower units c 2008 elsevier b v all rights reserved

single crystal 40ar 39ar dating of the olorgesailie formation southern kenya rift single crystal laser fusion sup 40 ar sup 39 ar analyses and several conventional bulk fusion sup 40 k sup 40 ar dates have been used to determine the age of volcaniclastic strata within the olorgesailie formation and of associated volcanic and sedimentary units of the southern kenya rift in the principal exposures along the southern edge of the legemunge plain the formation spans the interval from approximately 500 to 1 000 ka deposition continued to the east along the ol keju nyiro river where a tuff near the top of the formation has been dated at 215 ka in these exposures the formation is unconformably overlain by sediments dated at 49 ka a possible source for the olorgesailie tephra the ol doinyo nyokie volcanic complex contains as ash flow dated at approximately 1 ma extending the known age range of this complex to encompass that of virtually the entire olorgesailie formation in the legemunge plain these geologic examples illustrate the importance of the single crystal sup 40 ar sup 39 ar dating technique whereby contaminant altered or otherwise aberrant grains can be identified and eliminated from the determination of eruptive ages for reworked or altered pyroclastic deposits the authors have presented a computer modeling procedure based on an inverse isochron analysis thatmore promotes a more objective approach to trimming sup 40 ar sup 39 ar isotope data sets of this type less

dianeutral exchange between intermediate and deep water in the tropical atlantic 1 in the tropical atlantic the vertical distance between antarctic intermediate water aaiw and upper north atlantic deep water unadw cores defined by their salinity extrema exceeds 1000 m in this thick layer two additional water mass signals characterized mainly by temperature extrema are identified in the western boundary region they are the intrusive flows of upper circumpolar deep water ucdw and shallow unadw sunadw the latter is considered a water type of unadw since ucdw is a northward flow as a lower phase of aaiw and sunadw is a southward flow as an upper phase of nadw a reference of level of no motion lnm is defined between ucdw and sunadw at the neutral density surface n 27 70 at about 1150 m this surface is coincident with a minimum of dianeutral velocity and measured velocity by lowered acoustic doppler current profiler dianeutral motion processes are examined across the five selected neutral surfaces n 27 45 27 60 27 70 27 80 and 27 90 that span the depth range between aaiw and unadw and follow the major water mass signals dianeutral transport shows a decreasing tendency toward the middle n 27 70 neutral surface and reaches a minimum of 0 6 sv 1 sv 106 m3 s 1 integrated in the tropical region between 10 n and 10 s thus the weakening of dianeutral motion and required minimum of epineutral advection at lnm seem to be relevant

geohazards monitoring in roma from insar and in situ data outcomes of the pangeo project within the pangeo project financed by the european commission under the 7th framework program the geological survey of italy ispra and the urban planning department of the city of roma developed a geodatabase and map of the geological hazards for the territory of roma integrating remotely sensed data psinsar permanent scatterer interferometry synthetic aperture radar and in situ geological information numerous thematic layers maps and inventories of hazards e g landslides sinkholes cavities geological and hydrogeological data added to historical and recent urbanization information were compared to the permanent scatterer ps data from the european remote sensing satellites ers 1 2 1992 2000 and envisat 2002 2005 descending scenes in order to produce a ground stability layer gsl based on the ps data most of the territory appears stable almost 70 of ps velocities are within 1 mm year about 14 of the pss show positive line of sight los velocities measured along the los of the satellite between 1 and 3 mm year and more than 2 exceed 3 mm year more than 11 of pss show negative los velocities between 1 and 3 mm year while about 3 exceed 3 mm year with tens of the pss showing velocities over 20 mm year the gsl is comprised of polygons or multi polygons multipart polygons grouping individual polygons under a single identifier geohazard enclosing areas where geohazards have been pointed out by ps data and or in situ surveys observed instabilities and by polygons enclosing areas potentially affected by geohazards based on the available knowledge of the territory potential instabilities in roma s gsl 18 multi polygons covering ca 600 km2 related to observed instabilities have been outlined where ground movements could be detected through insar data or where landslides and sinkholes are known to have occurred other 13 multi polygons covering nearly 900 km2 concern areas where the potential occurrence of geohazards was inferred by combining geological and or geothematic data potential instabilities the geohazards mapped in roma have been landslides collapsible grounds compressible grounds groundwater abstraction mining man made ground tectonic movements and volcanic inflation deflation the lattermost is the likely cause of the significant uplift observed in the alban hills area however this paper focuses on two more currently impending hazards subsidence and sinkholes in general sinkhole prone areas areas of dense underground cavities are hard to discern from satellite data but can be revealed by ruling out other potential causes of observed ground movement based on in situ data subsiding zones are effectively detected by the available psinsar dataset over a total extent of about 60 km2 mostly overlapping the recent alluvial areas of the tiber and its tributaries pss show a very different behaviour inside and outside the historical centre inside loading by anthropogenic construction and man made ground since ancient times has led to an almost complete consolidation of the recent river deposits marked by modest to absent subsidence in contrast outside subsidence clearly stands out with negative los velocities that although generally within several mm year can locally exceed 25 mm year ps data have provided motion information at both a regional and local scale up to the scale of a single building closer to the sea in the tiber delta area velocities increase especially above recently reclaimed marsh areas rich in peat and organic clays velocities can change significantly over short distances as in the international airport area reflecting the local stratigraphic setting the same occurs in the two subsiding areas located within the alban hills volcanic complex which is generally affected by ground uplift as a whole psinsar ground motion velocities offer a significant contribution to susceptibility and hazard recognition studies in particular such a method provides a fast and effective tool available to local authorities to monitor ground and building behaviour possibly allowing for timely prevention activities especially when coupled with appropriate in situ knowledge

quaternary fluvial volcanic stratigraphy and geochronology of the capitoline hill in rome in and around rome coastal and fluvial sediments influenced by quaternary sea level changes interfinger with accurately datable highly potassic pyroclastic volcanic units we describe the complex internal geology of the capitoline hill for centuries a place of leading importance in ancient rome and more recently a focus of archaeological research outcrops and many new drill cores reveal at least four cycles of valley cutting and filling probably recording the history of the tiber river in response to changes in sea level single crystal 40 ar 39 ar dates on sanidine give ages of 518 6 413 5 and 353 2 ka for three prominent volcanic units filling separate paleovalleys the roman region offers the potential for direct age calibration of the quaternary sea level record

spectral signatures of submicron scale light absorbing impurities in snow and ice using hyperspectral microscopy light absorbing impurities lai can darken snow and ice surfaces reduce snow ice albedo and accelerate melt efforts to allocate the relative contribution of different lai to snow ice albedo reductions have been limited by uncertainties in the optical properties of lai we developed a new method to measure lai spectral reflectance at the submicron scale by modifying a hyperspectral imaging microscope spectrometer hims we present the instrument s internal calibration and the overall small influence of a particle s orientation on its measured reflectance spectrum we validated this new method through the comparison with a field spectroradiometer by measuring different standard materials measurements with hims at the submicron scale and the bulk measurements of the same standard materials with the field spectroradiometer are in good agreement with an average deviation between the spectra of 3 2 for the 400 1000 nm wavelength range the new method was used 1 to identify bc black carbon mineral dust including hematite and the humic substances present in an environmental sample from plaine morte glacier and 2 to collect the individual reflectance spectra of each of these types of impurity the results indicate that this method is applicable to heterogeneous samples such as the lai found in snow and ice

atlantic meridional overturning circulation and the southern hemisphere supergyre 1 the ocean s role in climate manifests itself through its high heat capacity its own rich internal dynamics and its ability to transport vast quantities of heat and freshwater of particular interest is the global ocean circulation associated with the atlantic meridional overturning amoc because observations are sparse the detailed global structure of the amoc remains poorly understood particularly the pathways along which water returns to the atlantic to compensate the export of north atlantic deep water nadw here we provide the first quantitative 3 dimensional global view of the amoc using a lagrangian reconstruction which integrates hundred of thousands water particle trajectories in an ocean model the resulting pattern elucidates the role of the wind in structuring the pathways of the amoc in particular the lagrangian analysis reveals a strong link with the three subtropical gyres of the southern hemisphere sh which merge into a supergyre spanning the three ocean basins the coupling between the upper ocean wind driven circulation and the overturning in the model suggests that changes in the sh winds can alter the pathways of the amoc and therefore the water properties and the associated heat and freshwater transports

