laboratory investigations on impulsive waves caused by underwater landslide laboratory investigations have been performed on the submarine landslide generated waves by performing 120 laboratory tests both rigid and deforming slide masses are considered the effects of bed slope angle initial submergence slide geometry shape and deformation on impulse wave characteristics have been inspected impulse wave amplitude period energy and nonlinearity are studied in this work the effects of bed slope angle on energy conversion from slide into wave are also investigated laboratory based prediction equations are presented for impulse wave amplitude and period in near and far field and are successfully verified using the available data in previous laboratory and numerical works

pacific ocean and cenozoic evolution of climate 1 the pacific ocean has played a major role in climate evolution throughout the cenozoic 65 0 ma it is a fundamental component of global heat transport and circulation the dominant locus of primary productivity and consequently the largest reservoir for carbon exchange between the oceans and the atmosphere a satisfactory understanding of the cenozoic evolutionary history of the pacific and its impact on global climate is currently data limited nevertheless the large dynamic range of cenozoic conditions sets the stage to greatly expand our understanding of global climate and biogeochemical cycles past earth experiments are particularly useful to understand interactions between climate and geosystems under different greenhouse gas loads we highlight in this review four important problems in which the pacific played a major role the effect of changing geographic boundary conditions on ocean circulation interactions between the carbon cycle and climate the pacific ocean s influence on north american climate and its water cycle and the gradual evolution of climate systems

information content of slug tests for estimating hydraulic properties in realistic high conductivity aquifer scenarios summary a recently developed unified model for partially penetrating slug tests in unconfined aquifers malama et al in press provides a semi analytical solution for aquifer response at the wellbore in the presence of inertial effects and wellbore skin and is able to model the full range of responses from overdamped monotonic to underdamped oscillatory while the model provides a unifying framework for realistically analyzing slug tests in aquifers with the ultimate goal of determining aquifer properties such as hydraulic conductivity k and specific storage s s it is currently unclear whether parameters of this model can be well identified without significant prior information and thus what degree of information content can be expected from such slug tests in this paper we examine the information content of slug tests in realistic field scenarios with respect to estimating aquifer properties through analysis of both numerical experiments and field datasets first through numerical experiments using markov chain monte carlo methods for gauging parameter uncertainty and identifiability we find that 1 as noted by previous researchers estimation of aquifer storage parameters using slug test data is highly unreliable and subject to significant uncertainty 2 joint estimation of aquifer and skin parameters contributes to significant uncertainty in both unless prior knowledge is available and 3 similarly without prior information joint estimation of both aquifer radial and vertical conductivity may be unreliable these results have significant implications for the types of information that must be collected prior to slug test analysis in order to obtain reliable aquifer parameter estimates for example plausible estimates of aquifer anisotropy ratios and bounds on wellbore skin k should be obtained if possible a priori secondly through analysis of field data consisting of over 2500 records from partially penetrating slug tests in a heterogeneous highly conductive aquifer we present some general findings that have applicability to slug testing in particular we find that aquifer hydraulic conductivity estimates obtained from larger slug heights tend to be lower on average presumably due to non linear wellbore losses and tend to be less variable presumably due to averaging over larger support volumes supporting the notion that using the smallest slug heights possible to produce measurable water level changes is an important strategy when mapping aquifer heterogeneity finally we present results specific to characterization of the aquifer at the boise hydrogeophysical research site specifically we note that 1 k estimates obtained using a range of different slug heights give similar results generally within 20 2 correlations between estimated k profiles with depth at closely spaced wells suggest that k values obtained from slug tests are representative of actual aquifer heterogeneity and not overly affected by near well media disturbance i e skin 3 geostatistical analysis of k values obtained indicates reasonable correlation lengths for sediments of this type and 4 overall k values obtained do not appear to correlate well with porosity data from previous studies

mineral magnetic studies of the vermiculated red soils in southeast china and their paleoclimatic significance abstract vermiculated red soil the main pedostratigraphical unit of the red soil sequences widespread in subtropical and tropical china has experienced a higher degree of pedogenesis than loess paleosols and the underlying red clays in the loess plateau of northern china previous studies suggested that magnetic properties of the vermiculated units of the red soils are significantly degraded compared to those of the non vermiculated counterparts the mechanism for this magnetic decrease however has not been well determined in order to resolve this problem this study has investigated two red soil sequences of different origin in southeast china by integrating environmental and mineral magnetic research the results show that the magnetic depletion in the vermiculated units was probably caused by both dissolution of magnetic minerals in the white veins and transformation of highly magnetic maghemite to weakly magnetic hematite it appears that stronger pedogenesis favors the transformation of more maghemite to hematite and magnetic properties associated with the relative concentration of maghemite to hematite can be used as climate indicator in the vermiculated red soils the variation trends of the magnetic parameters of the vermiculated red soils prior to 0 85 0 9 ma suggest a strengthening of the east asian summer monsoon the reverse trend of these parameters after 0 85 0 9 ma may correlate with a significant strengthening of the east asian winter monsoon since 0 85 ma

hydraulic tests in highly permeable aquifers 1 a semianalytical solution is presented for a mathematical model describing the flow of groundwater in response to a slug or pumping test in a highly permeable confined aquifer this solution which is appropriate for wells of any degree of penetration and incorporates inertial mechanisms at both the test and observation wells can be used to gain new insights into hydraulic tests in highly permeable settings the oscillatory character of slug and pumping induced responses will vary considerably across a site even in an essentially homogeneous formation when wells of different radii depths and screen lengths are used thus variations in the oscillatory character of responses do not necessarily indicate variations in hydraulic conductivity k existing models for slug tests in partially penetrating wells in high k aquifers neglect the storage properties of the media that assumption however appears reasonable for a wide range of common conditions unlike in less permeable formations drawdown at an observation well in a high k aquifer will be affected by head losses in the pumping well those losses which affect the form of the pumping induced oscillations can be difficult to characterize thus analyses of observation well drawdown should utilize data from the period after the oscillations have dissipated whenever possible although inertial mechanisms can have a large impact on early time drawdown that impact decreases rapidly with duration of pumping and distance to the observation well conventional methods that do not consider inertial mechanisms should therefore be viable options for the analysis of drawdown data at moderate to large times

major element and ree compositions of pliocene sediments in southwest japan implications for paleoweathering and paleoclimate abstract the history of the east asian monsoon and the relationship between the development of the monsoon climate tectonics and global climate are complicated and controversial earlier studies have indicated that the east asian monsoon fluctuated in the asian interior during the pliocene thus the chemical weathering record in coastal regions of east asia can be the key to elucidating its evolution as well as the kuroshio current variability the present study clarifies the chemical weathering conditions in southwest japan based on the concentrations of major elements and rare earth elements rees in lacustrine muddy sediments the chemical weathering was moderate between 4 4 and 3 8 ma between 3 8 and 3 4 ma chemical weathering significantly intensified as indicated by the high values of the chemical index of alteration that reached a maximum of 98 as well as the high concentrations of rees and light rees against heavy rees and kaolinite rich clay mineral compositions despite the wide variation in source rock compositions and grain sizes the degree of chemical weathering remained moderate during the early pleistocene the intense chemical weathering on land in southwest japan from 3 8 to 3 4 ma may have been regulated by alternating periods of warm and humid climate brought by the invasion of the kuroshio current and the intensification of the east asian summer monsoon

