geochemical and boron strontium and oxygen isotopic constraints on the origin of the salinity in groundwater from the mediterranean coast of israel in order to identify the origin of the salinity and formation of saline plumes in the central part of the mediterranean coastal aquifer of israel we determined the elemental and boron strontium and oxygen isotopic compositions of fresh and brackish groundwater cl up to 1500 mg l we distinguish between two key anthropogenic sources 1 sewage effluents used for irrigation with high na cl so4 cl and b c1 ratios and low br cl ratios relative to seawater ratios low 11b values 0 10 and high 18o values 4 and 2 imported water from the sea of galilee that is artificially recharged to the aquifer with high br cl 3 10 3 and 18o values 1 and a low 87sr 86sr ratio of 0 70753 the brackish groundwater from the saline plumes have relatively low na cl ratios 0 5 0 8 and high ca mg mg cl and ca so4 hco3 1 ratios relative to seawater ratios marine so4 cl and br cl ratios 11b values of 24 8 49 9 18o of 2 95 to 4 73 and 87sr 86sr ratios of 0 708275 0 708532 the composition of most of the investigated groundwater from the saline plumes differs from those of the anthropogenic sources imported water fresh uncontaminated groundwater 87sr 86sr of 0 70866 11b of 20 30 and saline water from the adjacent eocene aquitard only in areas of artificial recharge does local groundwater have high br cl and 18o values that are typical to the sea of galilee the linear relationships between chloride and most of the ions including b and sr the relatively high 11b 30 and low 18 o 4 values and the chemical signature of the saline plumes e g marine br cl and so4 cl ratios suggest that 1 mixing processes control the chemical composition of the brackish water within the aquifer and 2 the saline postulated end member has a chemical composition that resembles modified seawater with a marine and higher 11b values and a 87sr 86sr ratio of 0 7083 we propose that most of the salinization phenomena and the formation of saline plumes in the inner parts of the coastal aquifer are derived from upconing of underlying natural saline water bodies and enhanced by overexploitation and draw down of the overlying fresh groundwater

a multi isotope b sr o h and c and age dating 3h 3he and 14c study of groundwater from salinas valley california hydrochemistry dynamics and contamination processes 1 the chemical and isotope 11b 10b 87sr 86sr 18o 16o 2h h 13c 12c 14c and 3he 3h compositions of groundwater from the upper aquifer system of the salinas valley in coastal central california were investigated in order to delineate the origin and processes of groundwater contamination in this complex system the salinas valley has a relatively deep confined 400 foot aquifer overlain by a 180 foot aquifer and a shallower perched aquifer all made up of alluvial sand gravel and clay deposits groundwater from the aquifers have different 14c ages fossil 14c 21 3 percent modern carbon pmc for the 400 foot aquifer and modern 14c 72 2 98 2 pmc for the 180 foot aquifer fresh groundwater in all aquifers is recharged naturally and artificially through the salinas river the two modes of recharge can be distinguished chemically we identified several different saline components with distinguishable chemical and isotopic fingerprints 1 saltwater intrusion in the northern basin has c1 concentrations up to 1700 mg l a na cl ratio less than seawater a marine br cl ratio a ca cl ratio greater than seawater 11b between 17 and 38 and 87sr 86sr between 0 7088 and 0 7096 excess dissolved ca relative to the expected concentration for simple dilution of seawater correlates with 87sr 86sr ratios suggesting base exchange reaction with clay materials 2 agriculture return flow is high in no3 and so4 with a 87sr 86sr 0 7082 11b 19 and 13c between 23 and 17 the 3h 3he ages 5 17 years and 14c data suggest vertical infiltration rates of irrigation water of 3 10 m yr 3 nonmarine saline water in the southern part of the valley has high total dissolved solids up to 3800 mg l high so4 na cl ratio 1 11b between 24 and 30 and 87sr 86sr 0 70852 this groundwater may have acquired its geochemical signature from leaching of sedimentary rocks associated with the coast range marine deposits of mesozoic to early cenozoic age the combination of different geochemical and isotopic fingerprints enables us to delineate the impact of salt sources in different areas of the valley and to reconstruct the origin of the so4 enriched no3 depleted saline plume that is located west of the city of salinas we suggest that the latter is derived from a mixture of different natural saline waters rather than from anthropogenic contamination

