a framework for karst ecohydrology ecohydrology can be defined as the science of integrating hydrological and biological processes over varied spatial and temporal scales there exists in karst a strong and direct interaction between the circulation and storage of groundwater and surface water these fluxes in turn affect the spatial distribution of organisms in these habitats because of the fact that the appearance storage and circulation of water in karstified areas is significantly different from other more homogenous and isotropic terrains karst ecohydrology should develop original methods and approaches at the same time traditional approaches are also very useful large karst underground geomorphological patterns occur in many sizes and varieties ranging from a few meters long or deep to very large the deepest being deeper than 1km and longer than hundreds of kilometres in this article special attention is paid to ecohydrological functions of karst underground features caves pits conduits etc which play a crucial dual role in 1 hydrology and hydrogeology of water circulation and storage and 2 ecology of many rare and endangered species differences in morphology hydrology hydrogeology and climate have resulted in a range of different environments which provide the opportunity for the coexistence of different species the role of the epikarst and vadose zones as well as caves in ecohydrological processes is discussed the importance of the flood factor in karst ecology is analysed the aim of this article is to move forward the discussion among different disciplines to promote and develop a conceptual framework for karst ecohydrology

estimation of spatio temporal recharge of aquifers in mountainous karst terrains application to sierra de las nieves spain summary we describe a method for estimating the daily spatially distributed recharge of aquifers in mountainous karst terrains using a water balance water recharge into an aquifer is a highly variable process over both time and space many methods have been developed to assess aquifer recharge although most have been applied to detrital aquifers many karst aquifers especially in mediterranean areas occur in mountainous environments where rainfall and evapotranspiration can vary considerably over space and time and where there are usually few rainfall and temperature monitoring stations we have used an advanced geostatistical method to estimate daily rainfall and temperature the method involves kriging with an external drift using a climatological semi variogram model inferred by modified maximum likelihood the depth of the soil epikarst layer is estimated from remote sensing and terrain analysis data together with field observations and electrical resistivity tomography because of the karst nature of the mountainous terrain concentrated infiltration is allowed for in some places the parameters are calibrated against the cumulative discharge of various springs the method is illustrated by a case study of the sierra de las nieves aquifer in the mountainous karst region of southern spain

modification and preservation of environmental signals in speleothems speleothems are primarily studied in order to generate archives of climatic change and results have led to significant advances in identifying and dating major shifts in the climate system however the climatological meaning of many speleothem records cannot be interpreted unequivocally this is particularly so for more subtle shifts and shorter time periods but the use of multiple proxies and improving understanding of formation mechanisms offers a clear way forward

variations in the discharge and organic matter content of stalagmite drip waters in lower cave bristol six drip waters which were actively depositing stalagmites in lower cave bristol were analysed both for discharge and luminescence properties drip discharges were determined for two different years and show a complex response to surface precipitation variations inter annual variability in drip discharge is demonstrated to be significantly higher than intra annual variability and discharge was demonstrated both to increase and decrease non linearly with increased precipitation drip waters demonstrate a correlation between their luminescence intensity and drip discharge with increased luminescence in winter as more organic matter is flushed through the aquifer the strength of the relationship between luminescence intensity and discharge increases with increased discharge the results presented here have implications for the palaeoenvironmental interpretation of annual growth laminae and the growth rates of stalagmite samples 1997 john wiley sons ltd

dispersal and deposition of suspended sediment on the shelf off the tagus and sado estuaries s w portugal abstract the portuguese margin in front of the tagus and sado rivers is characterized by a narrow shelf incised by numerous canyons and by a large mud deposit the two estuaries that feed this continental margin have distinct impact the suspended particulate matter concentration values in the mouth of the tagus are four times higher than in the sado during the summer the surface nepheloid layer is always larger than during the winter when it is restricted near the mouth of the estuary this nepheloid layer may reach 30 km in length extending westward the bottom nepheloid layer usually shows higher nephelometer values and has a typical distribution it is usually diverted southward in the direction of the lisbon submarine canyon we estimate the amount of suspended matter being discharged annually from the tagus estuary to be between 0 4 and 1 10 6 t the area covered by fine deposits is about 560 km 2 hence the thickness of sediments deposited annually should be between 0 07 and 0 18 cm the sedimentation rates calculated from the 210 pb excess vary between 0 16 and 2 13 cm y 1 which correspond to the maximum rate for a layer of 1 cm thick 81 000 t of particulate organic carbon poc should be trapped that would represent with a minimum sedimentation rate between 0 07 and 0 18 cm y 1 an entrapment of 6000 15 000 t poc y 1 the trace metals content of box core samples clearly shows the anthropogenic impact in the uppermost level 5 cm thick in the tagus estuary and in all the sedimentary deposits 15 cm thick on the shelf muddy area despite the narrowness of the shelf a significant part of continental fluxes fails to reach the deep ocean

probabilistic forecasting of earthquakes we present long term and short term forecasts for magnitude 5 8 and larger earthquakes we discuss a method for optimizing both procedures and testing their forecasting effectiveness using the likelihood function our forecasts are expressed as the rate density that is the probability per unit area and time anywhere on the earth our forecasts are for scientific testing only they are not to be construed as earthquake predictions or warnings and they carry no official endorsement for our long term forecast we assume that the rate density is proportional to a smoothed version of past seismicity using the harvard cmt catalogue this is in some ways antithetical to the seismic gap model which assumes that recent earthquakes deter future ones the estimated rate density depends linearly on the magnitude of past earthquakes and approximately on a negative power of the epicentral distance out to a few hundred kilometres we assume no explicit time dependence although the estimated rate density will vary slightly from day to day as earthquakes enter the catalogue the forecast applies to the ensemble of earthquakes during the test period it is not meant to predict any single earthquake and no single earthquake or lack of one is adequate to evaluate such a hypothesis we assume that 1 per cent of all earthquakes are surprises assumed uniformly likely to occur in those areas with no earthquakes since 1977 we have made specific forecasts for the calendar year 1999 for the northwest pacific and southwest pacific regions and we plan to expand the forecast to the whole earth we test the forecast against the earthquake catalogue using a likelihood test and present the results our short term forecast updated daily makes explicit use of statistical models describing earthquake clustering like the long term forecast the short term version is expressed as a rate density in location magnitude and time however the short term forecasts will change significantly from day to day in response to recent earthquakes the forecast applies to main shocks aftershocks aftershocks of aftershocks and main shocks preceded by foreshocks however there is no need to label each event and the method is completely automatic according to the model nearly 10 per cent of moderately sized earthquakes will be followed by larger ones within a few weeks

heavy metal distribution in surface sediments from the continental shelf adjacent to nazare canyon abstract the continental shelf surface sediments around the nazare canyon have been analyzed for heavy metal contamination organic carbon content and grain size were also determined the shelf area around the nazare canyon shows mean concentrations of cr cu hg ni pb and zn within the limits recommended by ospar 2008 some enrichment and human impact was found for cr and especially pb local rivers mainly the mondego and southern creeks seem to be the major sources of heavy metals for the nazare area showing similar contamination levels a set of reference values for non contaminated fine surface sediments

a new view of italian seismicity using 20 years of instrumental recordings in this paper we show the seismicity of the past 20 years that occurred in italy and surrounding regions hypocentral locations have been obtained by using p and s wave arrival times from the ingv national and several regional permanent seismic networks more than 48 000 events selected from an original data set of about 99 780 are used to reconstruct the most complete seismic picture of the italian region so far the seismicity distribution allows inference on seismotectonics of this complex region of subduction versus continental collision our results clearly reveal the geometry of the adria and the ionian subduction and a continuous normal fault belt in the upper crust following the apennines mountain range the depth of the seismogenic layer is computed from the cut off of seismicity at depth and shows large variations along and across the seismic active regions earthquakes are generated by the different velocity of slab retreat and the subsequent asthenospheric upwelling d 2004 elsevier b v all rights reserved

tracing anthropogenic hg and pb input using stable hg and pb isotope ratios in sediments of the central portuguese margin abstract three short marine sediment cores from the cascais submarine canyon csc cores 252 32 and 252 35 and the estremadura spur core 252 16 on the central portuguese margin were analysed for hg pb al and mn concentrations and both pb and hg stable isotope compositions in order to reconstruct trends in hg and pb sources and accumulation sediment ages were determined based on 210pb measurements the studied cores reveal increasing hg and pb concentration independent of grain size variations since the middle of the 19th century towards the present concomitantly a decreasing trend of 206pb 207pb to less radiogenic values towards the surface was found indicating increasing anthropogenic inputs the lowest values of 202hg were generally observed in the older sediments characterized by low hg and pb concentrations suggesting a low input of anthropogenic metals odd mass number 199hg and 201hg hg isotopes in sediment samples from core 252 16 were characterized by positive mass independent fractionation mif while recent sediments from cores 252 32 and 252 35 did not reveal significant mif probably reflecting both the proximity to the source of anthropogenic hg contamination tagus estuary and the importance of the csc as a particle carrier the multi tracer approach based on both stable hg and pb isotopic signatures confirms anthropogenic hg and pb enrichment in recent marine sediments and also allows us to distinguish between areas dominated by detrital e g csc versus hemipelagic estremadura spur sedimentation

distribution and normalization of heavy metal concentrations in mangrove and lagoonal sediments from mazatlan harbor se gulf of california concentrations of heavy metals carbonates organic carbon and granulometry were examined in sediments from 60 sites within mazatlan harbor and adjacent areas regional distribution had a strong for al fe li and ni and weak for cd co cr pb v and zn seaward concentration gradient decreasing from the upper lagoon the highest concentrations for most metals occurred in fine grained sediments from infiernillo estuary the upper lagoon and the industrial zone in contrast lower levels were usually found in the sandy sediments of the navigation channel port entrance and an area associated with sewage outfall analysis of transects in mangrove and lagoonal sediments indicated that the amount of fine material and organic carbon increases towards the margins where mangrove sediments exist while metal variations were not clearly observed in most of the metals examined only ni v pb and cu showed a slight tendency to increase towards the margins sometimes lagoonal sediments had redox and texture characteristics comparable to those from mangrove substrate thus competing because of a similar capture capacity of metals metal data were normalized against al and li using a combination of normalization techniques 95 prediction intervals regional anomalies and enrichment factor it was found that al and li were good normalizers for most of the examined metals and they are important constituents of one or more of the major fine grained heavy metal carrier s and adequately reflect the granulometric variability in the sediments of the study area

