soil gas survey for tracing seismogenic faults a case study in the fucino basin central italy soil gas he rn co2 and ch4 surveys were performed to test their sensitivity for locating fault or fracture systems when masked by unconsolidated lithologies and to investigate the gas bearing properties of seismogenic faults the fucino basin central italy was chosen as a test site because it displays a network of surface and shallow buried active faults within the valley floor which were partially reactivated during the 1915 avezzano earthquake ms 7 0 the highest radon values were found aligned along the most important faults especially along the san benedetto gioia dei marsi fault sbgmf to the east and in the northwestern sector where the avezzano celano fault acf meets the northwestern prolongation of the 1915 coseismic rupture moderately anomalous values of radon occur along the faults located in the depression of the historical lake trasacco fault tf and ortucchio fault of anomalous values of co2 rn and he were detected north of borgo ottomila in a zone where coseismic scarps and liquefaction phenomena were responsible for a pervasive brittle deformation during the 1915 earthquake highest helium values prevail in the western part of the plain in correspondence with a horst structure bounded by the tf and considered to be the extension of the vallelonga trasacco ridge results of this research confirm the possible usefulness of soil gas methods for locating some tectonic faults when covered by unconsolidated deposits the study provides some clues on the spatial influence of tectonics and geology on deeply seated gas migration toward the surface

the influence of changing orbital parameters and surface boundary conditions on climate simulations for the past 18 000 years abstract general circulation model experiments at 3000 year intervals for the past 18 000 years were made to estimate the magnitude timing and pattern of the climatic response to prescribed changes of orbital parameters date of perihelion axial tilt eccentricity and glacial age lower boundary conditions ice sheets land albedo sea ice and sea surface temperature the experiments used the community climate model ccm of the national center for atmospheric research ncar the response of monsoon circulations and tropical precipitation to the orbitally produced solar radiation changes was much larger than the response to changes of glacial age boundary conditions the continental interior of eurasia was 2 4 k warmer in summer and summer monsoon precipitation of north africa south asia was increased by 10 20 between 12 000 and 6000 yr bp before present when perihelion occurred during northern summer rather than in winter as now and the earth s axial tilt was larger than now southern hemisphe

dating human occupation and adaptation in the southern european last glacial refuge the chronostratigraphy of grotta del romito italy grotta del romito has been the subject of numerous archaeological chronological and palaeoenvironmental investigations for more than a decade during the upper palaeolithic period the site contains evidence of human occupation through the gravettian and epigravettian periods multiple human burials changes in the pattern of human occupation and faunal isotopic and sedimentological evidence for local environmental change in spite of this rich record the chronological control is insufficient to resolve shifts in subsistence and mobility patterns at sufficiently high resolution to match the abrupt climate fluctuations at this time to resolve this we present new radiocarbon and tephrostratigraphic dates in combination with existing radiocarbon dates and develop a bayesian age model framework for the site this improved chronology reveals that local environmental conditions reflect abrupt and long term changes in climate and that these also directly influence changing patterns of human occupation of the site in particular we show that the environmental record for the site based on small mammal habitat preferences is chronologically in phase with the main changes in climate and environment seen in key regional archives from italy and greenland we also calculate the timing of the transitions between different cultural phases and their spans we also show that the intensification in occupation of the site is chronologically coincident with a rapid rise in mesic woody taxa seen in key regional pollen records and is associated with the late epigravettian occupation of the site this change in the record of grotta del romito is also closely associated stratigraphically with a new tephra the rom d30 tephra which may act as a critical marker in environmental records of the region

impact of human activities on quality and geochemistry of groundwater in the merdja area tebessa algeria chemical data are used to clarify the hydrogeological regime in the merdja area in tebessa as well as to determine the status of water quality in this area groundwater from the aquifer in the merdja area can be divided into two major groups according to geographical locations and chemical compositions water in the center part of the area of study is characterized by the dominance of chloride sulfate sodium and potassium whereas waters in the limestone aquifers in the west are dominated by the same cations but have higher concentrations of bicarbonate stable isotopes show that the tebessa aquifers contain a single water type which originated in a distinct climatic regime this water type deviates from the global meteoric water line mwl as well as from the mediterranean meteoric water line the water is poor in tritium and thus can be considered generally older than 50 years piezometric map suggests that water is moving from the west towards the center of the studied area and from east towards center degradation of water quality can be attributed to agricultural fertilizers in most cases although the wadi el kebir river is a contributor to pollution in the middle part of the studied area

