compression behaviour of minerogenic low energy intertidal sediments existing geotechnical approaches that describe volumetric changes in intertidal sediments in response to applied vertical effective stresses are limited by a lack of empirical research into their one dimensional compression behaviour in this paper we address this deficiency by presenting the results of an investigation into the compression behaviour of minerogenic low marsh and tidal flat sediments we have tested samples of these sediment types obtained from greatham creek cowpen marsh tees estuary uk analysis of physical properties and oedometer compression tests demonstrates that contrary to the implicit assumptions of existing models the surface sediments studied are overconsolidated structural variability between samples arises due to sedimentological factors notably variations in organic content we attribute overconsolidation to tidal exposure and falls in groundwater level that permit desiccation and cause capillary suction stresses greater rates of compression with respect to effective stress occur in sediments with higher initial voids ratios and more open unstable initial structures variability in structure decreases with application of higher effective stresses due to the destructuration of the sediments which also creates increased homogeneity of compression behaviour under higher effective stresses we subsequently develop a new conceptual framework to describe compression behaviour in minerogenic intertidal sediments that incorporates overconsolidation we advocate a statistical approach that accounts for structural variability and variations in compression behaviour at effective stresses less than and greater than the yield stress we argue that our conceptual framework is broadly applicable to minerogenic intertidal sediments at different locations and burial depths within holocene stratigraphic sequences providing site specific compression data are collected inter site transfer and application of measured material properties should not be undertaken due to local variations in compression behaviour resulting from varying ecological sedimentological geochemical climatic geomorphic and hydrographic conditions the individual characteristics of different field locations should be carefully considered before the suggested framework is routinely applied

permafrost and climate in europe monitoring and modelling thermal geomorphological and geotechnical responses we present a review of the changing state of european permafrost within a spatial zone that includes the continuous high latitude arctic permafrost of svalbard and the discontinuous high altitude mountain permafrost of iceland fennoscandia and the alps the paper focuses on methodological developments and data collection over the last decade or so including research associated with the continent scale network of instrumented permafrost boreholes established between 1998 and 2001 under the european union pace project data indicate recent warming trends with greatest warming at higher latitudes equally important are the impacts of shorter term extreme climatic events most immediately reflected in changes in active layer thickness a large number of complex variables including altitude topography insolation and snow distribution determine permafrost temperatures the development of regionally calibrated empirical statistical models and physically based process oriented models is described and it is shown that though more complex and data dependent process oriented approaches are better suited to estimating transient effects of climate change in complex mountain topography mapping and characterisation of permafrost depth and distribution requires integrated multiple geophysical approaches and recent advances are discussed we report on recent research into ground ice formation including ice segregation within bedrock and vein ice formation within ice wedge systems the potential impacts of climate change on rock weathering permafrost creep landslides rock falls debris flows and slow mass movements are also discussed recent engineering responses to the potentially damaging effects of climate warming are outlined and risk assessment strategies to minimise geological hazards are described we conclude that forecasting changes in hazard occurrence magnitude and frequency is likely to depend on process based modelling demanding improved understanding of geomorphological process response systems and their impacts on human activity

assessing δ13c and c n ratios from organic material in archived cores as holocene sea level and palaeoenvironmental indicators in the humber estuary uk organic 13c and c n analyses of estuarine deposits provide proxies for changes in the source of organic matter which can be driven by fluctuations in relative sea level river discharge and catchment disturbance here we present the results of a comprehensive vegetation and sediment 13c and c n survey of welwich marsh outer humber estuary uk together with high resolution 13c and c n analyses of holocene cores collected nine years previously from the humber estuary and the lincolnshire marshes eastern england uk the contemporary intertidal 13c and c n dataset shows a gradual increase in surface sediment 13c with decreasing marsh height and suggests that 13c is controlled by the degree of tidal inundation and thus reflects organic matter source however sediment c n ratios are less sensitive to tidal changes and the recent introduction of c4 salt marsh species complicates the contemporary analogue the holocene 13c and c n records are in general agreement with existing microfossil data and provide additional palaeoenvironmental information this includes support for an estuary wide expansion of marine conditions from c 3 3 ka cal yr bp followed by a contraction of marine conditions after c 2 7 ka cal yr bp and evidence for an increase in delivery of terrigenous organic matter to the inner estuary in the late holocene bulk organic 13c and c n analysis is shown to be a reliable and independent indicator of coastal environmental change and is therefore a complementary technique to the more commonly used microfossil approach however this study also shows that in some circumstances the technique may be compromised when applied to sediments from cores that have been stored for a period of time