partly pedogenic origin of magnetic variations in chinese loess quaternary sequences of interbedded aeolian silts loess and buried soils palaeosols potentially provide one of the best terrestrial records of past climates1 5 magnetic susceptibility variations in loess and palaeosol sequences from china are strongly correlated with climate induced fluctuations of oxygen isotope ratios in deep sea sediments2 4 6 8 as an explanation of this correlation it has been suggested that the recorded variations in magnetic susceptibility depend primarily on the degree of dilution by non magnetic bulk loess constituents of a uniform magnetic assemblage derived from remote but unknown sources6 8 it has also been suggested that such a model involving changes in the accumulation rate of loess superimposed on a constant flux of magnetic particles provides a relative geological timescale through the control of loess deposition by astronomically modulated climate fluctuations7 here we report a preliminary test of this model using rock magnetic properties especially sensitive to variations in magnetic grain size our results show that palaeosols are characterized by much finer magnetic grain size assemblages than are the intervening loess units this suggests that a simple model based on constant magnetic influx and dilution by variable amounts of non magnetic loess is inadequate our magnetic measurements establish the close comparability of the fine grained magnetic minerals in the palaeosol samples to those in contemporary soils and thus point to a partially pedogenic origin for the magnetic mineral assemblages in the palaeosols

observations and interpretations at vredefort sudbury and chicxulub towards an empirical model of terrestrial impact basin formation the structural topographic and other characteristics of the vredefort sudbury and chicxulub impact structures are described assuming that the structures originally had the same morphology the observations interpretations for each structure are compared and extended to the other structures this does not result in any major inconsistencies but requires that the observations be scaled spatially in the case of vredefort and sudbury this is accomplished by scaling the outer limit of particular shock metamorphic features in the case of chicxulub scaling requires a reasoned assumption as to the formation mechanism of an interior peak ring the observations interpretations are then used to construct an integrated empirical kinematic model for a terrestrial peak ring basin the major attributes of the model include a set of outward directed thrusts in the parautochthonous rocks of the outermost environs of the crater floor some of which are pre existing structures that have been reactivated during transient cavity formation inward directed motions along the same outermost structures and along a set of structures at intermediate radial distances during transient cavity collapse structural uplift in the center followed by a final set of radially outward directed thrusts at the outer edges of the structural uplift during uplift collapse the rock displacements on the intermediate inward and innermost outward sets of structures are consistent with the assumption that a peak ring will result from the convergence of the collapse of the transient cavity rim area and the collapse of the structural uplift

the contribution of loess magnetism in china to the retrieval of past global changes some problems abstract in the loess plateau of china the stratigraphical position of the brunhes matuyama boundary was not found in loess unit l8 at luochuan and jixian as is commonly accepted the interbedded palaeosols may be differentiated from the parent loess not only by their high magnetic susceptibility but also by their enhanced remanence properties these contrasts mainly result from concentration changes of the inherited magnetic minerals grain size changes and authigenic formation of magnetic minerals which are all linked to climate controlled soil formation processes

landslide generated tsunamis runup at the coast of a conical island new physical model experiments 1 this paper presents new physical model experiments on tsunamis generated by landslides at the coast of a conical island the experiments have been carried out in a large wave tank the radius of the island coastline and the falling height of the landslide have been varied during the experimental campaign the landslide is reproduced by a solid body shaped as a half of an ellipsoid tsunami runup is measured using special wave gauges a detailed analysis of the runup along the coastline is presented with special attention to the role of each wave in the packet and to the evolution of the envelope of the first group of waves

smoothing analysis of slug tests data for aquifer characterization at laboratory scale abstract the present paper proposes a smoothing analysis of hydraulic head data sets obtained by means of different slug tests introduced in a confined aquifer laboratory experiments were performed through a 3d large scale physical model built at the university of calabria the hydraulic head data were obtained by a pressure transducer placed in the injection well and subjected to a processing operation to smooth out the high frequency noise occurring in the recorded signals the adopted smoothing techniques working in time frequency and time frequency domain are the savitzky golay filter modeled by third order polynomial the fourier transform and two types of wavelet transform mexican hat and morlet the performances of the filtered time series of the hydraulic heads for different slug volumes and measurement frequencies were statistically analyzed in terms of optimal fitting of the classical cooper s equation for practical purposes the hydraulic heads smoothed by the involved techniques were used to determine the hydraulic conductivity of the aquifer the energy contents and the frequency oscillations of the hydraulic head variations in the aquifer were exploited in the time frequency domain by means of wavelet transform as well as the non linear features of the observed hydraulic head oscillations around the theoretical cooper s equation

twin tsunamis triggered by the 12 january 2010 haiti earthquake on 12 january 2010 a magnitude m w 7 0 earthquake occurred 25 km west southwest of haiti s capital port au prince causing an estimated 316 000 fatalities thereby exceeding any previous loss of life from a similar size earthquake in addition tsunami waves triggered by the earthquake caused at least three fatalities at petit paradis due to a complete lack of tsunami awareness the international tsunami survey team itst was deployed within weeks of the event and covered the greater bay of port au prince and more than 100 km of hispaniola s southern coastline the collected survey data include more than 21 tsunami heights along with observations of coastal land level change maximum tsunami heights of 3 m have been measured for two independently triggered tsunamis

origin and weathering properties of loess paleosol sequence in the goseong area on the east coast of south korea abstract this study aims to investigate the origin and weathering properties of the loess paleosol sequence in the goseong area on the east coast of south korea and to discuss the local sediment inputs and their paleoclimatic implications the geochemical properties suggest that the largest proportion of the sequence originated from the chinese loess plateau and or its source areas with a smaller quantity originating from the weathering products of the bedrock around the section although its origin can be regarded as the chinese loess plateau and or its source areas the sequence shows more weathered features than the chinese loess plateau moreover the weathering environments in south korea were different from those in the chinese loess plateau the difference in weathering properties may be attributed to the more humid climatic conditions in south korea the abundance of local sediment input to the sequence was controlled by sea level fluctuations in the east sea of korea and the global ice sheet developments during the glacial and interglacial cycles in the quaternary because local sediment occupies only minor proportions in the sequence the monsoon and westerly circulations in northeast asia played an important role in the loess formations in south korea as well as in the chinese loess plateau

correlation between climate events in the north atlantic and china during the last glaciation episodes of massive iceberg release heinrich events 1 3 into the north atlantic ocean during the last glaciation were associated with recurring episodes of unusually cold north atlantic surface water bond cycles 4 and cold air temperatures over greenland dansgaard oeschger events 5 6 four of the youngest of these cold events have also been reported in climate records from sites outside the north atlantic region7 but until now the entire suite has been identified only in north atlantic marine sediments greenland ice core records and tentatively in french lake sediments8 here we examine grain size data from chinese loess and intercalated accretionary palaeosols of last glacial age for evidence of similar climate signals remote from the north atlantic region we see grain size maxima with ages that match those of the last six heinrich events which we interpret as an indication of the changing strength of the east asian winter monsoon which largely controls the transport and deposition of central asian aeolian dust thus it seems that these heinrich events have left their signature in the chinese loess record this is consistent with simulations of the glacial climate9 which imply that the climates of the north atlantic and china were linked by the effect of westerly winds

tectonics of east indonesia abstract the complex processes resulting in basin formation and inversion during the tertiary tectonic evolution of indonesia owe their origin to the interplay between the indian eurasian australian and pacific plates within the framework of these major plates and their relative motions some microplates may be recognized whose tectonic development was constrained by motions of the large plates treated as small ridged microplates their boundaries define the sites of basin formation their dynamic development results in the formation and subsequent inversion of basins throughout the region this paper outlines the tectonic framework of indonesia throughout tertiary time in a series of reconstructions and considers the constraints that this implies for microplate motions and basin histories