late pleistocene glacial events in the central apennines italy the study of glacial evidence in the gran sasso massif of the central apennines italy has allowed the last maximum advance and the subsequent stadial phases to be dated and the mean annual temperature and quantity of precipitation in the form of snow to be assessed for a number of periods the glaciers probably reached their maximum extension campo imperatore stade ca 22 60014c yr b p and started to retreat ca 21 000 yr b p leaving behind three recessional moraines after a first interstade fornaca interstade the fontari stade appears to have taken place shortly after 16 000 yr ago ca 15 000 yr ago the glacier started retreating leaving behind four more recessional moraines an interstade venacquaro interstade preceded the mount aquila stade datable at ca 11 000 yr b p a strong correlation is evident between the glacial phases on land and the isotopic variations in cores from the tyrrhenian sea

palaeoenvironmental and palaeohydrological variability of mountain areas in the central mediterranean region a 190 ka long chronicle from the independently dated fucino palaeolake record central italy abstract proxy records of past climate change spanning beyond the radiocarbon range commonly derive their chronologies from orbital tuning strategies thus bounding our spatio temporal reconstructions to a priori assumptions that can not be directly tested here we present a tephrochronologically constrained framework of past environmental and climatic changes in the central mediterranean region during the last ca 190 ka our research is based on a high resolution multi proxy study of a sedimentary record cores f1 f3 retrieved from the fucino basin lacustrine succession central italy in 2015 we update the existing tephrostratigraphic framework of the f1 f3 record with the finding of the widespread campanian ignimbrite tephra marker layer and produce a robust and independent chronology based on new and published 40ar 39ar and 14c dating of 17 tephra layers observed palaeoenvironmental changes are tracked in other lacustrine marine and speleothem records across the mediterranean and north atlantic regions via tephrostratigraphic correlations and chronological matching providing a robust assessment of age uncertainties results show a complex interplay between local environmental changes and broad scale climatic processes highlighting a strong orbital forcing on glacial interglacial changes along with these major changes we detect prominent millennial scale variability during times of intermediate global ice volumes mediterranean mountain ecosystems oscillated around an interglacial state suggesting that climatic shifts although large did not exceed the local environmental tolerance resilience threshold conversely during periods of large global ice volume we observe subdued millennial scale variability with ecosystems operating in a strictly ruled glacial environment

geomorphic constraints on landscape sensitivity to climate in tectonically active areas abstract the geomorphology of fluvial landscapes is known to record information about uplift rate spatial patterns of faulting and tectonic history data is far less available when addressing the sensitivity of common geomorphological metrics such as channel steepness to climatic boundary conditions we test the relationship between channel steepness and precipitation rate by measuring a large number of channels in different mountainous areas these regions exhibit a tenfold variation in precipitation rate between them 100 1000 mm y 1 but have similar uplift rates allowing the tectonic variable to be controlled by accounting for the orographic coupling of rainfall with uplifted topography we find that channel steepness is significantly suppressed by higher precipitation rates in a measurable way that conforms to simple stream power erosion laws and empirical constraints on their parameters we demonstrate this using modern and estimated glacial precipitation rates and climate emerges as an important quantifiable control on channel geometry these findings help to explain why highly variable measurements of channel steepness are reported from different locations and provide important empirical constraints on how climate shapes tectonically active landscapes