instruments and methods geophysical imaging of alpine rock glaciers slope instabilities caused by the disappearance of ice within alpine rock glaciers are an issue of increasing concern design of suitable counter measures requires detailed knowledge of the internal structures of rock glaciers which can be obtained using geophysical methods we examine benefits and limitations of diffusive electromagnetics geoelectrics seismics and ground penetrating radar georadar for determining the depth and lateral variability of the active layer the distributions of ice and water the occurrence of shear horizons and the bedrock topography in particular we highlight new developments in data acquisition and data analysis that allow 2 d or even 3 d structures within rock glaciers to be imaged after describing peculiarities associated with acquiring appropriate geophysical datasets across rock glaciers and emphasizing the importance of state of the art tomographic inversion algorithms we demonstrate the applicability of 2 d imaging techniques using two case studies of rock glaciers in the eastern swiss alps we present joint interpretations of geoelectric seismic and georadar data appropriately constrained by information extracted from boreholes a key conclusion of our study is that the different geophysical images are largely complementary with each image resolving a different suite of subsurface features based on our results we propose a general template for the cost effective and reliable geophysical characterization of mountain permafrost

developments in the analysis of footwall slopes in surface coal mining abstract surface mining of coal particularly in areas of mountainous topography often involves the formation of extensive footwall slopes parallel to the strata dip due to structural deformation steep dips on the limbs of folds may be encountered in association with thrust faults jointing and residual shear strength conditions such an environment necessitates a rigorous assessment of footwall stability in order to ensure safe and economic exploitation of the coal this paper provides a detailed review of the factors influencing footwall slope instability in surface coal mining and the major instability mechanisms which have been recognized within the published literature the analysis of footwalls in the design stage and the back analysis of footwall slope failures has in general been undertaken using predominantly two dimensional limit equilibrium techniques often incorporating a simplistic elastic column analysis the application of numerical modelling techniques to surface coal mine footwalls has received little attention in this paper the authors attempt to illustrate the potential for investigating footwall failure mechanisms and stability using principally the distinct element method

holocene relative sea level changes and coastal vegetation history at kentra moss argyll northwest scotland abstract a late holocene fall in relative sea level in northwest scotland from ca 1 3mm yr 1 to ca 1 0 mm yr 1 is interpreted from lithostratigraphic biostratigraphic chronostratigraphic and numerical analyses of fossil tidal marsh and acidic peat bog communities elevated by isostatic uplift pollen diatom and stratigraphic data from contemporary depositional environments are used to define the indicative range 0 2 m and reference water level mean high water of spring tides or highest astronomical tide of thirteen dated sea level index points no holocene intertidal sediments are recorded above 7 7 m od and all sea level index points are younger than ca 4 kyr b p in parts of kentra moss beyond the limit of holocene intertidal clastic sedimentation raised bog communities were established by at least 8 3 kyr b p these age and altitude parameters differ from those interpolated for the main postglacial shoreline but support a regional model in which isostatic uplift continues at present in the kentra moss area

monitoring mountain permafrost evolution using electrical resistivity tomography a 7 year study of seasonal annual and long term variations at schilthorn swiss alps 1 a combined geophysical and thermal monitoring approach for improved observation of mountain permafrost degradation is presented time lapse inversion of repeated electrical resistivity tomography ert measurements allows both active layer dynamics and interannual permafrost conditions to be delineated analysis of a comprehensive ert monitoring data set from a 7 year study at schilthorn swiss alps confirmed the applicability of ert monitoring to observations of freezing and thawing processes on short term seasonal and long term scales long term resistivity changes were evaluated on the basis of seasonal resistivity variations showing an annual cycle with high resistivities in frozen and low resistivities in unfrozen state one important result is the detection of a sustained impact of the extraordinarily hot european summer of 2003 on the permafrost regime which is more severe than previously assumed from borehole temperatures combined analyses of ert monitoring and borehole temperature data revealed substantial ground ice degradation as a consequence of the 2003 summer which did not recover in the following years despite suitable subsurface temperature conditions resistivity changes that are nonconforming to long term temperature evolution are attributed to the limited availability of liquid water and or changes in material characteristics e g pore volume changes as a result of subsidence