on the effect of the water body geometry on landslide tsunamis physical insight from laboratory tests and 2d to 3d wave parameter transformation preliminary landslide tsunami hazard assessment is commonly based on empirical equations derived from wave channel 2d or wave basin 3d experiments the far field wave in 2d can easily be an order of magnitude larger than in 3d the present study systematically investigates the effect of the water body geometry on the wave characteristics in the near and far field subaerial landslide tsunami tests were conducted relying upon both a 2d and a 3d physical model undertaken with identical boundary conditions the test parameters included two water depths three rigid slides as well as various slide release positions empirical equations for 3d offshore and laterally onshore wave properties are presented and compared with previous work a direct comparison of the wave features reveals that the waves decay in 2d 3d onshore and 3d offshore with x 0 30 r 0 67 and r 1 0 where x 2d and r 3d describe the distance from the impact zone in 2d four wave types are observed whereas only the two least non linear types were observed in 3d this finding is further analysed with wavelet spectra for a large slide froude number f relative slide thickness s and relative slide mass m the 3d wave heights in the slide impact zone can be as large as in 2d however for small f s and m the 3d waves are considerably smaller both in the near and far field a novel method is presented and validated to transform data from 2d studies to 3d this method may have favourable implications on preliminary landslide tsunami hazard assessment

numerical simulations of large water waves due to landslides a mathematical model based on the hydrodynamic shallow water equations is developed for numerical simulation of slide generated waves in fjords the equations are solved numerically by a finite difference technique to examine the performance of the numerical model we have simulated the slide catastrophe in tafjord western norway 1934 the predicted runup heights are in good agreement with measured runup heights the effects of wave amplification are estimated in runup zones with gentle beach slopes the model results reveal wave energy trapping due to the fjord geometry this causes standing wave oscillations in accordance with the observations

laboratory study on a beach drainage system abstract in recent years beach drainage systems bds have been considered as an innovative approach to stabilize the beachface even if it still has to be proven to what extent they are effective in stabilizing the beach or causing accretion this paper describes tests carried out at the grosser wellenkanal in hannover aimed at improving the knowledge of the hydrodynamic and morphodynamic behaviour of a beach containing a buried drainage system scale effects that affected previous bds laboratory experiments are minimized by the large scale the morphodynamic response of the undrained beach compared to a beach drained under the same type of wave action is reported experiments were undertaken using a set of multiple drains up to three working simultaneously located below the beach and at variable distances from the shoreline the experimental program was organized in a series of tests with variable wave energy while a positive effect was observed under low energy conditions for medium and high energy conditions the benefit of having the drains operative was not always clear in any case it was evident that any positive effect of the drains on the beachface was limited to the position of the cone of depression represented by the lowering of the hydraulic head

application of wavelet transform analysis to landslide generated waves the aim of this paper is to illustrate the results of a preliminary study on aerial landslide generated waves which has been mainly intended to establish a method for analyzing water surface records some simple physical experiments reproducing the scott russell s wave generator were carried out in a small two dimensional wave flume the wavelet transform wt is applied to analyze wave measurements and it is shown that useful information can be obtained by means of this technique the celerity of impulsively generated waves reflection by an overflow structure and seiching phenomena of the flume are studied a discussion of the results along with some remarks about ongoing research is also given

magnetic susceptibility evidence of monsoon variation on the loess plateau of central china during the last 130 000 years the magnetic susceptibility of loess and paleosols in central china represents a proxy climate index closely related to past changes of precipitation and vegetation and thus to summer monsoon intensity time series of magnetic susceptibility constructed for three loess paleosol sequences in the southern part of the chinese loess plateau document the history of summer monsoon variation during the last 130 000 yr they correlate closely with the oxygen isotope record of stages 1 to 5 in deep sea sediments soils were forming during intervals of strong summer monsoon whereas loess units were deposited at times of reduced monsoon intensity the chinese loess paleosol sequence can thus be viewed as a proxy record of asian monsoon variability extending over the last 2 5 myr

cyclic variability in microstructure and physio mechanical properties of the xiashu loess palaeosol sequence in nanjing china abstract for the xiashu loess palaeosol sequence in nanjing china further to our work on the cyclic variability in its chemical composition and swelling shrinkage properties xia j huang g l liu z t chen x m 2007 cyclic variability in chemical composition and swelling shrinkage properties of the xiashu loess stratum near nanjing china pedosphere 17 5 666 672 this paper studies the cyclic variability in its microstructure and physico mechanical properties and the corresponding influence on its engineering behaviour for geotechnical and geological practices in addition the cyclic variability in the soil s grain size distribution and geochemical characteristics is compared with that of the loess palaeosol sequences at two other sites in china indicating a geographical pattern of cyclic variation of the sequences

a direct link between the china loess and marine δ 18 o records aeolian flux to the north pacific most studies of quaternary climates conducted during the past 150 years have focused on glacial sequences and for the past 25 years marine sediments have provided significant further understanding of glacial and interglacial palaeoclimates an important goal of palaeoclimatology however to link the well known detailed continental records to marine records of similar resolution has yet to be realized the classic loess sequences of china provide an apparently continuous record of continental climate over the past 2 4 million years1 2 the oxygen isotope 18o timescale developed from the marine record3 gives us a global chrono stratigraphy of late pleistocene climates previously it has been suggested in studies of the aeolian component in pelagic sediments that it may be possible to link these two records directly by finding a suitable core from the north west pacific downwind from china4 5 here we report the results of such an effort for core v21 146 fig 1 and tie the last 500 000 years of the chinese loess soil sequence directly to the 18o timescale and in so doing refine the dating of regional loess and soil horizons

three dimensional experiments on landslide generated waves at a sloping coast abstract this paper describes new three dimensional experiments on water waves generated by landslides the landslide is reproduced by a rigid elliptical body sliding along an inclined plane slope of 1 3 1 vertical 3 horizontal the generated water waves are free to propagate both offshore and alongshore since the plan dimensions of the used wave tank are of at least one order of magnitude larger than the width of the landslide which can be considered to be a scale of the wave length the experimental study has been carried out reproducing both subaerial and partially submerged landslides the wave generation process is studied by means of video records of the near field flow and measurement of the landslide movement the properties of the waves propagating along the coast are described on the basis of runup gauges the waves observed during the experiments always present first a crest and then a trough as the first wave propagates away from the generation area the crest tends to become smaller than the trough and the maximum runup along the coast is given by the second or by the third wave an important feature is that the observed runup along the coast firstly grows with the distance from the generation area it reaches a maximum value at about two times the width of the landslide and then decreases an estimate of the celerity at which the waves propagate along the coast is given on the basis of gauge measurements it results that the crests propagate faster than the troughs and the wave period increases

tectonic approach to the neogene evolution of pacific indian ocean seaways abstract one of the principal results of igcp 355 is a tectonic approach to understanding the changes in neogene surface water circulation between the tropical pacific and indian oceans this paper 1 outlines the tectonic framework of the indonesian region through tertiary times in a series of reconstructions and 2 considers the constraints these events imply for the motion of microplates and basin histories in this region in addition associated changes in biogeographic patterns reflect major changes in surface water circulation of the indo pacific region tectonic reconstructions and biogeographic data indicate that the neogene indonesian seaway was effectively closed during early middle miocene times 17 15 ma and completely severed by about 6 ma preventing further interchange between surface water of the tropical pacific and indian oceans