geoarchaeology and paleoseismology blend to define the fucino active normal fault slip history central italy abstract we first describe the late holocene slip history of one of the major segments of the fucino active normal fault in central italy by combining geoarchaeological investigations with paleoseismological trenching the fucino fault system released a mw 7 earthquake in 1915 with many other events with decimetre and or metre size palaeoseismic slip events in the past that is the strongest seismic shock occurred in this portion of the italian territory over at least the past millennium we dug trenches across the investigated tectonic structure then the sedimentary sequence and its relation with the exposed fault planes have been analysed vertically as typically made in paleoseismological investigations but also horizontally by deepening the excavations step by step while digging i e performing archaeological type stratigraphic excavations such a procedure permitted the recognition of different displacement events of the fault and the progressive surveying of different cultural levels since the neolithic period interposed with or cut into natural levels the reconstruction of the interplay between human occupation of the site and the local geomorphic evolution framed by the late holocene climatic changes permitted us to gain reliable chronological data for constraining the fault slip history in the last 5500 yr our analyses also confirmed that the investigated structure activated during the 1915 earthquake four previous displacement events were recognised a first event prior to the 1915 one occurred slightly after the roman period probably during the 5th 6th century ad two preceding events occurred between the late neolithic and the roman period the older of the two during the late neolithic while the later during the late bronze age early iron age the oldest event predates the neolithic period no evidence of a late middle ages faulting event found by others researchers along another branch of the fucino fault was found in our trenches from a methodological viewpoint the results of our study mark the effectiveness of adopting joint geoarchaeological paleoseismological approach in terms of chronological constraints for active faulting studies in such contexts where long human occupation took place where the natural and human events rhythmically interplay

transient landscape and stratigraphic responses to drainage integration in the actively extending central italian apennines abstract drainage networks in continental rifts are generally reported as dynamic features that produce transitions between endorheic and exorheic conditions while this is of major importance for landscape development sediment dispersal and basin stratigraphy the controls of drainage network evolution across an array of normal fault bounded basins are still not well understood in this study we use the central italian apennines an area that has been affected by active normal faulting and regional uplift over the last 3 myrs to determine the controls on drainage network evolution and its impact on transient landscape evolution and basin stratigraphy we compile previously published stratigraphic and fault related data with new geomorphological constraints for the aterno river system 1300 km2 for which a wealth of data has been collected following the destructive l aquila earthquake in 2009 we use this compilation to demonstrate how the different basins along the river system were initially isolated during the early pleistocene but became fluvially integrated with one another and the adriatic coast between ca 1 2 and 0 65 ma we conclude that the spatial and temporal pattern of drainage integration is mostly explained by a long term increase in sediment and water supply relative to basin subsidence due to the early to middle pleistocene climatic transition the progressive increase in fault related topography and the transport of sediment and water down system as drainage integration occurred overall we conclude that rates of sedimentation and basin subsidence in the central apennines are well matched allowing tipping points between over and under filled conditions to be easily reached we also show that consecutive drainage integration events produce discrete waves of river incision and terrace formation and conclude that drainage integration is of major importance at least equivalent to tectonics and climate in controlling transient landscape evolution and rift basin stratigraphy

pattern and forcing of northern hemisphere glacier variations during the last millennium time series depicting mountain glacier fluctuations in the alps display generally similar patterns over the last two centuries as do chronologies of glacier variations for the same interval from elsewhere in the northern hemisphere episodes of glacier advance consistently are associated with intervals of high average volcanic aerosol production as inferred from acidity variations in a greenland ice core advances occur whenever acidity levels rise sharply from background values to reach concentrations 1 2 equiv h kg above background a phase lag of about 10 15 yr equivalent to reported response lags of alpine glacier termini separates the beginning of acidity increases from the beginning of subsequent ice advances a similar relationship but based on limited and less reliable historical data and on lichenometric ages is found for the preceding 2 centuries calibrated radiocarbon dates related to advances of non calving and non surging glaciers during the earlier part of the little ice age display a comparable consistent pattern an interval of reduced acidity values between about 1090 and 1230 a d correlates with a time of inferred glacier contraction during the medieval optimum the observed close relation between noothern hemisphere glacier fluctuations and variations in greenland ice core acidity suggests that sulfur rich aerosols generated by volcanic eruptions are a primary forcing mechanism of glacier fluctuations and therefore of climate on a decadal scale the amount of surface cooling attributable to individual large eruptions or to episodes of eruptions is simlar to the probable average temperature reduction during culminations of little ice age alacier advances ca 0 5 1 2 c as inferred from depression of equilibrium line altitudes

