a tree ring based reconstruction of summer relative humidity variability in eastern mongolian plateau and its associations with the pacific and indian oceans a regional chronology rc based on tree ring width data at two sites was developed for the southern hulun buir sandy land a marginal area of the eastern mongolian plateau china this chronology significantly and positively correlated with the relative humidity from the previous december to september except in may the highest correlation of the rc with the mean june august relative humidity suggested that the growth of pinus sylvestris var mongolica strongly reflects seasonal moisture conditions consequently the variation in the mean june august relative humidity was reconstructed for the reliable time period of 1835 2013 41 6 of the variance occurred during the calibration period of 1953 2012 similar patterns of drought and pluvial fluctuations were found in other tree ring based moisture reconstructions our reconstruction implied that the characteristics of regional hydroclimatic variations such as the drought and low humidity of the late 1990s to 2000s were not unusual from the long term perspective as suggested by the hydrological records obtained from tree ring material spectrum analyses results and significant spatial correlations of our relative humidity reconstruction with the sea surface temperature sst in the eastern equatorial pacific ocean and tropical indian ocean implied close linkages between moisture in the eastern mongolian plateau and remote oceans when the sst related to the el nino southern oscillation was high low the intensity of the indian summer monsoon at the northern extremities weakened strengthened thus moisture decreased i e the relative humidity was low in north china and in our study area the low land sea thermal contrast between asia and the indian ocean due to the enhanced ssts in the tropical indian ocean also influenced the strength of the moisture transfer via the indian summer monsoon thereby reducing the moisture variations in the eastern mongolian plateau

barrier effect on mjo propagation by the maritime continent in the mjo task force gewex atmospheric system study models abstractthe simulated madden julian oscillation mjo events in 27 general circulation models gcms are identified using an mjo tracking method the results suggest that the occurrence frequencies

major explosive activity in the monti sabatini volcanic district central italy over the 800 390 ka interval geochronological geochemical overview and tephrostratigraphic implications abstract a review of the existing chronological stratigraphic and chemo petrologic data of the major eruptive units from the early phase of activity 800 390 ka in the monti sabatini volcanic district msvd belonging to the ultra potassic magmatic region of central italy is presented along with new radioisotopic age determinations and geochemical analyses through the combined use of electron microprobe glass compositions selected trace element compositions and single crystal 40ar 39ar age determinations we provide a new chrono and chemo stratigraphic classification of the products emplaced in the 800 390 ka time interval besides giving insights on the petrologic evolution of the roman comagmatic region the large dataset provides fundamental information that is applicable to tephrostratigraphic studies in the wide region encompassing the tyrrhenian sea margin to the adriatic sea basin distal tephras from this volcanic activity also act as important geochronologic markers for the coastal sedimentary successions deposited in response to glacio eustatic fluctuations as well as for successions in the quaternary tectonic basins of the central and southern apennines an innovative approach based on the use of discrimination diagrams of zr y vs nb y ratios for fingerprinting altered volcanic rocks recently developed and successfully employed in archaeometric studies is here combined to the glass compositions for classifying the msvd deposits and tested on two distal tephra layers showing its potentiality for tephrostratigraphic correlation

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

magnetic fabric and structural setting of plio pleistocene clayey units in an extensional regime the tyrrhenian margin of central italy abstract results are presented of structural analysis and anisotropy of magnetic susceptibility ams analysis of plio pleistocene clayey units from the extensional tyrrhenian margin of central italy data have been collected in different tectonic settings mainly strike slip and transverse extensional structures at the sites with major evidence of plio pleistocene tectonics there appears a close relationship between magnetic lineations and stretching directions stretching processes that were able to modify the original magnetic fabric pre dated significant normal fault related tilting and therefore were active at the very first stage of extensional deformation the relationships between ams and structural trends in an extensional regime seem distinctively different from those reported in compressional regimes this kind of analysis may be useful in the geodynamic interpretation of ambiguous structures

on the maintenance and initiation of the intraseasonal oscillation in the ncep ncar reanalysis and in the gla and ukmo amip simulations in this study satellite derived outgoing longwave radiation olr and the reanalysis from the national centers for environmental prediction national center for atmospheric research are used as verification data in a study of intraseasonal variability in the goddard laboratory for atmospheres gla and the united kingdom meteorological office ukmo atmospheric general circulation models these models simulated the most realistic intraseasonal oscillations io of the 15 atmospheric model intercomparison project models previously analyzed during the active phase of the intraseasonal oscillation convection is observed to migrate from the indian ocean to the western central pacific ocean and into the south pacific convergence zone spcz the simulated convection particularly in the gla model is most realistic over the western central pacific ocean and the spcz in the reanalysis the baroclinic structure of the io is evident in the eddy stream function and eastward migration of the anticyclone cyclone pairs occurs in conjunction with the eastward development of convection both the gla and ukmo models exhibit a baroclinic structure on intraseasonal time scales the gla model is more realistic than the ukmo model at simulating the eastward migration of the anticyclone cyclone pairs when the convection is active over the western central pacific in the ukmo model the main heating is located off the equator which contributes to the irregular structures seen in this model on intraseasonal time scales the maintenance and initiation of the intraseasonal oscillation has also been investigated analysis of the latent heat flux indicates that evaporative wind feedback is not the dominant mechanism for promoting the eastward propagation of the intraseasonal oscillation since evaporation to the west of the convection dominants the data suggest a wave cisk conditional instability of the secondkind type mechanism although the contribution by frictional convergence is not apparent in the gla model enhanced evaporation tends to develop in place over the west pacific warm pool while in the ukmo simulation westward propagation of enhanced evaporation is evident it is suggested that lack of an interactive ocean may be associated with the models systematic failure to simulate the eastward transition of convection from the indian ocean into the western pacific ocean this hypothesis is based upon the examination of observed sea surface temperature sst and its relationship to the active phase of the intraseasonal oscillation which indicates that the io may evolve as a coupled ocean atmosphere mode the eastward propagation of convection appears to be related to the gradient of sst with above normal sst to the east of the convection maintaining the eastward evolution and decreasing sst near the western portion of the convective envelope being associated with the cessation of convection

why the western pacific subtropical high has extended westward since the late 1970s the western pacific subtropical high wpsh is closely related to asian climate previous examination of changes in the wpsh found a westward extension since the late 1970s which has contributed to the inter decadal transition of east asian climate the reason for the westward extension is unknown however the present study suggests that this significant change of wpsh is partly due to the atmosphere s response to the observed indian ocean western pacific iwp warming coordinated by a european union s sixth framework programme understanding the dynamics of the coupled climate system dynamite five agcms were forced by identical idealized sea surface temperature patterns representative of the iwp warming and cooling the results of these numerical experiments suggest that the negative heating in the central and eastern tropical pacific and increased convective heating in the equatorial indian ocean maritime continent associated with iwp warming are in favor of the westward extension of wpsh the sst changes in iwp influences the walker circulation with a subsequent reduction of convections in the tropical central and eastern pacific which then forces an enso gill type response that modulates the wpsh the monsoon diabatic heating mechanism proposed by rodwell and hoskins plays a secondary reinforcing role in the westward extension of wpsh the low level equatorial flank of wpsh is interpreted as a kelvin response to monsoon condensational heating while the intensified poleward flow along the western flank of wpsh is in accord with sverdrup vorticity balance the iwp warming has led to an expansion of the south asian high in the upper troposphere as seen in the reanalysis

deep explosive focal depths during maar forming magmatic hydrothermal eruption baccano crater central italy we describe the eruptive activity of the pleistocene composite baccano maar crater in the sabatini volcanic complex central italy combining stratigraphy grain size componentry and rare earth element and yttrium rey composition of its eruptive products with the stratigraphy and geothermal data derived from deep wells drilled on the baccano structural high the main lithological characteristics of the basal baccano maar pyroclastic deposit composed of more than 60 wt of non thermometamorphosed lithic clasts from the sedimentary basement show that the first eruption was magmatic hydrothermal in nature the lithology of the sedimentary lithic clasts indicates that the fragmentation level was at a depth of 1 000 to 1 200 m with fragment depth verified by deep well stratigraphy the 15 wt juvenile non vesicular glass components suggest that magma played a minor role in powering the eruption assuming that the high salinity hot hydrothermal fluids 365 1 400 m by the aggressive hydrothermal fluids enriched in acid components hf hcl and h2so4 may have contributed to increased co2 partial pressure that helped to drive the hydrofracturing this could have caused rapid vapour separation and pressure drop allowing the almost simultaneous breaking of the aquifer cover and brecciation of the calcareous units down to 1 000 to 1 200 m depth the relative abundance of calcareous lithics in the basal part of the first baccano eruptive unit representing about the upper 200 m of stratigraphy below the top of the baccano structural high reveals the descent of the piezometric surface during the eruption combining deep well information and maar product stratigraphy using also rey data from maar pyroclastic fragments and the basement rocks we draw an interpretative model for the baccano maar forming eruption concluding that a magmatic hydrothermal eruptions may originate deeper than previously thought and b hydrothermal fluids circulating in limestone aquifers may play an important role in triggering such eruptions