a late miocene early pliocene biogenic silica crash in the andaman sea and bay of bengal abstract variations in the mass accumulation rate of biogenic silica bsi in continental margin sediments can be used to reconstruct relative changes in productivity through time in these settings in the northern bay of bengal a lack of long sedimentary records has historically precluded this type of reconstruction the acquisition of 21 new long sedimentary records during the 2006 indian national gas hydrate program nghp expedition 01 has made it possible for the first time to reconstruct paleoproductivity in this important region of the world that is dominated by intense changes in the geological and biological fluxes largely driven by tectonic and climate related mechanisms in the research presented here fluctuations in the mass accumulation rate of biogenic opal during the past 9 4 myrs are reconstructed using continental margin sediment cores from the andaman sea site nghp 01 17a and the northern bay of bengal site nghp 01 19 within these records a biogenic silica crash is recorded at 6 ma and is consistent with previous geotectonic geochemical and paleontological studies of the southern indian ocean and pacific ocean that suggest connectivity and thus exchange of nutrient rich water masses between the eastern tropical indian ocean and western tropical pacific ocean was diminished as a result of the tectonic restriction of the northerly sector of the indonesian throughflow itf the biogenic silica crash at sites 17 and 19 is consistent with a decrease in surface water productivity that may have been driven by the reduction of nutrient rich pacific waters delivered to the andaman sea and bay of bengal via the northerly route of the itf following the bsi crash at 6 ma subsequent recovery of the bsi mass accumulation rates at sites 17 and 19 occurred and was perhaps renewed by an enhanced supply of nutrient rich freshwater from the nearby irrawaddy and mahanadi rivers which could have occurred during a documented increase in the intensity of the indian monsoon at 5 ma although recovery is noted at both core locations biogenic silica mass accumulation rates did not fully recover in the andaman sea this could be explained by the restricted nature of the andaman basin and its more distal location from a major source of nutrient rich freshwater

reconstruction of oceanic circulation patterns in the tropical pacific across the early middle miocene boundary as inferred from radiolarian assemblages abstract although there have been attempts to infer neogene oceanic circulation patterns in the tropical pacific on the basis of multiple marine proxies oceanic circulation patterns across the early middle miocene boundary are still poorly understood despite paleoclimate having significantly changed during this interval in this study we reconstruct the changes in tropical oceanic circulation patterns in the pacific across the early middle miocene boundary based on radiolarian assemblages obtained at integrated ocean drilling program site u1335 in the eastern tropical pacific the radiolarian upwelling taxa increased during four intervals 18 4 18 1 ma 16 9 15 7 ma 15 2 14 6 ma 14 2 13 4 ma radiolarian temperature index rti was calculated using the relative abundances of the warm water cluster b1 and cool water taxa cluster b2 in order to evaluate relative temperature fluctuations of the surface water the sea surface temperature index was relatively high from 16 8 to 16 0 ma and gradually decreased from 16 0 to 14 6 ma subsequently the temperature index decreased stepwise at 13 9 and 13 4 ma and became relatively low from 13 4 to 12 7 ma comparison of the rti record in the eastern tropical pacific to the climatic index based on the benthic foraminiferal 18o record shows that variability in the two records follows a roughly similar trend from the early to the middle miocene however the sea surface temperature record does not indicate a sharp increase in warmth in the eastern tropical pacific during the mid miocene climatic optimum 1 mmco 1 as suggested by the benthic isotopic record this is likely because of increased upwelling of cool nutrient rich water at this time beginning in the latest early miocene 17 ma radiolarian assemblages were dominated by different taxa in the eastern and western tropical pacific this pattern is interpreted as indicating a shallower thermocline in the east and a deeper thermocline in the west based on the relative abundance of the upwelling taxa there is an overall increasing trend in this difference since the latest early miocene we tie these events to the effective closure of the indo pacific seaway and the development of a substantial western pacific warm pool along with the development of a strong equatorial undercurrent

marine climatic responses to neogene tectonics of the pacific ocean seaways abstract based upon surface marine climatic evolution on both sides of the pacific ocean recently revealed by biochronostratigraphy in japan and south america the tectonics of pacific ocean seaways and associated responses of adjacent seas and ocean currents are discussed the rapid opening of the sea of japan at about 15 ma in early middle miocene time mainly by the rotation of the southwest japan arc can be correlated with the abrupt appearance of a cold water fauna on the pacific coast of northeast japan beginning ca 15 ma and an extensive hiatus along the pacific coast of southwestern japan spanning 15 ma to 12 ma the abrupt and extensive development of biosiliceous lithofacies along the pacific coast of peru beginning about 14 ma might also represent a response to the tectonic anticlockwise rotation of the peruvian block of the andean mountain range estimated to have occurred sometime during the miocene as the tectonic closing of the indonesian seaway would have strongly intensified the warm kuroshio current in the northwest pacific it is most probable that this seaway was effectively closed just prior to 15 5 ma in the earliest middle miocene when tropical marine faunas were developed in most of the japanese islands the closing of the central american seaway is estimated to have been completed at 3 5 3 ma in pliocene time the closure of this seaway would likely have intensified the warm kuroshio current affecting the marine fauna along the pacific coast of southwestern japan it is also possible that a decrease in surface temperatures at about 3 ma along the pacific coast of ecuador was due to this pliocene tectonic event

the paleogeography of late neogene central crete inferred from the sedimentary record combined with albinaria land snail biogeography abstract phylogenetic and geographic relations of recent land organisms often agree with results from tectonical and paleogeographic reconstructions in the hellenic island arc greece albinaria land snails gastropoda pulmonata clausiliidae are used to provide paleogeographical information in a combined analysis of their present distributional ranges and the sedimentary record late tertiary neogene islands in the region of present day crete existed for 6 9 myear before the arc was uplifted 3 2 myear ago pliocene the albinaria fauna of crete is known to be relictual in central crete an area of 3800 km2 the distributional ranges of 15 parapatrically dispersed albinaria species were determined based on differences in their ecological behavour the species are subdivided into two groups group 1 exclusively living on pre neogene substrate is believed to have largely conserved pre pliocene ranges and group 2 partly living on neogene partly on pre neogene substrates is assumed to have occupied the land which appeared after late neogene uplift events together with the sedimentary record albinaria helps to reconstruct the dynamic paleogeographic developments and block movements in central crete since the serravallian the conclusions imply 1 that some of the involved populations have been separated from each other for up to 11 myear and 2 that providing information on paleoislands recent land snails may contribute to geoscientific questions concerning the rate and timing of uplift and erosion

the effect of weathering on the grain size distribution of red soils in south eastern china and its climatic implications abstract particle size analysis is a useful way to determine the source and deposition of sediments however there are inconsistencies when this method is used to constrain the origin of the red soils in south eastern china to address this problem we performed a detailed grain size analysis of two red soil sequences in xuancheng and qiliting located along the lower reaches of the yangtze river by comparing their particle size characteristics with those of the loess on the loess plateau in northern china we found that the aeolian samples plot in a particular zone in the c m grain size of the cumulative 1 versus median grain size plot and cluster nearer the lower left corner of the plot as their degree of weathering increases the grain size features suggest that the onset of large scale aeolian deposition along the lower reaches of the yangtze river occurred at approximately 0 8 ma although both sedimentary sorting and post depositional weathering control the grain size variations in the deposits the extremely strong weathering due to the humid warm climate along the lower reaches of the yangtze river primarily modified the grain size distributions of the primary red soil deposits strong weathering increased the very fine silt 2 5 m fraction and decreased the coarse 63 m fraction we also found that certain grain size parameters of the red soils varied with the weathering intensity which can be used as indicators of palaeoclimate variations the grain size variations in both the qiliting and xuancheng sequences suggest that the mid pleistocene climate transition mpt may have affected the lower reaches of the yangtze river at 0 9 ma

cenozoic history of phosphogenesis recorded in the ferromanganese crusts of central and western pacific seamounts implications for deepwater circulation and phosphorus budgets abstract ages of seamount phosphatization episodes have been revised for 14 mid plate seamounts in the western and central pacific using the most up to date marine sr isotope curve and 87 sr 86 sr data from the literature the new ages provide a composite geologic history of phosphatization consistent with cenozoic climate history phosphatization on mid pacific seamounts took place only between 36 and 12 ma and it peaked at the eocene oligocene e o transition 34 ma the unprecedented appearance of prominent amounts of phosphorites at the e o transition and frequent recurrences of it afterwards suggests that a new mechanism came into play at that time namely the intensification of the advective flow of bottom water which accelerated the phosphorus cycle in contrast the absence of phosphorites younger than 12 ma suggests another fundamental change in process associated with the shift to a dry and cold climate that probably resulted in a decrease in the riverine input of labile phosphorus the drastic decrease in the frequency of hiatuses in ocean floor depositional records also indicates weakened bottom currents as a possible explanation for the absence of seamount phosphorite since 12 ma a phosphorus flux is a critical variable in modeling the response of the earth system to climate forcing in the geologic past thus the changes in phosphorus flux across the e o boundary and around 12 ma justify further study