site effects and widespread susceptibility to permanent coseismic deformation in the avezzano town fucino basin central italy constraints from detailed geological study abstract the quaternary fucino basin in the central apennines of italy was struck by one of the strongest italian earthquakes of the last millennium 1915 mw 7 0 the avezzano town 9 0 km away from the epicentre was completely destroyed in the surrounding area sizable coseismic surface deformation were catalogued attesting the severity of earthquake the proximity to the causative fault and the geological and geomorphological complexity of a basin filled by thick lacustrine sediments the avezzano area provides a case study to understand how shallow subsurface geology influences site effects in a deep quaternary continental basin environment thus being of potential interest for similar geologic contexts worldwide within the investigated area different possible earthquake induced effects can occur such as a stratigraphic amplifications in a wide range of resonance frequencies from 0 4 to 15 20 hz b liquefaction c coseismic surface faulting d basin edge effects and e slope instability we present and discuss results of basic seismic microzonation study sm of the avezzano area focusing on geologic constraints aimed at the reconstruction of the shallow subsurface geology and associated potential for local seismic hazard we adopted an interdisciplinary approach based on detailed geological structural geophysical and seismic analyses to investigate the seismic response of high seismic risk area such as the avezzano town given the urban and industrial expansion since the last century we discuss methodological approaches and their uncertainties

determining the recharge mode of sahelian aquifers using water isotopes abstract it is proposed that the drainage network plays an important role in the recharge process of the fractured aquifers in the african precambrian shield and that the fractured aquifer system is likely to be hydraulically continuous this contrasts with most previous studies which suggested direct recharge by rainwater percolation two areas were selected in niger for the study of the aquifer recharge process using isotopic analyses of water 2 h 18 o 3 h the first area centred on the village of kobio is the 21 km 2 drainage basin of the lomona intermittent stream some 60 km southwest of niamey the capital city of niger the second area in the vicinity of niamey represents a portion of the niger basin draining a surface area many orders of magnitude larger than the lomona basin the mean 18 o composition of water from all wells in the kobio aquifer provides evidence for recharge by evaporated water this is confirmed by the concomitant increase of 18 o content with rising static water levels as recharge proceeded tritium data suggest progressive aging of the kobio aquifer water in the flow direction inferred from static water levels with a down gradient depletion of 18 o composition suggesting that enriched recharge water is progressively mixed with depleted aquifer water recharge by a reach of the lomona is proposed to explain these results in the niamey area wells the 18 o time series clearly define an injection of evaporated water from the surface into the fractured aquifer this recharging plume of evaporated water most likely originates from the niger river thus isotope data for two drainage basins of very different sizes indicate that aquifers are recharged by water from the rivers and that the flow regime of surface waters controls the recharge process

sedimentology dating and palaeoclimatic interpretation of a 76 3 ka record from lago grande di monticchio southern italy abstract detailed sedimentological and microstratigraphical investigations of lacustrine sediments from lago grande di monticchio southern italy provide a time scale based on rates of sedimentation obtained from annual laminations although not annually laminated throughout a time scale covering the last 76 3 ka is available by interpolation of sedimentation rates results of this chronology agree with radiocarbon dates and with ar ar dates on tephra layers from the same lacustrine sediment sequence occurrence of varves in combination with physical and geochemical properties are related to variations in the trophic state of the lake and to changing runoff both controlled by palaeoclimatic conditions water depth was relatively shallow with dominating bioturbation and only few varves preserved for most of the pleniglacial a marked increase in precipitation and related runoff characterises the early last glacial maximum when water depth reached a maximum and clastic varves were deposited subsequently water depth was shallower again a drastic change towards nutrient rich conditions occurred at the pleistocene holocene transition during the holocene organic varves were deposited two periods with higher organic productivity were recognised prior to the last glacial maximum around 50 ka and 73 ka these intervals are interpreted as the result of interstadial conditions the oldes of the two events shows laminations comparable to those at the glacial holocene transition the periods with increased minerogenic influx may be characterised as stadial conditions lasting from 14 40 ka and from 50 73 ka

late quaternary tephra derived paleosols in central italy s carbonate apennine range stratigraphical and paleoclimatological implications abstract detailed stratigraphical pedological and geochronological 14c dating research was carried out on numerous sections located in the carbonate apennine range of central italy two paleosols late pleistocene pedomarker a and holocene pedomarker b in age were recognized as having developed from air fall pyroclastic material given their special properties and widespread distribution both soils represent valuable markers in the late quaternary stratigraphy of central italy information about the climatic conditions that have influenced their pedogenesis through time has been obtained pedomarker a formed under temperate wet conditions related to the last interstadial fluctuations of the pleniglacial its development ceased after ca 30 ka because of the onset of last glacial maximum dry cold conditions pedomarker b formed at the beginning of the holocene under udic and perudic soil moisture regimes its development ceased in some localities because of a change towards a drier climate after ca 4 5 ka petrographic and geochemical characteristics of the parent materials are discussed and correlations with the campanian ignimbrite pedomarker a and neapolitan yellow tuff pedomarker b both related to activity in the phlegrean fields are proposed