δ13c and c n as potential coastal palaeoenvironmental indicators in the mersey estuary uk the reconstruction of former environments and ultimately relative sea level changes in coastal and estuarine environments normally utilises a range of microfossil proxies such as diatoms foraminifera and pollen as microfossils are sometimes poorly preserved sparse or absent from coastal sediments this study assesses the potential of using 13c and c n analysis of sedimentary organic matter as an alternative contemporary high inter tidal and sub tidal surface saltmarsh sediments of the mersey estuary uk reveal distinctly different 13c and c n values reflecting the contrasting sources of organic matter in relation to ground elevation within the tidal frame despite decomposition effects the relationship between ground elevation 13c and c n is preserved in the sediment record with a gradual increase in 13c and decrease in c n from supra tidal through to inter tidal and to sub tidal environments holocene variations in 13c and c n are compared with stratigraphical palaeoenvironmental changes inferred from diatom and pollen evidence and show a good correspondence although 13c and c n are not as accurate as microfossil analysis in terms of coastal palaeoenvironmental reconstruction they may be applied successfully in the field of relative sea level reconstruction by helping to verify sea level index points when microfossils are absent

geophysical imaging of alpine rock glaciers slope instabilities caused by the disappearance of ice within alpine rock glaciers are an issue of increasing concern design of suitable counter measures requires detailed knowledge of the internal structures of rock glaciers which can be obtained using geophysical methods we examine benefits and limitations of diffusive electromagnetics geoelectrics seismics and ground penetrating radar georadar for determining the depth and lateral variability of the active layer the distributions of ice and water the occurrence of shear horizons and the bedrock topography in particular we highlight new developments in data acquisition and data analysis that allow 2 d or even 3 d structures within rock glaciers to be imaged after describing peculiarities associated with acquiring appropriate geophysical datasets across rock glaciers and emphasizing the importance of state of the art tomographic inversion algorithms we demonstrate the applicability of 2 d imaging techniques using two case studies of rock glaciers in the eastern swiss alps we present joint interpretations of geoelectric seismic and georadar data appropriately constrained by information extracted from boreholes a key conclusion of our study is that the different geophysical images are largely complementary with each image resolving a different suite of subsurface features based on our results we propose a general template for the cost effective and reliable geophysical characterization of mountain permafrost

assessment of δ13c and c n ratios in bulk organic matter as palaeosalinity indicators in holocene and lateglacial isolation basin sediments northwest scotland carbon isotopes 13c and c n ratios from bulk organic matter have recently been used as alternative proxies for relative sea level rsl reconstruction where there are problems associated with conventional biological indictors a previous study on a single isolation basin upper loch nan eala in northwest scotland has shown a clear relationship between 13c c n ratios and palaeosalinity from younger dryas and holocene aged sediments in this paper we present results of 13c and c n ratio analyses from other isolation basins in northwest scotland over the holocene and the lateglacial period in order to validate this technique the results from the holocene sequences support the earlier findings that this technique can be used to identify rsl change from isolation basins over the holocene in this region the relationship between 13c c n ratios and rsl change is not apparent in sediments of lateglacial age other environmental variables such as atmospheric co2 concentration poor vegetation development and temperature influence 13c values during this period

resistivity and percolation study of preferential flow in vadose zone at bokhorst germany traditional nondestructive resistivity techniques have been applied in combination with tracer displacement and conventional soil moisture recording methods i e buried tensiometer and time domain reflectometry tdr for studying flow processes at an arable site in bokhorst germany three water infiltration experiments were carried out using tap water spiked with a nonreactive tracer at different concentrations the study aimed at exploring the capabilities of these combined techniques for tracing the preferential movement of water in the uppermost 1 5 m of the highly heterogeneous vadose zone the results illustrate that the applied tensiometer and tdr techniques can detect the relatively fast flow process at their position points and thus only tentatively trace the preferential flow the additional application of the resistivity method can trace the preferential flow paths continuously along the plane of measurements the results of the individual applied methods complement and confirm each other

is that a relict rock glacier abstract the distribution of rock glaciers is often used to investigate the occurrence of permafrost in mountain areas and to understand their climate and paleoclimate evolution this requires the creation of regional and global inventories capable of discriminating active and relict landforms in order to forecast the presence or absence of ice in the ground in this paper geomorphological geophysical and microclimatic surveys are performed on a rock glacier of the carnic alps eastern european alps in the classification currently used for implementing regional inventories of permafrost evidence in the alps this rock glacier would be defined as relict however the geophysical climatological and geomorphological results indicate that internal ice is widespread in large portions of the rock glacier these are generally interpreted as ice in pore spaces and local ice lenses probably without layers of massive ice moreover the occurrence of ice during the maximum thawing season at depths

organic carbon isotope systematics of coastal marshes abstract measurements of nitrogen organic carbon and 13c are presented forspartina dominated marsh sediments from a mineral marsh in sw netherlands and from a peaty marsh in massachusetts u s a 13c of organic carbon in the peaty marsh sediments is similar to that ofspartinamaterial whereas that in mineral marshes is depleted by 9 12 it is argued that this depletion in 13c of organic matter in marsh sediments is due to trapping of allochthonous organic matter which is depleted in13c the isotopic composition and concentration of organic carbon are used in a simple mass balance to constrain the amount of plant material accumulating in marsh sediments i e in terms of the so called net ecosystem production net ecosystem production 2 100 g c m 2year 1 is a small fraction 1 5 of plant production 2000 g c m 2year 1 this small amount of plant material being preserved is nevertheless sufficient to support marsh accretion rates similar to the rate of sea level rise