quantitative sediment source ascription using magnetic measurements in a reservoir catchment system near nijar s e spain the magnetic properties of sediments from a dried out reservoir and its inflowing streams were measured to provide a basis for sediment source determination quantitative estimates of source component proportions in the reservoir sediments were made using linear programming procedures the study confirms that this type of research must be based on a detailed knowledge of the relationship between magnetic properties and particle size in both the sediments and the potential sources in the case of the site studied the isabel ii reservoir near nijar s e spain the sediments generated by contemporary surface processes within the reservoir catchment fail to reflect fully the 19th century material largely responsible for the rapid infill of the reservoir an additional source type namely unweathered schist derived material not represented in the fine sediments sampled within channels upstream from the reservoir has to be included in the model before calculations of source component contributions can be made it is inferred that one or more high magnitude low frequency event outside the amplitude of the most recently operating processes was largely responsible for the infilling of the reservoir

geochemical and detrital zircon u pb geochronological constraints on provenance of the xiaomei red earth sediments bose basin guangxi province southern china abstract the bose basin in southern china is within a region influenced by the winter westerly monsoon and thus potentially subject to eolian dust accumulation a red earth sequence developed on terraces of the youjiang river a branch of the pearl river records information about climate variation during the pleistocene and its relationship to contemporaneous global climate changes in this study geochemical characteristics and u pb geochronology of detrital zircons of the red earth sequence at xiaomei were investigated using x ray diffraction xrd x ray fluorescence xrf inductively coupled plasma mass spectrometry icp ms thermal ionization mass spectrometry tims and detrital zircon u pb dating analyses our results show that the red earth sediments are composed of quartz and clay minerals kaolinite illite and mixed layer illite vermiculite with minor hematite and goethite mobile elements such as cao mgo na2o k2o sr and ba are depleted and immobile elements such as tio2 al2o3 fe2o3 t and zr are enriched in comparison with loess paleosols of the chinese loess plateau clp the upper continental crust ucc and post archean australian shale paas these data indicate that the xiaomei red earth sediments have experienced intense chemical weathering similar to that of the xuancheng and jiujiang red earth sections on the middle to lower reaches of the yangtze river the xiaomei sediments have similar la th ratios u pb vs th pb relationships and rare earth element ree distributions to the clp ucc and paas and their low end 0 values are indicative of an upper crustal origin the 147sm 144nd and 87sr 86sr ratios of the xiaomei sediments are different from loess paleosols of the clp but similar to those of well mixed river sediments u pb dating of detrital zircons in the xiaomei sediments shows that crystals from different units have slightly different age distributions the full xiaomei section yields a distribution similar to that of upper permian triassic clastic rocks in the youjiang area and the distribution of the middle to upper xiaomei section additionally shows similarities to upper crust of the south china craton our results indicate that the xiaomei red earth sequence which dates to the late early to early middle pleistocene 1 0 0 6 ma accumulated predominantly from fluvially transported locally weathered materials and therefore that the sediment carrying capacity of the east asian winter monsoon has been overestimated in previous provenance studies of red earth sediments in south china

mid pleistocene environmental reconstruction based on xiashu loess deposits in the yangtze delta china abstract a 5 67 m thick section in loess like sediments at xiashu was exposed during archaeological excavation of the fangniushan paleolithic site esr dating and grain size analysis suggested that the sediments are wind blown in origin and were deposited within a period of about 400 kyr environmental proxy indicators including magnetic susceptibility frequency dependent magnetism kd median grain size and clay grade percentage show that five warm and humid climatic periods occurred in the study region in the mid pleistocene namely at 130 90 192 195 198 203 230 and 345 357 ka these five periods roughly correspond to the s1 s2 s3 s4 and s5 paleosols in the chinese loess plateau stratigraphy and also to the deep sea oxygen isotope stages 5 7 9 11 and 13 15 the upper four climatic periods are comparable to the four warm climatic periods recorded in the laohushan xiashu loess section discovery of stone implements from the sixth and the seventh layers during the archaeological excavation indicates human activities at that time and the environmental proxies suggest that the environment was suitable for human activities

variability of monsoon climate in east asia at the end of the last glaciation abstract high resolution paleomonsoon proxy records from peat and eolian sand paleosol sequences at the desert loess transition zone in china denote a rapid oscillation from cold dry conditions 11 200 10 60014c yr b p to cool humid conditions 10 600 10 20014c yr b p followed by a return to cold dry climate 10 200 10 00014c yr b p variations in precipitation proxies suggest that significant climatic variability occurred in monsoonal eastern asia during the younger dryas interval late glacial climate in the chinese desert loess belt that lies downwind from europe was strongly influenced by cold air from high latitudes and from the north atlantic via the westerlies the inferred precipitation variations were likely caused by variations in the strength of the siberian high which influenced the pressure gradient between land and ocean and therefore influenced the position of the east asian monsoon front

plate tectonics radiogenic isotopic tracers and paleoceanography the case of the manganese crusts in the pacific abstract hydrogenous ferromanganese crust deposits on seafloor and volcanic seamounts are archives of past isotopic compositions of the ocean isotopic compositions of long life radiogenic isotopes that are dissolved in the ocean such as nd and pb are mixtures of different erosion products continents volcanics arcs ridges etc transported by oceanic currents or winds isotopic studies on mn crusts are thus potential paleogeographic and paleoceanographic tracers however global paleogeography can drastically evolve over the period of growth of crust as well as the latitude longitude and water depth of the mn crust thus each crust sampled a succession of geographic sites related to its spatial evolution through time for this reason valid information about the past ocean isotopic composition can only be extracted from mn crust under the condition that the successive paleogeographic and paleodepth positions can be reconstructed for each mn crust we followed this approach for six hydrogenous mn crusts from the pacific ocean that have recorded pb and nd isotopic signals for the past 80 myr the evolution of the isotopic data was considered within a proper geodynamical framework that takes into account the paleopositions of the pacific plate and surrounding continents of the hot spots and ridges as well as the paths of the six crusts the differences and similarities between the pb and nd revealed by our analysis emphasize their complementarity as paleoceanographic tracers the nd isotopes are strongly influenced by the exchange between indian and pacific waters specifically by the progressive closure of the indonesian gateway the closed central pacific characteristics are defined from the extrapolation of the isotopic trend this highlights the important role played by erosion of volcanic arcs in the nd isotopic value of seawater our approach also stresses the influence of local volcanic activity ridges or active hot spot for lead isotopes

experimental study of the impact factors of natural dam failure introduced by a landslide surge a large amount of loose deposit between the sides of a landslide lake may slide into a reservoir at any time because of influences such as earthquakes heavy rainfall or other triggering factors these factors can cause the formation of a huge surge and result in the instantaneous failure of a landslide dam the failure of a landslide dam can threaten people s lives and property downstream this paper analyzes the destruction mechanism of landslide dams because of a surge and the impact of the contact area the landslide height and the distance between the entry point and the dam site for a dam break through physical experiment and compares the experimental results with the calculated values experimental results show that the contact area and the landslide height have a significant impact on the dam break surge a measure based on the previously mentioned factors can be made to reduce the dam failure risk caused by a landslide surge two empirical methods pan s method and miller s method are used to predict the landslide surge wave and compared with the experimental results the simulated results show that the miller s method used for predicting the landslide surge wave is more reasonable