quasi 3d modelling of nearshore currents abstract existing concepts of wave induced nearshore current models in the cross shore vertical plane 2dv and depth integrated 2dh are combined to a quasi 3d mathematical model this combination is tested for reproducing correct results in 2dv and 2dh situations the importance of the various contributions to the wave induced secondary circulation in the vertical plane is investigated for realistic parameter ranges which leads to the conclusion that both the non breaking and the breaking fraction of a random wave field in the surf zone generate important secondary currents additional computations show the relevance of a 3d approach of nearshore currents even in seemingly simple situations like a plane sloping beach with obliquely incident waves

hydrochemical and isotopic investigation of a sandstone aquifer groundwater in a semi arid region el ma el abiod algeria this work present results of the hydrochemical and isotopic studies on groundwater samples from the study area chemical and environmental isotope data are presented and discussed in terms of the origin of dissolved species and of groundwater all of the investigated groundwater are categorized into two chemical types low and relatively high mineralized waters type interpretation of chemical data based on both thermodynamic calculations and stability diagrams suggests that the chemical evolution of groundwater is primarily controlled by water rock interactions interpretation of 18o and 2h suggests that the recharge of the investigated groundwater may result from differents mechanisms

tectonic and climatic controls on knickpoint retreat rates and landscape response times 1 the rate at which transient knickpoints propagate through a landscape fundamentally controls the rate of geomorphic response to tectonic and climatic perturbation here we present knickpoint retreat rates upstream of active faults for 19 bedrock catchments in turkey and 11 bedrock catchments in italy where we have very good constraints on both the magnitude and timing of the tectonic perturbation and where climate histories are well documented we show that the knickpoints have average retreat rates of between 0 2 and 2 mm yr for catchments with drainage areas between 6 and 65 km2 and we test whether differences in rock mass strength and catchment size are sufficient to explain this range in retreat rates our analysis suggests that even accounting for these two variables knickpoint propagation velocities differ markedly and we show that channels crossing faults with higher throw rates have knickpoints that are retreating faster the dependence of knickpoint retreat velocity on throw rate is at least as important as catchment drainage area these results indicate counterintuitively that landscapes forced by large amplitude tectonic perturbations will have shorter response times than those perturbed by smaller amplitude changes the link between the knickpoint propagation velocity and throw rate is largely but not completely explained by channel narrowing in areas of high uplift rate channel steepening upstream of the active faults may explain all of the residual dependency of knickpoint retreat rate on fault throw rate but only if the slope exponent n in the standard stream power model is greater than 1 3 however we cannot rule out a role for sediment supply in driving enhanced knickpoint retreat rate in addition to the well documented channel narrowing effect finally we find that mean knickpoints retreat rates in turkey are only half of those in italy for catchments of equivalent size crossing faults with similar throw rates this difference in fluvial response time is accounted for by long term differences in the ratio of precipitation to infiltration in the two areas over the last 1 my

an energetics total load sediment transport model for a plane sloping beach bagnold s energetics based total load sediment transport model for streams is used as a basis for the development of a total load model of time varying sediment transport over a plane sloping bed in both the bedload and suspended load the transport rate vectors are found to be composed of a velocity induced component directed parallel to the instantaneous velocity vector and a gravity induced component directed down slope the model is applied to idealized surfzone conditions leading to estimates of the local longshore and onshore offshore sediment transport rates as well as the equilibrium beach slope as a function of the local wave and current conditions the model is combined with a nonlinear longshore current model and spatially integrated to obtain predictions of the total longshore transport rate as a function of the incident wave conditions the results support the general form of the wave power equation except that the wave power coefficient is no longer constant but is instead a complex function of the incident wave and beach characteristics

bar generating cross shore flow mechanisms on a beach random waves normally incident on a dissipative beach induce a variety of cross shore flows such as asymmetric oscillatory flow wave grouping induced long wave flow breaking induced turbulent flow and momentum decay induced undertow these flows are identified analyzed and hindcasted in a set of laboratory experiments with the aim of revealing the role of each of the flow mechanisms in the two dimensional case of bar generation on a beach