structure and evolution of the sacrofano baccano caldera sabatini volcanic complex rome abstract sacrofano eruptive center in the eastern part of the sabatini volcanic complex was active between 0 5 and 0 09 m y ago the baccano geothermal area lies at the western edge of sacrofano caldera sedimentary substrata that form the reservoir for this geothermal system were exposed at the surface at the beginning of volcanic activity the volcanic history of the sacrofano center can be divided into three stages 1 1 construction of the sacrofano pyroclastic edifice by predominantly strombolian activity 2 2 collapse of sacrofano caldera following eruption of pyroclastic flows 3 3 development of the baccano explosive center at the western edge of sacrofano caldera and collapse of baccano caldera hydrovolcanic activity that began at the end of the first stage of sacrofano can be explained by a drop in the magma level in the conduit that relieved hydrostatic pressure in the aquifer as intense fracturing associated with caldera collapse penetrated the carbonate reservoir the entrapped water flowed towards the conduit to balance the pressure change the close link between tectonism and volcanism in the sacrofano center suggests that eruptions there may have been triggered by gravity faults related to regional tectonics

the montalbano jonico marine succession an archive for distal tephra layers at the early middle pleistocene boundary in southern italy abstract the lithological content and mineralogical assemblage of main tephra layers v1 v2 v3 v4 v5 v7 embedded in the montalbano jonico succession have been fully characterized major element analyses were carried out on the juvenile glass fractions and main crystal phases and trace element contents were determined on glasses extracted from the thickest layer of the sequence v5 single crystal 40 ar 39 ar laser fusions were performed on sanidine from the v4 layer yielding a weighted mean age of 773 9 1 3 ka the vulture volcano is likely the source of two tephra layers v3 and v4 embedded to the middle part of the interval b of the sequence which represent the oldest products of this center ever found moreover the v4 layer was emplaced near the matuyama bruhnes chron boundary and thus serves as an important chronostratigraphic marker complete chemical characterization of v5 allows us to suggest the campanian volcanic zone as its eruptive source corroborating the idea that activity there began at 720 ka and spanned most of the middle pleistocene finally we insert our new framework from the montalbano jonico sequence into a reappraised tephra sequence from the middle pleistocene to present in southern italy which results in a more robust series of tephrostratotypes and improves the reliability of inter archive correlations

stratigraphic and tectonic features of the middle pleistocene sedimentary and volcanic deposits in the area of rome italy the analysis of a large number of stratigraphic logs from boreholes as well as an extensive field survey suggests that the middle pleistocene sedimentary deposits in the area of rome can be subdivided into two groups each one characterised by a different stratigraphy and tectonic setting a north eastern sector corresponding to the eastern urban area of rome and a south western sector corresponding to the ponte galeria area in the north eastern sector the distribution of sediments is influenced by vertical block faulting showing a predominantly north south trend superimposed on a middle pleistocene ne sw extensional tectonic domain in the south western sector we suggest that the ponte galeria formation auct can be subdivided into two depositional sequences that can be linked to isotope stages 19 and 21 in addition a sedimentary hiatus is proposed at the top of the ponte galeria sequence it corresponds to the deposition of a continental succession in the north eastern sector before the emplacement of pyroclastic deposits from the colli albani and sabatini volcanic districts the correlation between these two depositional sequences that have been identified and the oxygen isotope time scale allowed us to extend our investigation across to the urban area of rome where we have recognised six sedimentary cycles all of pleistocene age which have been tentatively related to particular isotopes stages

40ar 39ar geochronology of roman volcanic province tephra in the tiber river valley age calibration of middle pleistocene sea level changes the close proximity of the roman volcanic province to the tyrrhenian sea coastline provides a unique opportunity to combine clastic stratigraphy with 40 ar 39 ar geochronology to constrain the timing of pleistocene sea level oscillations the main eruptions from the monti sabatini volcanic district occurred during the interval 560 280 ka and the alban hills volcanic district main eruptions span 560 350 ka the interfingering of volcanics from these two centers with fluvial and shallow marine sediments of the tiber river and delta provides a datable relative sea level record for this portion of middle pleistocene time we calculate the timing of glacial terminations using analytical errors only then assess age uncertainties that include analytical plus systematic errors the latter is required to compare 40 ar 39 ar ages with those from other dating methods terminations iii v and vi occur at 278 261 285 ka 95 confidence interval 430 422 442 ka and 534 520 541 ka respectively when only analytical uncertainties are used to calculate the ages of bracketing volcanic horizons the confidence interval expands significantly when full external errors are considered with predicted ages of 276 258 289 ka 430 416 448 ka and 533 512 548 ka for the terminations the resultant 40 ar 39 ar chronology is generally consistent with the deep sea 18 o record of sea level change tuned to earth9s obliquity cycle for glacial terminations vi v and iii in addition the 40 ar 39 ar constrained tiber river delta sea level record has the added benefit of identifying when coastal sections respond to complex multistep terminations

comment on large volume phreatomagmatic ignimbrites from the colli albani volcano middle pleistocene italy by d de rita g giordano a esposito m fabbri and s rodani jvgr 2002 118 77 98

implications of the nonlinear equation of state for upwelling in the ocean interior the nonlinear nature of the in situ density of seawater as a function of the potential temperature pressure and salinity causes two vertical advection processes thermobaricity and cabbeling and also complicates the use of microstructure data to deduce upwelling velocities cabbeling and thermobaricity are evaluated and mapped on some neutral surfaces in each of the world s oceans by taking the lateral flux of scalars to be parameterized by a lateral diffusivity in most of the ocean these two processes are weak but where there is a significant epineutral gradient of potential temperature the downwelling due to cabbeling is quite large in the southern ocean where there is a large slope of the neutral surfaces thermobaricity causes a larger downwelling velocity than cabbeling and the two processes together cause a dianeutral velocity of about 2 10 7 m s 1 the complementary roles of vertical mixing and vertical advection in achieving water mass conversion are demonstrated since maps of the dianeutral motion caused by vertical mixing are quite different to maps of water mass conversion caused by the same process this emphasizes the need to include both vertical advection and vertical mixing in ocean models the method that is used to infer the upwelling velocity from microstructure dissipation measurements is also significantly affected by the nonlinear nature of the equation of state the extra term that needs to be included in this method is a strong function of depth changing sign at a depth of about 1500m

the villa senni eruption alban hills central italy the role of h2o and co2 on the magma chamber evolution and on the eruptive scenario abstract the villa senni eruption unit vseu belongs to the tuscolano artemisio phase of volcanic activity in the alban hills volcanic district the closest to rome of the recent or active volcanoes of central italy the most important products of this eruption are represented by pyroclastic flow deposits named lower and upper flow unit lfu and ufu respectively three main rock types form vseu as follows 1 juvenile k foiditic scoria clasts of the lfu 2 juvenile phonotephritic scoria clasts of the ufu and 3 holocrystalline phonotephritic lithic inclusions italites in the ufu on the basis of the chemistry mineralogy and petrography of the three studied rock types their phase relations have been discussed other petrologic constraints from laboratory melting experiments are presented and used to investigate the role of volatiles on the evolution of the magma chamber system some broad implications on withdrawal pattern are also presented it has been verified the lfu rock type can be obtained from a parental melt of ufu composition by a co2 controlled crystal liquid fractionation of a solid assemblage close in composition to that of italites because it can be proved that the storage of magma occurred at shallow depth within the mesozoic carbonate country rocks it is proposed that co2 diffusion originating from thermal decomposition of wall rock carbonates controlled the evolution trend of the melt at the periphery of the magma chamber whereas the inner part of the magma body retained the volatile component essentially h2o of the original melt the corresponding eruption model is therefore comprehensive of an early eruptive phase lfu rock type involving the more differentiated central magma bulb whereas the late eruptive phase ufu rock type tapped the more mafic peripheral magma the italite xenoliths are believed to represent the chilled margins of the magma chamber