characterisation and modelling of conduit restricted karst aquifers example of the auja spring jordan valley summary the conduit system of mature karstified carbonate aquifers is typically characterised by a high hydraulic conductivity and does not impose a major flow constriction on catchment discharge as a result discharge at karst springs is usually flashy and displays pronounced peaks following recharge events in contrast some karst springs reported in literature display a discharge maximum attributed to reaching the finite discharge capacity of the conduit system flow threshold this phenomenon also often leads to a non standard recession behaviour a so called convex recession i e an increase in the recession coefficient during flow recession which in turn might be used as an indicator for conduit restricted aquifers the main objective of the study is the characterisation and modelling of those hydrogeologically challenging aquifers the applied approach consists of a combination of hydrometric monitoring a spring hydrograph recession and event analysis as well as the setup and calibration of a non linear reservoir model it is demonstrated for the auja spring the largest freshwater spring in the lower jordan valley the semi arid environment with its short but intensive precipitation events and an extended dry season leads to sharp input signals and undisturbed recession periods the spring displays complex recession behaviour exhibiting exponential coefficient and linear coefficient recession periods numerous different recession coefficients were observed 0 2 to 0 8 d 1 presumably main conduit system 0 004 d 1 fractured matrix 0 0009 d 1 plateau caused by flow threshold being exceeded plus many intermediate values the reasons for this observed behaviour are the outflow threshold at 0 47 m 3 s 1 and a variable conduit matrix cross flow in the aquifer despite system complexity and hence the necessity of incorporating features such as a flow threshold conduit matrix cross flow and a spatially variable soil epikarst field capacity the developed reservoir model is regarded as relatively simplistic as a number of required parameters were calculated from the hydrogeological analysis of the system it requires only six calibration parameters and performs well for the highly variable flow conditions observed calculated groundwater recharge in this semi arid environment displays high interannual variability for example during the 45 year simulation period only five wet winter seasons account for 33 of the total cumulative groundwater recharge

parsimonious recharge discharge modeling in carbonate fractured aquifers the groundwater flow in the gran sasso aquifer central italy summary in the carbonate fractured aquifer of the gran sasso central italy numerical simulations have been applied to validate a conceptual model of the recharge discharge cycle at regional scale to identify the effective aquifer features that mostly affect the spring discharges simple parsimonious models based on few key parameters whose effective values are well constrained by previous hydrological geological studies are used input data are represented by infiltration calculated considering rainfall snowmelt and runoff in endorheic basins and effective permeability distribution estimated by geological tectonic and hydrogeological settings of the aquifer discharges of tapped springs and tunnel drainages for the 1999 2009 period have been simulated after estimating the recharge area of each monitored spring by the hydrogeological setting and checking them by mean isotope elevation values discharge monitoring has been compared with the simulations obtaining a good agreement both at seasonal and yearly time basis the simulations will also be useful for previewing discharge in drought period and evaluating protection zones of tapped springs in the territory of a national park

coccoliths from recent sediments of the central portuguese margin taphonomical and ecological inferences abstract in this study we describe recent coccolith assemblages from surface sediments of the central portuguese continental margin by investigating variation in coccolith concentrations and relative abundances along north south and onshore offshore gradients and between submarine canyons and open shelf and slope areas and by correlation of coccolith distribution with sediment characteristics sediment bulk composition and particle size corg ntot and sediment accumulation rate we assess to what extent paleo ecological information can be distinguished from taphonomical effects dissolution and mechanical destruction lateral transport and dilution with terrigenous material the main finding of this study is that original distribution patterns reported for living coccolithophores from the portuguese margin surface waters are reflected by patterns in relative abundances of coccoliths in the underlying sediment despite the vigorous current dynamics and active sediment transport on the shelf and in the canyons like in the surface water assemblages gephyrocapsa oceanica coronosphaera mediterranea helicosphaera carteri and coccolithus pelagicus are more prevalent in sediments of the continental shelf and upper canyon reaches whereas gephyrocapsa muellerae calcidiscus leptoporus and the group comprising umbilicosphaera sibogae umbellosphaera irregularis and rhabdosphaera spp have higher relative abundances in sediments of the open slope greater abundance of the coastal assemblage in sediments of the upper nazare canyon appears associated with persistent high productivity driven by amplification of coastal upwelling and internal tidal pumping in the canyon head and the shelf area south of it enrichment of oceanic species in the upper reaches of both the nazare and lisbon setubal canyon compared with adjacent shelf areas suggests displacement of oceanic coccolithophores in oceanic surface water masses advected coastwards along the canyon axes while coccolith relative abundances in the sediment thus seem to reflect original distribution patterns precluding major post mortem redistribution of coccoliths we found a distinct inverse relationship between coccolith concentration and sediment particle size suggesting that sedimentary processes control the accumulation of coccoliths in the sediment we propose a taphonomy driven scenario in which coccolith preservation is favored by rapid incorporation in the sediment near their area of origin while coccoliths reworked by currents and transported away from their area of origin are subject to non selective destructive processes including dissolution and mechanical abrasion this scenario would explain the observed apparent paradox of the preservation of the primary ecological signal in an environment known for its dynamic sedimentary processes this study provides important insights on the processes governing the preservation of the ecological signature in the sedimentary record and testifies on the enormous potential of coccoliths in paleoapplications

trace metal enrichments in portuguese submarine canyons and open slope anthropogenic impact and links to sedimentary dynamics abstract in order to evaluate the role of submarine canyons as transport routes for the particulate matter including anthropogenic trace metals from coastal areas to the deep sea we analysed contents of ca al fe mn zn cr pb ni and cu organic carbon and calcium carbonate in surface sediments and sediment trap particulate material from canyon and open slope areas of the central portuguese continental margin the contribution of trace metals from anthropogenic sources was assessed by comparing present day concentrations and average elemental concentrations for the industrial period last 150 years with pre industrial baseline values baseline elemental concentrations are very similar for the lisbon setubal and nazare canyons but varying degrees of anthropogenic trace metal enrichments are recorded in more recent sediments the upper lisbon and cascais canyons appear the most affected by anthropogenic trace metal deposition excess pb zn and cu amount 55 57 and 21 respectively of total inventories over the last 150 years the upper nazare canyon follows with 42 21 and 17 respectively lower contributions of anthropogenic trace metals were found for the lower reaches of the canyons and adjacent open slopes indicating that the upper canyon areas act as trace metal depocentres whereas dispersal to deeper canyon and slope areas is limited the tagus and to a lesser extent the sado river appear the main sources of pb zn and cu to the canyons but atmospheric dispersal of pb seems also important especially in the southern area anthropogenic enrichment of pb and zn in the cascais and lisbon canyons is comparable to values published for canyons in the nw mediterranean and off taiwan located in close proximity to industrialized areas different from pb and zn present day cu enrichment appears to increase toward deeper water where pelagic sedimentation is predominant suggesting that dispersal of this trace metal is at least partly linked with surface water plankton production

the role of the subcutaneous zone in karst hydrology abstract the subcutaneous zone is the upper weathered layer of rock beneath the soil but above the permanently saturated phreatic zone it is of particular hydrological importance in karst because of its high secondary permeability arising from the considerable chemical solution in this zone however corrosional enlargement of fissures diminishes with depth thus permeability decreases in the same direction with the result that percolation is inhibited except down widened master joints and faults storage of water consequently occurs in this zone particularly after storms the upper surface of this suspended saturated layer in the subcutaneous zone is defined by a perched water table which slopes towards points of rapid vertical percolation the potential induces lateral water movement converging on the most permeable areas such as beneath dolines leakage from the subcutaneous store sustains slow percolation in the vadose zone cross correlation of rainfall with percolation rates in caves in new mexico u s a and new zealand reveal response lags of 2 14 weeks with no apparent relationship to depth below the surface other percolation sites show no correlation with rainfall interpreted as being a consequence of considerable friction in tight fissure networks the recognition of storage and rapid as well as very slow percolation from the subcutaneous zone requires re interpretation of the components of hydrographs from karst springs and of some conceptual models of karst aquifers the importance of subcutaneous storage in sustaining baseflow discharge at some sites must be recognised as must the contribution of subcutaneous water to flood hydrographs methods of estimating the volumes of subcutaneous and phreatic components of karst spring flood hydrographs are presented the paper concludes with a discussion of the significance of subcutaneous hydrologic processes for an understanding of karst geomorphology the desirability of explaining karst landform evolution in terms of hydrologic processes is stressed

induced seismicity in mines in canada an overview monitoring of mine induced seismicity in canada has improved with the expansion of regional seismograph networks into areas of active mining however the severity and in some cases the frequency of mine induced tremors has increased as mining extends to greater depths and at accelerated rates of extraction because of the complex design and large areal extent of many mines potash coal and metalliferous the most feasible and practical way to monitor these tremors at the present time is to deploy a network of seismometers in and on the surface above mines experiencing microearthquake activity a few of these mines already have a network of seismometers deployed around them and plans are under way to deploy seismograph networks around other mines that have experienced some rather severe tremors in recent times six possible mechanisms for mine induced tremors are described and the associated p and s wave radiation patterns presented a comparison of actual seismic radiation patterns with theoretical predictions is a quick way to diagnose the potential source mechanisms in addition recognizing the pattern of microearthquake activity preceding larger tremors can be used to mitigate the potential effects of severe tremors

correlations between mining and seismicity for re entry protocol development abstract re entry protocols are a strategic approach for controlling risk after large magnitude events or blasts in seismically active mines by monitoring the return of seismicity to background levels restricting access to areas of a mine affected by seismicity for sufficient time to allow this decay to occur is the main approach in most re entry protocols in the present study mining and seismicity are correlated for re entry protocol development by using a uniform statistical technique for the identification of background levels the relations are established relying on a theoretical framework that links the productivity of seismicity with the decay time of seismic sequences three case histories are presented and analyzed selected to illustrate the possible effects of factors such as volume of mined rock depth and magnitude of large events on the decay time of mining induced seismic sequences positive significant correlations between the decay time and the mining factors studied here are found

geostatistical approaches for incorporating elevation into the spatial interpolation of rainfall this paper presents three multivariate geostatistical algorithms for incorporating a digital elevation model into the spatial prediction of rainfall simple kriging with varying local means kriging with an external drift and colocated cokriging the techniques are illustrated using annual and monthly rainfall observations measured at 36 climatic stations in a 5000 km 2 region of portugal cross validation is used to compare the prediction performances of the three geostatistical interpolation algorithms with the straightforward linear regression of rainfall against elevation and three univariate techniques the thiessen polygon inverse square distance and ordinary kriging larger prediction errors are obtained for the two algorithms inverse square distance thiessen polygon that ignore both the elevation and rainfall records at surrounding stations the three multivariate geostatistical algorithms outperform other interpolators in particular the linear regression which stresses the importance of accounting for spatially dependent rainfall observations in addition to the colocated elevation last ordinary kriging yields more accurate predictions than linear regression when the correlation between rainfall and elevation is moderate less than 0 75 in the case study q 2000 elsevier science b v all rights reserved

properties of aftershock sequences in southern california the temporal behavior of 39 aftershock sequences in southern california 1933 1988 was modeled by the modified omori relation minimum magnitudes for completeness of each sequence catalog were determined and the maximum likelihood estimates of the parameters k p and c with the standard errors on each were determined by the ogata algorithm the b value of each sequence was also calculated many of the active faults in the region both strike slip and thrust were sampled the p values were graded in terms of the size of the standard error relative to the p value itself most of the sequences were modeled well by the omori relation many of the sequences had p values close to the mean of the whole data set 1 11 0 25 but values significantly different from the mean as low as 0 7 and as high as 1 8 exist no correlation of p with either the b value of the sequence or the mainshock magnitude was found the results suggest a direct correlation of p values is with surface heat flow with high values in the salton trough high heat flow and one low value in the san bernardino mountains and on the edge of the ventura basin both low heat flow the large fraction of the sequences with p values near the mean are at locations where the heat flow is near the regional mean 74 mw m2 if the hypothesis that aftershock decay rate is controlled by temperature at depth is valid the effects of other factors such as heterogeneity of the fault zone properties are superimposed on the background rate determined by temperature surface heat flow is taken as an indicator of crustal temperature at hypocentral depths but the effects on heat flow of convective heat transport and variations in near surface thermal conductivity invalidate any simple association of local variations in heat flow with details of the subsurface temperature distribution the interpretation is that higher temperatures in the aftershock source volume caused shortened stress relaxation times in the fault zone materials leading to a faster decay rate higher p value in 1967 mogi proposed such a relation on the basis of japanese data seismic velocity distributions published for southern california generally support the hypothesis with low velocities higher temperatures corresponding to high p values and vice versa