geomorphic significance of postglacial bedrock scarps on normal fault footwalls the existence of well preserved holocene bedrock fault scarps along active normal faults in the mediterranean region and elsewhere suggests a dramatic reduction in rates of rock weathering and erosion that correlates with the transition from glacial to interglacial climate we test and quantify this interpretation using a case study in the italian central apennines holocene rates are derived from measurements of weathering pit depth along the magnola scarp where previous cosmogenic cl 36 analyses constrain exposure history to estimate the average hillslope erosion rate over similar to 10 5 years we introduce a simple geometric model of normal fault footwall slope evolution the model predicts that the gradient of a weathering limited footwall hillslope is set by fault dip angle and the ratio of slip rate to erosion rate if either slip or erosion rate is known the other can be derived applying this model to the magnola fault yields an estimated average weathering rate on the order of 0 2 0 4 mm yr more than 10 times higher than either the holocene scarp weathering rate or modern regional limestone weathering rates a numerical model of footwall growth and erosion in which erosion rate tracks the oxygen isotope curve reproduces the main features of hillslope and scarp morphology and suggests that the hillslope erosion rate has varied by about a factor of 30 over the past one to two glacial cycles we conclude that preservation of carbonate fault scarps reflects strong climatic control on rock breakdown by frost cracking

lake levels and climate for the last 30 000 years in the fucino area abruzzo central italy a review abstract lake fucino was in a closed basin that was drained in 1875 a review of published data as well as new geological and geomorphological studies are used to define changes in lake level over the last 30 000 years the changes are summarized as follows 1 a general rise of level between 33 000 and 18 000 20 000 yr b p 2 a general lowering between 18 000 20 000 and 7500 6500 yr b p 3 a rise between 6000 5000 yr b p 4 a lowering between 5000 2800 yr b p 5 a rise between 2800 2300 yr b p 6 lower between 2300 1800 yr b p 7 very low levels in the 16th century and 8 a rise during the 1750 1861 period of the so called little ice age lake level fluctuations are attributed to climatic variations in particular there is a clear link between fluctuations and changes in seasonal insolation produced by the orbital parameters of the earth precession of the equinoxes and obliquity of the ecliptic and average annual rainfall the fluctuations of lake levels do not seem to have been influenced significantly by tectonic movements affecting the fucino plain or by karst drainage pits present along the periphery

slip history of the magnola fault apennines central italy from 36cl surface exposure dating evidence for strong earthquakes over the holocene to better understand the mechanics of deformation in the mediterranean and the role that the convergence between africa and europe plays it is necessary to know the deformation field at different time scales here we use in situ 36 cl surface exposure dating of exposed bedrock fault scarps to determine earthquake time slip histories and to quantify slip rates over the last several thousand years this information allows us to delineate the seismic history of normal faulting within the mediterranean area over that time period we have studied the limestone scarp produced by the magnola fault in the central apennines italy the magnola fault in the fucino area is an active 15 km long normal fault striking wnw and dipping ssw the range front morphology characterised by steep triangular facets separated by v shaped valleys and wine glass canyons suggests that the magnola fault has been active for at least the last several hundred thousand years at the base of the facets the fault cuts limestone bedrock to produce a well preserved normal fault scarp 10 to 12 m high the distribution of 36 cl concentration versus the height along that scarp is best explained by a minimum of five and a maximum of seven successive earthquake exhumations with slips varying between 1 5 and 3 m an age of 5 ka at the base of the scarp and of 12 ka at the top yields a slip rate of 0 8 mm year the absence of any event on this fault during the last 5000 years suggests either that a future event is imminent on the magnola fault or that the fault has entered a quiescent period with