verification of geophysical models in alpine permafrost using borehole information at two permafrost sites in the swiss alps a range of geophysical methods were applied to model the structure of the subsurface at both sites borehole information was used to verify the quality of the model results on the murtel corvatsch rock glacier 2700 m a s l upper engadine a 58 m deep core drilling was performed in 1987 d c resistivity measurements refraction seismics ground penetrating radar gpr and gravimetric surveys allowed the shape of the permafrost table beneath the marked surface microtopography to be determined and the lateral extent of a deeper shear horizon to be established the validity of each method was verified by the borehole information cores density log and temperature a coherent model of the rock glacier structure was developed at the schilthorn 2970 m a s l bernese oberland it was not clear whether permafrost is in fact present various geophysical surveys d c resistivity tomography refraction seismics gpr and em 31 gave results that were not typical of permafrost environments a 14 m percussion drilling revealed warm permafrost and a very low ice content these geotechnical and geothermal data allowed reinterpretation of the geophysical results improving modelling of ground conditions the paper demonstrates that in the difficult terrain of alpine permafrost boreholes may be critical in calibration and verification of the results of geophysical methods the most useful combinations of geophysical techniques proved to be a seismics with d c resistivity and b gravimetry with gpr

seismic and electrical properties of unconsolidated permafrost1 a model has been developed to relate the velocities of acoustic waves vp and vs in unconsolidated permafrost to the porosity and extent of freezing of the interstitial water the permafrost is idealized as an assemblage of spherical quartz grains embedded in a matrix composed of spherical inclusions of water in ice the wave scattering theory of kuster and toksoz is used to determine the effective elastic moduli and hence the acoustic velocities the model predicts vp and vs to be decreasing functions of both the porosity and the water to ice ratio the theory has been applied to laboratory measurements of vp and vs in 31 permafrost samples from the north american arctic although no direct measurements were made of the extent of freezing in these samples the data are consistent with the predictions of the model electrical resistivity measurements on the permafrost samples have demonstrated their essentially resistive behaviour the ratio of resistivity of permafrost in its frozen state to that in its unfrozen state has been related to the extent of freezing in the samples electromagnetic and seismic reflection surveys can be used together in areas of permafrost firstly an em survey to determine the extent of freezing and then the acoustic velocity model to predict the velocities in the permafrost the necessary transit time corrections can thus be made on seismic reflection records to compensate for the presence of permafrost

internal structure and permafrost distribution in two alpine periglacial talus slopes valais swiss alps in order to determine the spatial extension and the characteristics of permafrost within alpine talus slopes two sites located in the western part of the swiss alps were studied using borehole drilling and electrical resistivity tomography ert profiles three boreholes were drilled along an upslope downslope transect in both talus slopes in both sites frozen sediments are present only in the two lowest boreholes whereas the upper borehole does not present ice this stratigraphy is confirmed by ground temperatures registered in the boreholes in each site three upslope downslope ert profiles were crossed with five respectively four horizontal ert profiles all the upslope downslope profiles show a difference in resistivities between the upper and lower parts of the slope where a large resistive body with values higher than 35 k m is present in the uppermost part of the profiles the resistivities are lower than 10 15 k m the borehole data allowed the stratigraphy obtained from the ert inverted profiles to be validated with regards to the distribution of frozen sediments as well as the depth of the detected structures the results confirm that in the two studied sites permafrost is present in the lower sections of the talus slopes whereas it is absent in the upper parts finally the analysis of the talus structure showed that the permafrost stratigraphy and in particular the ice content may be an important element of interpretation of the palaeoclimatic significance of an alpine talus slope

a review of coastal palaeoclimate and relative sea level reconstructions using δ13c and c n ratios in organic material holocene reconstructions of relative sea level rsl and environmental change in the coastal zone have become progressively more numerous since the importance of assessing possible future sea level rises has become apparent traditionally this has been achieved using a combination of biological and physical indicators e g pollen diatoms foraminifera grain size etc in some circumstances microfossils can be rare or absent from holocene sediments and in these cases carbon isotope ratios 13c and organic carbon to total nitrogen ratios c n can be used because they have the potential to provide information as to the origin of organic material preserved in coastal environments the distinction in 13c and c n of the various sources of carbon to estuarine sediments has led to its wide use as a tracer of carbon pathways and storage in estuaries more recently these techniques have been applied to holocene sediments to decipher changes in palaeocoastal environments and thus position relative to sea level and or palaeoriver discharge which have direct relevance to palaeoclimate this paper reviews the studies that have utilised this technique and explores examples from a wide range of coastal environments saltmarshes estuaries lagoons isolation basins and fjords it also discusses the potential alteration of geochemical signatures as a result of decompositional processes organic matter decomposition has been shown to change sediment 13c and c n values and thus an understanding of the processes involved is necessary in order to have confidence in the palaeoenvironmental interpretation of holocene 13c and c n decompositional shifts in c n and particularly 13c can occur over a relatively short time period however it is the direction of change in 13c and c n rather than absolute values that is key for interpreting changes in relative sea level and thus such changes are commonly preserved