implications of cabbeling on the formation and transformation mechanism of north pacific intermediate water 1 the world ocean atlas 1994 is used to study the formation and transformation of north pacific intermediate water npiw paying attention to the broad subarctic tropical frontal zone satfz four neutral density surfaces n 26 5 26 9 27 2 and 27 4 are mapped to span the npiw layer with the n 26 9 surface identified with the salinity minimum of npiw various dianeutral motion processes cabbeling thermobaricity vertical turbulent mixing and double diffusion and water mass property conversion are quantified cabbeling appears to be the most important spatially dianeutral transport is strongest in the satfz within the satfz subdomain 36 n 44 n 142 e 140 w with assumed epineutral and dianeutral diffusivities of k 103 m2 s 1 and d 10 5 m2 s 1 cabbeling contributes to a maximum dianeutral downwelling transport of 0 9 sv on the n 26 5 neutral density surface the upper boundary of npiw and 0 7 sv on the n 26 9 surface at the npiw core in meridional sections cabbeling shows epineutral extension from the satfz towards the subtropical gyre most apparent along the n 26 9 surface dianeutral transport is found to be sensitive to the epineutral diffusivity k on the upper two surfaces n 26 5 and 26 9 where the transport is dominated by cabbeling with only half an order of magnitude increase in diffusivity k 103 5m2 s 1 the total npiw about 3 sv can be accomplished by cabbeling alone these results suggest that cabbeling plays a crucial role in the npiw transformation since cabbeling describes physically the dianeutral downwelling resulted from epineutral mixing strong cabbeling in the satfz implies that npiw sources are first transformed by cabbeling from the upper to the lower neutral density surfaces and subsequently npiw is carried by epineutral advection and gyre circulation into the subtropical interior thus cabbeling is revealed as the principle mechanism responsible for transforming subpolar source waters into subtropical npiw water via the satfz

strike slip faulting and block rotation a possible triggering mechanism for lava flows in the alban hills abstract it is suggested in this paper that two distinct tectonic triggers tapping different depths of a magma reservoir may be the cause of nearly contemporaneous eruptions of lava flows and ignimbrites in the alban hills the area between the alban hills and rome underwent alternating regional extensional and strike slip faulting during the middle pleistocene the geometries of the main structural dislocations in quaternary strata combined with a statistical analysis of drainage network trends show a structural pattern that is consistent with local strain partitioning in transpressive zones at strike slip fault bends superimposed on regional extension based on this analysis it is suggested that local clockwise block rotation between parallel n s strike slip faults might have generated local crustal decompression allowing relatively volatile free magma to rise from deep reservoirs beneath the alban hills triggering peripheral fissure lava flows in contrast the main ignimbrite eruptions appear to tap shallow volatile rich magma reservoirs and are controlled by extensional processes

the geochemistry of potassic lavas from vulsini central italy and implications for mantle enrichment processes beneath the roman region major and trace element and 143nd 144nd 0 51209 0 51216 and 87sr 86sr 0 70879 0 71105 isotope analyses are presented on a representative group of lavas from the vulsini district of the roman magmatic province three distinct series are identified the high k and low k series are similar to those described from other italian volcanoes while the third is represented by a group of relative ly undifferentiated leucite basanites which are thought to be near primary mantle melts major and trace element variations within the high k series are consistent with fractional crystallisation from a parental magma similar to the most magnesian leucitites crustal contamination resulted in an increase in 87sr 86sr with increasing fractionation but it was superimposed on magmas which had already inherited a range of incompatible element and isotope ratios from enrichment processes in the sub continental mantle these are reviewed using the available results from vulsini roccamonfina and ernici transition element abundances and ta yb ratios indicate that the pre enrichment mantle was similar to that of e type morb and that these elements were not mobilised by the enrichment process mixing calculations suggest that three components were involved in the enrichment process mantle comparable with the source of morb and two other components rich in trace elements one the low k component had high sr nd th ta and ba nb and no europium anomaly while the second had lower sr nd a negative europium anomaly and very high th ta it was also characterised by low nb ba and high rb ba ratios similar to those reported from phlogopite rich peridotite xenoliths the trace element enrichment processes are therefore thought to have occurred in the mantle wedge above a subduction zone with the trace element characteristics of the high k end member reflecting the subduction of sediments and the stabilisation of mantle phlogopite

thermocline circulation and ventilation of the east japan sea part i water mass characteristics and transports abstract the east japan sea ejs has unique water mass characteristics in the western pacific marginal seas due to limited exchange with the open north pacific the major inflow of source water mass is north pacific subtropical water npsw carried by the kuroshio branching and tsushima current the locally formed cold fresh waters from the tatar strait and russia coast by winter convection mix with npsw contributing to water mass transformation especially during winter when upper isopycnal surfaces outcrop and thermocline is ventilated the geographic limit of the korea tsushima strait kts with a sill depth of about 120 140 dbar confines the inflow of lower npsw and so the ejs thermocline layer is somewhat truncated with a rather thin layer for about 100 dbar this study uses high resolution conductivity temperature depth ctd and argo data with a third decimal or higher accuracy for temperature and salinity obtained mainly by research institute of oceanography seoul national university through domestic and international collaboration with several korean ocean research institutes and russia and usa partners since early 1990s the basin covered data were divided into summer and winter half year representing seasonal difference since most ctd surveys were conducted purposely in summer and winter analysis is made for the upper layer about 50 70 dbar from the surface to the upper main thermocline and the thermocline layer down to about 150 180 dbar south of the subpolar front spf the lower thermocline is defined slightly below the sill depth of the kts considering the deepening of npsw after passing through the kts the thermocline layer is encompassed by three selected neutral density surfaces n 25 8 26 4 and 27 0 with a distance of about 40 dbar between two neighboring surfaces the core of thermocline is followed by the n 25 8 surface characterized by a salinity maximum and a minimum of potential vorticity winter convection is discussed and compared with three other major convection sites of the world s oceans the gulf of lions labrador sea and greenland sea showing some common and distinctive features especially the extremely low salinity of the ejs water mass properties on neutral density surfaces are analyzed with the water mass turner angle wtu and circulation and transport are deducted from geostrophic calculations from the 15 year mean hydrography a basin wide net annual mean transport of about 2 10 0 29 sv 1 sv 106 m3 s 1 is estimated with summer and winter transports of 2 56 0 36 and 1 63 0 23 sv respectively this transport is slightly less than the annual mean transport of the tsushima current at the kts 2 4 sv from cable and 2 3 sv from other direct current meter and geostrophic methods but matches the 14 error bar of 0 29 sv adjusted by 150 dbar from the reference level of 800 dbar this error bar is close to the error of 0 34 sv determined from water mass conservation residual in a separated study three mechanisms are discovered to explain the seasonal difference in the tsushima current transports the stronger winter ekman pumping outcropping and southward crossing flow during winter the tsushima current branches are imposed under strong wind stress curl in the ulleung basin and yamato basin showing a doubling ekman downwelling transport partly weakening the tsushima current flow in the eastern boundary meanwhile the thermocline isopycnal surfaces outcrop in winter reducing volume transport due to reduced space and thickness the southward currents in the southern ulleung basin and yamato basin are perpendicular to the tsushima current branches west of japan which weakens the eastern boundary current in winter

optimum multiparameter analysis of mixing in the thermocline of the eastern indian ocean a method of water mass analysis is developed which optimizes the use of all information contained in a hydrographic data set by solving an overdetermined linear set of mixing equations it requires representation of water masses by a finite number of water types and observations from at least as many oceanographic parameters as water types the procedure to establish the water types find the correct weights for the parameters and solve the mixing equations through minimization of the residuals is described in detail the method is applied to a data set from the eastern indian ocean where indian central water and australasian mediterranean water meet to produce a strong front in the thermocline it is shown that although most of the water from the indonesian archipelago is carried westward north of 11 s contributions from the australasian mediterranean water are found as far south as 25 s particularly along the australian shelf as a result of advection with the leeuwin current