palaeoflood record of the tagus river central spain during the late pleistocene and holocene abstract palaeoflood hydrology of the tagus river central spain was reconstructed from slackwater deposits and palaeostage indicators in two canyon reaches located at el puente del arzobispo in the central part of the catchment 35 000 km 2 in drainage area and in alcantara at the lower part of the catchment 52 000 km 2 in drainage area near the portuguese border the palaeoflood record with more than 80 flood events shows clusters of floods at specific periods from 9440 to 9210 14 c yr bp 8540 8110 bc 8500 to 8000 14 c yr bp 7500 7000 bc 6750 14 c yr bp 5000 bc 1200 to 950 14 c yr bp ad 785 1205 410 14 c yr bp ad 1450 1500 170 to 80 14 c yr bp ad 1670 1950 the largest flood s occurred during the periods 9440 to 9210 14 c yr bp 6750 14 c yr bp and 1200 to 950 14 c yr bp reaching minimum discharge estimates of between 4000 and 4100 m 3 s 1 in the el puente del arzobispo reach and 13 700 15 000 m 3 s 1 in the alcantara reach these periods with increased flood magnitude and or frequency in the tagus river are strongly related to increased moisture influx and winter precipitation in the iberian peninsula especially in the western zone proxy records sensitive to winter precipitation such as lake levels and vegetation changes indicated by pollen records are in good agreement with the clusters of floods found in the tagus river this flood variability seems to correspond to changes in the prevailing atmospheric circulation pattern affecting the iberian peninsula

aftershock occurrence rate decay properties for intermediate and deep earthquake sequences we perform a detailed analysis of seven aftershock sequences with intermediate or deep focus mainshocks occurring in the aleutian islands japan the pamir hindu kush phk tonga and bolivia for each sequence we determine the modified omori law mol p value and goodness of fit for all sequences we are able to find a time interval where the sequence conforms to mol decay with either c 0 or c variable the two sequences with deep focus mainshocks have slightly larger p values than the intermediate depth sequences despite the rarity of well defined intermediate or deep aftershock sequences neither the observed p values nor the overall sequence decay behavior significantly differ from that observed for shallow sequences

relation between mainshock rupture process and omori s law for aftershock moment release rate summary we compare the source time functions i e moment release rates of three large california mainshocks with the seismic moment release rates during their aftershock sequences aftershock moment release rates computed by summing aftershock moments in time intervals follow a power law time dependence similar to omori s law from minutes to months after the mainshock furthermore in contrast to the previously observed saturation in numbers of aftershocks shortly after the mainshock rupture no such saturation is seen in the aftershock moment release rates which are dominated by the largest aftershocks we argue that the observed saturation in aftershock numbers described by the time offset parameter c in omori s law is likely an artefact due to the underreporting of small aftershocks which is related to the difficulty of detecting large numbers of small aftershocks in the mainshock coda we further propose that it is more natural for c to be negative i e singularity follows the onset of mainshock rupture than positive singularity precedes onset of rupture to make a more general comparison of mainshock rupture process and aftershock moment rates we then scale mainshock time functions to equalize the effects of the varied seismic moments for the three california mainshocks we compare the scaled time functions with similarly scaled aftershock moment rates finally we compare global averages of scaled time functions of many shallow events to the average scaled aftershock moment release rate for six california mainshocks in each of these comparisons the extrapolation using omori s law of the aftershock moment rates back in time to the onset of the mainshock rupture indicates that the temporal intensity of the aftershock moment release is about 1 5 orders of magnitude less than the maximum reached by the mainshock rupture this may be due to the differing amplitudes and relative importance of static and dynamic stresses in aftershock initiation compared to mainshock rupture propagation

ground water behaviour in karst example of the ombla spring croatia abstract the hydro electric power plant hepp which will exclusively use water from a karst underground storage basin will be built in the vicinity of the abundant karst spring ombla in croatia this paper presents the results obtained by hydrogeologic hydrologic and hydraulic investigations related to the principles of ground water circulation in the karst the analyses included the determination of the effective porosity ne of the karst aquifer and the definition of the volume of large conduits and small fractures in the karst which form the aquifer volume the position and dimensions of large karst conduits have also been defined it was established that in three small springs zaton zavrelje and slavljan water overflows from the ombla spring in periods of high ground water levels it was also discovered that at certain periods the dupuit expression for steady state flow in an unconfined aquifer can be used in accordance with this it was possible to determine the values of hydraulic conductivity k in m s 1 for the ombla aquifer they range from 2 10 3 to 5 10 3 m s 1 and are inversely proportional to the ombla spring discharge continuous measurements of the ground water level by several piezometers located in the karst hinterland of the ombla spring and simultaneous measurement of the discharge made it possible to define discharge curves of the ombla spring dependent upon the ground water levels at various locations characteristic features of the discharge curves made the identification of the position and dimensions of the main karst conduits possible

modeling the influence of epikarst evolution on karst aquifer genesis a time variant recharge boundary condition for joint karst epikarst development 1 the epikarst a zone of increased weathering near the land surface determines the distribution of recharge to a karst aquifer in both space and time it links climatic and near surface geological conditions with the karstification of a limestone aquifer defining both the hydraulic and the chemical boundary conditions for the development of the karst system realistic modeling of the epikarst is therefore a prerequisite for the simulation of karst aquifer genesis a conceptual model of the joint karst epikarst evolution is presented in this paper an epikarst module is developed and implemented in a numerical continuum discrete conduit flow model for karst genesis which accounts for the joint evolution of the epikarst and the main karstic conduit network under unconfined conditions the influence of epikarst genesis on the evolution of the underlying karst aquifer is investigated in four scenarios it is found that only the interaction of epikarst and initial heterogeneity in the underlying carbonate rock leads to the development of a dendritic cave system if no heterogeneity in the initial conduit network or in the recharge distribution is included maze type caves develop

significance of preferential flow at the rock soil interface in a semi arid karst environment abstract in many semi arid environments the surface materials are frequently characterized by thin soils and large proportions of bare rock both of which are expected to considerably influence infiltration and groundwater recharge processes in this study small plot scale irrigation experiments in combination with dye tracer application as well as real time and subsequent soil moisture measurements and soil particle size analysis were conducted to investigate the significance of preferential flow at the rock soil interface large scale assessments of soil depth and surface type distribution were used to upscale the findings of the irrigation experiments to the scale of a complete hillslope and further to estimate percolation properties of a hypothetical rainfall event the two experimental plots were each located in the west bank mountains close to ramallah each irrigation experiment was designed with 50 mm of precipitation applied on an area of 1 m 2 during the course of ca 2 5 h each irrigation plot had a surface share of approximately 50 rock outcrop and 50 soil surface percolation properties were investigated by subsequent soil moisture measurements at high spatial resolution on vertical soil profiles on the irrigated plot dye tracer application on the rock outcrop during the sprinkling allowed for tracking of resulting outcrop runoff in the subsurface the soil depth survey included 2100 measurement points on 7 transects which allowed the estimation of local soil depth distribution results of the irrigation experiments showed that precipitation induced runoff from rock outcrops continued below ground as preferential flow along the rock soil interface while water from the soil surface percolated mainly vertically and much more homogeneously this was evident from the high density soil moisture measurements as well as from the dye tracer patterns outcrop runoff percolated faster and to greater depths than water infiltrating directly from the soil surface thus possessing a greater potential for groundwater recharge

interaction between a dam site and karst springs the case of supramonte central east sardinia italy abstract sardinia is one of the italian regions with the greatest number of dams per inhabitants almost 60 for a population of only 1 5 million people many of these dam sites are located on non carbonate rocks along the main rivers of the island and their waters are used for irrigation industrial energy supply drinking and flood regulation purposes the pedra e othoni dam on the cedrino river dorgali central east sardinia is located along the threshold of the palaeozoic basement on the northern border of the supramonte karst area where water is forced to flow out of the system through several resurgences the most famous of which is the su gologone vauclusian spring used for drinking water supply the other main outflows of the system su tippari and san pantaleo springs are at present almost permanently submerged by the high water level of the pedra e othoni dam in the near future water will be supplied also to other communities with a possible increase of water taken from the spring the dam originally meant to regulate the flooding of cedrino river but actually used for all sorts of purposes electricity supply drinking water irrigation of farmlands industrial uses has a maximum regulation altitude of 103 m a s l only slightly less than a meter below the su gologone spring level 103 7 m and 4 and 9 m respectively above the submerged su tippari and san pantaleo springs during floods of the cedrino river occurring on average twice a year also the su gologone spring becomes submerged by the muddy waters of the lake for a time ranging between a couple of hours up to several days making water supply impossible the analysis of the available meteorological and hydrogeological data relative to the december 2004 flood one of the severest of the past 100 years suggests that the reservoir is filled in a few days time several flooding scenarios have been reconstructed using digital terrain models showing that backflooding submerges most of the discharge area of the aquifer having important repercussions also on the inland underground drainage system the upstream flood prone areas prevalently comprise agricultural lands with some sparse houses but also highly frequented tourist facilities fortunately flooding occurs outside the tourist season thus limiting risk to a limited number of local inhabitants massive discharge at the dam site instead determines a more hazardous situation in the cedrino coastal plain where population density in low lying areas is much higher to avoid flooding hazard upstream the water level in the lake should be regulated keeping it low in the flood prone seasons and having it filled from the end of the winter in order to have enough water stocked before the beginning of the summer discharge at the dam site instead should be done cautiously preventing severe flooding of the coastal cedrino plain

review of arsenic geochemical characteristics and its significance on arsenic pollution studies in karst groundwater southwest china abstract as a metalloid element arsenic as is widely distributed in the natural environment its ingestion can cause cancer deformities and mutations therefore it has become an important environmental problem in recent years there are large amounts of arsenic ore and coal with high arsenic content in southwest china a karst area there arsenic occurs in wastewater from mines contaminate soil vegetation and surface water karst underground aquifers are also contaminated through pipes cracks scuttles and sinkholes leading to a more serious arsenic pollution problem than in non karst areas due to the unique karst hydrogeological conditions to prevent and curb karst underground water contamination and guarantee water resource security and public health a review on the arsenic contamination in the karst area is necessary this paper discusses the progress of geochemical studies on arsenic through an analysis of the hydrogeology of karst areas this paper proposes that studies on arsenic pollution in karst regions should be combined with the spatial distribution and redox characteristics of groundwater more attention should be paid to chemical compositions of water soil and rocks as well as adsorption desorption processes between water and sediment when conducting arsenic geochemical research in karst groundwater