on the transfer of momentum from a granular landslide to a water wave abstract the momentum flux from a landslide at impact in a water body is the driving force behind the generation of landslide tsunamis analysis of this problem is presented and used to derive idealized theoretical relationships for the maximum wave amplitude in the near field zone this is accomplished for momentum transfer using both hydrostatic and hydrodynamic assumptions for rapidly evolving near field waves with a supercritical densimetric froude number the maximum wave amplitude is also constrained according to the fluid continuity equation simplification of the hydrostatic momentum equation is also presented by considering fluid acceleration resulting in an expression that is independent of length and time scales during wave generation the results of the novel momentum based equations are in agreement with laboratory data collected using high speed digital cameras for granular landslides and previously published experimental data used to develop a semi empirical equation furthermore the results provide new insight on the range of applicability of theoretical and semi empirical equations for predicting the maximum near field wave amplitude of landslide generated tsunamis

numerical analysis of landslide generated impulse waves affected by the reservoir geometry abstract impulse waves generated by landslides are a potential major hazard for the operation of hydropower reservoirs as they pose a serious threat to the dam to residents and to properties along the shoreline a number of experimental studies have been conducted based on generalized models to predict the wave characteristics but using the results from these models to predict landslide generated impulse waves may result in significant errors due to wave reflection caused by changes in the reservoir width to investigate the effects of reservoir geometry on the characteristics of landslide generated waves during propagation 14 numerical experiments were performed using tsunami squares the real sized numerical models were based on statistical data from the yangtze river and a generalized cross section of the gongjiafang landslide located in the three gorges reservoir china two types of generalized reservoir geometries were investigated namely with converging and diverging reservoir widths it is shown that the wave amplitudes decrease with increasing reservoir width while wave heights and troughs have a complicated dependence on changes in reservoir width compared to the amplitudes of the leading waves the wavelengths and start up time of wave amplitudes were more affected in the converging reservoir models by variations in the reservoir width

numerical modeling of tsunami waves generated by the flank collapse of the cumbre vieja volcano la palma canary islands tsunami source and near field effects 1 in this work we study waves generated by the potential collapse of the west flank of the cumbre vieja volcano cvv la palma canary island spain through numerical simulations performed in two stages i the initial slide motion and resulting free surface elevation are first calculated using a 3d navier stokes model ii generated waves are then input into a 2d horizontal boussinesq model to further simulate propagation to the nearby islands unlike in earlier work on cvv besides a similar extreme slide volume scenario of 450 km3 in our simulations i we consider several slide scenarios featuring different volumes i e 20 40 80 km3 which partly result from a geotechnical slope stability analysis ii we use a more accurate bathymetry and iii an incompressible version of a multiple fluid material navier stokes model we find wave trains for each scenario share common features in terms of wave directivity frequency and time evolution but maximum elevations near cvv significantly differ ranging from 600 to 1200 m for increasing slide volume additionally our computations show that significant energy transfer from slide to waves only lasts for a short duration order 200 s which justifies concentrating our best modeling efforts on the early slide motion phase the anticipated consequences of such wave trains on la palma and other canary islands are assessed in detail in the paper

the dynamics and origin of groundwater salinity in the northeast hufu plain the aim of this research is to identify the dynamic characteristics and origins of groundwater salinity in the hufu plain samples of groundwater were taken from wells throughout the hufu plain geochemical analyses using integrated ionic ratios with a variety of graphical approaches saturation indices and the gis method were performed to distinguish the sources of groundwater salinity the results indicated that the groundwater can be classified into five main types the cation and anion trends were ca2 na mg2 k and hco3 so42 cl no3 respectively groundwater quality in the hufu plain is influenced by the chemical weathering of rock forming minerals the variation in saturation indices for different minerals indicated that groundwater salinization was controlled to some degree by human activities in the hufu plain groundwater salinity is not only governed by mineral weathering and dissolution such as calcite aragonite dolomite and gypsum but also significantly influenced by anthropogenic inputs such as fertilizer pesticide and sewage irrigation groundwater salinity originates mainly from the dissolving of gypsum and anhydrite and from anthropogenic inputs rather than from the weathering precipitation and dissolution of calcite dolomite and aragonite