age and kinematics of the burdur basin inferences for the existence of the fethiye burdur fault zone in sw anatolia turkey abstract the burdur basin is a late miocene to pliocene fluvio lacustrine basin in sw anatolia it is developed within the postulated fethiye burdur fault zone which was argued to be a sinistral strike slip fault zone developed in response to propagation of the pliny strabo step fault into sw anatolia turkey in order to assess the presence and tectonic characteristics of the fault zone we conducted a paleomagnetic study in the burdur basin that involved rock magnetic experiments anisotropy of magnetic susceptibility ams measurements and developing a magnetostratigraphy for dating purposes the obtained age model constrains most part of the tectonic evolution of the basin the well exposed 270 m thick burdur section revealed 3 normal and 2 reverse polarity magnetozones we propose that the burdur formation spans most of the gauss chron 3 4 2 5 ma which implies a sedimentation rate of 18 cm kyr the ams results in the section indicate nw se directed extension in addition we have also conducted kinematic analyses from 1790 fault slip data collected at 44 sites distributed within the supposed fethiye burdur fault zone in the region the results indicate that the region has been developed under a nw se directed extensional deformation regime and was dominated by ne sw striking normal faults from late miocene to recent few nw se striking normal faults with strike slip components are categorized as transfer faults which accommodated differential stretching between the burdur and cameli basins stretching amounts increase southwards demonstrating a dextral transtensional character of the transfer faults we have not observed any significant strike slip motion along the ne sw striking faults which challenges the presence and sinistral transcurrent nature of the supposed fethiye burdur fault zone

propagation and initiation mechanisms of the madden julian oscillation 1 an observational study of the propagation and onset mechanisms of the madden julian oscillation mjo is performed using cyclostationary empirical orthogonal function analysis and a kelvin rossby wave decomposition method for the noaa outgoing longwave radiation and the ncep ncar reanalysis data in these analyses two different regions of surface convergence are observed ahead of mjo convection by different wind components as previously found in a sst coupled gcm simulation at the leading edge of enhanced convection the friction induced meridional convergence appears during the developing phase when the enhanced convection is located over the indian ocean and the maritime continents another region of surface convergence is identified just east of an enhanced convection core and this tends to pull the convective core to the east the surface convergence is formed by zonal wind convergence and kelvin and rossby waves both play a comparable role in the formation of the convergence zone therefore the frictional kelvin rossby wave cisk conditional instability of the second kind is regarded as a primary factor for the eastward propagation of the mjo over the western indian ocean moistening in the boundary layer occurs 2 weeks earlier than the beginning of a new mjo cycle this moistening accompanies low level convergence by encircling kelvin waves which propagated from the region of enhanced convection during the previous cycle as well as by rossby waves generated from the region of reduced convection over the indian ocean this earlier formation of the boundary layer moisture convergence provides a favorable environment for triggering new convection this interaction of kelvin and rossby waves also accounts for the suppression of convection from the western side of the convection core for example over the indian ocean anomalous surface divergence appears at the western edge of the enhanced convection due to both circumnavigating kelvin waves from the region of reduced convection of the previous cycle and rossby waves from the region of the enhanced convection itself thus the mjo is a self maintaining and self generating form of tropical variability through the interaction between convection and large scale circulation in the presence of boundary layer dynamics

magnetic fabric strain and paleostress in the canadian rocky mountains abstract the paper reports a detailed study of the anisotropy of magnetic susceptibility at two localities 100 km apart in the canadian rocky mountains both in the miette group of precambrian sediments which was folded during the laramide orogeny from the orientations of the susceptibility ellipsoids we infer principal strain axes and assuming irrotational deformation possible laramide paleostress orientations at wynd siding near jasper in the main ranges oriented samples were taken from both limbs and the nose of a plunging syncline near tete jaune cache at the western boundary of the main ranges a small syncline and steeply dipping beds of one limb of a large anticline were sampled minimum principal susceptibilities transverse to the strike of the rockies dominate the magnetic fabric at both localities and it is clear that regional shortening of the whole rock mass has obliterated any original depositional fabric and any small scale fold related fabric at both sites writing k1 k2 k3 for the principal susceptibilities the k3 axis and by inference the axis of principal shortening is horizontal with azimuth n52 e at wynd and plunges 10 20 along azimuth n26 e at tete jaune cache k1 is vertical at wynd but horizontal and along the fold axis n61 w at tete the uniformity of axes of susceptibility and inferred strain through each locality suggests irrotational deformation and encourages the further inference of possible paleostress orientations with 1 aligned with k3 2 with k2 and 3 with k1 the magnetic fabrics then indicate a thrust type paleostress field at wynd consistent with the laramide thrusts in the eastern rockies but a strike slip type paleostress field at tete jaune cache the change of stress orientation may reflect deeper burial in laramide times of the rocks sampled at tete jaune cache consistent with the much higher grade of metamorphism there

characteristics of the tropical intraseasonal oscillation in the ncar community climate model summary the structure of the intraseasonal oscillation in a perpetual january integration of the ncar community climate model ccm is analysed and compared with observations the simulated oscillation is identified as an eastward moving perturbation in the equatorial velocity potential field with predominantly zonal wavenumber 1 structure analysis of its vertical and horizontal structure based on composites shows good agreement with the observed oscillation from station data and from numerical weather prediction model analyses the simulated intraseasonal oscillation is evident in the wind fields at all longitudes but its appearance in the precipitation and outgoing long wave radiation is confined to the eastern hemisphere the perturbation to the zonal wind component is characterized by an out of phase behaviour between the lower and upper troposphere which is most coherent in the convective regions of the indian ocean and west pacific the streamfunction anomalies in these regions are suggestive of a coupled rossby kelvin wave whilst in the western hemisphere the oscillation is more characteristic of a kelvin wave the role of cloud radiation interaction was studied using a parallel integration in which the cloud longwave forcing in the atmosphere was removed this was found to influence the strength of the oscillation but had no significant impact on the period in common with other model simulations of the intraseasonal oscillation the period was found to be too short near 25 days reasons for this are discussed in the context of a similar analysis of a perpetual july integration in which a much slower period near 54 days and less coherent oscillation was identified

the alban hills and monti sabatini volcanic products used in ancient roman masonry italy an integrated stratigraphic archaeological environmental and geochemical approach abstract the rocks of alban hills and monti sabatini volcanoes central italy and their associated epiclastic deposits have been extensively used as building material in ancient rome from about viiith century bce to ivth century ce however the identification of the source areas of these rocks is difficult due to the lack of an integrated stratigraphic and geochemical analysis of the relationships between the two volcanic districts and to the alteration affecting the primary products as consequence of weathering and pedogenetic processes here a comprehensive upgraded stratigraphic and geochronological review of the two volcanic districts corroborated by new geochronological data for several eruptive units and altered deposits is presented coupled to a complete geochemical background achieved by means of newly determined major and trace element analyses for all the main eruptive units a study of the alteration processes of the primary products is also presented and the age of the main weathering and pedogenetic phases associated to quaternary climatic changes are also investigated the results are integrated with those from literature in order to construct discriminant diagrams based on selected trace elements and allow us to characterize the primary and altered volcanic deposits in the rome area distinguish products of different volcanic districts discuss the effects of different weathering processes on the mobility of some elements and provide a reference frame for the provenance of the volcanic materials employed in ancient roman masonry the interdisciplinary data set and results presented here provide groundwork for volcanological climate pedological and archaeological provenance studies

principal oscillation pattern analysis of the 30 to 60 day oscillation in general circulation model equatorial troposphere a new technique is described for identifying time dependent patterns i e principal oscillation patterns or pops in a set of geophysical time series pops are defined as the normal modes of a linear dynamical representation of the data in terms of a first order autoregressive vector process with residual noise forcing pops associated with real eigenvalues represent nonpropagating nonoscillatory patterns which decay exponentially pops associated with complex eigenvalues occur in complex conjugate pairs and can represent standing wave structures if one pattern is much stronger than the other propagating waves if both patterns are periodic and have the same structure except for a quarter wavelength shift or in general an arbitrary amphidromal oscillation after the pops have been defined for a selected set of primary variables associated correlation or composite patterns may be derived for additional secondary fields to gain further insight into the structure of the interaction mechanisms the method is illustrated by analyzing the tropical variability structure of a 10 year numerical simulation with the t21 general circulation model gcm of the european centre for medium range weather forecasts reading england the pop analysis is applied to the 200 hpa horizontal divergence field along the equator for time scales shorter than 10 weeks the associated patterns are determined for a number of additional fields in the tropical belt between 30 s and 30 n one dominant pop pair is found its spatial scale corresponds to zonal wave number 1 the patterns travel eastward with an average period of 24 days and an e folding decay time of 10 days the maximum variance occurs in the area with maximum tropical precipitation between 100 e and the dateline these features correspond rather closely to the characteristics of the observed tropical 30 to 60 day wave except for the smaller period a frequency wave number analysis confirms that this 30 to 60 day wave is the most dominant regular oscillation in the tropical gcm troposphere the associated patterns of sea level pressure precipitation and other quantities exhibit a number of intriguing aspects namely 1 the phase velocity of the 30 to 60 day wave varies with longitude from 6 m s 1 in the indonesian area to more than 30 m s 1 over the eastern pacific small phase speeds being associated with large amplitudes and high phase speeds with small amplitudes 2 in the high amplitude regions rainfall and upper air velocity potential are in phase while in the low amplitude regions rainfall and velocity potential appear uncorrelated 3 at the surface a pattern strongly resembling gill s theoretical response to an equatorial heating source is found with a trough to the east and two off equatorial cyclones to the west of the heating the lack of meridional winds is probably related to the disregard of the seasonal asymmetries