chronostratigraphic constraints on middle pleistocene faunal assemblages and acheulian industries from the cretone lacustrine basin central italy integrated 40ar 39ar trace element stratigraphic palaeontological and palaethnological data provide geochronological and biochronological constraints for the sedimentary and tectonic history of a middle pleistocene fluvial lacustrine basin near rome cretone basin central italy which has yielded a significant record of mammal fossil remains and palaeolithic industry this work is a case study of the interplay between tectonics and glacio eustacy which strongly influenced the evolution of the tyrrhenian sea margin of central italy dating of tephra layers interbedded within the cretone basin lacustrine succession and reconstruction of relict terraced surfaces allow correlation with similar geochronologically constrained marine isotopic stages mis 15 5 terraced deposits along the coast coupled extensional tectonics and regional uplift over the last 600 ka caused the progressive uplifting and westward migration of the main fluvial lacustrine basin and the formation of a smaller satellite basin at its eastern margin here stable environmental conditions during mis 13 5 indicated continuous human and large mammal frequentation as testified by lithic industry and fossil remains ascribable to the acheulean and later early middle palaeolithic technocomplexes and galerian aurelian mammal faunas respectively in addition to providing independent age constraints to glacial sea level oscillations of this region the reconstructed chronostratigraphic setting for the cretone basin provides evidence for one of the oldest acheulean lithic assemblage of central italy as well as new biochronological and palaeobiogeographical data for some middle pleistocene mammal species of italy

the 1989 1990 seismic swarm in the alban hills volcanic area central italy abstract a long seismic swarm has been recorded by a digital microseismic network that the istituto nazionale di geo fisica ing deployed from april 1989 to march 1990 in the alban hills quaternary volcanic region about 20 km southeast of rome the network consisted of thirteen digital stations equipped with four six component weak motion and strong motion sensors three three component and six vertical weak motion seismometers including both broad band and short period sensors more than 3000 earthquakes were detected during about one year of operation the data recorded during the sequence provided an unprecedented opportunity to resolve details of the seismogenic features of this area that has experienced earthquakes since the roman age although the temporal distribution of seismicity reveals a volcanic type swarm activity the recorded seismic signals show medium high frequency waveforms and clear s wave arrivals typical of tectonic earthquakes about 1100 earthquakes in a magnitude range between m d 1 5 and md 4 0 have been located the seismicity delineates a 6 12 km 2 nw se elongated region that corresponds to the area where the most recent 0 027 ma phreato magmatic activity took place almost no earthquakes occurred beneath the central cone and the eastern side of the caldera the seismicity is shallow and is mostly concentrated in two clusters that are offset laterally and are at sligthly different depths 3 5 and 4 6 km the fault plane solutions of the strongest earthquakes reveal a ne sw extension consistent with the regional orientation of the stress field along the apenninic chain as obtained by other seismo logical data

high level triggers for explosive mafic volcanism albano maar italy abstract colli albani is a quiescent caldera complex located within the roman magmatic province rmp italy the recent via dei laghi phreatomagmatic eruptions led to the formation of nested maars albano maar is the largest and has erupted seven times between ca 69 33 ka the highly explosive nature of the albano maar eruptions is at odds with the predominant relatively mafic sio 2 48 52 wt foiditic k 2 o 9 wt composition of the magma the deposits have been previously interpreted as phreatomagmatic however they contain large amounts up to 30 vol of deep seated xenoliths skarns and all pre volcanic subsurface units all of the xenoliths have been excavated from depths of up to 6 km rather than being limited to the depth at which magma and water interaction is likely to have occurred suggesting an alternative trigger for eruption high precision geochemical glass and mineral data of fresh juvenile magmatic clasts from the small volume explosive deposits indicate that the magmas have evolved along one of two evolutionary paths towards foidite or phonolite the foiditic melts record ca 50 mixing between the most primitive magma and ca rich melt late stage prior to eruption a major result of our study is finding that the generation of ca rich melts via assimilation of limestone may provide storage for significant amounts of co 2 that can be released during a mixing event with silicate magma differences in melt evolution are inferred as having been controlled by variations in storage conditions residence time and magma volume

oxygen isotope geochemistry of pyroclastic clinopyroxene monitors carbonate contributions to roman type ultrapotassic magmas the oxygen isotope geochemistry and chemical composition of clinopyroxene crystals from alban hills pyroclastic deposits constrain the petrological evolution of ultrapotassic roman type rocks volcanic eruptions in the 560 35 ka time interval produced thick pyroclastic deposits bearing clinopyroxene phenocrysts with recurrent chemical characteristics clinopyroxenes vary from si mg rich to al fe rich with no compositional break indicating that they were derived from a continuous process of crystal fractionation based on the 18o and trace element data no primitive samples were recovered monomineralic clinopyroxene cumulates set the oxygen isotope composition of primary magmas in the range of uncontaminated mantle rocks 5 5 but their ree composition resulted from extensive crystal fractionation departing from these mantle like 18ocpx values the effects of crustal contamination of clinopyroxene o isotope composition were identified and used to monitor chemical variations in the parental magma 18o values in si mg rich clinopyroxene are slightly higher than typical mantle values 5 9 6 2 and the low ree contents are representative of early stages of magmatic differentiation 18o values as high as 8 2 are associated with al fe3 rich clinopyroxene showing high ree contents these 18o values are characteristic of crystals formed during the late magmatic stages of each main eruptive phase geochemical modelling of 18o values vs trace element contents indicates that these ultrapotassic magmas were derived from fractional crystallization plus assimilation of limited amounts of carbonate wall rocks starting from a primary melt and from interaction with co2 derived from country rocks during crystal fractionation

dianeutral mixing and transformation of antarctic intermediate water in the indian ocean transformation of antarctic intermediate water aaiw is achieved through one or more processes of epineutral advection epineutral diffusion dianeutral advection and dianeutral diffusion this paper points to the importance of dianeutral mixing in achieving the aaiw water mass transformation in the indian ocean six neutral surfaces were mapped to span the intermediate water of the indian ocean between 580 and 1500 m at the reference cast south of the antarctic frontal zone aaiw shows a diffusive tongue in the meridional turner angle after j stewart turner sections on its equatorward transition the transformed aaiw is characterized by a tongue of doubly stable conditions extending a great distance to as far as about 5 s a maximum downwelling dianeutral velocity of 2 10 7 m s 1 due to cabbeling is found in the antarctic frontal zone which is 3 orders larger than that in the subtropical gyre thermobaricity acts similarly to cabbeling in the antarctic frontal zone and contributes a maximum downwelling dianeutral velocity of 1 10 7 m s 1 but mainly arises in upwelling north of the frontal zone a strong downwelling dianeutral velocity of 2 10 7 m s 1 contributed by vertical turbulent mixing occurs on the upper two neutral surfaces south of the frontal zone with assumed constant epineutral diffusivity k of 103 m2 s 1 and dianeutral diffusivity d of 10 5 m2 s 1 an area mean net dianeutral upwelling velocity of 0 11 10 7 m s 1 is found north of 32 s across the lowermost neutral surface 27 66 it means a net upward volume transport of 0 6 sv 1 sv 106 m3 s 1 this weak but net upwelling transport roughly corresponds to a net 0 5 sv transported downward with a downwelling dianeutral velocity of 0 25 10 7 m s 1 across the same neutral surface south of 45 s toward the core of aaiw the net dianeutral velocity increases to 0 15 10 7 m s 1 across the 27 37 neutral surface the corresponding net dianeutral transport increases to 0 8 sv you 1996 has estimated a net dianeutral upwelling transport of 1 4 sv across the lower thermocline north of 32 s which suggests about the same amount of volume transport upward across the upper intermediate layer however south of 45 s a much stronger area mean net downwelling dianeutral velocity of 2 63 10 7 m s 1 is found across the uppermost neutral surface 27 1 indicative of a net 5 4 sv transported downward that the downwelling transport across the uppermost surface is 10 times larger than that across the lowermost surface south of 45 s has a strong implication for the equatorward advection of aaiw between the uppermost and lowermost neutral surfaces when both the epineutral and dianeutral diffusivities are increased by 1 order of magnitude to k 104 m2 s 1 and d 10 4 m2 s 1 the above estimated integrated total dianeutral velocity and transport would increase by almost 10 times however when the diffusivities are decreased by 1 order of magnitude to k 102 m2 s 1 and d 10 6 m2 s 1 the integrated total dianeutral velocity and transport would decrease by only less than one time