a practical procedure for the back analysis of slope failures in closely jointed rock masses abstract where closely jointed rock masses are encountered in slopes failure can occur both through the rock mass as a result of combination of macro and micro jointing and through the rock substance determination of the strength of this category of rock mass is extraordinarily difficult since the size of representative specimens is too large for laboratory testing this difficulty can be overcome by using a non linear rock mass failure criterion or by back analysis of such slopes to estimate the rock mass strength in this paper a practical procedure and a computer program are presented for the back determination of shear strength parameters mobilized in slopes cut in closely jointed rock masses which obey a non linear failure criterion rather than a linear one the procedure shows that the constants to derive normal stress dependent shear strength parameters of the failed rock masses can be determined by utilizing a main cross section and without a pre determined value of rock mass rating rmr trials are made for different rmr m and rmr s values corresponding to various possible combinations of the constant m and s which are used in the hoek brown failure criterion satisfying the limit equilibrium condition it is also noted that the procedure provides a quick check for the rock mass rating obtained from the site investigations the method is used in conjunction with the bishop s method of analysis based on circular slip surfaces the procedure outlined in this paper has also been satisfactorily applied to documented slope failure case histories in three open pit mines in turkey

middle to late holocene fluctuations of c3 and c4 vegetation in a northern new england salt marsh sprague marsh phippsburg maine abstract a 3 1 m sediment core was analyzed for stable carbon isotope composition of organic matter and higher plant leaf wax hplw lipid biomarkers to determine holocene shifts in c 3 higher high marsh and c 4 low and or high marsh plant deposition at the sprague river salt marsh phippsburg maine the carbon isotope composition of the bulk sediment and the hplw parallel each other throughout most of the core suggesting that terrestrial plants are an important source of organic matter to the sediments and diagenetic alteration of the bulk sediments is minimal the current salt marsh began to form 2500 cal yr bp low and or high c 4 marsh plants dominated deposition at 2000 cal yr bp 700 cal yr bp and for the last 200 cal yr bp expansion of higher high marsh c 3 plants occurred at 1300 and 600 cal yr bp these major vegetation shifts result from a combination of changes in relative sea level rise and sediment accumulation rates average annual carbon sequestration rates for the last 2500 years approximate 40 g c yr 1 m 2 and are in strong agreement with other values published for the gulf of maine given that maine salt marshes cover an area of 79 km 2 they represent an important component of the terrestrial carbon sink more detailed isotopic and age records from a network of sediment cores at sprague marsh are needed to truly evaluate the long term changes in salt marsh plant communities and the impact of more recent human activity including global warming on salt marsh vegetation

tidal marsh stratigraphy sea level change and large earthquakes i a 5000 year record in washington u s a abstract many of the estuaries of the pacific northwest of the u s a and canada contain stratigraphic sequences typified by alternating peat mud couplets recent studies in this region interpret such couplets as the product of repeated large magnitude s or 9 earthquakes on the cascadia subduction zone the resultant pattern of land level movements is described by a model the earthquake deformation cycle of coseismic land subsidence followed by land uplift during interseismic strain accumulation however peat mud couplets similar to those recorded in the pacific northwest are found on other less tectonically active temperate latitude coasts such as northwest europe and the atlantic coast of the u s a where they have been interpreted as the product of non seismic coastal processes in this paper we apply the methods and scientific framework common to sea level investigations in northwest europe to a sequence of peat mud couplets recorded in the lower johns river an estuary in southern washington to provide a test of the earthquake deformation cycle stratigraphic investigations of the intertidal sediments along the lower johns river using lithological pollen diatom and foraminiferal data show evidence for eight coastal submergence events during the last 5000 years to evaluate the earthquake deformation cycle we assess the lateral extent of peat mud couplets the synchroneity of submergence the presence of tsunami deposits accompanying submergence and the suddenness and amount of submergence each submergence is shown to be accompanied by changes in coastal sedimentation broadly commensurate with those predicted by the earthquake deformation cycle demonstrating the continued intermittent seismic activity of the cascadia subduction zone throughout the mid and late holocene quantitative analyses of contemporary and fossil biostratigraphic data using twinspan and detrended correspondence analysis enable us to estimate the magnitude of submergence accompanying each peat mud couplet one event was accompanied by submergence of about 1 5 m or more four events by intermediate submergence of about 1 0 5 m and a further three events by submergence of