hydrovolcanic explosions the systematics of water pyroclast equilibration the initial contact of external water with erupting magma and the mass ratio of water to magma govern the development of hydrovolcanic phenomena the phase relations of water within the runout system and the separation of vapor or liquid from the pyroclasts explain gradational transitions between some pyroclastic flows base surges mud hurricanes mudflows and sheetfloods

drought reconstructions for the continental united states abstract the development of a 2 lat 3 long grid of summer drought reconstructions for the continental united states estimated from a dense network of annual tree ring chronologies is described the drought metric used is the palmer drought severity index pdsi the number of grid points is 154 and the reconstructions cover the common period 1700 1978 in producing this grid an automated gridpoint regression method called point by point regression was developed and tested in so doing a near optimal global solution was found for its implementation the reconstructions have been thoroughly tested for validity using pdsi data not used in regression modeling in general most of the gridpoint estimates of drought pass the verification tests used in addition the spatial features of drought in the united states have been faithfully recorded in the reconstructions even though the method of reconstruction is not explicitly spatial in its design the drought reconstructions show that the 1930s dust bow

on the anatomy of magma chamber and caldera collapse the example of trachy phonolitic explosive eruptions of the roman province central italy abstract textural and compositional features of pyroclastic products erupted during caldera forming events often reveal the tapping of different portions of variably zoned magma chambers due to changing geometries of the conduit vent systems here we report on ultrapotassic trachytic phonolitic explosive eruptions of the roman province central italy which show remarkable changes of textural features and glass compositions in the juvenile material even if the bulk chemical composition is essentially constant in each example the lower eruption sequence contains whitish crystal poor leucite free highly vesicular pumice emplaced by early plinian fallout and or pyroclastic currents upsection the eruption sequence contains black low porphyritic sanidine leucite bearing moderately vesicular scoria or spatter emplaced by major pyroclastic flows red tuff with black scoria and associated co ignimbrite coarse lithic rich breccias this suggests a shift from a central feeder conduit tapping the central part of the magma chamber to a ring fracture vent system tapping the peripheral portions of the magma chamber during caldera collapse key features of these evacuating magma chambers are the thermal and volatile concentration xvol gradients that produce the observed textural and compositional spectrum of trachy phonolitic rock types in particular the degrees of freedom during the crystallization of these ultrapotassic magmas are increased by the variation of the leucite stability field at different ph2o conditions both leucite free and leucite bearing differentiated ultrapotassic rock types can be produced in the course of individual eruptions as a result of pre eruptive conditions in the feeder magma with no need to invoke different differentiation suites related to mantle source heterogeneities of parental magmas

reconstruction of drought variability in north china and its association with sea surface temperature in the joining area of asia and indian pacific ocean abstract using tree ring data from the northernmost marginal area of the east asian summer monsoon easm in north china may july mean palmer drought severity index pdsi was reconstructed back to 1767 ad the reconstruction captured 52 8 of the variance over the calibration period from 1945 to 2005 ad and showed pronounced pluvial periods during 1850 1905 1803 1811 and 1940 1961 and dry periods during 1814 1844 1916 1932 and 1984 2012 these anomalous periods have previously been reported in other parts of north china spatial correlation analyses and comparisons with other hydroclimatic indices in north china indicated that our new pdsi reconstruction could represent spatial and temporal drought variability in this region well our work also suggested that the drying tendency currently observed in the northern part of north china including the study area is consistent with the weakening of the easm meanwhile the drying trend was seemingly restrained at present in the southern part of north china spatial correlation patterns with global sea surface temperature sst indicated that the regional hydroclimatic variability in north china was tightly linked to sst over the joining area of asia and indian pacific ocean aipo especially over the tropical western pacific when sst from prior november to current july nj sst in the aipo area was anomalously high low the thermal contrast between asian land and ocean was weakened strengthened and the easm was correspondingly weakened strengthened thereby causing droughts pluvials in north china the results of this study do not only provide useful information for assessing the long term climate change in north china but also suggest that abnormal variability in nj sst over the aipo area could be used to forecast hydroclimatic conditions in north china

drought reconstruction in eastern hulun buir steppe china and its linkages to the sea surface temperatures in the pacific ocean abstract a tree ring width chronology covering the period 1780 2013 ad was developed from pinus sylvestris var mongolica for the eastern hulun buir steppe a region located on the edge of the eastern mongolian plateau china climate growth response analysis revealed drought stress to be the primary limiting factor for tree growth therefore the mean february july standardized precipitation evapotranspiration index spei was reconstructed over the period 1819 2013 where the reconstruction could account for 32 8 of the variance in the instrumental record over the calibration period 1953 2011 comparison with other tree ring based moisture sequences from nearby areas confirmed a high degree of confidence in our reconstruction severe drought intervals since the late 1970s in our study area consisted with the weakening east asian summer monsoon which modulating regional moisture conditions in semi arid zone over northern china drought variations in the study area significantly correlated with sea surface temperatures ssts in north pacific ocean suggesting a possible connection of regional hydroclimatic variations to the pacific decadal oscillation pdo the potential influence associated with el nino southern oscillation enso was primarily analyzed

stable isotope geochemistry and structural elements of the sabina region central apennines italy various tectonic features are present in the meso cenozoic basin units of the sabina region central apennines italy mio pliocene northeasterly verging thrusts are followed by plio pleistocene n s oriented right lateral strike slip faults stable isotope geochemistry and examination of meso and microstructures show that strain conditions differed through the course of tectonic history carbon and oxygen isotope analyses of the calate filled extensional fractures the sigmoidal veins present between stylolitic cleavage surfaces and fault plane surfaces with differing motion demonstrate those different geneses the c c of the older calcite filling fractures present both in the thrust and the strike slip systems suggests a deposition from shallow fresh water circulation furthermore the calcite fill of en echelon systems that occur in the southernmost plio pleistocene units is clearly the result of a more recent right lateral strike slip movement connected with shallow water circulation within mesozoic limestones the sigmoidal vein fills are derived from solid state pressure solution processes which were the result of strike slip movement the deformation pattern related to the older thrust system is similar but less intense this also demonstrates general recrystallization processes in a closed system this suggests that the total shortening of the deformed sections is lower than that obtained on the basis of solution on stylolitic planes because a sigruficant volume of dissolved carbonates remained in the system stable isotope analysis also confirms that the deformational history of strongly cleaved rocks in the sabina region took place in two phases and that extensional fractures formed before stylolithic planes as suggested by structural and field observations

magnetic mineralogy changes in the pleistocene marine sequence of montalto di castro central italy and influences on the magnetic anisotropy summary the magnetic mineralogy of a pleistocene sedimentary sequence drilled near montalto di castro latium italy shows an extreme variability in a 40 m thick stratigraphic interval sedimentary fades in this interval also show rapid and strtng changes in the granulometry and colours of the deposits reflecting deposition in a coastal environment under a variety of energy and redox conditions rock magnetism analysed of the finegrained sediments from this stratigraphic interval indicate the presence in variable proportions of several magnetic minerals a new semi quantitative best fit method has been specifically developed for the estimation of the relative percentage contribution of the various magnetic minerals to the isothermal remanent magnetization the variability in the magnetic mineralogy throughout the whole sequence produces remarkable changes in the anisotropy of magnetic susceptibility of the deposits the interval with the major sedimentological and magnetic mineralogy changes is characterized by a fairly isotropic magnetic fabric unexpected for sediments this anomalous magnetic fabric is probably due to the balance between the inverse magnetic fabric produced by antiferromagnetic goethite and the normal magnetic fabric due to the paramagnetic matrix and other magnetic minerals

the magnetic fabric relationship between sedimentary and basement nappes in the high tatra mountains n slovakia abstract in the high tatra mountains n slovakia the magnetic fabrics are deformational in origin in sedimentary rocks of the kri na nappe in sedimentary rocks covering the underlying crystalline complex and in granitoids and metamorphic rocks of this complex the patterns of the principal susceptibilities are similar in all these units their most important feature is a girdle in magnetic foliation poles oriented nnw sse to n s in sedimentary formations the magnetic fabric pattern is compatible with that predicted by mathematical modelling to develop during a complex deformation comprising lateral shortening and simple shear which is characteristic of nappe deformation consequently the magnetic fabric in the high tatra mountains probably resulted from deformation associated with the formation and movement of the nappes during which not only the sedimentary strata but also the crystalline complex were thrust over the north european platform

extensional tectonics on sardinia italy insights into the arc back arc transitional regime although the tectonic features and stress regime typical for accretionary complexes and back arc domains have been widely documented so far few are known on the transitional zone separating these two systems here we report on structural analysis and anisotropy of magnetic susceptibility ams results from eocene pliocene sediments exposed in western sardinia from late oligocene to middle miocene the studied area was located between the alpine apennine wedge to the east which was undergoing shortening and accretion and the liguro provencal basin undergoing extension and spreading we find that prior to the formation of the liguro provencal basin the middle eocene lower oligocene sediments cropping out at the southwesternmost edge of sardinia were subjected to ne sw shortening in present day coordinates in agreement with recently reported geological information conversely the upper oligocene pliocene sedimentary sequences record a different evolutionary stage of extensional processes upper oligocene middle upper burdigalian sediments clearly show a n s oriented magnetic lineation that can be related to extensional direction along the prevalent e w oriented normal faults on the other hand no magnetic lineation has been detected in upper burdigalian serravallian sediments which mark the end of the first rifting process in sardinia which likely coincides with the rift to drift transition at the core of the liguro provencal basin finally a ne sw extension is observed in two tortonian pliocene sites at the northwestern margin of the nnw sse oriented campidano graben our study confirms that ams may represent a valuable strain trajectory proxy and significantly help to unravel the characters of temporally superimposed tectonic events