swash an operational public domain code for simulating wave fields and rapidly varied flows in coastal waters abstract a computational procedure has been developed for simulating non hydrostatic free surface rotational flows in one and two horizontal dimensions its implementation in the publicly available swash an acronym of simulating waves till shore is intended to be used for predicting transformation of surface waves and rapidly varied shallow water flows in coastal waters this open source code http swash sourceforge net has been developed based on the work of stelling and zijlema 2003 stelling and duinmeijer 2003 zijlema and stelling 2005 zijlema and stelling 2008 the governing equations are the nonlinear shallow water equations including non hydrostatic pressure and provide a general basis for describing complex changes to rapidly varied flows typically found in coastal flooding resulting from e g dike breaks and tsunamis and wave transformation in both surf and swash zones due to nonlinear wave wave interactions interaction of waves with currents and wave breaking as well as runup at the shoreline the present paper provides a complete description of the numerical algorithms currently used in the code the code is benchmarked using some analytical problems moreover the numerical results are validated with various cases of laboratory data with the principal aim to convey the capabilities of the swash code in particular emphasis is put on an analysis of model performance and associated physical implications serial and parallel performance scalings are also presented

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

combinations of volcanic flank and seafloor sediment failure offshore montserrat and their implications for tsunami generation recent seafloor mapping around volcanic islands shows that submarine landslide deposits are common and widespread such landslides may cause devastating tsunamis but accurate assessment of tsunami hazard relies on understanding failure processes and sources here we use high resolution geophysical data offshore from montserrat in the lesser antilles to show that landslides around volcanic islands may involve two fundamentally different sources of sediment island flank and larger seafloor sediment failures and can occur in multiple stages a combination of these processes produces elongate deposits with a blocky centre associated with island flank collapse surrounded by a smoother surfaced deposit that is dominated by failed seafloor sediment the failure of seafloor sediment is associated with little marginal accumulation and involves only limited downslope motion submarine landslide deposits with similar blocky and smooth surfaced associations are observed in several locations worldwide but the complex emplacement processes implied by this morphological relationship can only be revealed by high resolution geophysical data such complexity shows that the volume of landslide deposits offshore of volcanic islands cannot simply be used in tsunami models to reflect a single stage collapse of primary volcanic material by applying predictive equations for tsunami amplitude to investigate general scenarios of volcanic island landslide generation we show that the tsunami hazard associated with volcanic island collapse remains highly significant volcanic flank failures even if relatively small may generate large local tsunamis but associated seafloor sediment failures even if they have a much greater volume have a substantially lower potential for tsunami generation

the combined role of bay and shelf modes in tsunami amplification along the coast 1 the role of free modes of oscillation of coastal areas in tsunami amplification at the coast is investigated here a finite element numerical model for modal analysis was applied and the numerically calculated natural frequencies were compared to those resulting from the spectra of measured sea level time series two case studies have been selected that of poverty bay new zealand and that of kuluk bay adak island alaska usa the natural modes of the sea areas that extend in front of these locations are shown to play an important role in tsunami amplification at both the considered bays in fact the enhancement of wave height is found to be related to both the small scale resonance controlled by the coastal shape and the large scale one governed by the continental shelf bathymetry in particular the model application to poverty bay reveals that some of the continental shelf modes are more energetic and occur at frequencies higher than the bay fundamental one these modes are identified as both cross shelf modes and trapped edge waves on the other hand the application to kuluk bay shows that geographical entrapment can be relevant for chain islands making the bay and the continental shelf modes almost coincident