identification of aftershocks of deep earthquakes by a new ratios method we describe a new statistical method for identifying pairs or groups of related events in sequences which resemble but are not identical to a poisson process for a particular earthquake we form the ratio r nb na of the relative origin times of the na th subsequent event and the nb th previous event we then find the probability that such a ratio could occur if the sequence were a poisson process presumably sequences where the ratio is too small to be probable contain related events and the subsequent events are aftershocks since the method requires knowledge of the origin times of only a few preceding and subsequent events it is more powerful than methods which require knowledge of the mean activity rate of the poisson process using this ratios method we searched the isc catalog for aftershocks of earthquakes with focal depths exceeding 70 km from the world as a whole events with at least one aftershock can be found in all depth ranges including 250 km to 450 km however the incidence of aftershocks is significantly lower for events between 100 and 450 km than for shallower or deeper events

origin and transport of trace metals deposited in the canyons off lisboa and adjacent slopes portuguese margin in the last century abstract submarine canyons play an important role in the transfer of contaminated sediments from shelf areas to the deeper ocean to evaluate the importance of submarine canyons adjacent to the tagus and sado estuaries portuguese margin as sediment pathway major and trace elements 210 pb radionuclides organic carbon calcium carbonate and grain size were analyzed in fifteen short sediment cores from the cascais and lisboa setubal submarine canyons and neighbor slopes at the estremadura spur and off sines mass accumulation rates mar vary between 0 02 and 0 40 g cm 2 y 1 with the highest values in the upper cascais and lisboa canyons mercury and pb enrichment factors exceed 2 and show a continuously increasing trend since 1950 ad in the upper sections of the cascais canyon and in the lisboa setubal canyon system implying an anthropogenic source mercury and pb anthropogenic inventories also present highest values in the canyon heads which is consistent with its proximity to the tagus and sado river mouths to a lesser extent the estremadura and sines slopes and the deeper sections of the canyons also have slightly increasing hg and pb enrichment factor trends towards the present day for these areas with a major influence of pelagic sedimentation we infer atmospheric transport as a complementary source of contaminants therefore our data suggest that although canyons are preferential conduits to transport sediments to the deep sea when compared to the slopes hg and pb derived from human activities have reached both domains with different intensities down to a depth of 2000 mwd

sinkholes related to discontinuous pumping susceptibility mapping based on geophysical studies the case of crestatx majorca spain the crestatx aquifer is the main source of water supply to the bay of alcudia one of the largest resorts on the island of majorca spain this water has been used since the 1970s using several pumping wells which draw an annual volume of 1 5 hm3 the seasonal exploitation of this karstic aquifer causes a substantial cone of depression with great variations in the piezometric level up to 120 m and dynamic water levels of down to 87 m below sea level at the end of the 1990s several sinkholes and subsidence depressions started being detected in a highly karstified area twenty subsidence and sinkhole morphologies have been inventoried in an area measuring 70 000 m2 with diameters up to 23 m and depth more than 15 m the intense and continuous rainfall during recent years 2008 2010 has considerably accelerated the process increasing the dimensions of existing sinkholes and the appearance of new morphologies by means of electrical tomography techniques a ground study was carried out numerous cavities have been identified in the upper 30 m using a map of the surface morphologies and the geophysical profiles we can determine that the propagation and orientation of the sinkholes lie along three main directions n30 e n130 e and n60 e the first is the most relevant which is parallel to the main tectonic structures in the area the interpretation of the electrical profiles has enabled us to identify the potentially most unstable areas which is an effective tool to assess risk in the area as there are roads and a housing development nearby the high but discontinuous exploitation of the aquifer is considered the main trigger for these sinkholes and subsidence depressions as it causes large variations of pressure and accelerates the dissolution process in the underlying rock

role of karstification and rainfall in the behavior of a heterogeneous karst system the complex functioning of karst systems depends on several factors e g geology karstification status climate which influence flow conditions understanding a system requires monitoring that includes a sampling interval well adapted to the system s size and the use of hydrodynamic and geochemical approaches from our own observations the general physical and geochemical characteristics of the aquifers are perennial and representative of karst evolution at a given moment the notre dame des anges karst system which is situated in france on the rim of the vaucluse karst region was studied during 2 water years this study demonstrates that several parameters are not definitive and that they do not provide information about the actual status of the karst evolution of the system we were able to observe that hydrological parameters in particular are dependent on the configuration of the outlets which can dramatically change for example a heavy storm 300 mm of rain in 4 h which occurred in the intake area on 22 september 1992 produced a piston effect in the aquifer which was expressed by extensive unclogging of the whole aquifer the appearance of a new gryphon at the outlet induced a change in the flow rate and added to the unclogging

spatial variability of seismicity parameters in aftershock zones the spatial variability of the b value of the frequency magnitude relationship and the decay rate of aftershocks as described by the p value of the modified omori law is investigated by using dense spatial grids we map out the distribution of b and p values within the landers northridge morgan hill and kobe aftershock sequences considerable spatial variability is found with b values of independent subvolumes ranging from 0 6 to 1 4 and p values ranging from 0 6 to 1 8 these systematic and statistically highly significant differences argue that it is an oversimplification to assign one single p and b value to an aftershock sequence that extends up to 100 km the spatial distribution of these two parameters is compared with the slip distribution during the mainshock suggesting that the areas of largest slip release correlate with high b value regions we hypothesize that the frictional heat created during the event may influence the p value distribution within an aftershock zone while applied shear stress crack density and pore pressure govern the frequency magnitude distribution by investigating the frequency magnitude distribution separately for preseismic and postseismic periods for the morgan hill mainshock we find that only the volume in the vicinity of the highest slip release shows a significant increase in the b value which decays to premainshock values within a year surrounding areas of the aftershock zone show an approximately constant b value with time because the aftershock hazard after a mainshock depends strongly on both the b and p value we propose that aftershock hazard assessment can be improved by taking into account the spatial distribution of the parameters

distribution and origin of heavy metals in the sand sediments in a sector of the oman sea the sistan and baluchestan province iran in order to study natural concentration of heavy metal in sand sediments of the oman sea and its relationship with composition and provenance of the deposits the concentrations of cd co cu sr pb cr zn ni mn and fe were determined relationships between the heavy metal concentration with composition of the sediments and rocks existing in the rivers drainage basins of the area were studied the results indicate that the zn and cu concentrations are closely related to biotite and muscovite contents of the sediments the amounts of sr cd and pb change similarly to the variation of calcium carbonate content in the sand sediments the fe and mn concentrations show correlations with the total amount of heavy minerals the distribution pattern of cr resembles the pyroxene content the co and ni concentrations fluctuate similarly to the variation of the amphiboles and the intrusive igneous fragments respectively

delineating vulnerability of karst aquifers using hydrochemical tracers in southwestern china karst groundwater is particularly vulnerable to contamination long term hydrochemistry auto monitoring combined with laboratory analyses has shown that the chemograph demonstrates changes in the system in order to determine the primary groundwater vulnerability a relationship between hydrochemical changes and the origin of vulnerability in six karst spring catchments in southwestern china is discussed the reason and physical meaning of the hydrochemical changes in the spring are explained based on tracer tests and physical chemical process in the s31 spring the results prove that the hydrochemical changes show the origin of vulnerability and also can be its expression generally autogenic recharge in bare karst is concentrated in epikarst zone forming bypass flow and shaft flow which causes dilution of ca2 the chemograph reflects the percentage of concentrated and diffuse recharge the higher the ratio of concentrated recharge the higher the grade of groundwater vulnerability due to ca2 hco3 sec ph and temperature in water can change for kinds of reasons during their transport more karst systems with variable natural and human factors are discussed protective layer allogenic water recharge and transform of surface stream and subterranean river can change the origin shape of hydrochemical curve under this circumstance more indicators need to be monitored especially contaminant related ions such as nitrate in order to clearly understand the contribution of concentrated and diffuse recharge to water chemistry after comparing the traditional groundwater vulnerability assessment and the methods based on hydrochemical change rainfall protective layer epikarst transient storage and karst network should be more concerned when the work is done auto monitoring of karst is more and more popular in southwestern china therefore it is suggested that the hydrochemical methods should be used as a primary expression of vulnerability giving a direct reference for karst water management

validating the kagis black box gis based model in a mediterranean karst aquifer case of study of mela aquifer se spain this research was funded by the spanish ministry of science and innovation projects cgl2013 48802 c3 3 r and cgl2015 69773 c2 1 p and by the university of alicante projects gre15 19 and gre17 12

soil and karst aquifer hydrological controls on the geochemical evolution of speleothem forming drip waters crag cave southwest ireland abstract in recent years there has been increased interest in cave speleothems as archives of palaeoclimate monitoring of rainfall and soil and karst water chemistries was performed at crag cave castleisland co kerry southwest ireland in august 1997 and january 1998 in order to understand temporal and spatial variations in karst water hydrology and chemistry and their implications for interpreting the potential palaeohydrological signal preserved by speleothems at this site temporal variations in karst water drip rates and geochemistry allow drips to be classified by hydrological response to rainfall and the associated processes of dilution piston flow source change and prior calcite precipitation during aquifer throughflow evolution from soil matrix and preferential flow solutions has also been determined to exert an important control on karst water chemistries as a result of these findings we present hydrogeochemical models and plumbing diagrams that delineate the controls on karst water evolution at a number of sampling locations within the cave at this site we propose that a palaeohydrological signal may be recorded by crag cave speleothems that may be interpreted via the study of mg ca ratios in speleothems linked to monitoring of modern drip water chemistry

solute transport processes in a karst vadose zone characterized by long term tracer tests the cave system of postojnska jama slovenia summary the processes influencing the solute transport in the karst vadose zone were studied by long term tracer tests with artificial tracers the results of three successive tracer tests with different modes of injection were compared tracer breakthrough curves were monitored at three drips of different hydrological types inside one of the cave galleries of the system of postojnska jama over several years comparison of the results indicates the highly significant influence of preceding hydrological conditions dry vs wet injection mode artificial flushing vs natural infiltration by subsequent rainfall and on a bare rock vs on an overlying layer and geologic heterogeneities within the vadose zone on solute transport in the karst vadose zone injection with artificial flushing resulted in rapid infiltration and the tracer traversed almost one hundred meters of bedrock in hours however the majority of tracer can be stored within less permeable parts of the vadose zone and then gradually flushed out after additional abundant and intensive precipitation in the period of several years long continued sampling in each of the tests proved to be important for reliable characterization of the long term solute transport dynamics

minimum magnitude of completeness in earthquake catalogs examples from alaska the western united states and japan we mapped the minimum magnitude of complete reporting m c for alaska the western united states and for the junec earthquake catalog of japan mc was estimated based on its departure from the linear frequency magnitude relation of the 250 closest earthquakes to grid nodes spaced 10 km apart in all catalogs studied mc was strongly heterogeneous in offshore areas the mc was typically one unit of magnitude higher than onshore on land also mc can vary by one order of magnitude over distance less than 50 km we recommend that seismicity studies that depend on complete sets of small earthquakes should be limited to areas with similar mc or the minimum magnitude for the analysis has to be raised to the highest com mon value of mc we believe that the data quality as reflected by the mc level should be used to define the spatial extent of seismicity studies where mc plays a role the method we use calculates the goodness of fit between a power law fit to the data and the observed frequency magnitude distribution as a function of a lower cutoff of the magnitude data mc is defined as the magnitude at which 90 of the data can be modeled by a power law fit mc in the 1990s is approximately 1 2 0 4 in most parts of california 1 8 0 4 in most of alaska aleutians and panhandle excluded and at a higher level in the junec catalog for japan various sources such as ex plosions and earthquake families beneath volcanoes can lead to distributions that cannot be fit well by power laws for the hokkaido region we demonstrate how neglecting the spatial variability of m c can lead to erroneous assumptions about deviations from self similarity of earthquake scaling