extensional tectonics in the amantea basin calabria italy a comparison between structural and magnetic anisotropy data abstract we report on structural and anisotropy of magnetic susceptibility ams results from the upper miocene sediments of the amantea basin located on the tyrrhenian coast of the calabrian arc southern italy the stratigraphic succession of the basin is organized in three depositional sequences separated by two major angular unconformities detailed geological mapping and structural analysis demonstrate that the stratigraphic evolution of the amantea basin is strongly controlled by a synsedimentary extensional tectonic regime several nne ssw trending normal fault arrays with large scatter in inclination values have been interpreted as due to a domino faulting mechanism consistent with a wnw ese stretching direction ams data have been obtained for 13 sites both in the not constrained in age first depositional sequence 3 sites and in the upper tortonian lower messinian clays from the second depositional sequence 10 sites all the sites show a strong magnetic foliation parallel to the bedding planes and a well defined magnetic lineation subparallel to the local bedding dip directions the magnetic lineations cluster around a wnw ese trend and are parallel to the stretching directions inferred by fault slip analysis and basin architecture these new data then confirm the possibility to use the magnetic lineation to map the strain trajectory in weakly deformed extensional sedimentary basins paleomagnetic data from previous studies show that the whole calabrian block underwent a 15 20 clockwise rotation probably in the pleistocene postdating the extensional tectonic events which controlled the amantea basin geometry therefore we suggest for the amantea basin an original e w oriented stretching direction which may be considered as the older extensional direction characterizing the late miocene evolution of the southern tyrrhenian sea domain

distinct magnetic fabric in weakly deformed sediments from extensional basins and fold and thrust structures in the northern apennine orogenic belt italy we report on results from anisotropy of magnetic susceptibility ams analyses carried out on weakly deformed fine grained sediments from the northern apennine orogenic system italy we sampled 63 sites from preorogenic synorogenic and postorogenic sequences which differ in age composition depositional environment degrees of deformation and tectonic regimes the magnetic fabric is typical of weakly deformed sediments with a magnetic foliation subparallel to the bedding plane and a magnetic lineation well defined in this plane northern apennine chain deposits are characterized by strongly oblate magnetic susceptibility ellipsoids indicating that the magnetic fabric is the result of both compaction process and tectonic load experienced by the sediments during diagenesis and orogenic events the orientation of magnetic lineation is significantly different depending whether the studied sites underwent extensional or compressional tectonic regimes in the northern apennine chain the magnetic lineation is mostly oriented nnw sse parallel to the main compressional structures it suggests a tectonic origin of the magnetic lineation with an acquisition related to the apennines compressional phases in the extensional tuscan tyrrhenian margin magnetic lineation is oriented ene wsw almost perpendicular to the main extensional faults which represent the main deformation elements of the area our results demonstrate a close relationship between the shape and orientation of magnetic fabric and the tectonic history of rocks confirming that ams represents a valuable tool to investigate the tectonic history of weakly deformed sedimentary rocks

the origin of tectonic lineation in extensional basins combined neutron texture and magnetic analyses on undeformed clays abstract in extensional sedimentary basins fine grained sediments that appear undeformed at the outcrop scale can carry a magnetic fabric consistent with the regional deformation pattern the origin of the magnetic lineation which is often found in extensional basins is not yet well understood in clays from extensional basins in southern italy the magnetic lineation is tectonically controlled and oriented perpendicular to the main normal faults a combined analysis of magnetic and mineral fabrics was made to gain insight into the processes that lead to a lineation in extensional settings low field high field and low temperature susceptibility measurements were used to distinguish the ferrimagnetic and paramagnetic contributions to the magnetic susceptibility and its anisotropy the magnetic anisotropy of the sediments is predominantly carried by paramagnetic phyllosilicates neutron texture analysis was used to evaluate the spatial distribution of chlorite basal planes results demonstrate that the orientation of the magnetic lineation is related to the spatial distribution of chlorite lying parallel to the common axis of differently oriented basal planes a quantitative correlation between the magnetic and rock fabric was made comparing the low and high field magnetic anisotropy ams hfa to the theoretical anisotropy calculated from the chlorite preferred orientation a good linear correlation is found between the degree of theoretical anisotropy and the ams and hfa results show that the integrated approach of magnetic and mineral fabric investigations represents a valid alternative tool for detecting grain scale and regional deformation patterns in weakly deformed extensional basins where macroscopic evidence of deformation is often not visible

mis 9 to mis 5 terraces along the tyrrhenian sea coast of latium central italy assessing interplay between sea level oscillations and tectonic activity abstract we present a review of the geomorphology of the tyrrhenian sea coast of central italy integrated by a novel structural geomorphological study coupled with statistical analysis of topographic culminations and comparison with a digital elevation model aimed at reconstructing a suite of paleo surfaces corresponding to remnant portions of marine terraces we performed geochronological sedimentological micromorphological and mineralogical investigations on the deposits forming the different paleo surfaces between civitavecchia and anzio towns in order to provide chronostratigraphical paleogeographical and paleoenvironmental constraints using the newly achieved dataset we correlate these paleo surfaces with the coastal terraces formed during past sea level highstands as recognized by previous studies and we refine their correlation with the marine isotope stage mis timescale in particular we have extended our geomorphological analyses landward in the area between the tiber river mouth and anzio in order to include the oldest paleo surface developed above the deposits of the last large explosive eruption at 365 4 ka in the colli albani volcanic district results of this study allow us to recognize a set of higher paleo surfaces at elevation ranging 108 thought 71 m a s l which we interpret as one tectonically displaced widespread coastal terrace originated during the mis 9 1 highstand we correlate the previously identified paleo surfaces of 66 62 m a s l and 56 52 m a s l with the equivalent coastal terraces developed during the sea level highstands of sub stages 7 5 and 7 3 7 1 moreover based on data from literature on relative elevation of maximum sea level during the highstands of mis 11 through mis 5 1 we assess the regional uplift and the concurrent tectonic displacements that have occurred since 900 ka in this area

monitoring the madden julian oscillation with geopotential height this paper examines the three dimensional geopotential height structure of the madden julian oscillation mjo and proposes that the mjo convection signals can be well reflected by upper tropospheric zonal anomalous height gradient zahg nabla x z a case study in 2011 and composite analyses have been done by applying a wavenumber frequency filtering method on daily variable anomalies derived from different reanalysis datasets results show that the upper level eastward moving intraseasonal geopotential height anomaly does not exactly display a rossby kelvin wave structure of the gill model instead it shows a height quadrupole pattern and is well associated with temperature and zonal wind anomalies the notable tilted upper tropospheric temperature structure can be derived from the height anomalies by the hydrostatic balance relationship the first baroclinic mode vertical structure of zonal wind anomalies can be approximated from the height anomalies by the geostrophic equation a highlight of the paper is the proposal of tracing the mjo convection center by the upper tropospheric zahg nabla x z composite analyses of all mjo events during extended winter ndjfm from 1979 to 2013 suggest that positive upper tropospheric zahg is exactly in phase with negative outgoing longwave radiation olr anomalies in the eastern indian ocean and maritime continent during a mjo event on the other hand positive upper tropospheric zahg leads lags negative olr anomalies by 1 2 days in the western indian ocean western pacific ocean where mjo events generally initiate dissipate zahg can also be applied to modeling data and observation data before the satellite era this study provides a new diagnostic parameter option to monitor mjo events and an alternative for studying mjos before the satellite era and model evaluation

a synchronous alpine and corsica sardinia rotation 1 we report on the paleomagnetism of 34 sites from lower oligocene middle miocene sediments exposed in the tertiary piedmont basin tpb northern italy the tpb is formed by a thick 4000 m and virtually undeformed sedimentary succession unconformably lying upon alpine nappes decapitated by extensional exhumation which in turn are tectonically stacked over the adriatic foreland paleomagnetic directions from 23 mostly oligocene sites were chronologically framed using new biostratigraphic evidence from calcareous nannoplankton our data along with published paleomagnetic results show that the tpb rotated 50 counterclockwise with respect to africa in aquitanian serravallian times the rotation was likely driven by underneath nappe stacking and was synchronous with further bending of the alpine chain both the rotation magnitude and its timing are similar to those documented for the corsica sardinia microplate therefore the formation of the western alpine arc or at least part of its present day curvature occurred during the rollback of the apenninic slab and related back arc spreading of the liguro provencal basin and drift of the corsica sardinia block this suggests a common dynamics driving both the alpine and the apennine slab motions paleomagnetic data also document that the adriatic plate has undergone no paleomagnetic rotation since mid late miocene times anisotropy of magnetic susceptibility data suggests that the tpb an enigmatic basin arising from a controversial tectonic setting formed in an extensional regime characterized by a stretching direction approximately orthogonal to the main trend of the underlying chain

evidence of middle pleistocene marine transgressions along the mediterranean coast abstract typical middle pleistocene sequences outcropping along french and italian coasts are described age determination from palaeolithic industries and absolute dating methods correspond to oxygen isotope stages 9 and 11 evidence of the same transgressive cycles are also indicated in other mediterranean districts