three dimensional modeling of tsunami generation due to a submarine mudslide abstract submarine landslides are a common cause of tsunamis in coastal and estuarine areas to study this phenomenon a numerical model is developed to simulate tsunami generation due to a viscous mudslide on a gentle uniform slope a formulation of the dynamics of the problem is presented where the mudslide is treated as an incompressible three dimensional viscous flow seawater is treated as an inviscid fluid and the water motion is assumed irrotational the long wave approximation is adopted for both water waves and the mudslide the resulting differential equations are solved by a finite difference method the focus of this paper is to examine the effects of the longitudinal spreading as well as the transversal spreading of the slide upon surface wave generation and the spreading of water waves sideways three dimensional pictures are presented for successive profiles of the mud surface the horizontal velocities of the mudslide the evolution of the surface elevations and the velocities of the w

impulse waves generated by snow avalanches momentum and energy transfer to a water body when a snow avalanche enters a body of water it creates an impulse wave whose effects may be catastrophic assessing the risk posed by such events requires estimates of the wave s features empirical equations have been developed for this purpose in the context of landslides and rock avalanches despite the density difference between snow and rock these equations are also used in avalanche protection engineering we developed a theoretical model which describes the momentum transfers between the particle and water phases of such events scaling analysis showed that these momentum transfers were controlled by a number of dimensionless parameters approximate solutions could be worked out by aggregating the dimensionless numbers into a single dimensionless group which then made it possible to reduce the system s degree of freedom we carried out experiments that mimicked a snow avalanche striking a reservoir a lightweight granular material was used as a substitute for snow the setup was devised so as to satisfy the froude similarity criterion between the real world and laboratory scenarios our experiments in a water channel showed that the numerical solutions underestimated wave amplitude by a factor of 2 on average we also compared our experimental data with those obtained by heller and hager 2010 who used the same relative particle density as in our runs but at higher slide froude numbers

rockslide tsunamis in complex fjords from an unstable rock slope at akerneset to tsunami risk in western norway abstract an unstable rock volume of more than 50 million m 3 has been detected in the akerneset rock slope in the narrow fjord storfjorden more romsdal county western norway if large portions of the volume are released as a whole the rockslide will generate a tsunami that may be devastating to several settlements and numerous visiting tourists along the fjord the threat is analysed by a multidisciplinary approach spanning from rock slope stability via rockslide and wave mechanics to hazard zoning and risk assessment the rockslide tsunami hazard and the tsunami early warning system related to the two unstable rock slopes at akerneset and hegguraksla in the complex fjord system are managed by aknes tafjord beredskap iks previously the aknes tafjord project the present paper focuses on the tsunami analyses performed for this company to better understand the effects of rockslide generated tsunamis from akerneset and hegguraksla two and three dimensional site specific laboratory experiments are conducted to study the generation propagation and run up of the wave for several potential rockslide scenarios from akerneset furthermore the two models globouss and dpwaves are applied for numerical simulations of the generation propagation phase and a third model most is applied for numerical simulations of the near shore propagation and inundation of the wave in selected locations strong emphasis is put on verification validation and sensitivity of the numerical models the best match between the numerical simulations and the laboratory experiments is found for the larger scenarios with the linear dispersive solution for the propagation phase the corresponding calculated run up values are remarkably similar to the ones observed during the laboratory experiments during the risk assessment it was found that the rockslide tsunami hazard probability of impact is higher than accepted by the norwegian planning and building act this should at that time prevent any further development in all the exposed areas of the entire fjord system the act is today altered to open for specified further development in the various hazard zones the results of the tsunami analyses are applied in risk management in terms of hazard map production and land use planning two failure scenarios for each of the two unstable rock slopes are designed for the hazard zoning the larger and less probable scenarios 1 in 5000 years are applied for evacuation zones and routes while the smaller and more probable scenarios larger than 1 in 1000 years are applied for location and design of less critical facilities accepted in the inundation zone