modern foraminifera δ13c and bulk geochemistry of central oregon tidal marshes and their application in paleoseismology we assessed the utility of 13c and bulk geochemistry total organic content and c n to reconstruct relative sea level changes on the cascadia subduction zone through comparison with an established sea level indicator benthic foraminifera four modern transects collected from three tidal environments at siletz bay oregon usa produced three elevation dependent groups in both the foraminiferal and 13c bulk geochemistry datasets foraminiferal samples from the tidal flat and low marsh are identified by miliammina fusca abundances of 45 middle and high marsh by m fusca abundances of 25 the 13c values from the groups defined with 13c bulk geochemistry analyses decrease with an increasing elevation 24 1 1 7 in the tidal flat and low marsh 27 3 1 4 in the middle and high marsh and 29 6 0 8 in the highest marsh samples we applied the modern foraminiferal and 13c distributions to a core that contained a stratigraphic contact marking the great cascadia earthquake of ad 1700 both techniques gave similar values for coseismic subsidence across the contact 0 88 0 39 m and 0 71 0 56 m suggesting that 13c has potential for identifying amounts of relative sea level change due to tectonics

carbon isotope diatom and pollen evidence for late holocene salinity change in a brackish marsh in the san francisco estuary analysis of diatoms pollen and the carbon isotopic composition of a sediment core from a brackish marsh in the northern part of the san francisco estuary has provided a paleosalinity record that covers the past 3000 yr changes in marsh composition and diatom frequencies are assumed to represent variations in freshwater inflow to the estuary three periods of relatively high salinity low freshwater inflow are indicated 3000 to 2500 cal yr b p 1700 to 730 cal yr b p and ca a d 1930 to the present the most recent period of high salinity is primarily due to upstream storage and water diversion within the sacramento san joaquin watershed although drought may also have been a factor the two earlier high salinity periods are likely the result of reduced precipitation low salinity high freshwater flow is indicated for the period 750 cal yr b p to a d 1930 c 2001 university of washington

3d geoelectric tomography and archaeological applications following a previous paper in which the principles of a 3d ground surface tomographic processing of self potential data were established we extend the method to active source geoelectric surveying the main purpose of the new tomographic approach is to obtain a physical image reconstruction of the induced electric charges distributed over buried resistivity discontinuities the information is produced in a probabilistic sense as the mathematical formulation underlying the method treats only the intrinsic physical nature of the generated electric field underground and the method of its ground surface detection independently of the geometry of the unknown structures in practice a 3d tomography is realized by cross correlating a set of distributed electric field ground surface data with a scanning function representing a unit positive point charge located anywhere in the lower half space the resolution of the method is tested on the synthetic response of a 3d structural simulation of an archaeological target consisting of an infinitely resistive prismatic body immersed in a half space including surface inhomogeneities and layering finally the field response of a 3d structure consisting of a hypogeal dromos chamber tomb inside the sabine necropolis at colle del forno close to rome is presented and discussed

carbon stable isotope δ13c and elemental toc tn geochemistry in saltmarsh surface sediments western brittany france a useful tool for reconstructing holocene relative sea level providing a dense network of holocene relative sea level rsl records still faces some challenges such as the paucity of microfossil assemblages within some holocene sedimentary sequences recently the isotopic 13c and elemental geochemistry total organic carbon toc total nitrogen tn and c n ratios of saltmarsh sediments has showed potential for rsl reconstruction this study presents the results of new 13c toc and tn measurements obtained on surface sediments of two marshes of the brittany region france overall the distribution of 13c toc tn and c n values shows clear dependencies with elevation sediments from above and below the high tide level show contrasting tn contents clustering analyses identified three elevation dependent groups characterized by specific values of 13c toc and tn the use of this geochemical reference for rsl reconstruction is tested on a core retrieved from one of the marshes the sea level index points obtained plot in good accordance with the microfauna based rsl positions previously obtained in the region some diagenetic losses in tn are observed between modern and holocene sediments this does not appear to be harmful to the accuracy of the rsl reconstructions but suggests that c n ratios may be unreliable palaeoenvironmental proxies in this specific context