diffuse emission of hydrogen from poas volcano costa rica america central we report the results of four soil h2 surveys carried out in 2000 2003 at poas volcano costa rica to investigate the soil h2 distribution and evaluate the diffuse h2 emission as a potential surveillance tool for poas volcano soil gas h2 contents showed a wide range of concentration from 0 2 to 7 059 ppmv during the four surveys maps of soil gas h2 based on sequential gaussian simulation showed low h2 concentration values in the soil atmosphere 0 7 ppmv for most of the study area whereas high soil gas h2 values were observed inside the active crater of poas a significant increase in soil gas h2 concentration was observed inside the active crater during 2001 and 2002 with respect to year 2000 followed by a decrease in 2003 the observed spatial and temporal variations of soil h2 concentration have been well correlated with seismicity microgravimetry and fumarolic chemistry changes which occurred during this study these observations evidence changes in the shallow magmatic hydrothermal system of poas and it might be related to a potential magmatic intrusion during the period 1998 2004 therefore monitoring diffuse h2 emission of poas has become an important geochemical tool for the monitoring of its volcanic activity

hydrogeochemistry of the volcanic district in the tolfa and sabatini mountains in central italy abstract a geochemical study on 26 thermal springs and 5 samples from thermal wells t 20 c 19 cold springs 11 cold gas pools and 14 stream samples from the tolfa and sabatini mountains volcanic district about 1300 km2 has clarified their genesis and evolution meteoric waters infiltrate the more permeable exposed rocks carbonates and or volcanites and percolate down into two main aquifers one is deep and located in mesozoic anhydritic carbonate formations and is the regional geothermal reservoir that feeds springs that emerge at the margins of the carbonate series either exposed or barely covered its waters display typical bicarbonate sulfate alkaline earth composition the other aquifer s is shallower consisting of waters that circulate primarily in volcanic deposits the chemical characteristics of these shallow waters are heavily influenced by lithology and by a gas phase mainly co2 originating at depth temperature estimates obtained with sio2 and gas geothermometers which seem to be the most reliable under these conditions indicate the widespread occurrence of deep fluids at temperatures higher than 110 c under the area covered by the sabatini volcanites in some areas manziana trevignano nepi and cesano the subsurface waters reach temperatures within the range characteristic of medium to high enthalpy systems 120 160 c

ciprianiite and mottanaite ce two new minerals of the hellandite group from latium italy two new minerals of the hellandite group were found within alkali syenitic ejecta enclosed in pyroclastic formations of the roman comagmatic province latium italy mottanaite ce ideally x ca4 y ceca z al t be2 si4b4o22 w o2 and ciprianiite ideally x ca4 y th u ree z al t 2 si4b4o22 w oh f 2 occur as transparent brown colored tabular euhedral crystals in miarolitic cavities and voids of the ejecta which consist mainly of sanidine and plagioclase an ranging from 20 to 80 with minor amounts of feldspathoid clinopyroxene and or clinoamphibole magnetite titanite and zircon locally accessory minerals include britholite ce baddeleyite phosphate to silico phosphate phases close in composition to the brabantite cheralite series thorite fluorite danburite and vonsenite the genesis of the new hellandite end members can be related to late stage post magmatic hydrothermal fluids enriched in zr ti rees and actinide elements both mottanaite ce and ciprianiite have a vitreous luster and are non fluorescent cleavage is absent in mottanaite ce fair to good in ciprianiite 100 twinning is frequently observed in ciprianiite due to the strong intra crystalline chemical zoning and twinning physical properties could be measured only for mottanaite ce dmeas is 3 61 4 g cm 3 dcalc is 3 88 g cm 3 mottanaite ce is biaxial negative with 1 680 5 1 694 2 1 708 5 2vmeas 90 both minerals are monoclinic space group p2 a z 2 unit cell parameters for the crystals studied are a 19 032 9 a b 4 746 3 a c 10 248 5 a 110 97 5 v 864 3 8 a 3 for

geochronology of the most recent activity in the sabatini volcanic district roman province central italy abstract the presence of young highly explosive volcanoes in the densely populated roman area central italy makes the evaluation of the long term volcanic hazard a crucial point the sabatini volcanic district svd part of the potassic quaternary roman province extends over an area of 1800 km2 including the city of rome here we report twenty six new 40ar 39ar age analyses of pyroclastic and lava units in order to put time constraints on the most recent svd eruptive activity i e post dating 400 ka as a groundwork for a detailed reconstruction of the whole volcano tectonic evolution integrated geochronological and field evidence shows that svd volcanism maintained a typical areal character through the whole history both effusive and explosive activity phases from different source areas and volcano tectonic settings overlapped in time and space while climactic phases migrated repeatedly through time in particular new geochronological data better constrain a climactic phase of activity at around 300 ka related to the bracciano volcano tectonic depression and the sacrofano caldera and point out that the most recent eruptive activity in the svd took place from time space clustered hydromagmatic centres at least up to 90 ka in addition we remark some parallelism among major activity phases in the svd and the nearby districts of the roman province with possible implications on quaternary regional tectonics finally new age data put constraints on tephrostratigraphic correlations through the apennine chain and the adriatic sea

the early pleistocene in latium central italy palaeoecology from benthic foraminiferal record the palaeoecological information upon santernian benthic foraminiferal assemblages collected in the 1990s from many sites in latium has been gathered and analysed in order to create a regionally consistent picture of the palaeoenvironment three sites were selected because they were considered most significant valle ricca monte mario and the anzio coast and were studied using statistical analysis in order to identify the different structural and palaeomorphogical settings cluster analysis identified the presence of three main environments lower circalittoral upper circalittoral and infralittoral which confirm the palaeoecological results obtained from previous quantitative studies the identification of the benthic assemblages that are indicative of these environments at other sites was used to reconstruct the regional palaeoenvironmental evolution during the santernian

a pedostratigraphic marker in the geomorphological evolution of the campanian apennines southern italy the paleosol of eboli abstract the paleosol of eboli is interbedded within an early pleistocene coarse alluvial succession the eboli conglomerates located in the campanian apennines southern italy infilling the morphostructural depression of the sele river plain quaternary climatic changes and related morphodynamic response were investigated using a multidisciplinary geomorphological sedimentological and pedological approach the alluvial sequence of the eboli conglomerates shows remarkable vertical changes marked by clear erosional discontinuities that identify four stacked formations called from the bottom fontana del fico colle mancuso castelluccia and s anna formations the clastic facies of these formations are mainly indicative of an alluvial fan environment with most sediments emplaced by flooding of distributary streams the paleosol of eboli is formed at the top of the castelluccia formation we investigated its morphological physical chemical micromorphological and mineralogical properties many discontinuities appear in the field due to various erosional events that are related to hillslope dynamics each of these events was followed by the emplacement of new and different colluvial deposits that were derived from upslope and were subsequently affected by pedogenesis all the horizons of the paleosol of eboli have reddish and brown matrix colours secondary carbonate angular blocky structure and clayey texture on the basis of the field data and chemical and physical analysis three different pedogenetic cycles can be distinguished in the paleosol of eboli these cycles depict differing degrees of pedogenic expression depending on water regime and duration of pedogenesis the micromorphology showed the presence of eluvial tongues fe dynamics coatings segregations vertic features optically anisotropic lines in the soil matrix and pedorelicts kaolinite is the most abundant clay mineral but vermiculite and illite are also present the fe minerals especially the hematite goethite ratio have provided a new approach to understand the main paleoclimatic changes through the studied sequence the overall pedogenetic scenario depicts a highly weathered environment disordered kaolinite fe oxides low feo fed ratio depletion zones characterized by marked climatic seasonality witnessed by vertic properties and abundant rainfall depletion zones the general scenario is coherent with a highly weathered subtropical environment that probably occurred during mis 25 based on age control the widespread outcrop pattern consistent stratigraphic position thickness ranging from 1 to 5 m and the uniformity of pedological features of the paleosol of eboli make it clearly recognizable in the field and allow us to consider the paleosol of eboli a reliable pedostratigraphic marker

rossby wave propagation into the tropics in two gfdl general circulation models during the northern winter the eastern pacific is characterized by upper level westerly flow extending from the equator into the midlatitudes of both hemispheres theoretical and simple modeling studies suggest that such a region should favor the penetration of rossby waves into the tropics from higher latitudes observational results by kiladis and weickmann using 200 mb data indicate that rossby waves do indeed propagate freely into the tropical eastern pacific during the northern winter from the asian jet exit region they also confirmed that cross equatorial dispersion of energy from the northern into the southern hemisphere occurs frequently the present study examines these interactions in climatological runs of two gfdl gcms the northern wintertime mean states of these models are characterized by a rather realistically simulated upper level westerly regime in the tropical pacific despite the relative weakness of the asian jet and wave activity with respect to observations propagation of rossby waves into the tropics is present in both models and these waves are strongly positively tilted as seen in the observations a momentum budget of the zonal wind and e vector diagnostics over the tropical pacific indicate that these transients are an important component of the momentum balance of the equatorial westerlies in both the observations and in the models