late quaternary lake level record from northern eurasia lake records from northern eurasia show regionally coherent patterns of changes during the late quaternary lakes peripheral to the scandinavian ice sheet were lower than those today but lakes in the mediterranean zone were high at the glacial maximum reflecting the dominance of glacial anticyclonic conditions in northern europe and a southward shift of the westerlies the influence of the glacial anticyclonic circulation attenuated through the late glacial period and the westerlies gradually shifted northward such that drier conditions south of the ice sheet were confined to a progressively narrower zone and the mediterranean became drier the early holocene shows a gradual shift to conditions wetter than present in central asia associated with the expanded asian monsoon and in the mediterranean in response to local monsoon type circulation there is no evidence of mid continental aridity in northern eurasia during the mid holocene in contrast the circum baltic region was drier reflecting the increased incidence of blocking anticyclones centered on scandinavia in summer there is a gradual transition to modern conditions after ca 5000 yr b p although these broad scale patterns are interrupted by shorter term fluctuations the long term trends in lake behavior show a clear response to changes in insolation and glaciation

nearshore circulation and dredged material transport at waikiki beach abstract the possibility of using offshore sand deposits as a source of material was recently studied as part of a beach nourishment project at waikiki beach hawaii the borrow site is located approximately 1100 meters off the beach a finite difference model of water circulation and fine particle transport is used to study dredge induced far field turbidity concentrations the influence of the dredging pit at the borrow site on the stability of the nearshore ocean bottom and on the beach is analyzed using the bailard sediment transport model in the onshore offshore direction model results show that effects of the dredging operation on the beach would be negligible a maximum sediment accumulation on the ocean bottom of 0 3 kg m 2 or equivalently a 0 2 mm thick layer is predicted for one day of operation which is considered acceptable

climate evolution and forcing during the last 40 ka from the oscillations in apennine glaciers and high mountain lakes italy the results of studies carried out on the variations of glaciers and lakes in the higher apennines during the last 40 ka are considered for correlation with some climate forcing agents e g changes in insolation variations in origin of the air masses carrying moisture and north atlantic events acting both at regional and hemispheric scales the origin of air masses was assessed using the apennine equilibrium line altitude pattern the presence of a quartz rich loess in the former glacial environment and the sedimentation rate of sahara quartz in maar lakes temperature and humidity variations have been deduced from glacier expansions and retreats and lake oscillations the data discussed in the paper show that variations in insolation have driven climatic changes in the apennines for most of the considered time span producing gradual changes that took place during periods lasting several thousand years however during some periods insolation seems to have been of minor importance compared to variations in frequency and intensity of southern air currents and to the influence of north atlantic events the data as a whole allow us to highlight the climatic evolution of the high apennine mountains during the last 40k cal a bp

active oblique extension in the central apennines italy evidence from the fucino region the fucino basin is a flat quaternary depression within the central apennines it is surrounded by active normal faults with small oblique slip components surface faulting was observed along the east side of the basin during the ms 7 0 avezzano earthquake of 1915 in order to understand the kinematics of recent strain better and to assess the seismic hazard of this region we carried out a detailed geomorphic and structural study of the faults around the basin fault scarp heights were accurately measured with total station profiles and vertical slip rates were estimated assuming slope offsets to post date the end of periglacial abrasion 14 4 kyr bp to the north the most prominent fault the magnola fault appears to have an average postglacial throw rate of 0 7 0 3 mm yr 1 and together with the velino fault to be capable of generating earthquakes of maximum magnitudes of 6 9 7 3 with recurrence intervals of 1000 3000 yr east of the basin the serrone parasano and ventrino faults form a right stepping horsetail of the giovenco fault current vertical slip rates on the three former faults appear to be between 0 5 and 1 4 0 5 and 1 0 and 0 3 and 1 1 mm yr 1 respectively infrequent maximum magnitude earthquakes on them may also exceed 7 particularly in the case of coupled rupture with loosely constrained recurrence intervals up to several thousand years the right lateral slip components implied by the most recent slickensides and by geomorphic offsets on the nw se trending normal faults of the area suggest that the blocks they bound rotate counterclockwise consistent with oblique left slip on the nnw sse trending giovenco and ovindoli faults to the east sinistral shear parallel to the latter faults the maximum relief across the magnola fault and the postglacial slope offsets measured suggest that the extension rate across the central apennines might be of the order of 6 3 mm yr 1 in a n20 10 e direction more northerly than hitherto inferred