large volume phreatomagmatic ignimbrites from the colli albani volcano middle pleistocene italy abstract in this paper we describe four large volume ash and accretionary lapilli rich phreatomagmatic compound ignimbrite units mafic in composition from colli albani volcano south of rome the four units that form the pisolitic tuffs succession are separated by paleosols and represent the earliest explosive large volume eruptive episodes from the quaternary alban hills volcano the occurrence of large volume phreatomagmatic phreatoplinian eruptions implies the availability of large quantities of water interacting with the rising magma the paleogeography of the area below the volcano has been reconstructed by the analysis of stratigraphic data from more than a thousand bore holes distributed around the volcano that allowed to identify nw trending and ne trending paleotopographic lows that underlie the central area of the volcano and interpreted as extensional tectonic basins these lows are filled with lower to middle pleistocene pre volcanic lacustrine and fluvial deposits and suggest that at least the central part of the colli albani volcanic area hosted a large lake or lagoon the absence of sedimentary xenoliths in the pisolitic tuffs and the low vesicularity of scoria and shards suggest that water interacted with a poorly fragmented magma at very shallow level triggering the large explosivity of the eruptions we suggest that water interacting with magma was mostly surficial water related to the presence of the lagoon or lake in this environment it is likely that vents were subaqueous allowing a continuous access of water to the conduit considering that the minimum calculated volume of products for the pisolitic tuffs succession is 37 km3 and each eruption unit averages approximately around minimum volume of 10 km3 we suggest that each eruption was related to a caldera collapse which would have allowed the persistence of a taupo like lake in the central area and of phreatoplinian activity after the last phreatomagmatic eruption however the fragmentation style of large volume ignimbrites from colli albani became magmatic suggesting the extinction of the lake after that date each of the four units show a basal phreatoplinian fallout level overlain by a complex association of low aspect ratio surge deposits and ignimbrites phreatomagmatic pyroclastic flow deposits are found at distances of more than 40 km from the central area of the volcano and show important facies variation according to the paleotopography to the west of the volcano pyroclastic flows reached the tyrrhenian coast and emplaced mostly stratified facies on a flat topography interpreted to reflect both the spreading of pyroclastic flows on an unconfined topography and their interaction with lacustrine and lagoon areas by contrast to the east of the volcano where pyroclastic flows were confined within paleovalleys the main facies is thick and massive

cryoconite on a glacier on the north eastern tibetan plateau light absorbing impurities albedo and enhanced melting cryoconite is a dark coloured granular sediment that contains biological and mineralogical components and it plays a pivotal role in geochemistry carbon cycling and glacier mass balance in this work we collected cryoconite samples from laohugou glacier no 12 lhg on the north eastern tibetan plateau during the summer of 2015 and measured the spectral albedo to explore the impacts of this sediment on surface ablation the ice melting differences between the cryoconite free removed ice and the intact layers were compared the results showed that the mean concentrations of black carbon bc organic carbon oc and total iron fe in the lhg cryoconite were 1 28 11 18 and 39 94 mg g 1 respectively bc was found to play a stronger role in solar light adsorption than oc and free fe in addition ice covered by cryoconite exhibited the lowest mean reflectance i e 1 and free fe bc and oc were estimated to contribute 1 01 0 99 and 0 76 cm d 1 respectively this study provides important insights for understanding the role of cryoconite in the glacier mass balance of the northern tibetan plateau

clay clast aggregates in gouges new textural evidence for seismic faulting 1 spherical aggregates named clay clast aggregates ccas have been reported from recent investigations on retrieved clay bearing fault gouges from shallow depth seismogenic faults and rotary shear experiments conducted on clay bearing gouge at seismic slip rates the formation of ccas appears to be related to the shearing of a smectite rich granular material that expands and becomes fluidized we have conducted additional high velocity rotary shear experiments and low velocity double shear experiments we demonstrate that a critical temperature depending on dynamic pressure temperature conditions is needed for the formation of ccas this temperature corresponds to the phase transition of pore water from liquid to vapor or to critical which induced gouge pore fluid expansion and therefore a thermal pressurization of the fault a detailed examination by energy dispersive x ray spectrometry edx sem element mapping sem and transmission electron microscopy tem shows strong similar characteristics of experimental and natural ccas with a concentric well organized fabric of the cortex and reveals that their development may result from the combination of electrostatic and capillary forces in a critical reactive medium during the dynamic slip weakening accordingly the occurrence of ccas in natural clay rich fault gouges constitutes new unequivocal textural evidence for shallow depth thermal pressurization and consequently for past seismic faulting

assessment of material characteristics of ancient concretes grande aula markets of trajan rome abstract the grande aula or great hall of the markets of trajan ad 96 to 115 is an intact example of the domed concrete architecture of imperial rome petrographic x ray diffraction chemical and sem analyses demonstrate that wall mortars contain pozzolane rosse volcanic ash aggregate harenae fossiciae and stratlingite a complex calcium aluminate cement hydrate c 2 ash 8 that gives modern cements good durability and compressive strength specific gravity tests and a new petrographic method for assessing bulk densities indicate unit weights of about 1750 kg m 3 for the wall mortars and 1430 1640 kg m 3 for the pumice bearing vaulted ceiling mortars innovative point load source tests record the tensile strengths f t of the aggregate and interfacial elements of the conglomeratic concrete fabric these suggest f t of about 2 7 mpa for brick 1 2 mpa for tufo lionato tuff and 0 9 mpa for tufo giallo della via tiberina tuff coarse aggregate caementa based on a tentative approximate correlation with splitting brazilian tests the pozzolanic mortar and interfacial zones have lower f t in the range of 0 8 mpa to 0 5 mpa the relatively low mortar strength and its somewhat tenuous adhesion to the coarse aggregate suggests that the caementa may have arrested the propagation of tensile microcracks that formed in the mortar thereby increasing the composite tensile strength of the concrete roman builders selected the complex aggregate mixes to optimize the performance of the wall and vault concretes

representing the global scale water masses in ocean general circulation models abstract a hierarchy of coarse resolution world ocean experiments were integrated with a view to determining the most appropriate representation of the global scale water masses in ocean general circulation models the largest scale response of the simulated ocean to the prescribed forcing in each model run is described the world ocean model eventually has a realistic approximation of continental outlines and bottom bathymetry the model forcing at the sea surface is derived from climatological fields of temperature salinity and wind stress the first experiment begins with a quite unrealistic and idealized world ocean subsequent experiments then employ more realistic surface boundary conditions model geometry and internal physical processes in all 16 changes to the model configuration are investigated a fundamental dynamical constraint in the drake passage gap appears to limit the outflow rate of bottom water in the antarctic region this constraint acts to decouple the extreme antarctic waters

water mass distributions at intermediate layers off the somali coast during the onset of the southwest monsoon 1979 abstract hydrographic observations at intermediate depth in the somali basin have been made during and after the transition from the northeast monsoon to the southwest monsoon 1979 the data are discussed in relation to measurements of absolute currents during the same time period earlier water mass identification by warren et al 1966 is confirmed and extended by introducing a well defined equatorial water mass the distribution of water masses and its temporal evolution with the changing monsoonal wind field is analyzed on three different spatial scales equatorial and near coastal undercurrents are an important factor in the large scale redistribution of water masses in the intermediate layers cross equatorial exchange of water in particular highly saline red sea water is largely confined to a narrow region off the east african coast no obvious response of these currents to the onset of the southwest monsoon is detected in the mesoscale range anticyclonic subsurface eddies containing equatoria