variations in earthquake size distribution across different stress regimes the earthquake size distribution follows in most instances a power law1 2 with the slope of this power law the b value commonly used to describe the relative occurrence of large and small events a high b value indicates a larger proportion of small earthquakes and vice versa statistically significant variations of b values have been measured in laboratory experiments mines and various tectonic regimes such as subducting slabs near magma chambers along fault zones and in aftershock zones3 however it has remained uncertain whether these differences are due to differing stress regimes as it was questionable that samples in small volumes such as in laboratory specimens mines and the shallow earth s crust are representative of earthquakes in general given the lack of physical understanding of these differences the observation that b values approach the constant 1 if large volumes are sampled4 was interpreted to indicate that b 1 is a universal constant for earthquakes in general5 here we show that the b value varies systematically for different styles of faulting we find that normal faulting events have the highest b values thrust events the lowest and strike slip events intermediate values given that thrust faults tend to be under higher stress than normal faults we infer that the b value acts as a stress meter that depends inversely on differential stress

aftershock sequence parameters in new zealand abstract regional generic models describing the temporal and magnitude distribution of aftershocks are routinely used in california to assess aftershock hazard this note applies the reasenberg and jones 1989 formulation of aftershock parameters to 17 new zealand earthquake sequences of m 5 5 from 1987 through 1995 the median values of the aftershock parameters are similar to those obtained for california

earthquake hazard after a mainshock in california after a strong earthquake the possibility of the occurrence of either significant aftershocks or an even stronger mainshock is a continuing hazard that threatens the resumption of critical services and reoccupation of essential but partially damaged structures a stochastic parametric model allows determination of probabilities for aftershocks and larger mainshocks during intervals following the mainshock the probabilities depend strongly on the model parameters which are estimated with bayesian statistics from both the ongoing aftershock sequence and from a suite of historic california aftershock sequences probabilities for damaging aftershocks and greater mainshocks are typically well constrained after the first day of the sequence with accuracy increasing with time

karst massif susceptibility from rock matrix fracture and conduit porosities a case study of the sierra de las nieves malaga spain the potential contamination of a karst massif from surface sources can be evaluated and represented in a susceptibility map in the case of a carbonate aquifer the susceptibility assessment must take into account their very complex and heterogeneous nature the complexity originates in the presence of three types of porosity matrix rock fracture and conduit porosity this paper presents a method for karst susceptibility mapping by estimating the three porosity types and evaluates their integration in a single susceptibility index matrix rock porosity is measured in the laboratory from samples collected in the field and is well correlated with lithology fracture porosity is estimated from fracture mapping and field measurements of secondary fracture porosity geostatistical methods are used to obtain continuous fields of rock matrix porosity and fracture porosity conduit porosity is calculated from a power model fitted to speleological cave mapping data however because of the scarcity and sampling bias of conduit data probabilistic models are conjectured a fourth porosity factor evaluated is the detritic filling of karst depressions the integration of the different porosities in a single susceptibility factor gives a quantitative map that is reclassified to provide a qualitative easy to interpret susceptibility index map of the karst system porosity estimation may also be of interest in recharge estimation and mathematical modelling of flow and transport in karst systems the case study used to illustrate this approach is the sierra de las nieves karstified rock mass a high relief mediterranean karst in the province of malaga in southern spain

compositional data analysis coda as a tool to study the paleo ecology of coccolithophores from coastal neritic settings off central portugal abstract whereas using the species percentages is the standard analytical procedure used to infer species ecological preferences independently of taphonomical effects the closure problem associated with closed number systems and subsequent inconsistency of determining percentages may lead to spurious correlations biased statistical analysis and misleading interpretations to avoid these problems we applied compositional data analysis coda to investigate the paleo ecological preferences and spatial distribution of coccolith assemblages preserved in seafloor sediments using as a case study the central portuguese submarine canyons and adjacent shelf slope areas results from using the isometric log ratio ilr approach from coda are compared with results from using classical analytical methods and further discussed while providing scale invariance and subcompositional coherence coda is revealed to be a consistent statistical tool to infer the paleo ecological preferences of coccolithophores corroborating earlier work based on from percentage determinations results of this study clearly confirmed the coastal neritic distribution of coccoliths from gephyrocapsa oceanica helicosphaera carteri and coronosphaera mediterranea whereas coccoliths from calcidiscus leptoporus umbilicosphaera sibogae umbellosphaera irregularis and rhabdosphaera spp more typically occur offshore differences between canyons and adjacent shelf and slope areas were also confirmed namely the a greater importance of the coastal neritic assemblage possibly resulting from local and persistent nutrient pumping in these areas and b stronger mixing of coccoliths from coastal and oceanic species in upper canyon reaches resulting from the focused coastward advection of more oceanic water masses along their axes unlike the results from both ilr coordinates and the percentage approaches both coccolith concentrations and fluxes showed that spatial trends in which the species ecological inter relationships appear to be masked by taphonomical phenomena especially towards the coast and in the canyons suggesting the two latter approaches are not suitable to perform paleo ecological inferences in more dynamic coastal neritic settings our study suggests that the paleo ecological signal preserved in the studied sediment samples is persistent enough to be revealed by both coda and percentages yet given that coda provides the only statistical solution to coherently draw paleo ecological interpretations from compositional data our recommendation is that coda should always be used to test and validate any ecological signals obtained from percentage distributions

infiltration processes and flow rates in developed karst vadose zone using tracers in cave drips the purpose of this research was to identify groundwater recharge mechanisms and measure flow velocities through the epikarst and the vadose zone in a typical site of mediterranean carbonate karst in natural rain conditions by avoiding artificial flushing more realistic travel times could be measured and the effective resultant vadose flow velocity could be inferred additionally detailed monitoring enabled better description and quantification of infiltration and percolation processes nine different cave drips were monitored and sampled for three hydrological years in fractured karst lithology on mount carmel israel at three drips discharge was measured continuously by tipping buckets rainfall and soil water content were recorded above the cave an artificial tracer experiment was conducted using uranine placed in a joint and at the soil rock interface at soil pockets both 27 m above the cave four hydrological types of drips post storm seasonal perennial and overflow were identified each demonstrating different characteristics in terms of discharge and chemistry the maximum effective flow velocities uranine dye arrival times were 41 76 cm h tracer mass flux was computed from the uranine breakthrough curves and drip hydrographs the dominant flow velocities derived from the peak of tracer mass flux were 0 35 0 41 cm h from post storm drips and 22 24 cm h from the other drips pulse through intra event piston flow was indicated by the time lags between the increase in drip rate and the time of drop in salinity and appearance of the tracer in most of the measured drips chloride concentrations were used to distinguish between old matrix water and preferential flow water in the perennial drips demonstrating a two component mixing model in 2005 2006 preferential flow water reached up to 20 25 from annual discharge of these drips this study promoted a method to compute dominant effective flow rates in the vadose zone in natural rain conditions copyright 2010 john wiley sons ltd

hydrochemical variations during flood pulses in the south west china peak cluster karst impacts of caco3 h2o co2 interactions high resolution measurements of rainfall water level ph conductivity temperature and carbonate chemistry parameters of groundwater at two adjacent locations within the peak cluster karst of the guilin karst experimental site in guangxi province china were made with different types of multiparameter sonde the data were stored using data loggers recording with 2 min or 15 min resolution waters from a large perennial spring represent the exit for the aquifer s conduit flow and a nearby well measures water in the conduit adjacent fractured media during flood pulses the ph of the conduit flow water rises as the conductivity falls in contrast and at the same time the ph of groundwater in the fractures drops as conductivity rises as ca 2c and hco3 were the dominant 90 ions we developed linear relationships both r 2 0 91 between conductivity and those ions respectively and in turn

flow and solute transport monitoring in the karst aquifer in sw slovenia the role of the unsaturated zone in the karst aquifer hydraulic behaviour was brought into focus in these studies of the catchment of the hubelj spring sw slovenia the variations of natural tracers in precipitation and in groundwater during a summer storm event made it possible to trace local flow and solute transport in the observed aquifer the results produced data on the aquifer recharge storage and discharge processes as well as on mechanisms that affected them which reflects a karst groundwater dynamics also at a regional scale they point out the significance of effects of the fast preferential flow epiflow that is the main factor controlling solute contaminant transport towards the aquifer saturated zone numerous arguments indicate that the karst aquifer flow and solute transport mechanisms depend on the hydraulic behaviour of the epikarst zone

anthropogenic trace metals in the sedimentary record of the llobregat continental shelf and adjacent foix submarine canyon northwestern mediterranean abstract anthropogenic trace metal concentrations and inventories were studied on the llobregat continental margin from the llobregat river mouth to the foix submarine canyon a prodelta sedimentary depocentre was identified along with a previously known canyon depocentre significant upward increases in trace metal contents were detected in sediment cores of the prodelta and upper part of the canyon down to 860 m depth metal enrichment factors ranged between 1 8 and 10 on the continental shelf and between 1 2 and 2 7 in the submarine canyon these metal enrichments occurred during the 20th century and can be correlated with the period of maximum increase of population and industrial activities in the barcelona area and the consequent anthropogenic metal inputs maximum trace metal enrichments are located in the prodelta depocentre and significant enrichments were also measured in the southern prodelta and in the foix upper canyon as a consequence of efficient shelf canyon sediment and metal transfer deeper in the canyon at 1370 m depth no metal enrichments were detected probably because of particle dispersion and dilution with uncontaminated sediment within the canyon this study shows that in some mediterranean sedimentation systems anthropogenic trace metal contamination is affecting not only the littoral and the continental shelf but also the adjacent continental slope sediments through submarine canyons

climate influence on geochemistry parameters of waters from santana perolas cave system brazil abstract a four year study of water geochemistry and hydrology was performed in a relatively deep cave system overlying bedrock thickness varies from 100 to 300 m as part of two monitoring programs from june 1990 to february 1992 and from march 2000 to march 2002 the ph saturation index for calcite ca and so 4 concentrations and elemental ratios of mg ca and sr ca were measured in surface well and drip waters throughout the system despite local hydrological and geological differences among sampling sites the monitoring revealed significant synchronous intersite variations in these parameters that are related to seasonal changes in rainfall recharge suggesting that element ratios of speleothems formed in deep caves are capable of recording short term climate variations groundwater residence time appears to be the main factor affecting the water composition in the epikarst epikarstic waters are always undersaturated with respect to calcite but both saturation index s i and dissolved solids content increase substantially during drier periods because of longer residence times and longer interaction between meteoric water and limestone by contrast results from cave drips and rimstone pools indicate constant supersaturation for calcite and demonstrate that a major control on trace element ratios of waters in the deep vadose zone is the degree of prior calcite precipitation this mechanism is more effective during drier periods when higher mg ca and sr ca values are observed in all drip and pool sites however variations do occur independently of the general trend of drip discharge which suggest non linear features in cave seepage water geochemistry in addition synchronous variations in so 4 and cl concentration indicate high connectivity between different water flow pathways characterized by similar response to interseasonal changes in vadose water level fluctuations in trace element ratios of cave streams appear to reflect increased contribution of waters flushed from the vadose fissure aquifer during very wet periods by a piston flow mechanism flushing episodes are also responsible for maintaining more positive saturation indices in streams even during periods of high river discharge our results suggest that trace elements are a potential proxy for past rainfall changes but they also reveal different scenarios for interpreting trace elements ratios of speleothems and freshwater tufa deposited in a deep cave systems located in tropical humid areas