modern saltmarsh diatom distributions of the outer banks north carolina and the development of a transfer function for high resolution reconstructions of sea level we collected modern diatom samples from currituck barrier island oregon inlet and pea island marshes outer banks north carolina usa which have different salinity regimes due to their varying distances from a major barrier island inlet multivariate analyses separate the saltmarsh diatom assemblages into distinct elevational zones dominated by differing abundances of polyhalobous mesohalobous and oligohalobous taxa suggesting that the distribution of saltmarsh diatoms is a direct function of elevation with the most important controlling factors being the duration and frequency of subaerial exposure we developed the first diatom based transfer function for the east coast of north america to reconstruct former sea levels based upon the relationship between diatom assemblage and elevation results imply that this is possible to a precision of 0 08 m superior to most similar studies from temperate mid latitude environments the transfer function is used to construct a relative sea level curve from fossil assemblages from salvo north carolina these results suggest a sea level rise of 0 7 m over the last c 150 years at an average of c 3 7 mm year 1 this is

slope stability probability classification waikato coal measures new zealand abstract ferm classified lithological units have been identified and described in the waikato coal measures in open pits in the waikato coal region these lithological units have been classified geotechnically by mechanical tests and discontinuity measurements using these measurements slope stability probability classifications sspc have been quantified based on an adaptation of hack s slope stability probability classification itc delft publication enschede netherlands vol 43 1998 273 pp sspc system which places less influence on rock quality designation and unconfined compressive strength than previous slope rock mass rating systems the hack weathering susceptibility rating has been modified by using chemical index of alteration values determined from xrf major element analyses slaking is an important parameter in slope stability in the waikato coal measures lithologies and hence a non subjective method of assessing slaking in relation to the chemical index of alteration has been introduced another major component of this adapted sspc system is the inclusion of rock moisture content effects on slope stability the main modifications of hack s sspc system are the introduction of rock intact strength derived from the modified mohr coulomb failure criterion which has been adapted for varying moisture content weathering state and confining pressure it is suggested that the subjectivity in assessing intact rock strength within broad bands in the initial sspc system is a major weakness of the initial system initial results indicate a close relationship between rock mass strength values calculated from rock mass friction angles and rock mass cohesion values derived from two established rock mass classification methods modified hoek brown failure criteria and mrmr and the adapted sspc system the advantage of the modified sspc system is that slope stability probabilities based on discontinuity independent and discontinuity dependent data and a maximum slope height are predicted the modified sspc system may be useful in predicting initial optimum pit slope designs in proposed greenfield mine sites xrf major element and chemical index of alteration cia results obtained for lithologies in the waikato coal region may be a useful mine management tool to quantify stratigraphic thickness and palaeoweathering from wash drill cuttings this paper explains the systematic approach of using the adapted sspc system to classify slope stability in the waikato open pit coal mines

relationships between glacier and rock glacier in the maritime alps schiantala valley italy abstract in the schiantala valley of the maritime alps the relationship between a till like body and a contiguous rock glacier has been analyzed using geomorphologic geoelectric and ice petrographic methodologies dc resistivity tomographies undertaken in the till and in the rock glacier show the presence of buried massive ice and ice rich sediments respectively ice samples from a massive ice outcrop show spherical gas inclusions and equidimensional ice crystals that are randomly orientated confirming the typical petrographic characteristics of sedimentary ice the rock glacier formation began after a phase of glacier expansion about 2550 50 14c yr bp further ice advance during the little ice age lia overrode the rock glacier root and caused partial shrinkage of the pre existing permafrost finally during the 19th and 20th centuries the glacial surface became totally debris covered geomorphological and geophysical methods combined with analyses of ice structure and fabric can effectively interpret the genesis of landforms in an environment where glaciers and permafrost interact ice petrography proved especially useful for differentiating ice of past glaciers versus ice formed under permafrost conditions these two mechanisms of ice formation are common in the maritime alps where many sites of modern rock glaciers were formerly occupied by lia glaciers

coal mining under difficult geological conditions the can lignite open pit canakkale turkey abstract this paper describes the slope instability problems in the can canakkale northwestern turkey coal mine slope instabilities have been one of the major problems in the pit mine since the beginning of mining activities in particular the west and east sector panels in front of the tki turkish coal enterprises buildings and the seramic factory located in the vicinity of the pit mine have been suffering from slope instability problems to assess the instabilities field data collection from boreholes surface sampling and monitoring studies were performed deterministic stability analyses such as limit equilibrium sensitivity and back analyses were applied based on the results the active passive wedge type of failure was determined as the most dominant instability type based on the back analysis results mean values of residual shear strength parameters were determined as c 42 kpa o 8 the results also indicate that the excessive excavation of the toe along the huge lignite open pit was the main cause of the instability the weak contacts between the lithological units were also an important factor taking into consideration the results of the analyses some remedial measures were also suggested for the coal mine such as decreasing the inclination of the toe safe benching and effective drainage of surface water and groundwater