accelerated glacier melt on snow dome mount olympus washington usa due to deposition of black carbon and mineral dust from wildfire assessing the potential for black carbon bc and dust deposition to reduce albedo and accelerate glacier melt is of interest in washington because snow and glacier melt are an important source of water resources and glaciers are retreating in august 2012 on snow dome mount olympus washington we measured snow surface spectral albedo and collected surface snow samples and a 7 m ice core the snow and ice samples were analyzed for iron fe used as a dust proxy via inductively coupled plasma sector field mass spectrometry total impurity content gravimetrically bc using a single particle soot photometer sp2 and charcoal through microscopy in the 2012 summer surface snow bc 54 50 g l fe 367 236 g l and gravimetric impurity 35 18 mg l concentrations were spatially variable and measured broadband albedo varied between 0 67 0 74 bc and dust concentrations in the ice core 2011 summer horizon were a magnitude higher bc 3120 g l fe 22000 g l and gravimetric impurity 1870 mg l corresponding to a modeled broadband albedo of 0 45 based on the measured bc and gravimetric impurity concentrations the big hump forest fire is the likely source for the higher concentrations modeling constrained by measurements indicates that the all sky 12 h daily mean radiative forcings in summer 2012 and 2011 range between 37 53 w m 2 and 112 149 w m 2 respectively with the greater forcings in 2011 corresponding to a 29 38 mm d enhancement in snowmelt the timing of the forest fire impurity deposition is coincident with an increase in observed discharge in the hoh river highlighting the potential for bc and dust deposition on glaciers from forest fires to accelerate melt

a newly emerged august 2013 artificially triggered fumarole near the fiumicino airport rome italy abstract early in the morning of 24 august 2013 following by hours the drilling of a shallow borehole in the same spot a new fumarole producing emissions of co2 rich gas water and mud suddenly appeared at a crossroad along the fenced area of the fiumicino international airport of rome italy similar episodes have been scientifically documented or simply reported in recent and past years to understand why gases are easily entrapped in the shallow subsurface of the fiumicino area we used five borehole cores drilled by us analyzed the stratigraphy of these and other nearby cores acquired a 2d seismic refraction tomogram and performed chemical and isotopic analyses of water samples collected from aquifers intercepted by two drilled boreholes our boreholes were realized with proper anti gas measures as while drilling we recorded the presence of pressurized gases at a specific permeable gravel level results show that in the study area gases become mainly entrapped in a mid pleistocene gravel horizon at about 40 50 m depth this horizon contains a confined aquifer that stores the endogenous upwelling gases the gravel is interposed between two silty clayey units the lower unit very hard and overconsolidated is affected by fractures that allow ascending gases to bypass the otherwise impermeable shale permeate the gravel and dissolve into the aquifer in contrast the upper unit is impermeable to fluids and seals the gas pressurized aquifer which therefore constitutes a source of hazard during human activities such as well drilling quarrying and various building related excavations as the stratigraphy of the fiumicino area is very common in large portions of the densely populated roman area and as the adjacent volcanic districts are hydrothermally active we conclude that phenomena similar to that observed at fiumicino could again occur both at fiumicino and elsewhere in the surrounding region as a prompt confirmation of our conclusion we signal that while writing this paper new artificially triggered degassing phenomena occurred off fiumicino in connection with the construction of the new harbor

the history of the monti sabatini and alban hills volcanoes groundwork for assessing volcanic tectonic hazards for rome abstract the volcanic rocks of rome provide chronostratigraphic constraint that is of use to geologists archaeologists and paleontologists identifying the areal distribution of these rocks their mode of emplacement and a detailed chronology of the eruptive events also is crucial for assessing local natural hazards in a volcanic tectonic context and for recognizing whether the volcanoes may erupt again in the future we have identified and dated many of the volumetrically significant eruptive units from the monti sabatini and alban hills colli albani and propose a formalized volcanic stratigraphy for rome it is probable that seismic events triggered some eruptions as several ignimbrites from the two volcanoes have statistically indistinguishable ages following a 200 kyr period of dormancy that was coincident with a pulse of regional uplift the alban hills appears to have begun recently circa 45 ka a new eruptive cycle therefore accurate assessment of volcanic tectonic hazards and estimation of possible future volcanic activity is necessary for the safety of the five million people living near these volcanoes

optical characteristics of cryoconite surface dust on glaciers the relationship between light absorbency and the property of organic matter contained in the cryoconite

a source to sink compositional model of a present highstand an example in the low rank tiber depositional sequence latium tyrrhenian margin italy abstract our source to sink compositional model of sediment distribution in the present highstand of the tiber depositional sequence has important implications for sediment source lithology generation transport and deposition in the tiber river system sand compositional trends reflect provenance mixing anthropic intervention and the effects of local autogenic factors in continental to marine depositional environments fluvial feldspatho quartzo lithic sand results from the contribution of the major tributaries of the tiber drainage basin which can be divided into two sub basins separated by the corbara dam built in the 1950s upstream drainage basin sand has a siliciclastic sedimentary lithic signature whereas carbonate and volcanic lithic fragments dominate downstream drainage basin sand downstream sand is further modified in the coastal environment by hydraulic sorting and mixed with detritus derived from the recycling of coastal dune sand and altered volcaniclastic paleosols the latter are associated with lower course floodplain and channel deposits which produce a quartzo feldspatho lithic sand sediment grain size zonation in the marine environment is influenced by coastal hydrodynamics which in turn produce two detrital populations with distinct compositional signatures and hydraulic behavior coarser minerals essentially pyroxene phenocrysts and finer feldspar grains are progressively concentrated in higher energy and lower energy environments respectively biogenic continental shelf and slope deposits off the tiber river mouth show very little riverine influence this study of the last highstand system tract in the tiber depositional sequence clarifies the effects of hydraulic sorting grain size dependence and sediment reworking in controlling the final composition of modern sand this knowledge can be used to better understand detrital modes of ancient sedimentary successions

integrated geochronology of acheulian sites from the southern latium central italy insights on human environment interaction and the technological innovations during the mis 11 mis 10 period abstract we have explored the multimethod approach combining 40ar 39ar on single crystal esr on bleached quartz and esr u series on teeth to improve the age of four neighbours acheulian sites of the frosinone province latium italy fontana ranuccio cava pompi pofi isoletta and lademagne ages obtained by the three methods are in mutual agreement and confirm the potential of dating with confidence middle pleistocene sites of italy using these methods at fontana ranuccio the 40ar 39ar age 408 10 ka full external error at 2 obtained for the archaeological level unit fr4 and geochemical analyses of glass shards performed on the unit fr2a layer allow us to attribute the studied volcanic material to the pozzolane nere volcanic series a well known caldera forming event originated from the colli albani volcanic district these new data ascribe the fontana ranuccio site as well as the eponym faunal unit to the climatic optimum of marine isotope stage mis 11 ages obtained for the cava pompi isoletta and lademagne sites cover a relatively short period of time between 408 ka and 375 ka spanning mis 11 climatic optimum to the mis 11 10 transition analysis of small collections of lithic industries bifacial tools and small cores technologies from isoletta lademagne and the neighbour site of ceprano campogrande shows common technical strategies for the period comprised between mis 11 and mis 9 410 325 ka such as the elaboration of flaked elephant bone industries found over the whole latium region however some features found only in the frosinone province area like large sized bifaces suggest particular regional behaviours the presence of one levallois core in the oldest layer of lademagne i e 405 9 ka suggests a punctual practice of this technology also proposed as early as mis 10 11 in the neighbour site of guado san nicola molise in central italy