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

applicability of magnetic fabrics in rocks associated with the emplacement of salt structures the bicorb quesa and navarres salt walls prebetics se spain abstract this work assesses the applicability of the analysis of the anisotropy of magnetic susceptibility ams to rocks associated with salt structures magnetic fabrics from 16 sites sampled on upper triassic clays keuper facies interbedded within the salt layers of the bicorb quesa and navarres salt walls prebetic zone se spain are mostly characterized by oblate magnetic ellipsoids with their magnetic foliation parallel to the bedding and magnetic lineation contained in the bedding plane but without a constant relationship with dip direction to evaluate the quality and significance of the low field ams several experiments were carried out to characterize the magnetic mineralogy of representative samples and enable separation of the contributions from paramagnetic and ferromagnetic s l minerals the comparison between the orientation of the observed magnetic lineation and that of the structural elements characterizing the internal geometry of the studied salt structures antiforms minor folds faults and shear zones and flanks indicates that the magnetic fabric is controlled by deformation processes affecting the salt walls during their growth and or evolution samples were also analyzed from sixteen sites from miocene rocks outcropping in several syn diapiric miocene half grabens related to the salt walls studied their magnetic fabric is interpreted to reflect the dominant stretching direction at the syn diapiric half grabens during and or shortly after deposition our results indicate that caution is required in interpreting magnetic lineations related to salt flow mechanics from rocks associated with salt structures

anisotropy of magnetic susceptibility in the scaglia rossa pelagic limestone abstract during folding of the scaglia rossa limestone in umbria italy deformation was mainly accommodated by pressure solution cleavage fossils between the cleavage planes appear visibly undeformed yet the limestone possesses a weak magnetic fabric the maximum and intermediate principal axes of the magnetic anisotropy ellipsoid define a distinct magnetic foliation plane within which a weak concentration of the maximum axes forms a magnetic lineation neither of these features is of sedimentary origin results from a slumped outcrop where bedding and a cleavage induced by overburden compaction have different attitudes show that the magnetic foliation is caused by the compaction comparisons with field derived structural data suggest that the magnetic lineation was produced tectonically during deformation of the apennine fold belt

tropical intraseasonal variability in the mri 20km60l agcm this study documents the detailed characteristics of the tropical intraseasonal variability tisv in the mri 20km60l agcm that uses a variant of the arakawa schubert cumulus parameterization mean states power spectra propagation features leading eof modes horizontal and vertical structures and seasonality associated with the tisv are analyzed results show that the model reproduces the mean states in winds realistically and in convection comparable to that of the observations however the simulated tisv is less realistic it shows low amplitudes in convection and low level winds in the 30 60 day band filtered anomalies have standing structures power spectra and lag correlation of the signals do not propagate dominantly either in the eastward direction during boreal winter or in the northward direction during boreal summer a combined eof ceof analysis shows that winds and convection have a loose coupling that cannot sustain the simulated tisv as realistically as that observed in the composited mature phase of the simulated mjo the low level convergence does not lead convection clearly so that the moisture anomalies do not tilt westward in the vertical indicating that the low level convergence does not favor the eastward propagation the less realistic tisv suggests that the representation of cumulus convection needs to be improved in this model

a coupled moisture dynamics model of the madden julian oscillation convection interaction with first and second baroclinic modes and planetary boundary layer a theoretical model with a single prognostic variable column integrated moist static energy mse was constructed to understand the dynamics of mjo eastward propagation and planetary scale selection a key process in the model is the interaction of mse dependent convection with free atmospheric first second baroclinic modes and planetary boundary layer under a realistic parameter regime the model reproduces the most unstable mode at zonal wavenumber 1 with a slow eastward phase speed of about 5 ms 1 the slow eastward phase speed in the model arises from the competition of eastward moving mse tendencies caused by horizontal mse advection vertical mse advection and boundary layer moistening with westward moving tendencies contributed by surface latent heat flux and atmospheric longwave radiative heating the planetary scale selection is primarily attributed to the phase lag of longwave radiative heating associated with upper level stratiform clouds that occur in the rear of mjo deep convection

paleomagnetic evidence for no tectonic rotation of the central italy tyrrhenian margin since upper pliocene we present paleomagnetic results from 141 samples collected at 12 sites from plio pleistocene clayey units in the extensional central italy tyrrhenian margin all samples were subjected to stepwise alternating field and or thermal demagnetization positive fold and reversal tests indicate that the results refer to a primary component of magnetization paleomagnetic mean direction declination 358 0 inclination 55 2 95 4 1 reflects the expected geocentric axial dipole field for the locality thus indicating that this sector of the tyrrhenian margin did not undergo any tectonic rotation during the past 4 million years

the 40 to 50 day oscillation in a perpetual january simulation with a general circulation model a 1200 day record from a perpetual january simulation with a general circulation model is analyzed for the presence of an oscillation resembling the 40 to 50 day oscillation observed in the atmosphere representation of the global velocity potential at 200 mbar by empirical orthogonal functions eofs reveals an eastward propagating disturbance having a principally zonal wave number 1 character it is determined from power spectra of the velocity potential at points around the equator that the period of the oscillation is in the range of 28 31 days time series of the coefficients of the first two eofs are used to define epochs for the compositing in equatorial latitudes of anomalies in zonal winds in 500 mbar convective heating and in precipitation time longitude diagrams of the zonal wind anomalies indicate the presence of an eastward propagating disturbance characterized by two longitudinal scales the principal anomalies in convective heating and precipitation appear as two stationary oscillations one situated in a zone extending from 120 e to the dateline and the other in a relatively narrow zone near 60 w

simulations of the madden julian oscillation in four pairs of coupled and uncoupled global models the status of the numerical reproduction of the madden julian oscillation mjo by current global models was assessed through diagnoses of four pairs of coupled and uncoupled simulations slow eastward propagation of the mjo especially in low level zonal wind is realistic in all these simulations however the simulated mjo suffers from several common problems the mjo signal in precipitation is generally too weak and often eroded by an unrealistic split of an equatorial maximum of precipitation into a double itcz structure over the western pacific the mjo signal in low level zonal wind on the other hand is sometimes too strong over the eastern pacific but too weak over the indian ocean the observed phase relationship between pre cipitation and low level zonal wind associated with the mjo in the western pacific and their coherence in gen eral are not reproduced by the models the seasonal migration in latitude of mjo activity is missing in most simulations air sea coupling generally strengthens the simulated eastward propagating signal but its effects on the phase relationship and coherence between precipi tation and low level zonal wind and on their geographic distributions seasonal cycles and interannual variability are inconsistent among the simulations such inconsis tency cautions generalization of results from mjo sim ulations using a single model in comparison to observations biases in the simulated mjo appear to be related to biases in the background state of mean pre cipitation low level zonal wind and boundary layer moisture convergence this study concludes that while the realistic simulations of the eastward propagation of the mjo are encouraging reproducing other funda mental features of the mjo by current global models remains an unmet challenge

a new look at the midlatitude mjo teleconnection in the northern hemisphere winter the midlatitude to madden julian mjo teleconnection in the northern hemisphere wintertime was investigated using twenty years of outgoing long wave radiation and national center for atmospheric research national centers for environmental prediction re analysis data it is revealed through empirical orthogonal functions and regression analyses that the tropical upper level divergence convergence associated with enhanced reduced tropical convection has a subtropical counterpart of upper level convergence divergence as the convective region of mjo moves eastward from the indian ocean to the western pacific the divergent circulation connecting the tropics and subtropics moves eastward from an analysis of vertical motion diagnosed by the generalized omega equation it was revealed that the position of the subtropical rossby gyres of the mjo with respect to the asian pacific jet was the most important factor affecting the existence of the localized divergence convergence and associated lower level vertical motion in the subtropics as the subtropical rossby gyres pass by the longitudinal position of the asian pacific jet vertical motion occurs to meet the balance required by quasi geostrophic theory since this anomalous vertical motion is large enough to cause convection at that region the diabatic heating process reinforces the vertical motion furthermore other dynamical processes neglected in quasi geostrophic theory are activated and contribute to the vertical motion balancing the diabatic heating as a result of the vertical motion near the jet entrance region in the subtropics the vorticity advection by vertical wind and the tilting of vorticity become important since these two terms are similar in shape and magnitude they reinforce each other during the development phase of the midlatitude mjo teleconnection combining these two terms we define the baroclinic jet source bjs in order to evaluate the bjs as a source for the midlatitude mjo teleconnection a numerical experiment is carried out the linear barotropic model is forced by only two terms yet the model captured clearly the main feature of the midlatitude mjo teleconnection copyright 2006 royal meteorological society

geologic volcanologic and tectonic setting of the vico cimino area italy abstract although the cimino and vico volcanic complexes are located close to each other in a structural low they belong to two different provinces cimino is connected to the tuscan roman anatectic magmatic province and vico to the roman campanian potassic alkaline province barberi et al 1971 marinelli 1975 the two volcanic centers lie on a basement formed by clays and sands of a miocene pliocene aged sedimentary cycle the mount cimino complex forms a central volcano composed of a series of rhyodacitic domes it was emplaced along a nw se trending fracture zone which can be followed for about 16 km cimino volcano was active from 1 4 m y to 0 95 m y ago eruption of rhyodacitic ignimbrites were preceded and followed by the emplacement of domes of the same composition fluid lavas of latitic and olivine latitic composition were emitted from the central volcano during the final phase of activity vico is a central volcano mainly composed of lava with a composite summit caldera it was emplaced along a ne sw trending fracture system the vico stratovolcano is formed by lavas of various compositions including phonolitic tephrites tephritic phonolites and slightly undersaturated trachytes the construction of the stratovolcano the most ancient exposed products of which have an age of 0 4 m y was followed by the eruption of four pyroclastic flows totalling several cubic kilometers which are dated at 0 3 0 15 m y the collapse of the caldera is most likely connected to the eruption of these pyroclastic flows the ring fractures of the caldera are associated with the emplacement of a pyroclastic unit most of which erupted along the inner northeast and north rim of the caldera post caldera activity is characterized by the emission of tephritic phonolitic and tephritic products that form the intra caldera stratovolcano named mount venere the vico cimino area northern latium located between the apennine chain and the tyrrhenian sea lies along the circum tyrrhenian belt that extends from northern tuscany to campania this zone has experienced post orogenic tensional movements since the middle miocene the teconic evolution of the tyrrhenian basin is closely associated with acid anatectic and potassic alkaline volcanism along the tyrrhenian margin of the apennines the age composition and geographic position of the volcanoes are controlled by different magnitudes of tensional tectonics and crustal thinning processes of the western margin of the apennine chain