omori utsu law c values associated with recent moderate earthquakes in japan we investigate the early aftershock activity associated with four moderate earthquakes m w 6 6 6 7 that occurred recently in japan for each aftershock sequence we examine continuous high pass filtered seismograms recorded at seismic stations nearby the main fault to identify as many early events as possible the magnitude of these events is calibrated using aftershocks that are listed in the earthquake catalog of japan meteorological agency jma the analysis of the aftershock decay rates reveals a power law time dependence with a scaling exponent close to 1 0 that starts from about one minute from the mainshock our results demonstrate that the c value of the omori utsu law is very small although a lower bound is not established due to completeness problems in the first minute after the mainshock and statistical fluctuations

stemflow influences on the formation of solution pipes in bermuda eolianite abstract soil filled pipes consisting of calcite casings were found in all of the eolianite formations of bermuda except the rocky bay formation the pipes are cylindrical in shape taper vertically downwards and occur in aggregated clusters they are most commonly exposed in areas of shoreline erosion in the form of soil filled cylindrical rims of calcite projecting up from the surrounding host eolianite in the early literature on the geology of bermuda it was suggested that these features were fossilized stumps of the bermuda palmetto tree sabal bermudiana in the study presented here this hypothesis is rejected on the basis of the morphology and stratigraphic position of these geomorphic features and their basal area and areal density compared with existing natural stands of s bermudiana the soil filled pipes of bermuda however cannot be simply explained as random solutional features that correspond to points where percolating soil water happened to converge and cause localized subsurface dissolution in situ measurements of stemflow from indigenous tree species suggest that the soil filled solution pipes of bermuda may be the product of stemflow drainage from particular tree species stemflow from s bermudiana was the most acidic with ph values as low as 4 29 compared to the gross rainfall in the open which had a ph of 5 58 the crowns of the bermuda cedar juniperus bermudiana and the subtropical tree species eugenia axillaris had the most significant funnelling effect stemflow volumes from individual trees representing these two species were 20 times greater than the volume of water that would have been collected in rain gauges with orifice areas equivalent to the trees trunk basal areas tree species capable of acidifying intercepted rainwater and funnelling large quantities down their trunks as stemflow may be the cause of subsurface dissolution loci extending vertically downward through bermuda s soluble eolianite formations stemflow from long lived trees representing these species could account for the diameters the cyclindrical shape the vertical orientation and the soil filled interiors of the pipes successive generations of these trees in preferred habitats could explain their clustered distribution and high areal densities 103 pipes ha

modeling doline populations with logistic growth functions initiation and evolution of a large karst depression population consisting of parent and daughter dolines were spatially and temporally modeled using logistic growth functions logistic growth models are well suited for analyzing doline population initiation and evolution because they reflect the density dependent growth mechanisms present in the evolution of karst depressions seven assumptions based upon previous studies were refined into mathematical statements and tested using more than 2000 dolines from a subpopulation of both parent and daughter karst depressions on the western highland rim and pennyroyal plain of tennessee and kentucky logistic growth models quantify the initiation and evolution of doline populations and interface well with recent models describing the evolution of three dimensional conduit systems logistic growth models should apply to modeling other doline populations in karst terranes with hydraulically efficient three dimensional conduit systems copyright 2006 john wiley sons ltd

omori s law applied to mining induced seismicity and re entry protocol development this paper describes a detailed study of the modified omori s law n t k c t p applied to 163 mining induced aftershock sequences from four different mine environments in ontario canada we demonstrate using a rigorous statistical analysis that this equation can be adequately used to describe the decay rate of mining induced aftershock sequences the parameters k p and c are estimated using a uniform method that employs the maximum likelihood procedure and the anderson darling statistic to estimate consistent decay parameters the method considers only the time interval that satisfies power law behavior the p value differs from sequence to sequence with most 98 ranging from 0 4 to 1 6 the parameter k can be satisfactorily expressed by k n1 where is an activity ratio and n1 is the measured number of events occurring during the first hour after the principal event the average values are in a well defined range theoretically 0 8 and empirically 0 3 0 5 these two findings enable us to develop a real time event rate re entry protocol 1 h after the principal event despite the fact that the omori formula is temporally self similar we found a characteristic time tmc at the maximum curvature point which is a function of omori s law parameters for a time sequence obeying an omori process tmc marks the transition from highest to lowest event rate change using solely the aftershock decay rate therefore we recommend tmc as a preliminary estimate of the time at which it may be considered appropriate to re enter an area affected by a blast or large event we found that tmc can be estimated without specifying a p value by the expression tmc an1b where a and b are two parameters dependent on local conditions both parameters presented well constrained empirical ranges for the sites analyzed a 0 3 0 5 and b 0 5 0 7 these findings provide concise and well justified guidelines for event rate re entry protocol development

general patterns of circulation sediment fluxes and ecology of the palamos la fonera submarine canyon northwestern mediterranean abstract currents particle fluxes and ecology were studied in the palamos submarine canyon also known as the fonera canyon located in the northwestern mediterranean seven mooring arrays equipped with current meters and sediment traps were deployed along the main canyon axis on the canyon walls and on the adjacent slope additionally local and regional hydrographic cruises were carried out current data showed that mean near surface and mid depth currents were oriented along the mean flow direction ne sw although at 400 and 1200 m depth within the canyon current reversals were significant indicating a more closed circulation inside the canyon mean near bottom currents were constrained by the local bathymetry especially at the canyon head the most significant frequency at all levels was the inertial frequency a second frequency of about three days attributed to a topographic wave was observed at all depths suggesting that this wave was probably not trapped near the bottom the current field observed during the most complete survey revealed a meandering pattern with cyclonic vorticity just upstream from and within the canyon the associated vertical velocity ranged between 10 and 20 m day and was constrained to the upper 300 m this latter feature together with other computations suggests that during this survey the meander was not induced by the canyon but by some kind of instability of the mean flow in the canyon suspended sediment concentration downward particle fluxes chlorophyll and particulate c and n were significantly higher up canyon from about 1200 m depth than offshore defining along with the different hydrodynamics two canyon domains one from the canyon head to about 1200 m depth more affected by the canyon confinement and the other deeper than 1200 m depth more controlled by the mean flow and the shelf slope front the higher near bottom downward total mass fluxes were recorded in the canyon axis at 1200 m depth along with sharp turbidity increases and are related to sediment gravity flows during the deployment period the increase in downward particle fluxes occurred by mid november when a severe storm took place on the canyon walls at 1200 m depth suspended sediment concentrations downward particle fluxes chlorophyll and particulate c and n were higher on the southern wall than on the northern wall inversely to the current s energy this could be caused by an upward water supply on the southern canyon wall and or the mean flow interacting with the canyon bathymetry in the swimmers collected by the sediment traps the dominant species was an elasipod holothurian which has not been recorded in other canyons or elsewhere in the mediterranean indicating particular speciation

comparison of the luminescence properties of waters depositing flowstone and stalagmites at lower cave bristol discharge and luminescence properties of waters feeding a flowstone in lower cave bristol were measured at both three weekly and 30 minute sampling intervals within rainfall events over the period april 1994 april 1995 and july december 1995 respectively results are compared with the discharge and luminescence of lower 0 01 ml s 1 feeding flowstones when 30 minute sampling results are considered dilution and hysteresis effects can be observed in the discharge luminescence relationship both on an intra event basis and over the winter as a whole exhaustion of organic matter within the karst groundwater system over the hydrological year may also be important a very rapid flux of luminescent organic matter in early autumn generates a non linear order of magnitude change in water luminescence intensity flowstone water luminescence properties can be interpreted as having i higher concentrations of luminescent organic matter compared with stalagmites from luminescence intensity data 2 a greater proportion of humic acid in relation to fulvic acid from luminescence wavelength data 3 a more rapid response to surface rainfall events and 4 a consequently greater proportion of non linear responses to surface rainfall variations these results are considered in terms of the utility of the analysis of luminescence variations in solid samples of stalagmites and flowstones in aiding the reconstruction of past rainfall variations and it is suggested that stalagmites are more useful than flowstones

a comparison of characteristic parameters of mining related and tectonic seismic aftershock sequences abstract the temporal decay pattern of seismicity following rock bursts and large magnitude events is studied for aftershock sequences in several mines in ontario canada the decay phenomenon is described by the so called modified omori s law the dependency of the parameters k c and p with the magnitude of large mine seismic events is analyzed a total of eleven mining related seismic sequences with mainshock magnitudes ranging from 0 5 to 4 0 mn nuttli magnitude scale and from four different mine environments are examined results including the calculation of the gutenberg richter s and reasenberg jones parameters b and a are compared with previous research in tectonic seismicity using available data from new zealand italy and u s a further parameters were derived and applied in a correlation study of mining related and tectonic events the study revealed a good correlation between the productivity parameter a and b values particularly the b values show significant different number ranges for mining related and tectonic data which was applied to derive a direct numerical relationship between mining related and tectonic parameters and the aftershock number estimation finally numerical values for the b values in mining related seismic activity were obtained

recent sediment transport and deposition in the nazare canyon portuguese continental margin processes pathways and fluxes of sediment transport and deposition in the nazare submarine canyon portuguese continental margin were investigated by water column profiling of suspended particulate matter recording of near bottom currents and suspended particulate matter fluxes with benthic landers and by analysis of surface sediment cores the results show that fine grained suspended sediment from the adjacent shelf is captured in the upper canyon and actively transported through the canyon to the abyssal plain under influence of tidal currents and intermittent sediment gravity flows tidal currents are actively resuspending and transporting sediment in the upper to middle canyon as reflected by high concentration of suspended particles in bottom waters high horizontal and vertical sediment fluxes in the bottom water layer and high sediment accumulation rate on the seabed diminishing strength of tidal currents leads to focussed sediment deposition in the middle canyon further transport of sediments toward the lower canyon takes place predominantly by sediment gravity flows occurring on yearly or longer timescale turbidity currents strong enough to transport sand sized material to the lower canyon occur only on centennial or longer timescales

comparing different models of aftershock rate decay the role of catalog incompleteness in the first times after main shock abstract we evaluated the efficiency of various models in describing the time decay of aftershock rate of 47 simple sequences occurred in california 37 from 1933 to 2004 and in italy 10 from 1976 to 2004 we compared the models by the corrected akaike information criterion aic c and the bayesian information criterion bic both based on the log likelihood function and also including a penalty term that takes into account the number of independent observations and of free parameters of each model these criteria follow two different approaches probabilistic and bayesian respectively well covering the wide spectra of current views on model comparison to evaluate the role of catalog incompleteness in the first times after the main shock we compared the performance of different models by varying the starting time t s and the minimum magnitude threshold m min for each sequence we found that omori type models including parameter c are preferable to those not including it only for short t s and low m min while the latters generally perform better than the formers for t s longer than a few hours and m min larger than the main shock magnitude m m minus 3 units for t s 1 day or m min m m 2 5 only about 15 of the sequences still give a preference to models including c this clearly indicates that a value of parameter c different from zero does not represent a general property of aftershock sequences in california and italy but it is very likely induced in most cases by catalog incompleteness in the first times after the main shock we also considered other models of aftershock decay proposed in the literature the stretched exponential law in two forms including and not including a time shift and the band limited power law lpl we found that such models perform worse than the modified omori model mom and other omori type models for the large majority of sequences although for lpl the relatively short duration of the analyzed sequences one year might also contribute to its poor performance our analysis demonstrates that the mom with c kept fixed to 0 represent the better choice for the modeling and the forecasting of simple sequence behavior in california and italy