probabilistic hazard analysis of impulse waves generated by multiple subaerial landslides and its application to wu gorge in three gorges reservoir china abstract subaerial landslides can generate impulse waves in reservoirs fjords and other water bodies and cause severe damage to the shipping industry infrastructure and human communities along the shorelines compared with deterministic hazard models probabilistic hazard analysis is an important tool for assessing the intensity and exceedance probability of impulse waves generated by multiple landslide sources which are essential for evidence based risk mitigation and contingency planning this paper proposes a methodological procedure for systematic probabilistic hazard analysis of impulse waves generated by subaerial landslides considering all relevant landslide sources and multiple uncertainties i e landslide mechanisms triggering scenarios and material parameters the main steps include 1 definition of the source parameters by parameterizing the epistemic and aleatory uncertainties in this respect the logic tree event tree and monte carlo models were used to organize the uncertainties of landslide mechanism models parametric scenarios and material parameters respectively 2 estimation of generated waves based on a landslide dynamic analytical model and previously validated empirical wave models derived from prototype scaled experiments and 3 aggregation of the hazard analysis results in the form of hazard maps and probability maps under parametric scenarios and a specific scenario considering the wu gorge in the three gorges reservoir as a case study soil slides and unstable rock slopes were analyzed to quantify the wave hazard along the reservoir under parametric and specific scenarios while considering rainfall and water level fluctuations the results show considerable wave hazard in the wu gorge for a 20 year return period the maximum expected height of propagation waves is 14 41 m the probability of experiencing propagation waves higher than 2 m in 20 years is over 50 in the river segment with high landslide density the results of the probabilistic wave hazard analysis could be aggregated and disaggregated to accommodate specific requirements of wave risk management

hydrogeochemical evaluation of groundwater in the lower offin basin ghana alumino silicate mineral dissolution cation exchange reductive dissolution of hematite and goethite oxidation of pyrite and arsenopyrite are processes that influence groundwater quality in the offin basin the main aim of this study was to characterise groundwater and delineate relevant water rock interactions that control the evolution of water quality in offin basin a major gold mining area in ghana boreholes dug wells springs and mine drainage samples were analysed for major ions minor and trace elements major ion study results show that the groundwater is principally ca mg hco3 or na mg ca hco3 in character mildly acidic and low in conductivity groundwater acidification is principally due to natural biogeochemical processes though acidic the groundwater has positive acid neutralising potential provided by the dissolution of alumino silicates and mafic rocks trace elements loading except arsenic and iron of groundwater is generally low reductive dissolution of iron minerals in the presence of organic matter is responsible for high iron concentration in areas underlain by granitoids elsewhere pyrite and arsenopyrite oxidation is the plausible process for iron and arsenic mobilisation approximately 19 and 46 of the boreholes have arsenic and iron concentrations exceeding the who s guidelines for drinking water quality final task group meeting who press world health organization geneva 2004 maximum acceptable limits of 10 g l 1 and 0 3 mg l 1 for drinking water

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

landslide tsunamis in lakes landslides plunging into lakes and reservoirs can result in extreme wave runup at the shores this phenomenon has claimed lives and caused damage to near shore properties landslide tsunamis in lakes are different from typical earthquake tsunamis in the open ocean in that i the affected areas are usually within the near field of the source ii the highest runup occurs within the time period of the geophysical event and iii the enclosed geometry of a lake does not let the tsunami energy escape to address the problem of transient landslide tsunami runup and to predict the resulting inundation we utilize a nonlinear model equation in the lagrangian frame of reference the motivation for using such a scheme lies in the fact that the runup on an inclined boundary is directly and readily computed in the lagrangian framework without the need to resort to approximations in this work we investigate the inundation patterns due to landslide tsunamis in a lake we show by numerical computations that airy s approximation of an irrotational theory using lagrangian coordinates can legitimately predict runup of large amplitude we also demonstrate that in a lake of finite size the highest runup may be magnified by constructive interference between edge waves that are trapped along the shore and multiple reflections of outgoing waves from opposite shores and may occur somewhat after the first inundation