neogene quaternary evolution of the central apennine orogenic system italy a structural and palaeomagnetic approach in the molise region abstract we report on new palaeomagnetic and magnetic fabric analyses of mainly upper miocene sedimentary sequences from the external central apennine fold and thrust belt molise area where the principal compressive structures are clearly non coaxial the sampling was carried out on the e w oriented matese frosolone thrust sheet that for its geographical position and structural setting superposition of thrusting strike slip and extensional tectonics since late miocene to present day represents a key structure for the comprehension of the neogene quaternary evolution of the entire molise area palaeomagnetic results suggest that the matese frosolone thrust sheet counterclockwise rotated at least 35 after messinian times these data confirm that the present day trend variability observed in the main compressional structures in the apennine chain can be related to rotations about vertical axes rather than to changes in the stress field orientation at least since late miocene times magnetic fabric analyses indicate that the studied sediments were subjected to very mild deformation suggesting that the surface emergence of the thrust front of the matese frosolone unit is located farther north far from the studied area well defined magnetic lineations of tectonic origin were only observed in sites close to localised belts of strike slip deformation

bio and magneto stratigraphy in the tiber valley revised abstract the stratigraphy of three sections of marine deposits in the tiber valley north of rome was investigated in detail biostratigraphic investigation covered the valle ricca tini quarry fosso liano and lugnano sections the valle ricca and lugnano sections show continuity in sedimentation from the latest pliocene to early pleistocene in the fosso liano section upper pliocene sediments are missing as in other outcrops in central italy and the lower pleistocene deposits lie unconformably on the middle pliocene ones possible causes of these features are discussed magnetostratigraphy and rock magnetism analyses were performed only in the valle ricca section the data shows that the previously recognised reversal around a volcanic level is the effect of strong changes in the magnetic mineralogy and it is not representative of true geomagnetic changes

the structure and propagation of intraseasonal oscillations appearing in a gfdl general circulation model abstract the three dimensional structure and temporal evolution of quasi periodic planetary scale tropospheric oscillations simulated by a 15 wavenurnber gcm are investigated by applying cross spectral eigenvector composite and temporal correlation techniques to 12 years of model output evident from this diagnostic study is the presence in the model tropics of well defined eastward traveling features with spatial scales of zonal wavenumbers 1 and 2 and with temporal scales of 25 40 and 15 20 days respectively the flow pattern associated with the oscillations of both spatial scales is characterized by circulation cells oriented along the equatorial zonal plane with the zonal wind and geopotential height fluctuations near the sea level being negatively correlated with the corresponding fluctuations in the upper troposphere the movement of these zonal circulation cells along the equatorial bell is accompanied by systematic migration of the global scale horizontal divergence field and by dipole like

tree ring width based precipitation reconstruction in zhaogaoguan china since 1805 ad abstract in order to further understand the past climate variation especially the history of drought and flood events in the east asian summer monsoon easm marginal area precipitation from previous august to current july for the period of 1805 2014 ad was reconstructed from a ring width chronology of pinus tabulaeformis in zhaogaoguan zgg a site located in the easm marginal area in northern china the transfer function can explain 46 4 adjusted to 45 4 for the loss of degrees of freedom of the variance of the observed precipitation during the calibration period 1958 2014 ad the reconstructed precipitation series revealed that the inter annual variability was very prominent 1843 and 1844 ad were the two wettest years while 1931 and 1999 ad were the two driest years we noticed that the droughts in 1900 1906 1931 1955 and 1999 ad in the reconstruction series corresponded to the severe floods in the yangtze river watershed in southern china during those same years this phenomenon confirmed the typical climate pattern of northern droughts and southern floods in china moreover the reconstructed precipitation series in zgg showed synchronous variation patterns with the other tree ring based hydrological reconstructions in the marginal area of easm on both inter annual and inter decadal scales indicating the common precipitation variation characteristics of the easm marginal area

a simple tropical moist model applied to the 40 day wave the 40 day wave is a baroclinic eastward propagating disturbance commonly observed in the tropical atmosphere with a period that actually lies in the band 30 to 60 days its structure resembles an equatorially trapped kelvin wave predominantly with zonal wavenumber 1 in this paper a simple model with marginally stable moist static stability is used to investigate one possible mechanism for its appearance namely as the response to variable thermal forcing amplified by the effect of interactive latent heating the model has just one vertical baroclinic mode forced by prescribed heating and by interactively determined latent heating latent heating only occurs when and where there is low level convergence and moisture is tending to increase beyond some saturation level in such regions the static stability takes its moist value which is considerably less than the dry value acting in regions without precipitation analytic solutions are first provided for cases with static stability everywhere constant waves propagate more slowly when the moist value is used so the peak linear response to wave like thermal forcing essentially a resonant response occurs at longer periods than for dry static stability for dry conditions the period of a free kelvin wave with zonal wavenumber one is about 10 days but for wet conditions the period increases toward the 40 day range when static stability varies the model must be solved numerically solutions show that the increase in period predicted analytically is indeed realized even when precipitation is patchy and dry static stability is acting almost everywhere effectively the amplified waves travel at a speed consistent with the maintenance of their latent heating energy source eastward waves are prominent near the equator by analysing particular moisture dependent combinations of variables these eastward waves can be dynamically identified as kelvin waves saturation moisture content is closely linked to sea surface temperature the warm western pacific and indian oceans are regions of high atmospheric moisture content and hence of very low moist static stability this ocean temperature effect is studied using the simple model showing that intraseasonal waves are largest in such regions as observed

mesozoic extension in the basque cantabrian basin n spain contributions from ams and brittle mesostructures abstract in this work we analyse and check the results of anisotropy of magnetic susceptibility ams by means of a comparison with palaeostress orientations obtained from the analysis of brittle mesostructures in the cabuerniga cretaceous basin located in the western end of the basque cantabrian basin north spain the ams data refer to 23 sites including triassic red beds jurassic and lower cretaceous limestones sandstones and shales these deposits are weakly deformed and represent the syn rift sequence linked to basins formed during the mesozoic and later inverted during the pyrenean compression the observed magnetic fabrics are typical of early stages of deformation and show oblate triaxial and prolate magnetic ellipsoids the magnetic fabric seems to be related to a tectonic overprint of an original compaction sedimentary fabric most sites display a ne sw magnetic lineation that is interpreted to represent the stretching direction of the early cretaceous extensional stage of the basin without recording of the tertiary compressional events except for sites with compression related cleavage brittle mesostructures include normal faults calcite and quartz tension gashes and joints related to the extensional stage the results obtained from joints and tension gashes show a dominant n s to ne sw and secondary nw se extension direction paleostresses obtained from fault analysis right dihedra and stress inversion methods indicate nw se to e w and n s extension direction the results obtained from brittle mesostructures show a complex pattern resulting from the superposition of several tectonic processes during the mesozoic linked to the tectonic activity related to the opening of the bay of biscay during the early cretaceous this work shows the potential in using ams analysis in inverted basins to unravel its previous extensional history when the magnetic fabric is not expected to be modified by subsequent deformational events brittle mesostructure analysis seems to be more sensitive to far field stress conditions and record longer time spans whereas ams records deformation on the near distance during shorter intervals of time

evaluating magnetic lineations ams in deformed rocks magnetic lineation in rocks is given by a cluster of the principal axes of maximum susceptibility kmax of the anisotropy of magnetic susceptibility ams tensor in deformed rocks magnetic lineations are generally considered to be the result of either bedding and cleavage intersection or they parallel the tectonic extension direction in high strain zones our ams determinations based on a variety of samples that were taken from mudstones slates and schists from the pyrenees and appalachians show that strain is not the only factor controlling the development of magnetic lineation we find that the development and extent to which the magnetic lineation parallels the tectonic extension direction depends on both the original ams tensor which in turn depends on the lithology and the deformation intensity rocks having a weak pre deformational fabric will develop magnetic lineations that more readily will track the tectonic extension

imaging the bracciano caldera system by aeromagnetic data inversion sabatini volcanic district central italy abstract bracciano lake located in central italy 30 km northwest of rome is a volcano tectonic depression developed in pleistocene time representing the sabatini volcanic district svd western eruptive center little is known about bracciano caldera deep structure and potential field methods are appropriate to probe through a volcanic pile in this paper we present a 3d magnetic inversion model of the bracciano caldera system based upon new aeromagnetic data and paleomagnetic measurements carried out by istituto nazionale di geofisica e vulcanologia ingv magnetic modelling provides a reconstruction of bracciano caldera morphology whose extension is about 20 km north south and 15 km east west the maximum collapse depth is up to 1 km and the depocentre area appears localised to the north of the present bracciano lake shoreline considering the geological records of the main bracciano caldera forming events we have interpreted the resulting magnetic model as an overlap of two collapse structures generating a nested system whose location was strictly influenced by tectonic processes our 3d magnetic model confirms and consolidates the validity of the magnetic method to highlight deep structures in volcanic environments