the sudbury igneous complex a differentiated impact melt sheet the sudbury structure ontario is the remnant of a 1 85 ga old impact crater which originally had a diameter of 200 to 250 km the sudbury igneous complex occurs within the sudbury structure the sudbury igneous complex is a 2 5 to 3 0 km thick 60 27 km elliptical igneous rock body which consists of four major lithologies from top to bottom traditionally termed granophyre quartz gabbro norite and contact sublayer sulfide and inclusion bearing noritic rock with the exception of the latter all these lithologies are continuous across the structure modal analyses reveal that following the iugs system of nomenclature quartz gabbro samples are in fact quartz monzogabbros a few of the norite samples are quartz gabbros and most norite samples are quartz monzogabbros in view of these observations and in order to clarify the nomenclature an updated terminology is proposed from top to bottom upper unit middle unit lower unit and contact sublayer the bulk composition of the sudbury igneous complex from north range data is granodioritic continuous and gradational mineralogical and geochemical variations between the lithological units are evidence that the complex behaved as a single melt system all the sudbury igneous complex lithologies have the same light to heavy rare earth element ree ratio and an overall pattern of increased light ree and depleted heavy ree the occurrence of primary hydrous minerals hornblende and biotite deuteric alteration and abundant micrographic and granophyric intergrowths demonstrate that the melt was rich in h2o moreover the granophyric and other far from equilibrium textures are most likely due to rapid crystallization triggered by exsolution of a volatile phase the sudbury igneous complex differs from traditional layered mafic complexes in the following aspects it has an overall intermediate composition a hydrous nature a crustal isotopic signature normative corundum and an unusually large volume of granophyre the sudbury complex differs from known terrestrial impact melt sheets only by its great thickness and the presence of chemical and therefore mineralogical layering reported here for the first time and similar to those found in impact melt rocks elsewhere are the occurrences of plagioclase xenocrysts with complex twinning and zoning patterns and planar deformation features in quartz xenocrysts the well known ore deposits of the sudbury region are directly related to the genesis of the sudbury igneous complex some ores precipitated from the sudbury melt whereas others were concentrated by hydrothermal fluids that percolated through the crystallized complex it is concluded that the sudbury igneous complex is the best exposed and only well documented to date terrestrial impact melt sheet to have differentiated

a new seismic hazard model for new zealand we present a new probabilistic seismic hazard analysis psha for new zealand an important feature of the analysis is the application of a new method for the treatment of historical distributed seismicity data in psha the psha uses the seismicity recorded across and beneath the country to define a three dimensional grid of a values i e parameter a of a gutenberg richter distribution log n yr a bm in which n yr is the number of earthquakes per year recorded inside each grid cell equal to or greater than magnitude m parameter b and the limiting maximum cutoff magnitude of the gutenberg richter distribution are defined from the surrounding region 14 crustal and 23 subcrustal seismotectonic zones are defined for the country and then smoothed across the boundaries of the zones the methodology therefore combines the modern method of defining continuous distributions of seismicity parameters frankel 1995 frankel et al 1996 with the traditional method of defining large area sources and the associated seismicity parameters e g algermissen et al 1990 the methodology provides a means of including deep subduction zone seismicity in a psha preserves the finer scale spatial variations of seismicity rates across a region avoids the undesirable edge effects produced in the traditional method when adjacent area sources enclose areas of significantly different seismicity rates and also enables parameters most reliably defined at a regional scale parameter b and maximum cutoff magnitude of a gutenberg richter distribution and slip type to be incorporated into the psha the psha combines the modeled seismicity data with geological data describing the location and earthquake recurrence behavior of 305 active faults and new attenuation relationships for peak ground acceleration and spectral acceleration developed specifically for new zealand different attenuation expressions are used for crustal and subduction zone earthquakes the resulting psh maps for a 150 year return period show the highest hazard to occur in the center and southwest of the country in the areas of highest historical crustal and deep subduction zone seismicity in contrast the longer return period maps 475 and 1000 year return period show the highest hazard to occur from the southwest to northeast ends of the country along the faults that accommodate the majority of the motion between the pacific and australian plates the maps are currently being used to revise new zealand s building code which has previously been based on pshas that did not explicitly include individual faults as earthquake sources manuscript received 10 april 2001

how can the epikarst zone influence the karst aquifer hydraulic behaviour the role of an epikarst zone in the karst aquifer hydraulic behaviour was brought into focus in our studies referring to the catchment area of the hubelj spring sw slovenia this study points out the significance of effects of the fast preferential flow epiflow which is the main factor controlling solute contaminant transport towards the aquifer saturated zone the so called epikarstic hypothesis is verified on the basis of the most significant research results that are supported by the most important findings from the literature

influence of rainfall quantity on the isotopic composition 18o and 2h of water in mountainous areas application for groundwater research in the yunquera nieves karst aquifers s spain abstract the isotopic composition 18 o and 2 h of rainwater and groundwater was determined in the yunquera nieves hydrogeological unit a karstic massif in s spain with complex orography and hydrogeology the aims were to identify 1 the source of the water 2 the main factors determining the isotopic content 3 the catchment area of the springs and 4 the aquifer behaviour the isotopic content of the sampled waters is of mixed atlantic mediterranean origin and is opposite to the quantity of rainwater distribution both in space and time spatially water is isotopically less depleted toward the eastern sector where rainwater quantity is lower which is locally affected by the orography thus it is possible to differentiate the catchment areas of the main springs aquifer recharge is produced by winter precipitation when rainfall water is isotopically more negative and evaporation is lower the decrease in rainfall quantity during the study period provoked an increase in 18 o and 2 h values both in rainwater and in groundwater the recorded variations of the isotopic content of the rainfall are rapidly evident in the spring waters which demonstrates a well developed karst network inside the carbonate aquifers and thus the existence of conduit flow systems

validation of accumulation rates in teluk banten indonesia from commonly applied 210pb models using the 1883 krakatau tephra as time marker abstract teluk banten is a tropical shallow marine embayment on the north coast of java close to the krakatau volcanic complex the tsunami generated by the 1883 krakatau eruption resulted in the deposition of a tsunamite tephra layer on the bottom of teluk banten the krakatau event layer has been used as a time marker to validate 210 pb geochronological dating models this validation was performed to answer the question why should we believe excess 210 pb derived mass accumulation rates the commonly used models have therefore been applied to 210 pb activity profiles from 25 gravity cores models that have been validated are the constant flux and constant sedimentation cf cs with and without a surface mixed layer the constant initial concentration cic the constant rate of supply crs and the flux balance model after comparison of the mass accumulation rates mars of the different models with the mars obtained from the krakatau layer the following could be concluded firstly activity profiles without a surface mixed layer gave cf cs mars which were on average a factor 1 4 0 3 n 8 too high including a mixing rate of 0 5 0 4 cm 2 yr 1 into the model could explain this overestimation secondly for 210 pb activity profiles with a surface mixed layer the mars were in good comparison 1 0 0 3 n 12 with the mars derived from the krakatau event layer thirdly increased accumulation instead of reworking had to be the main cause of the comparatively thick upper layer of five cores with very high inventories fourthly assuming a variable accumulation rate and applying the cic model and crs model for these five cores the weighted average cic mars were in general more accurate than the crs mar finally the flux balance model which is not often used gave mars that were a factor 1 3 0 2 n 25 too high the advantage of this model is that it is independent of the profile shape the disadvantage is that a reliable and accurate initial activity over longer time scales has to be obtained

review on groundwater recharge in carbonate aquifers from sw mediterranean betic cordillera s spain this paper presents a review of groundwater recharge assessment in some 50 carbonate aquifers of the extreme sw mediterranean domain betic cordillera southern spain an area highly vulnerable to climate change the selected aquifers represent a broad range of meteorological and geological conditions and consequently results can be expanded eastward to other mediterranean aquifers the methods most commonly applied for recharge assessment over the past 20 years are aquifer water budget and soil water balance while these methods support the first steps in groundwater management in spain precision in quantification requires other methods to be incorporated they include chloride mass balance diverse lumped model codes and empirical methods such as aplis in eastern areas of the betic cordillera where semiarid conditions prevail lumped and distributed models for recharge assessment and calibration are based on the time series of water table data the mean annual rainfall recharge and coefficient infiltration as percentage of rainfall are respectively 648 262 mm year and 38 a high correlation was observed between annual rainfall and annual recharge in all the studied aquifers however the infiltration coefficient can vary substantially even with the same annual rainfall recharge this reflects significant differences in the degree of surface karstification and the development of the vegetal cover soil epikarst system in the carbonate aquifers of the betic cordillera the results of this work may serve to improve the assessment and management of renewable water resources in western mediterranean carbonate aquifers the findings are moreover useful for future comparisons involving recharge assessments under different scenarios of climate change and changes in land use

water tracing through the vadose zone above postojnska jama slovenia a study of pollution transport from the surface through 100 m of upper cretaceous limestone into the underlying postojnska jama found the highest pollution in three seeps flushing of nitrates and chlorides continued for 11 years after source removal while sulphates and phosphates continued even longer a tracing test from the surface with uranin dye and added water in the dry season caused a rapid reaction in the most conductive seep expulsion of the remaining dye forced by precipitation occurred with a delay of up to 3 months dye injected during the wet season was transported only by precipitation and appeared in the cave within 21 43 h the best connection between the surface and the cave exists along a subvertical tectonically fissured zone to a broken zone 80 90 90 percolation through a less permeable trickle is limited to the tectonically broken zone 70 90 percolation through dripping follows the subvertical fissured to broken zones and the dip direction of bedding planes

a four component mixing model for water in a karst terrain in south central indiana usa using solute concentration and stable isotopes as tracers the study area lies in a highly karstified carbonate terrain in south central indiana sinkholes conduits and caves form large secondary pathways for the subsurface flow as a result the discharge from a main emergence point for the subsurface flow system the orangeville rise quickly responds to the storm events and shows wide variations in flow rate water chemistry and stable isotopic compositions these responses are attributed to the mixing of water in secondary pathways in the study area recharge occurs through the thick mantled karst plain and the sinkhole plains and the role of soil layer and epikarst in the recharge process is of great importance rain dic 2 hco3 mg l 13cdic 7 soil water dic 544 hco3 mg l 13cdic 14 7 epikarstic water dic 224 hco3 mg l 13cdic 13 6 and phreatic diffuse flow water dic 299 hco3 mg l 13cdic 11 8 generally showed unique and constant dissolved inorganic carbon dic and 13cdic values over time using dic and 13cdic as tracers a four component mixing model was established for the karstic flow system by constructing the discharge hydrograph separation curves the mixing ratio of each component rain 10 6 soil 3 1 epikarstic 52 3 and phreatic 34 0 water was determined for the orangeville rise discharge over the testing period of 104 h after the storm event of 10 4 90 vadose water occupied 55 4 of spring discharge and this demonstrates the importance of the unsaturated zone especially the epikarst in the karstic flow systems