composite modelling of subaerial landslide tsunamis in different water body geometries and novel insight into slide and wave kinematics this article addresses subaerial landslide tsunamis with a composite experimental numerical modelling approach a shortcoming of generic empirical equations used for hazard assessment is that they are commonly based on the two idealised water body geometries of a wave channel 2d or a wave basin 3d a recent systematic comparison of 2d and 3d physical block model tests revealed wave amplitude differences of up to a factor of 17 the present article investigates two of these recently presented 2d 3d test pairs in detail involving a solitary like wave scenario 1 and stokes like waves scenario 2 results discussed include slide and water particle kinematics and novel pressure measurements on the slide front instantaneous slide water interaction power graphs are derived and potential and kinetic wave energies are analysed solitary wave theory is found most appropriate to describe the wave kinematics associated with scenario 1 whereas stokes theory accurately describes the tsunami in scenario 2 the data of both scenarios are further used to calibrate the smoothed particle hydrodynamics sph code dualsphysics v3 1 which includes a discrete element method dem based model to simulate the slide ramp interaction five intermediate geometries lying between the ideal 2d and 3d cases are then investigated purely numerically for a channel geometry with a diverging side wall angle of 7 5 the wave amplitudes along the slide axes were found to lie approximately halfway between the values observed in 2d and 3d at 45 the amplitudes are practically identical to those in 3d the study finally discusses the implications of the findings for engineering applications and illustrates the potential and current limitations of dualsphysics for landslide tsunami hazard assessment

chemical evolution of groundwater in triassic gypsum bearing carbonate aquifers las alpujarras southern spain a hydrochemical study employing modelling techniques was carried out using samples taken at 65 points springs and wells in triassic carbonate aquifers lujar gador unit alpujarride complex betic cordillera these aquifers are made up of limestones and dolomites with some gypsum scattered or interbedded though the area is semi arid recharge is relatively high because of their mountainous nature the carbonate rocks contain dense microfissuration the groundwater flow regime is predominantly diffuse the karstic forms are in general poorly developed two main hydrochemical processes have been identified in these aquifers one is incongruent dissolution of dolomite that determines the chemical composition of the less mineralised water the other is dedolomitisation dolomite dissolution together with calcite precipitation caused by dissolution of gypsum which becomes predominant when the flow encounters interbedded gypsum this reaction is also frequently associated with low temperature thermalism and can play a part in more intense local karstification cavities sinkholes high transmisivity in wells observed in the sectors of these aquifers where gypsum is more abundant a reaction path model has been used to simulate the geochemical processes through a hypothetical aquifer with similar lithology to the alpujarride carbonate aquifers successive stages of evolution through the carbonate sequence represented by different saturation states with respect to calcite dolomite gypsum and co2 have been modelled and then compared with the field data

simultaneous inversion for local earthquake hypocentres station corrections and 1 d velocity model of the jamaican crust abstract a new 1 d velocity model for jamaica has been obtained from the simultaneous inversion of p and s wave travel times of well solved local earthquakes the crust is modelled as four flat uniform layers with compressional velocities of 5 15 km s to 4 5 km depth 6 30 km s to 9 5 km 6 60 km s to 22 0 km and 7 11 km s to 30 0 km the upper mantle p velocity is 7 81 km s which is consistent with upper mantle velocities found elsewhere in the caribbean basin the new model reduces significantly the root mean square misfit of the selected data from 0 128 to 0 112 when compared to the best model previously used in addition the model solves events to more acceptable focal depths of 10 to 25 km station corrections of 0 20 to 0 06 for p and 0 75 to 0 13 for s waves relative to the reference station were obtained the new model is expected to improve jamaican earthquake locations particularly in obtaining more reliable focal depths which in turn will enhance the interpretation and understanding of local seismicity and neotectonics

sources of deep groundwater salinity in the southwestern zone of bangladesh twenty groundwater samples were collected from two different areas in satkhira sadar upazila to identify the source of salinity in deep groundwater aquifer most of the analyzed groundwater is of na cl hco3 type water the trends of anion and cation are cl hco3 no3 so4 2 and na ca2 mg2 k respectively groundwater chemistry in the study area is mainly governed by rock dissolution and ion exchange the dissolved minerals in groundwater mainly come from silicate weathering the salinity of groundwater samples varies from 1 to 5 and its source is possibly the paleo brackish water which may be entrapped during past geologic periods