the madden julian oscillation in the canadian climate centre general circulation model the madden julian oscillation mjo simulated by the canadian climate centre general circulation model ccc gcm is identified by a principal oscillation pattern pop analysis and compared with that observed in the real atmosphere the results are based upon two integrations of the ccc gcm one with a parameterization of penetrative cumulus convection exp1 and the other with a moist convective adjustment scheme exp2 the signal of mjo can be detected in both integrations as the first pop of the 200 hpa velocity potential along the equator the disturbances show a distinctive wave number one structure with the strongest local amplitude found in the longitudes corresponding to the region of the asian monsoon the phase speed of the eastward wave propagation is higher in the eastern pacific and lower in the monsoon region where the convective activities are strongest these features are in good agreement with the observations the energy spectrum of the velocity potential peaks at the frequency corresponding to a period of about 38 days for exp1 which is somewhat shorter compared to the observed periods of 40 50 days on the other hand two spectral peaks can be clearly identified for exp2 one with a period of 24 days and the other with a much longer period somewhere near 112 days both peaks appear statistically significant at 95 level long term data of the observed atmosphere show little indication of such spectral separation the horizontal patterns identified by the pop analysis resemble to some extent the baroclinic response of tropical flow to a heat source travelling with the speed of mjo at the upper level rossby wave energy propagates westward with winds generally following the height contours whereas kelvin wave energy propagates to the east from the heat source with strong cross contour flow near the equator at the lower level the patterns are essentially reversed the model generated precipitation and diabatic heating are examined by compositing against the moving mjo it is found in exp2 that the composite heating distribution is coherent with the flow pattern only in a certain sector of the equator depending on whether the fast or slow mode is used to determine the reference point the composite vertical heating profile of a slower mode tends to have a maximum found at a lower level the sensitivity of simulated mjo to the cumulus convection scheme in the model is discussed

strain variations in a seismogenic normal fault baza sub basin betic chain insights from magnetic fabrics ams abstract ams and structural analysis are here applied to study the deformed zone associated with a large scale active normal fault in the central betic cordillera spain namely the baza fault system to determine i the kinematics of structures and their relation with fault zone architecture and segmentation degree ii the correlation between deformational structures and the different types of magnetic fabrics and iii the evolution of magnetic fabrics patterns from sedimentary to shear related associated with normal faults five outcrops 969 samples were analysed along the fault trace which shows different degrees of segmentation along strike and strong localization of deformation along narrow fault zones a first main set of magnetic fabric data corroborates the normal kinematics of the baza fault showing magnetic lineations parallel to the dip slip transport direction a second secondary set of magnetic lineations is parallel to the intersection lineation and can be related to less intense deformation in the fault rocks furthermore a detailed study 523 samples of a trench excavated across the fault zone where two fault splays tend to coalesce in a linkage relay zone indicates that i lithology and distance to fault planes are two factors that control the development of extension related magnetic fabrics in weakly deformed sediments ii the development of shear related fabrics in fault zones entails the mechanical rotation of minerals iii different orientation of magnetic lineations are related to different intensity of bulk deformation and iv magnetic lineation is useful to define local deviations of deformation axes produced by changes in the local extension direction from fault perpendicular to fault parallel extension in the linkage zone between adjacent fault splays

beryllium mineral evolution beryllium is a quintessential upper crustal element being enriched in the upper crust by a factor of 30 relative to primitive mantle 2 1 vs 0 07 ppm most of the 112 minerals with be as an essential element are found in granitic pegmatites and alkalic rocks or in hydrothermal deposits associated with volcanic and shallow level plutonic rocks and skarns because of the extensive differentiation needed to enrich rocks sufficiently in beryllium for beryllium minerals to form these minerals are relative latecomers in the geologic record the oldest known is beryl in pegmatites associated with the sinceni pluton swaziland 3000 ma in general beryllium mineral diversity reflects the diversity in the chemical elements available for incorporation in the minerals and increases with the passage of geologic time furthermore the increase is episodic that is steep increases at specific times are separated by longer time intervals with little or no increase in diversity nonetheless a closer examination of the record suggests that at about 1700 ma the rate of increase in diversity decreases and eventually levels off at 35 species formed in a given 50 ma time interval between 1125 and 475 ma then increases to 39 species at 125 ma except for four spikes before dropping off to 30 species for the last 100 ma these features appear to reflect several trends at work 1 diversifications at 2475 1775 and 525 ma which are associated with highly fractionated rare element granitic pegmatites and with skarns at langban and similar deposits in the bergslagen ore region of central sweden and which are inferred to correspond to the collisional phases of the supercontinents kenorland nuna and gondwana respectively 2 diversification at 1175 ma due to the rich assemblage of beryllium minerals in the ilimaussaq peralkaline complex gardar province west greenland in an extensional environment 3 diversification at 275 ma which is largely attributable to granitic pegmatites appalachian mountains u s a and urals russia and the larvik alkalic complex norway but nonetheless related to continental collision and 4 limited exhumation of environments where beryllium minerals could have formed in the last 100 ma that the maximum diversity of be minerals in any one geologic environment could be finite is suggested by the marked slowing of the increase in the number of species formed in a given 50 ma time interval whereas the drop off at 100 ma could be due to 100 myr being too short a time interval to exhume the deep seated occurrences where many be minerals had formed the relative roles of chance vs necessity in complex evolving systems has been a matter of considerable debate one equally applicable to what extent the temporal distribution of beryllium minerals is a matter of contingency on the one hand the appearance of the most abundant be minerals such as beryl and phenakite early in the history of be mineralization appears to be a deterministic aspect since these minerals only require the abundant cations al and si and crystallize at relatively low concentrations of be in aqueous solution or granitic magmas on the other hand it could be argued that the very existence of most other be minerals as well as the temporal sequence of their appearance is a matter of chance since 55 of the 112 approved be minerals are known from a single locality and many of these phases require an unusual combination of relatively rare elements consequently we cannot exclude the possibility that other equally rare and thus contingent potential be minerals await discovery in as yet unexposed subsurface deposits on earth and we suggest that details of be mineral evolution on other earth like planets could differ significantly from those on earth

constraints on deformation of the southern andes since the cretaceous from anisotropy of magnetic susceptibility the southernmost segment of the andean cordillera underwent a complex deformation history characterized by alternation of contractional extensional and strike slip tectonics key elements of southern andean deformation that remain poorly constrained include the origin of the orogenic bend known as the patagonian orocline here renamed as patagonian arc and the exhumation mechanism of an upper amphibolite facies metamorphic complex currently exposed in cordillera darwin here we present results of anisotropy of magnetic susceptibility ams from 22 sites in upper cretaceous to upper eocene sedimentary rocks within the internal structural domain of the magallanes fold and thrust belt in tierra del fuego argentina ams parameters from most sites reveal a weak tectonic overprint of the original magnetic fabric which was likely acquired upon layer parallel shortening soon after sedimentation magnetic lineation from 17 sites is interpreted to have formed during compressive tectonic phases associated to a continuous n s contraction our data combined with the existing ams database from adjacent areas show that the early cretaceous late oligocene tectonic phases in the southern andes yielded continuous contraction variable from e w in the patagonian andes to n s in the fuegian andes which defined a radial strain field a direct implication is that the exhumation of the cordillera darwin metamorphic complex occurred under compressive rather than extensional or strike slip tectonics as alternatively proposed if we agree with recent works considering the curved magallanes fold and thrust belt as a primary arc i e no relative vertical axis rotation of the limbs occurs during its formation then other mechanisms different from oroclinal bending should be invoked to explain the documented radial strain field we tentatively propose a kinematic model in which reactivation of variably oriented jurassic faults at the south american continental margin controlled the late cretaceous to cenozoic evolution of the magallanes fold and thrust belt yielding the observed deformation pattern

an exceptionally thick middle pleistocene tephra layer from epirus greece abstract a newly recognized 2 m thick trachytic volcanic ash deposit from northwestern greece is dated at 374 000 7000 yr and correlated with the middle pleistocene volcanic activity of central italy the deposit represents ash fallout from one of the largest volcanic eruptions in europe of the past 400 000 yr and should provide an important stratigraphic marker within the poorly dated middle pleistocene deposits of italy and greece

two centuries temperature variations over subtropical southeast china inferred from pinus taiwanensis hayata tree ring width high resolution long term temperature reconstructions in subtropical southeast china ssc are very scarce yet indispensable for the comprehensive understanding of climate change in china even in east asia we reconstructed the first previous growth season temperature in the sanqingshan mountains sqs southeast china since 1806 based on tree ring width data the reconstruction accounts for 56 4 of the total variance in the instrumental record over 1954 2009 unlike the northern hemispheric warming during recent two centuries the reconstruction captured a slowly cooling trend from 1806 to 1980 followed by a rapid warming afterward 2003 2009 was the warmest period in the reconstruction 1970 2000 was colder than the last stage of the little ice age lia most of the warm and cold periods in this reconstruction could be found in the tree ring based temperature reconstructions of vicinity area indicating that the temperature variations in ssc were almost synchronous at least at decadal scale this regional coherence of temperature variation was further confirmed by the spatial correlation patterns with the cru ts3 22 grid dataset a strong positive relationship between the temperature over sqs region and sea surface temperature sst over the north pacific ocean np has been noted suggesting that sst variations over np and the related pacific decadal oscillation significantly influenced the temperature variability over ssc to better understand the climate variability during the lia and the regional differences in temperature variations over sqs and northern hemisphere long data sets from more diverse areas of southern china are needed