early to middle pleistocene homo dispersals from africa to eurasia geological climatic and environmental constraints abstract although the pleistocene human dispersal is one of the most intriguing issues of paleoanthropology large sectors along possible migratory pathways are ill defined or poorly documented this paper examines the geological geomorphological climatic and environmental conditions that could have determined hominin transit from their motherland in the east africa rift valley toward the circummediterranean regions or arabian peninsula for their choice between these two alternatives the danakil depression afar rift immediately north of the ethiopian rift valley was a strategic area they could reach the mediterranean sea through a northern route along the nile river valley the trans sahara megalake or riverine belts or else navigate an eastern route into the arabian peninsula after crossing the bab el mandeb straits it is assumed all of these pathways were possible during convenient geological climatic and or sea level conditions hominins had three additional choices once they arrived at the mediterranean sea shores with eurasia as their final destination the levant corridor was the easiest because walkable and almost always under favorable conditions two other possibilities were the sicily channel and the strait of gibraltar these sea arms are located in two extremely active settings of the mediterranean sea and were at their embryonic stage during the early pleistocene because large scale deformations of the sea floor were associated to prolonged sea level lowstands these two sea arms could have been passable similar considerations apply to the bab el mandeb straits region for the trans mediterranean and the trans red sea routes of dispersal the environmental conditions and the submarine and terrestrial topographical features that could have made sea transit possible even without land bridges are underscored to track the dispersal relations between northern africa and eurasia three schematic maps are presented to show the distribution of the archeological and paleoanthropological sites currently regarded as reliably dated they document three groups of dates between 2 0 and 1 5 ma 1 4 and 0 7 ma and 0 6 and 0 1 ma their distribution is matched with coeval paleoclimatic proxies such as marine oxygen isotope stages aeolian dust in the atlantic ocean and sapropels levels and dust fluxes in the eastern mediterranean dispersal was temporally arranged into cycles of four major exodus waves 2 0 1 6 ma 1 4 1 2 ma 1 0 0 8 ma and 0 6 0 1 ma controlled by climatic and environmental changes

late quaternary dust flow on the chinese loess plateau abstract the dust flux of over 25 g cm2 103yr was reached in the central part of the chinese loess plateau during the last glacial maximum this is more than three times higher than during the last interglacial and early glacial time the grain size of the pleniglacial dust reached a peak shortly after 20 000 years ago and testifies to the occurrence of strong winds and frequent dust storms

physical modeling of tsunamis generated by three dimensional deformable granular landslides 1 tsunamis generated by deformable granular landslides are physically modeled in a three dimensional tsunami wave basin based on the generalized froude similarity the dynamic landslide impact characteristics were controlled by means of a novel pneumatic landslide generator the wave amplitudes periods and wavelengths are related to the landslide parameters at impact with the landslide froude number being a dominant parameter between 1 and 15 of the landslide kinetic energy at impact is converted into the wave train energy the wave amplitudes decay in radial and angular directions from the landslide axis the first wave crest mostly travels with speeds close to the theoretical approximation of the solitary wave speed the measured tsunami wave profiles were either of the nonlinear oscillatory or nonlinear transition type depending primarily on the landslide froude number and relative slide thickness at impact the generated waves range from shallow to deep water depth regimes with the majority being in the intermediate water depth regime wave characteristics are compared with other two and three dimensional landslide tsunami studies and the results are discussed

improved landslide tsunami prediction effects of block model parameters and slide model 1 subaerial landslide tsunamis and impulse waves are caused by mass movements impacting into a water body and the hazards they pose have to be reliably assessed empirical equations developed with physical froude model studies can be an efficient method for such predictions the present study improves this methodology and addresses two significant shortcomings in detail for the first time these are the effect of three commonly ignored block model parameters and whether the slide is represented by a rigid block or a deformable granular material a total of 144 block slide tests were conducted in a wave flume under systematic variation of three important block model parameters the slide froude number the relative slide thickness and the relative slide mass empirical equations for the maximum wave amplitude height and period as well as their evolution with propagation distance are derived for most wave parameters remarkably small data scatter is achieved the combined influence of the three block model parameters affects the wave amplitude and wave height by up to a factor of two the newly derived equations for block slides are then related to published equations for granular slides this comparison reveals that block slides do not necessarily generate larger waves than granular slides as often argued in the technical literature in fact it is shown that they may also generate significant smaller waves the new findings can readily be integrated in existing hazard assessment methodologies and they explain a large part of the discrepancy between previously published data

sedimentary environment and paleosols of middle miocene fluvial and lacustrine sediments in central japan implications for paleoclimate interpretations abstract sedimentary facies analysis and description of paleosols were carried out for the middle miocene tokiguchi porcelain clay formation pcf in central japan in order to interpret the soil forming environments during a long hiatus in the japanese islands the sedimentary facies suggests that deposition occurred mainly in a lacustrine environment with minor channel fill and debris flow deposits associated with alluvial fan environments the coarse grained sediments which are inferred to have been deposited in channel bar and debris flow deposits are present only in the marginal area of the sedimentary basin mature paleosols are identified in the tokiguchi pcf characterized by illuviated clay identifiable soil horizons including bt horizons and many in situ plant fossils and are then similar to ultisols most tree trunk fossils however were preserved by burial beneath debris flow deposits most of paleosols formed on lacustrine deposits and were covered by lacustrine clay and silt deposits without intervening coarse grained deposits such as flood flow deposits this change of sedimentary facies indicates a dramatic change of hydrologic environment from stagnant water to entirely desiccated conditions promoting weathering and soil formation the relationship between sedimentary facies and pedotypes consequently implies the repetition of specific events i e submergence and emergence of lake bottom most likely due to formation and drainage of a dammed lake these isolated events and development of mature paleosols might suggest specific characteristics of middle miocene weathering conditions such as seasonally heavy rainfall and or warm climatic conditions in the japanese islands

linear systems analysis in a karst aquifer abstract a linear systems analysis applied to groundwater flow is presented as an alternative modeling technique to traditional discretized groundwater models i e finite difference and finite element which require elaborate parameters and boundary conditions linear systems analysis has been used extensively for surface water modeling and to a lesser extent for groundwater applications we present a method for the analysis of an aquifer s response in hydraulic head to recharge that comprises two major components the first component is to predict the drop in hydraulic head over time if recharge is eliminated by fitting logarithmic curves to selected short term hydraulic head recession periods a long term recession or base head can be established the estimation of base head is necessary for the second component of the method which is the derivation of an impulse response function or transfer function the transfer function was derived by deconvolution of two time series data sets estimated recharge and the measured response in hydraulic head an aquifer s response to recharge can be characterized and modeled by using the transfer function which also establishes the time to peak response the response time distribution and the total memory length of the system the method requires fitting smooth curves to the oscillatory transfer function derived by deconvolution in the fourier transform domain the smooth curve is considered to be the physically valid transfer function in this analysis curve fitting was more effective than other smoothing techniques commonly used we applied the method to the karstic madison aquifer and found that the time to peak response is less than one month the system s total memory is about six years and a logarithmic curve best fits the system response this method has potential to be useful as a predictive tool in aquifer management

circum mediterranean oligo miocene biogeographic evolution the gastropods point of view based on studies in iran qom basin esfahan sirjan basin zagros mountains in turkey mut and sivas basins in the mesohellenic basin and in northeastern egypt a new palaeobiogeographic concept for the oligocene and miocene in the circum mediterranean area with special emphasis on the distribution patterns of gastropod faunas is presented a very strict biogeographic terminology is proposed to avoid the common fusion of geographic faunistic and geodynamic terms in the palaeontologists jargon our main interest focuses on the affinities and the faunistic interactions between the early mediterranean and the early indo pacific regions during the oligo miocene especially the role of the early indo pacific faunas as the mythic centre of origination of early neogene european mollusc faunas as often vaguely indicated in the literature is critically evaluated this leads to the establishment of a mediterranean iranian province and a western indian eastern african province as palaeobiogeographic subunits of the western tethys region during the oligocene due to major geodynamic and related biogeographic changes in the early miocene the western tethys region no longer existed and was replaced by the proto mediterranean atlantic region for the area of the paratethys the palaeobiogeographic unit danubian province which includes the protocaspian subprovince is proposed furthermore the underrated transatlantic communication of the oligo miocene nearshore mollusc faunas is demonstrated altogether this paper is a contribution to the discussion on the biogeographic concepts classification and nomenclature in palaeontology as initiated by westermann palaeogeogr palaeoclimatol palaeobiogeogr 158 2000 1 13 163 2000 49 68 2002 elsevier science b v all rights reserved