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 hypermobility of huge landslides and avalanches abstract catastrophic failure of large land masses which generate landslides rockfalls and debris avalanches can have hazardous consequences extending far beyond the source observations show that the mobility of such events depends strongly on the volume for volumes larger than 10 6 m 3 with many different processes invoked to explain higher mobilities hypermobility for both terrestrial and extraterrestrial events although the mobility of large events has been extensively studied there is no generally accepted mechanism for predicting extreme travel distances because the underlying physical processes are poorly understood here we show using physical and rheological arguments that the wide scatter observed for very large mass wasting events in all environments collapses to a single relationship between event volume or inundation area and mobility hypermobility is defined to be the reciprocal of the effective friction coefficient e where the scale dependent e is derived analytically as a function of the mechanical volumetric and topographical parameters of the flow the dominant term in the coefficient is the degree of fluidization involved in the flow our results show that fluidization is limited in extraterrestrial events that significant fluidization occurs in non volcanic and volcanic events and fluidization dominates submarine events this analysis demonstrates that fluidization is associated with long run out distances and that the degree of fluidization can be predicted by the volume and physical and topographic parameters the methodology is simple physically based and validated with datasets of very large terrestrial and extraterrestrial avalanche events we demonstrate that the effective coulomb friction rheology and the hypermobility function are applicable to avalanche events of any size providing an opportunity to simulate past and or potential huge landslide and debris avalanche events run out distances destructive impact and assessment of risk the model can be used to estimate the overrun area and volume in terms of known mobility data

wavenumber frequency analysis of the landslide generated tsunamis at a conical island abstract in this paper we investigate the propagation of tsunamis generated by landslides around the coast of an island to understand the propagation and trapping mechanisms of the waves records of shoreline displacement have been processed using the wavenumber frequency analysis k f we identify the dispersion relation followed by the waves that propagate alongshore it appears that the 0th order edge wave mode is the only one relevant for shoreline run up furthermore it is shown that the edge wave dispersion relation is a quantitative tool to estimate the phase and group wave celerities a very good agreement is found when comparing the wave celerities as calculated from the experimental records against those predicted by the edge wave theory furthermore the analysis of the tsunami around the island has been carried out by means of the two dimensional k f using as input data a high space resolution dataset of free surface elevations it is found that other modes both trapped 1st order edge waves and non trapped free radiating waves occur during the propagation

numerical modelling of landslide tsunami propagation in a wide range of idealised water body geometries abstract large landslide tsunamis are caused by mass movements such as landslides or rock falls impacting into a water body research of these phenomena is essentially based on the two idealised water body geometries i wave flume 2d laterally confined wave propagation and ii wave basin 3d unconfined wave propagation the wave height in 2d and 3d differs by over one order of magnitude in the far field further the wave characteristics in intermediate geometries are currently not well understood this article focuses on numerical landslide tsunami propagation in the far field to quantify the effect of the water body geometry the hydrodynamic numerical model swash based on the non hydrostatic non linear shallow water equations was used to simulate approximate linear stokes cnoidal and solitary waves in 6 different idealised water body geometries this includes 2d 3d as well as intermediate geometries consisting of channels with diverging side walls the wavefront length was found to be an excellent parameter to correlate the wave decay along the slide axis in all these geometries in agreement with green s law and with diffraction theory in 3d semi theoretical equations to predict the wave magnitude of the idealised waves at any desired point of the water bodies are also presented further simulations of experimental landslide tsunami time series were performed in 2d to quantify the effect of frequency dispersion this process may be negligible for solitary and cnoidal like waves for initial landslide tsunami hazard assessment but becomes more important for stokes like waves in deeper water the findings herein significantly improve the reliability of initial landslide tsunami hazard assessment in water body geometries between 2d and 3d as demonstrated with the 2014 landslide tsunami event in lake askja