solution doline development on glaciokarst in alpine and dinaric areas abstract in this study the evolution the development and the development environment of solution dolines of glaciokarst the alps and the dinarides are studied based on morphological observations partly with the help of literary data the dolines of sample sites were put into doline types giant solution doline small sized solution doline and schachtdoline the various features of the dolines belonging to different doline types were analysed and compared their size shape elongated nature and the slope angle of their side slope giant solution dolines are much more similar to the dolines of the temperate belt rather than to small sized solution dolines or schachtdolines at temperate climate giant solution dolines developed under the tree line similarly to dolines of the temperate belt and not above the tree line below the tree line the dolines grew horizontally to the effect of horizontal dissolution later in the glacials they developed laterally mainly along their longer axis by glacial erosion they got into their periglacial environment during the uplifting of the bearing area in mountains where they are absent the circumstances of their environment were not present either because the uplifting of the mountain was fast or it was covered by non karstic rock the shapes of small sized solution dolines and schachtdolines prove that their increase happened by deepening their deepening was caused by the meltwater of the snow patches of snow drifts which water does not move laterally because of the rock debris of the floor and thus solution works downwards in the features deepening and snow accumulation strengthen each other these karstic depressions are connected to the periglacial zone because treeless environment favours snow drifts if the depression is completely filled with snow in most part of the year the snow patch is wide thus dissolution affects the total width of the doline a doline schachtdoline with vertical sides and plain floor develops if snow fill is only partial in most part of the year the snow patch and thus dissolution will have a smaller area and a small sized solution doline with funnel shape develops

depth dependence of earthquake frequency magnitude distributions in california implications for rupture initiation statistics of earthquakes in california show linear frequency magnitude relationships in the range of m2 0 to m5 5 for various data sets assuming gutenberg richter distributions there is a systematic decrease in b value with increasing depth of earthquakes we find consistent results for various data sets from northern and southern california that both include and exclude the larger aftershock sequences we suggest that at shallow depth 0 to 6 km conditions with more heterogeneous material properties and lower lithospheric stress prevail rupture initiations are more likely to stop before growing into large earthquakes producing relatively more smaller earthquakes and consequently higher b values these ideas help to explain the depth dependent observations of foreshocks in the western united states the higher occurrence rate of foreshocks preceding shallow earthquakes can be interpreted in terms of rupture initiations that are stopped before growing into the mainshock at greater depth 9 15 km any rupture initiation is more likely to continue growing into a larger event so there are fewer foreshocks if one assumes that frequency magnitude statistics can be used to estimate probabilities of a small rupture initiation growing into a larger earthquake then a small m2 rupture initiation at 9 to 12 km depth is 18 times more likely to grow into a m5 5 or larger event compared to the same small rupture initiation at 0 to 3 km

karst features of a glaciated dolomite peninsula door county wisconsin abstract a geologic investigation of the northern part of door peninsula wisconsin for a state funded water quality project revealed that karstification of the silurian aquifer is more extensive than previously believed sinkholes and small insurgent features solution modified crevices pavements caves and springs were inventories and mapped these features are generally smaller and less densely developed than those in most limestone terranes however they are important to the geomorphology and water quality of the peninsula continental glaciation has strongly influenced both the distribution and the present surface morphology of the karst features ice scour has formed a stepped bedrock topography contributed to pavement formation and may have removed some preglacial features deposition has plugged and masked features in places in addition subglacial water circulation and ice loading and unloading may have influenced karst development

recent sediment transport and deposition in the lisbon setubal and cascais submarine canyons portuguese continental margin abstract recent sediment transport and deposition in the lisbon setubal and cascais submarine canyons portuguese continental margin were investigated on the basis of water column profiles of suspended particulate matter records of near bottom currents and settling fluxes of particulate matter obtained with benthic landers and analysis of surface sediments the results show that fine grained predominantly lithogenic sediment derived from adjacent shelf areas accumulates in the upper reaches of the canyons sediment deposited further down in the middle and lower reaches of the canyons is essentially similar to the hemipelagic sediment found on the adjacent continental slope indicating that down canyon transport of sediment from the upper to the lower canyon is limited tidal currents measured at various depths in the lisbon setubal canyon appear sufficiently strong to resuspend and transport sediment but net up canyon flow of the bottom water may retain shelf derived lithogenic sediment in the upper canyon sediment gravity flows which in the nearby nazare canyon are an effective mechanism for down canyon sediment transport appear rare in the lisbon setubal canyon and probably also in the cascais canyon turbidity current events recorded in the sedimentary record of the canyons may correspond to seismic events of 1969 and 1755 ad

tunnel channels and associated landforms south central ontario their implications for ice sheet hydrology the peterborough trenton drumlin field and associated meltwater erosion marks s forms were interpreted as the products of erosion by turbulent separated flows within a catastrophically released subglacial meltwater sheet the algonquin event recent theoretical modelling of ice sheet hydrology suggests progressive channelization of meltwater during the collapse of such a sheet inductive testing of this hypothesis using observations in south central ontario forms the crux of this paper a geometric model of the interaction of rough ice base and bed surfaces gives inferred meltwater flow patterns such a rough interactive geometry is suggested as the bed is drumlinized and flows responsible for drumlins may be expected to have eroded similar forms into the ice base three landforms in south central ontario namely tunnel channels megachannels and late stage sheet flow scours are described and interpreted as evidence of progressive channelization and flow diversion processes governed by the geometri

the hydrochemical response of cave drip waters to sub annual and inter annual climate variability wombeyan caves se australia abstract a thorough understanding of cave seepage waters is necessary to interpret geochemical variations in speleothem calcite in terms of changing surface climatic conditions at a particular site here we present the hydrochemistry of ten cave drip waters from a karst system in se australia based on up to 5 5 years of monitoring discharge was continuously measured at six sites and manually at the other sites dripwater samples were analysed for ph electrical conductivity cations and anions at all sites at monthly or more frequent intervals each drip possesses a unique chemistry and not all drip waters responded to antecedent short term hydrological variations for example the hydrochemical behaviour of three adjacent drips at a bedrock depth of 45 m was completely different to that of shallower sites and was apparently un related to surface hydrology throughout the investigation based on modelled calcite precipitation vectors prior calcite precipitation was demonstrated at several sites but can only be linked directly to changes in surface recharge at the shallowest sites at extremely low flow shallow drip waters accessed a high mg sr and ba source thought to be the overlying soil high frequency sample collection allows for the calculation of predicted mg ca calcite and sr ca calcite values highlighting that the sites with the greatest potential to record high resolution palaeohydrological records are those situated at shallow depth longer temporal resolution palaeohydrological records may be recorded at deeper sites but longer term monitoring is required to identify probable time scales inherent system non linearities dissolution of secondary calcite in pore spaces of the aquifer changes in the source of trace elements and the presence of multiple reservoirs confirm the need for the use of multiple speleothems and a multi proxy approach to gain accurate palaeohydrological records from this site

a 164 ka record of environmental change in the american southwest from a carlsbad cavern speleothem abstract a horizontal core 2 8 m in length drilled from the georgia giant column in carlsbad cavern provides climate information for the last 164 ka forty six alpha spectrometric u series ages determined at intervals of 7 6 cm along the core indicate five periods of deposition and five hiatuses the longest from 136 to 110 ka variations in growth rate 0 to 70 mm ka in the abundance of aragonite chalcedony and fe bearing phases and in 13c indicate that glacial intervals of the last 164 ka ois 6 4 and 2 were much wetter than today as were the colder substages 5d and 5b of ois 5 by contrast during the two warmest periods of the past 164 ka namely ois 5e and 1 there was no deposition on either side of the speleothem suggesting conditions as dry or drier than today the record from carlsbad parallels data from many other sites in the southwestern usa and northern mexico and data from marine sediments and ice cores demonstrating the extent to which ice sheet fluctuations influenced conditions in southern new mexico detailed correlation of 13c values in the georgia giant which range from 6 6 to 0 9 relative to pdb with distant speleothem records and with data from ice cores further documents the linkage of southwestern climate with global scale extent of glaciation values of 18o in the georgia giant core range from 9 7 to 4 7 relative to pdb and average 6 6 18o depleted carbonate in the georgia giant during ois 6 at a time when the world s oceans were enriched in 18o suggests that precipitation during cold intervals was brought largely by pacific air masses in fall winter and spring as a result of the southward displacement of the polar jet stream by the growth of the laurentide ice sheet termination ii marking the end of the penultimate glaciation is well defined in the core s 18o data analytical uncertainties in the radiometric ages do not preclude a start of termination ii as late as 128 ka as suggested by specmap data however data from the georgia giant core are more compatible with an earlier start like that obtained from devils hole and vostok data raising the possibility that early warming was widespread in the u s southwest region by 145 ka

slope form erosion and hydrology in some belizean karst depressions detailed slope surveys were made in seven karst depressions in central belize four major slope types were identified inclined bedrock slopes staircases broken cliffs and talus slopes depression bases are dominated by inclined bedrock and talus slopes midslopes largely by broken cliffs and near hill summits by staircases erosional weight loss tablets deployed in 1975 1981 and 1980 1985 show significant variations between the different slope types with a maximum near depression bases throughfall measurements in 1980 and 1985 show that midslope and near summit sites receive 10 20 per cent less water than do depression bases surface runoff monitored using coloured dyes is of limited distance and duration but still contributes to surface corrosion and morphology vadose seepage monitored by tracing water from the surface to a small shallow cave is rapid and subsurface corrosion exceeds that at the surface overall near surface form and process are consistent with hydrological models of depression development williams 1983 1985 and surface processes contribute significantly to overall depression form moreover surface activity complements that in the subcutaneous zone by directing recharge into the epikarstic aquifer

karst groundwater resources in the countries of eastern mediterranean the example of lebanon the hydrogeological study of some karst systems in lebanon shows important storage capacity up to 27 billions m3 for zarka system the spring of orontes river their geological and morphological settings as well as their hydrodynamic function show structures developed below the level of present springs probably up to several hundreds meters at depth since miocene those carbonate formations were subject to a remarkable instability of their base levels variations of sea level of which the messinian salinity crisis is the major phase and effects of the alpine orogenesis combined with climate variations to develop complex multiphased karst systems karstification occurs frequently in the whole formation often deeply below sea level or underneath sediment filling of continental basins the surface karst landscape is often intensely eroded those multiple superimposed karst phases give the carbonate aquifers their large extension and storage capacity these karst aquifers show the typical easy restoration of storage they have the ability to bear large interannual recharge variations and support exploitation under high pumping rates however these aquifers have some disadvantages for sustainable management in some regions successful boreholes which allow high pumping rates also induce uncontrolled exploitation another consequence is natural seawater intrusion as well as the submarine discharge of fresh groundwater in coastal aquifers those carbonate aquifers are subject to important economical stress which jeopardizes their durability the systematic study and understanding of carbonate aquifers in eastern mediterranean is a preliminary condition to any integrated and sustainable management of water resources studies in progress in lebanon may serve as examples to the whole region