age of the ponta grossa dike swarm brazil and implications to parana flood volcanism the ponta grossa dike swarm pgds occurs in a nw trending 200 km wide zone exposed just east of the parana basin in southeastern brazil the predominantly basaltic dikes intrude crystalline basement paleozoic mesozoic sediments and rarely flows of the parana etendeka flood volcanic province pep the pgds resembles the failed arm of a rift rift rift triple junction related to the separation of south america and africa detailed geochemical studies of the dikes including major minor trace element and sr nd isotopic analyses indicate that they probably represent feeders for the voluminous phase of flood volcanism represented by relatively uncontaminated predominantly high tio2 lavas of the northern pep where lava accumulations reach 1700 m thick 40ar 39ar stepwise degassing data using both laser and radiofrequency induction furnace on plagioclase separates from eighteen dikes and one sill yield seventeen plateau ages three are between 120 7 1 3 ma and 125 8 0 6 ma and fourteen are clustered between 129 2 0 4 ma and 131 4 0 5 ma isochron ages are not significantly different from the plateau ages and plateau ages are adopted in all but two cases as being the most accurate age estimates the age probability distribution for the dominant pulse 131 4 0 4 to 129 2 0 4 ma shows a pronounced peak at 130 5 ma this distribution probably reflects the magma production history in the region the new geochronologic data are consistent with conclusions based on paleomagnetic and chemical stratigraphic data that the pgds is younger than the volumetrically dominant majority of volcanism in the southern pep which occurred at 133 132 ma the younger commonly ne trending dikes may reflect the initiation of full drift which was coincident with major basin development in the adjacent continental borderland at 125 120 ma the pgds may indeed represent the failed arm of a rift rift rift triple junction but the triple junction did not coincide exactly in time or space with the site that would be inferred for plume impact

recent uplift of the alban hills volcano italy evidence for magmatic inflation first order leveling surveyed in 1951 and 1994 along a line across the alban hills volcano reveals maximum vertical uplift of 30 cm average of 7 mm yr in the region of geologically recent 0 020 0 030 ma explosive activity the uplifted region corresponds to an area where seismic activity is concentrated at depths of 3 6 km uplift exceeding 10 cm is observed over a 14 km wide zone in the center of a 40 km long line with the deformation tapering to zero at both ends of the line data from a few sparse older benchmarks measured in 1891 and 1927 suggest that the deformation in the first half of this century was very small compared to the period 1951 1994 the observed uplift together with increased seismic activity suggest that recent magma injection has occurred in the upper crust beneath the alban hills volcano

reconstruction of the mis 5 5 5 3 and 5 1 coastal terraces in latium central italy a re evaluation of the sea level history in the mediterranean sea during the last interglacial abstract we present a geomorphological stratigraphical and geochronological study reconstructing a suite of paleo surfaces in a 200 km long coastal sector of the central tyrrhenian sea between argentario and circeo promontories identification of the near shore deposits associated with these paleo surfaces allow us to define corresponding marine terraces and paleo sea levels 40ar 39ar and esr u th geochronologic constraints on key deposits provide correlation with the terraces previously recognized in the coast of central latium refining their correlation with the marine isotopic stages results of this study enable us to propose a re assessment of the ages for the sea level markers of mis 5 5 5 3 5 1 in the central tyrrhenian sea suggest that a continuous tectonic uplift with an average rate of 0 224 mm yr affects the latium coast since 200 ka provide new evidence for a mis 5 5 paleo sea level marker occurring at 35 m a s l on the coastal sector extending from montalto di castro to latina while it possibly drops down and connects to a paleo sea level ranging 10 5 m between monte circeo and gaeta previously attributed to this interglacial discussing possible evidence of similar elevation of the sea level during mis 5 5 5 3 and 5 1 interglacials in the tyrrhenian sea compare this datum with those from the western pacific and several coral reefs where the differences with respect to tectonically stable regions were attributed either to tectonics or to the glacial isostatic adjustment showing that the presented record of sea level markers may have a strong impact on modeling the post glacial effects in the mediterranean sea and on the paleoclimatic and paleoceanographic studies in this region

the bag tephra a widespread tephrochronological marker in middle europe chemical and mineralogical investigations the bag tephra is a widespread tephra layer interbedded in quaternary loess deposits along the danubian valley of hungary and slovakia its age is poorly defined between 788 and 380 ka b p the glass and mineral composition micropumice clasts of phono tephrite and blocky shards of tephri phonolite associated with two kinds of clinopyroxene fassaitic diopside and salite is very distinctive this tephra could be used as a chronological marker as soon as its age is refined the probable origin is the middle italian volcanic area

roles of the okhotsk sea and gulf of alaska in forming the north pacific intermediate water recently obtained world ocean circulation experiment woce sections and pre woce hydrography are used to study the water mass structure and formation and transformation of north pacific intermediate water npiw five neutral density surfaces are selected and mapped encompassing npiw from 400 to 900 m in the subtropical latitudes with a distance of 100 m between a pair of surfaces npiw is defined as a subtropical gyre salinity minimum which is well followed by a neutral density surface n 26 9 formation and transformation of npiw is examined by the mapped turner angle on neutral density surfaces apparent diffusive double diffusion is found in the alaskan gyre on n 26 5 neutral surface in the northwest subpolar gyre and the okhotsk sea on n 26 9 neutral surface and mainly in the okhotsk sea on the two deep neutral surfaces n 27 2 and n 27 4 these diffusive regions indicate transformation sources for npiw along with additional information of potential vorticity and stream function it is found that there are two different npiw formation sources one in the gulf of alaska characterized by high potential vorticity and the other in the okhotsk sea characterized by low potential vorticity the former lies shallower at n 26 2 26 5 but its effect deepens to npiw core density level at n 26 8 on the basis of potential vorticity distribution the latter includes the influence of the northwest subpolar gyre and extends much deeper to n 27 4 we call them gulf of alaska intermediate water gaiw and okhotsk intermediate water oiw respectively gaiw contributes to npiw in the eastern part of the subtropical gyre east of date line whilst oiw dominates in the west and entire lower part of npiw seasonal flow stream function mapped on neutral surfaces shows that the contribution of gaiw to npiw occurs mainly in the wintertime because in winter a significant northward shift of zero wind stress curl makes the gulf of alaska an additional source for npiw

a review of the stratigraphy of rome italy according to geochronologically and paleomagnetically constrained aggradational successions glacio eustatic forcing and volcano tectonic processes abstract in this paper we provide a critical review of the studies conducted on the geology of rome since the first half of the 20th century aimed at presenting an updated state of the art on the stratigraphy of this area following this introductory summary we present a complete reconstruction of the geological evolution and the resulting chrono litho stratigraphic setting of the greater area of rome according to a series of works that in the last 20 years have adopted an innovative methodological approach based on the conceptual model of aggradational successions deposited in response to sea level rise during the glacial terminations and on the strict geochronologic constraints to the sedimentary record achieved by paleomagnetic investigation of clay sections and 40ar 39ar dating of interbedded volcanic materials we also present a complete overview on the chronostratigraphy of the two volcanic districts of colli albani and monti sabatini located se and nw of rome respectively that has been achieved integrating the field work with the large number of radiometric ages provided in these years on their eruptive products moreover we propose a revised stratigraphic column to compare the most recent official 1 50 000 and 1 10 000 geologic mapping of rome which is intended as a tool of correlation for an international audience of quaternary scientists to approach the study of this area a detailed discussion of the proposed revisions is also provided as supplementary information to this paper

low magnitude earthquakes in rome structural interpretation and implications for the local stress field on 1995 june 12 a ml 3 6 earthquake occurred in the cecchignola area of southern rome a detailed structural investigation of this area and an analysis of macroseismic and instrumental data indicate a seismogenic area for the local low magnitude seismicity that affects the city of rome a peripheral volcanic field in cecchignola shows that the local seismicity could be related to the same volcanotectonics that affects the colli albani alban hills region fracture field emission is proposed for the emplacement of about 2 5 km3 of lava which developed a small plateau that was subsequently intruded by the feeder dyke of a large ignimbrite the geometry of this dyke as well as the faults disrupting the lava field indicates ne sw extension younger tectonic features show a nw striking 3 in the studied area suggesting that dextral n s strike slip displacement generated structures that are not compatible with the local present day stress field characterized by a ne striking 3 an analysis of focal solutions and the spatial distribution of the 1995 june 12 microearthquake sequence suggests an e w seismogenic structure whose trend is atypical of the structural setting of the area the present study identifies surface faulting with the same trend as the focal mechanisms in the epicentral area and suggests that these faults represent an inactive surface expression of the deeper structures it is also suggested that these structures originated during a different tectonic regime and are presently reactivated at depth by the ne sw extension the general ne orientation of the t axes from focal mechanisms for the colli albani earthquakes and for the 1995 june 12 cecchignola event strongly supports a regional interpretation for the present day stress field previously observed only in the colli albani area it is likely that a combination of different tectonic styles during the last 600 kyr is necessary to explain the structural features of the cecchignola area and of the central tyrrhenian sea margin of italy in general