mineral magnetic record of the chinese loess and paleosols variations in the magnetic susceptiblity of the chinese loess and its interbedded paleosols correlate strikingly well with the deep sea oxygen isotope record low susceptibility values are found for the loess layers and high values are found for the soil horizons two interpretative models have been advanced to account for these magnetic variations both of these models discount any significant in situ formation of magnetite during soil forming periods instead they infer relative concentration of detrital or atmospheric magnetite at these times we critically examine the assumptions made in these models and on the basis of some new mineral magnetic data and fromalized magnetic flux calculations offer an alternative explanation of the loess magnetic record our model identifies pedogenic formation of magnetite as the major contributor to the high magnetic susceptibility of the paleosols the formation and preservation of this pedogenic magnetite is dependent on soil froming conditions and hence reflects the regional climate

grain size partitioning in loess paleosol sequence on the west coast of south korea using the weibull function abstract this study aims to partition the grain size of the loess paleosol sequence on the west coast of south korea and investigates the limitations and applicability with the partitioning method through the help of a laser diffraction grain size analyzer two to four components depending on the samples and theories employed to convert the laser diffraction data to grain size data are identified through the partitioning process however the identification of one component is thought to be contingent upon the theories employed rather than natural processes the partitioning results reveal that the sequence consists mostly of fine and coarse components transported by the same mechanisms as in the chinese loess plateau and shares common source areas with the chinese loess plateau the sequence also contains a small quantity of material from the local sources and this component is expected to provide crucial information about paleoclimatic variations in korea this study suggests that considerations of the theories are essential in modeling processes of grain size because the theories greatly influence the results of grain size analysis and the number of components and that conversions using the fraunhofer approximation seem to provide more reliable results than those using the mie theory

sensitivity analysis of slug tests part 2 observation wells abstract an earlier paper part 1 this issue dealt with the use of sensitivity analysis for the design of a slug test that would give reasonably accurate estimates of the aquifer parameters by an informed choice of the number and times of measurements an investigation of the radial dependence of the cooper et al analytical solution for a slug test in a confined aquifer shows that the use of one or more observation wells can vastly improve the parameter estimates particularly the estimate of the storage parameter generally the observation well must be fairly close about 10 m or less to the slugged well to be effective the storage coefficient must be small in order to see the effect of the slug at greater distances from the stressed well since the temporal and spatial dependence of the sensitivities for transmissivity and storage are considerably different the addition of one or more observation wells will substantially reduce the correlation between these two parameters which will result in much better estimates than are usually obtained in slug tests these ideas are illustrated using typical data representative of our research sites

palaeoclimatic and sedimentary history from magnetic susceptibility of loess in china the magnetostratigraphic age of the oldest loess sediments in the central chinese loess plateau investigated so far has recently been placed at ca 2 4 million years b p thus glaciations in central asia which are believed to provide the detritus for the formation of chinese loess commenced at the same time as the first ice rafted debris sank into the ocean basins of the northern hemisphere shackleton et al 1984 lithologic palaeontologic geochemical and especially rock magnetic variations throughout the loess column are indicative of palaeoclimatic fluctuations during loess deposition the variations of magnetic low field susceptibility in loess closely resemble those of the marine oxygen isotope record shackleton and opdyke 1976 and establish for the first time a continuous record of the pleistocene glacial and interglacial stages in a continental section spectral analysis of the rock magnetic time series indicates slow apparent sedimentation during interglacial periods which are characterized mainly by calcium dissolution and related compaction of the soils variable aeolic sediment influx as well as erosion and or polygenetic soil formation may also strongly influence the sedimentary history

lituya bay landslide impact generated mega tsunami 50th anniversary on july 10 1958 an earthquake mw 8 3 along the fairweather fault triggered a major subaerial landslide into gilbert inlet at the head of lituya bay on the southern coast of alaska the landslide impacted the water at high speed generating a giant tsunami and the highest wave runup in recorded history the mega tsunami runup to an elevation of 524 m caused total forest destruction and erosion down to bedrock on a spur ridge in direct prolongation of the slide axis a cross section of gilbert inlet was rebuilt at 1 675 scale in a two dimensional physical laboratory model based on the generalized froude similarity a pneumatic landslide tsunami generator was used to generate a high speed granular slide with controlled impact characteristics state of the art laser measurement techniques such as particle image velocimetry piv and laser distance sensors lds were applied to the decisive initial phase with landslide impact and wave generation as well as the runup on the headland piv provided instantaneous velocity vector fields in a large area of interest and gave insight into kinematics of wave generation and runup the entire process of a high speed granular landslide impact may be subdivided into two main stages a landslide impact and penetration with flow separation cavity formation and wave generation and b air cavity collapse with landslide run out and debris detrainment causing massive phase mixing formation of a large air cavity similar to an asteroid impact in the back of the landslide is highlighted a three dimenional pneumatic landslide tsunami generator was designed constructed and successfully deployed in the tsunami wave basin at osu the lituya bay landslide was reproduced in a three dimensional physical model at 1 400 scale the landslide surface velocities distribution was measured with piv the measured tsunami amplitude and runup heights serve as benchmark for analytical and numerical models

a nd isotopic study of southern sourced waters and indonesian throughflow at intermediate depths in the cenozoic indian ocean we present nd isotopic data for fossil fish teeth recovered from the past 40 m y at odp site 757 currently located at 1650 m water depth on the ninetyeast ridge in the indian ocean although site 757 sits in a region strongly influenced by weathering inputs from the himalayas and volcanic inputs from the indonesian arc the pattern of nd isotopic variations does not appear to respond to these potential sources of nd instead secular variations correlate to changes in the composition of intermediate to deep water masses bathing the site and circulation patterns in the indian ocean from 40 to 10 ma nd values and the pattern of change at site 757 closely match those of odp site 1090 a deep water site in the atlantic sector of the southern ocean comparison to data from several fe mn crusts in the indian ocean suggests that intermediate to deep water flow paths were similar to the modern distribution of circumpolar deep water at approximately 10 ma nd isotopic values increase in a step function by 2 nd units suggesting that plate motions had carried site 757 into a region influenced by indonesian throughflow estimates of the vertical and horizontal position of this site at 10 ma imply that indonesian throughflow extended as far south as 20 s and to a depth of 1500 m from 10 to 0 ma nd isotopic variations at site 757 appear to record variations in indonesian throughflow from 10 to 5 5 ma values at site 757 overlap with those from crusts located in the southwest pacific indicating extensive flow through the indonesian seaway from 5 5 to 3 4 ma nd values become less radiogenic at site 757 and more radiogenic in the southwest pacific suggesting increasing closure of the seaway and concomitant rerouting of equatorial pacific waters beginning at 3 4 ma nd values become more radiogenic again at site 757 which may be attributed to enhanced opening of the seaway or to a change in the source of throughflow waters from a southern to a northern pacific region