the hydrogeochemical characterization of morsott el aouinet aquifer northeastern algeria a study of the hydrogeochemical processes in the morsott el aouinet aquifer was carried out with the objective of identifying the geochemical processes and their relation with groundwater quality as well as to get an insight into the hydrochemical evaluation of groundwater the high salinity coupled with groundwater level decline pose serious problems for current irrigation and domestic water supplies as well as future exploitation a combined hydrogeologic and isotopic investigation have been carried out using chemical and isotopic data to deduce a hydrochemical evaluation of the aquifer system based on the ionic constituents water types hydrochemical facies and factors controlling groundwater quality the ionic speciation and mineral dissolution precipitation was calculated by wateqf package software the increase in salinity is related to the dissolution and or precipitation processes during the water rock interaction and to the cationic exchange reactions between groundwater and clay minerals the isotopic analysis of some groundwater samples shows a similarity with the meteoric waters reflect their short residence time and a lowest evaporation phenomenon of infiltrated groundwater

late glacial and holocene aeolian deposits and geomorphological features near roccaraso abruzzo central italy abstract aeolian deposits and geomorphological features due to wind erosion have been recorded in the aremogna plain near roccaraso central apennines at this site three different aeolian deposits can be distinguished 1 silty loess deposits composed mainly of quartz 2 aeolian sand deriving from the reworking of tephra which lies on a peat level dated to 12 850 200 bp and 3 aeolian silt coming from the deflation of the deposits 2 which is associated to deflation geomorphological features in part still active the onset of these processes is more recent than 4690 200 bp the first and the second aeolian deposits are related to cold and dry phases of the late glacial period the third set of aeolian deposits and deflation features corresponds to wind erosion on a denudated landscape as a consequence of a dry climatic phase the effect of which was amplified by winter freezing thawing activity

the last interglacial pedocomplexes in the litho and morpho stratigraphical framework of the central northern apennines central italy recently in italy a great deal of effort has been devoted to the mapping of quaternary continental deposits several unconformity bounded stratigraphic units ubsu have been defined the unconformities indicate important phases of changing dynamics linked to quaternary climatic changes and have been related to valley downcutting simultaneous with paleosol formation during interglacials however glacial periods are characterised by deposition of thick continental sequences we suggest that the ubsu s belonging to the late middle pleistocene mis 6 and late pleistocene can also be defined under a pedostratigraphic point of view locally at the top of the ubsu attributed to mis 6 buried or relict paleosols are preserved the paleosols developed in calcareous fluvial and moraine gravels with minor flints the pedocomplexes are made of three paleosols separated by erosion surfaces and or stonelines the older paleosol mis 5e is severely truncated and is characterised by a ck horizon overlain by strongly leached reddish bt horizons with flinty rock fragments with a diagnostic wavy lower boundary in some sites subsequent secondary precipitation of carbonates transformed this horizon into a btk this paleosol is buried by a younger paleosol mis 5c with less leached reddish btk horizons quartz of aeolian origin and very small and scarce calcareous clasts the main pedofeatures are associated with colluvial processes biological activity and carbonate precipitation this paleosol is also truncated and buried under a similar paleosol mis 5a therefore the lower paleosol of the pedocomplex can be attributed to the eemian and constitutes a valid marker for the definition and mapping of the underlying and overlying sedimentary units in other parts of the apennines no sedimentary units have been found that correspond to the unconformities separating different pedostratigraphical units in order to map the different ubsu s due to the poor lateral continuity of the preserved paleosols morpho and litho stratigraphical investigations and correlation are always recommended

age dating and the orbital theory of the ice ages development of a high resolution 0 to 300 000 year chronostratigraphy using the concept of orbital tuning a continuous high resolution deep sea chronostratigraphy has been developed spanning the last 300 000 yr the chronology is developed using a stacked oxygen isotope stratigraphy and four different orbital tuning approaches each of which is based upon a different assumption concerning the response of the orbital signal recorded in the data each approach yields a separate chronology the error measured by the standard deviation about the average of these four results which represents the best chronology has an average magnitude of only 2500 yr this small value indicates that the chronology produced is insensitive to the specific orbital tuning technique used excellent convergence between chronologies developed using each of five different paleoclimatological indicators from a single core is also obtained the resultant chronology is also insensitive to the specific indicator used the error associated with each tuning approach is estimated independently and propagated through to the average result the resulting error estimate is independent of that associated with the degree of convergence and has an average magnitude of 3500 yr in excellent agreement with the 2500 yr estimate transfer of the final chronology to the stacked record leads to an estimated error of 1500 yr thus the final chronology has an average error of 5000 yr