pitfalls with the numerical representation of isopycnal diapycnal mixing abstract current numerical models of ocean circulation parameterize diffusion using a diagonal diffusivity tensor in a horizontal vertical coordinate system rather than in the isopycnal diapycnal directions it is pointed out that this procedure introduces a fictitious flux of density in the horizontal direction a solution to this problem is available in the work of redi also we show that care must be used in simple models of the deep ocean not to confuse the diapycnal velocity with the vertical velocity which simply occurs as a component of along isopycnal motion

on the origins of deep and bottom waters of the indian ocean the characteristics of the deep and bottom waters of the indian ocean when illustrated on potential density anomaly surfaces indicate that the waters enter from both the atlantic and pacific oceans the paths of spreading are constrained by the complex topography and characteristics are seen to be altered by exchange with the overlying and underlying water and with the sediments especially in the northern indian ocean the weddell sea contributes to the densest waters found in the western basins and the ross sea and adelie coast to the densest waters found in the eastern basins both dense water varieties are altered by and incorporated in the less dense water above initially water carried by the circumpolar current then water from the north atlantic and finally by deep water whose characteristics are derived in the northern indian ocean contact with the sediments increases the silica content of the bottom water in the southern ocean in the northern indian ocean the sediments alter the silica of the water at the bottom and together with enhanced salinity from diffusion of saline overflows from the marginal seas above imprint unique markers to the deep water that flows back to the south at middepths the series of ridges between madagascar and australia confine the flow to a series of gyres that carry characteristics from the circumpolar current equatorward and the northern indian ocean characteristics southward within the circumpolar current low oxygen deep water from the pacific is carried across the atlantic and into the indian ocean south of africa part flows around the cyclonic weddell sea gyre and part extends across the southern ocean water from another pacific source can be seen near 2000 m extending westward from the tasman sea south of aus tralia and across the indian ocean and perhaps to the aghulas current region southeast of africa in this study we show some maps of deep and bottom water characteristics of the indian ocean which may be used in a qualitative sense to infer pathways of spreading of water below a depth of about 2000 m the indian ocean has numerous ridges and basins figure 1 that severely restrict possible pathways of deep and bottom wa ter flow in the following we will begin by looking at char acteristics at the bottom of the ocean to reveal the path ways of spreading of the densest bottom waters from basin to basin then a series of six potential density anomaly surfaces at progressively shallower depths from about 4000 m up to about 2000 m will be shown to see what character istics influence the deep waters and how pathways of flow are constrained by the bathymetry of the indian ocean the choice of the specific density levels table 1 was based primarily on various property extrema shown by the 18os atlantis ii cruise 93 colored sections that accompany warren s 1981 detailed discussion of the major features of the central indian ocean between madagascar and aus tralia the sections approximately midway between antarctica and the northern indian ocean boundaries are well positioned to show features originating from both the north and the south as well as some brought into the indi an ocean by the antarctic circumpolar current the full ocean area isopycnal maps provide essential evidence on the origins and fates of features seen in the sections and

imaging spectroscopy to assess the composition of ice surface materials and their impact on glacier mass balance abstract glacier surfaces are not only composed of ice or snow but are heterogeneous mixtures of different materials the occurrence and dynamics of light absorbing impurities affect ice surface characteristics and strongly influence glacier melt processes however our understanding of the spatial distribution of impurities and their impact on ice surface characteristics and the glacier s energy budget is still limited we use imaging spectroscopy in combination with in situ experiments to assess the composition of ice surface materials and their respective impact on surface albedo and glacier melt rates spectroscopy data were acquired in august 2013 using the airborne prism experiment apex imaging spectrometer and were used to map the abundances of six predominant surface materials on glacier de la plaine morte swiss alps a pixel based classification revealed that about 10 of the ice surface is covered with snow water or debris the remaining 90 of the surface can be divided into three types of glacier ice namely 7 dirty ice 43 pure ice and 39 bright ice spatially distributed spectral albedo derived from apex reflectance data in combination with in situ multi angular spectroscopic measurements was used to analyse albedo patterns present on the glacier surface about 85 of all pixels exhibit a low albedo between 0 1 and 0 4 mean albedo 0 29 0 12 indicating that glacier de la plaine morte is covered with a significant amount of light absorbing impurities resulting in a strong ice albedo feedback during the ablation season using a pixel based albedo map instead of a constant albedo for ice 0 34 as input for a mass balance model revealed that the glacier wide total ablation remained similar 10 difference however the large local variations in mass balance can only be reproduced using the pixel based albedo derived from apex emphasizing the need to quantify spatial albedo differences as an important input for glacier mass balance models

correlation of fluviodeltaic aggradational sections with glacial climate history a revision of the pleistocene stratigraphy of rome volcanic horizons interbedded with fluviodeltaic clastic sediments of the tiber and fosso galeria river valleys near rome provide a unique opportunity to date five middle pleistocene fining upward aggradational sections 40 ar 39 ar ages from the interbedded volcanic beds illustrate that aggradation occurred on an approximate 100 k y cycle and was initiated by sea level rise associated with glacial melting the age constraint additionally shows that aggradation occurs rapidly in response to sea level change and thus ages from volcanic strata within the aggradational sections provide high resolution constraint on the timing of relative sea level rise the established chronology is consistent with other glacial proxies and their radioisotopically or orbitally based time scales for the timing of glacial terminations vi and v but is significantly older than most records for the timing of termination iii ultimately the age of each termination should be determined by radioisotopic means and to that end the work here shows that fluviodeltaic sedimentology provides valuable information for middle pleistocene time scale calibration

water mass analysis with three conservative variables with one conservative tracer in addition to salinity and potential temperature it is possible to determine the relative strengths of lateral and vertical mixing processes this is achieved by first eliminating vertical advection through neutral surfaces and then forming a linear combination of the three conservative tracers so that the epineutral gradient i e the lateral gradient along the neutral surface of the new variable is zero thereby eliminating lateral advection the resulting expression for the ratio of the vertical and lateral diffusivities involves the curvatures of property property diagrams formed both from vertical casts and from data measured on a neutral surface the method requires that the epineutral gradients of potential temperature salinity and the third conservative tracer are parallel this condition is often met in the common situation where water parcels are the result of mixing between just two parent water masses

genesis evolution and tectonic significance of k rich volcanics from the alban hills roman comagmatic region as inferred from trace element geochemistry trace element data are reported in 21 lava samples from the alban hills one of the most important volcanic complexes of the roman comagmatic region the samples consist mostly of tephritic leucitites with minor phonolitic tephrites and tephritic phonolites emplaced during two distinct phases of activity separated by a caldera collapse

crustal structure and moho depth profile crossing the central apennines italy along the n42 parallel 1 we present results from a teleseismic receiver function study of the crustal structure in the central apennines italy data from 15 stations deployed in a linear transect running along the n42 parallel were used for the analysis a total number of 364 receiver functions were analyzed the crustal structure has been investigated using the neighborhood algorithm inversion scheme proposed by sambridge 1999a obtaining crustal thicknesses bulk crustal vp vs ratio and velocity depth models in each inversion the degree of constraint of the different parameters has been appraised by the bayesian inference algorithm by sambridge 1999b the study region is characterized by crustal complexities and intense tectonic activity recent volcanism orogenesis active extensional processes and these complexities are reflected in the receiver functions however the relatively close spacing among the seismometers about 20 km helped us in the reconstruction of the crustal structure and moho geometry along the transect crossing the apennines from west to east the moho depth varies by more than 20 km going from a relatively shallow depth around 20 km on the tyrrhenian side deepening down to about 45 km depth beneath the external front of the apenninic orogen and rising up again to about 30 km depth in correspondence of the adriatic foreland despite the strong variability of the crustal thickness the average crustal vs values show little variation along the transect fluctuating around 3 km s the average vp values obtained from the vs and vp vs are generally lower than 6 km s