forecasting impulse waves generated by subaerial landslides 1 subaerial landslides falling into reservoirs or open seas generate impulsive water waves that are usually referred to as a class of tsunami waves it is important to study landslide generated waves occurring both in closed water basins where the waves interact with the shorelines and eventually the dam and in open seas where the generated waves can travel and deliver devastating damages hundreds of kilometers away in order to gain insight on subaerial landslide generated waves the italian national dam office recently funded an experimental and numerical research program geared to better understand and forecast tsunamis waves this paper introduces the experimental work which has been carried out in order to define empirical formulations able to forecast the principal features of the generated waves in a three dimensional water body as a function of the landslide movement wave types observed during the experiments are here characterized using a wavelet analysis approach new forecasting formulations named rid formulas are defined on the basis of the experimental study and tested using an artificial neural network model results are finally compared to those presented in past experimental studies

the landslides and tsunamis of the 30th of december 2002 in stromboli analysed through numerical simulations on the 30th of december 2002 two tsunamis were generated only 7 min apart in stromboli southern tyrrhenian sea italy they represented the peak of a volcanic crisis that started 2 days before with a large emission of lava flows from a lateral vent that opened some hundreds of meters below the summit craters both tsunamis were produced by landslides that detached from the sciara del fuoco this is a morphological scar and is the result of the last collapse of the northwestern flank of the volcanic edifice that occurred less than 5 ka b p the first tsunami was due to a submarine mass movement that started very close to the coastline and that involved about 20 106 m3 of material the second tsunami was engendered by a subaerial landslide that detached at about 500 m above sea level and that involved a volume estimated at 4 9 106 m3 the latter landslide can be seen as the retrogressive continuation of the first failure the tsunamis were not perceived as distinct events by most people they attacked all the coasts of stromboli within a few minutes and arrived at the neighbouring island of panarea 20 km ssw of stromboli in less than 5 min the tsunamis caused severe damage at stromboli

discussion of experimental investigation of impact generated tsunami related to a potential rock slide western norway by g saelevik a jensen g pedersen coastal eng 56 2009 897 906 this paper is a discussion of saelevik et al 2009 their comparison between block and granular model results is described in more detail along with a discussion of five parameters which may be in general responsible for deviations between block and granular models new small scale physical model tests have been performed to support some of the statements made finally it is argued that the use of physical model testing based on simplified geometries are justified in practice and normally produce results that are considerably better than an order of magnitude

optimal initial conditions for simulation of seismotectonic tsunamis numerical simulation of seismotectonic tsunamis usually starts with specification of the initial elevation of the water surface in the tsunami source the initial elevation is traditionally set equal to the vertical residual bottom deformation resulting from earthquakes we discuss the imperfectness of the traditional approach and suggest an improved practical method of calculating the initial elevation from the solution of the 3d problem in the framework of potential theory the method takes into account horizontal and vertical components of bottom deformation and bathymetry in the source area within the assumption of instant tsunami generation the suggested method represents the optimal way to specify the initial condition in the tsunami propagation problem the tsunamis in the central kuril islands on 15 november 2006 and 13 january 2007 are taken as examples to demonstrate the efficiency of the new method

observations of physical effects from tsunamis of december 30 2002 at stromboli volcano southern italy on december 30 2002 following an intense period of activity of stromboli volcano south tyrrhenian sea italy complex mass failures occurred on the northwest slope of the mountain which also involved the underwater portion of the volcanic edifice for a total volume of about 2 3 107 m3 two main landslides occurred within a time separation of 7 min and both set tsunami waves in motion that hit the coasts of stromboli causing injuries to three people and severe damage to buildings and structures the tsunamis also caused damage on the island of panarea some 20 km to the sse from the source they were observed all over the aeolian archipelago at the island of ustica to the west along the northern sicily coasts to the south as well as along the tyrrhenian coasts of calabria to the east and in campania to the north this paper presents field observations that were made in the days and weeks immediately following the events the results of the quantitative investigations undertaken in the most affected places namely along the coasts of stromboli and on the island of panarea are reported in order to highlight the dynamics of the attacking waves and their impact on the physical environment on the coastal structures and on the coastal residential zone in stromboli the tsunami waves were most violent along the northern and northeastern coastal belt between punta frontone and the village of scari with maximum runup heights of about 11 m measured on the beach of spiaggia longa measured runups were observed to decay rapidly with distance from the source typical of tsunami waves generated by limited area sources such as landslides

simulation of small amplitude frequency dispersive transient waves by means of the mild slope equation a numerical model based on the mild slope equation is applied to reproduce the propagation of small amplitude transient waves the model makes use of the fourier transform to convert the time dependent hyperbolic equation into a set of elliptic equations in the frequency domain the results of two available experimental studies on tsunamis generated by landslides are used to validate the model which appears to be able of carefully reproducing the effects of the frequency dispersion an example application of tsunamis propagating around the stromboli island is also presented to show the applicability of the present approach to real life scenarios it is finally discussed how this model could be applied as support to a tsunami early warning system

tectonically driven changes in the indian ocean circulation over the last 25 ma neodymium isotope evidence abstract changes in ancient oceanic current patterns have been strongly influenced by plate tectonics particularly by the opening or closing of gateways between different oceans such modifications of oceanic circulation have important consequences on climate we studied the nd seawater isotopic composition of indian and pacific ocean cores using nd isotopes which are good paleo oceanographic tracers we focused on the past 25 ma which are marked by the closure of the indonesian gateway as well as the mediterranean connection we show that a strong westerly oceanic surface current which we refer to the miocene indian ocean equatorial jet miojet linked the eastern and western indian ocean from 14 ma to 3 ma and infer that this major change in oceanic circulation probably induced important variations of global climate

a modal decomposition method for the analysis of long waves amplification at coastal areas abstract this paper presents a model for the evaluation of long waves amplification at coastal areas based on a modal decomposition method it is able of modelling the growth and the decay of the natural modes of the area under investigation and their contribution to the total wave field the model is an improvement of that developed by bellotti et al 2012b that was able of calculating the frequencies and the shapes of the natural modes but not their amplification under the action of forcing waves three test cases are used for the validation and to show the capabilities of the model the first considers the long waves resonance into a long and narrow harbour bay over a constant water depth it is a case for which a high degree of wave trapping into the semi enclosed coastal area is induced by the specific shape of the coastline the second test deals with the propagation of a group of edge waves along a straight coast with a constant sloping bottom generated in proximity of the shoreline by a special wave maker the model in this case properly evaluates what are the edge waves modes that contribute to the total wave field the third case involves the interaction of a solitary wave with a conical island for which laboratory data are available in this test a low degree of trapping exists but it is interesting for the present aims as the propagation of the waves around the island is expected to occur under the form of wave modes partially trapped by the bathymetry i e edge waves excited by the transient wave arriving from offshore on the basis of the tests results it is shown what is the role of the more relevant natural modes in the formation of the total surface elevation

temporal and spatial scaling of hydraulic response to recharge in fractured aquifers insights from a frequency domain analysis quantification of the recharge in fractured aquifers is particularly challenging because of the multiscale heterogeneity and the range of temporal scales involved here we investigate the hydraulic response to recharge of a fractured aquifer using a frequency domain approach transfer functions are calculated in a range of temporal scales from 1 day up to a few years for a fractured crystalline rock aquifer located in ploemeur s brittany france using recharge and groundwater level fluctuations as input and output respectively the spatial variability of the response to recharge characteristic response time amplitude temporal scaling is analyzed for 10 wells sampling the different compartments of the aquifer some of the transfer functions follow the linear reservoir model behavior on the contrary others display a temporal scaling at high frequency that cannot be represented by classic models large scale hydraulic parameters estimated from the low frequency response are compared with those estimated from hydraulic tests at different scales the variability of transmissivity and storage coefficient tends to decrease with scale and the average estimates converge toward the highest values at large scale the small scale variability of diffusivities which implies the existence of a range of characteristic temporal scales associated with different pathways is suggested to be at the origin of the unconventional temporal scaling of the hydraulic response to recharge at high frequency