multidisciplinary geophysical investigations over an alpine rock glacier we have performed a multidisciplinary geophysical survey combined with geotechnical investigations over a degrading alpine rock glacier a dense grid of helicopter borne groundpenetrating radar data allowed the 3d shape of the bedrock topography and the gross transition from ice rich to ice poor parts of the rock glacier to be delineated the bedrock topography served as a 2d structural constraint for tomographic inversions of seismic and geoelectric data acquired on coincident profiles parallel and perpendicular to the rock glacier flow direction these profile data were complemented by a small 3d geoelectric tomography experiment only a combined interpretation of all the results allowed reliable and unambiguous interpretation of the tomograms we could distinguish between the active layer bedrock ice bearing rock glacier material and degraded permafrost within the rock glacier the latter could be further distinguished in areas where the ice must have melted only recently and regions that had degraded some time ago additionally high resolution cross hole radar tomography performed in an area of opening crevices allowed small scale structures to be resolved which were indicative of the dominant deformation mechanisms style of the rock glacier the success of our study was primarily based on the availability of 3d data sets that allowed important structures to be traced over larger areas and the integrated interpretation of several data types we have identified the internal structure of the rock glacier to be surprisingly heterogeneous with several small scale features that were judged to be critical for assessing its stability this underpinned the need for comprehensive 3d structural investigations to augment geotechnical measurements linearly with inclinometers or at points in boreholes

assessment of subsurface lithology in mountain environments using 2d resistivity imaging abstract the use of 2d resistivity imaging for the investigation of typical periglacial phenomena is shown on different case studies from a mid latitude high alpine and a high latitude subarctic periglacial environment important parameters that need to be determined for geomorphological studies in mountain environments are the location and extent of permafrost and its characteristics the spatial variability of the active layer as well as the internal structure of different periglacial landforms the investigations on different typical periglacial features demonstrate that 2d electrical resistivity imaging is a suitable method to detect permafrost with an appropriate accuracy delineation of active layer thickness is possible but depends on the contrast in resistivity between the active layer and the permafrost underneath the detection of small scale variability within the internal structure of some typical periglacial landforms can be limited because of the smoothing effect of the wenner array and the high ground resistances and weak signal strength which do not allow the successful application of the dipole dipole array hence limitations of application of geoelectric methods can arise from the rugged terrain conditions in periglacial mountain environments since good electrical coupling between the electrodes and the ground is a prerequisite for geoelectrical surveys nevertheless it is demonstrated that even on rough terrain conditions 2d electrical resistivity imaging could be used successfully to obtain reproducible results which are required to use changes in the apparent resistivity measurements to monitor changes in the subsurface resistivity distribution and hence permafrost aggradation and degradation

quantitative vertical zonation of salt marsh foraminifera for reconstructing former sea level an example from new jersey usa we present a quantitative technique to reconstruct sea level from assemblages of salt marsh foraminifera using partitioning around medoids pam and linear discriminant functions ldf the modern distribution of foraminifera was described from 62 surface samples at three salt marshes in southern new jersey pam objectively estimated the number and composition of assemblages present at each site and showed that foraminifera adhered to the concept of elevation dependent ecological zones making them appropriate sea level indicators application of pam to a combined dataset identified five distinctive biozones occupying defined elevation ranges which were similar to those identified elsewhere on the u s mid atlantic coast biozone a had high abundances of jadammina macrescens and trochammina inflata biozone b was dominated by miliammina fusca biozone c was associated with arenoparrella mexicana biozone d was dominated by tiphotrocha comprimata and biozone e was dominated by haplophragmoides manilaensis foraminiferal assemblages from transitional and high salt marsh environments occupied the narrowest elevational range and are the most precise sea level indicators recognition of biozones in sequences of salt marsh sediment using ldfs provides a probabilistic means to reconstruct sea level we collected a core to investigate the practical application of this approach ldfs indicated the faunal origin of 38 core samples and in cross validation tests were accurate in 54 of 56 cases we compared reconstructions from ldfs and a transfer function the transfer function provides smaller error terms and can reconstruct smaller rsl changes but ldfs are well suited to rsl reconstructions focused on larger changes and using varied assemblages agreement between these techniques suggests that the approach we describe can be used as an independent means to reconstruct sea level or importantly to check the ecological plausibility of results from other techniques

glacial to holocene terrigenous organic matter input to sediments from orca basin gulf of mexico a combined optical and biomarker approach in this study we assessed changes in the contribution of terrigenous organic matter om to the gulf of mexico over the course of the last deglaciation the last 25 kyr to this end we combined optical kerogen analyses with bulk sedimentary biomarker and compound specific carbon isotope analyses samples were obtained from core md02 2550 from orca basin 2249 m water depth at 26 56 77n 91 20 74w with temporal resolution ranging from multi decadal to millennial scale depending on the proxy all proxies confirmed larger terrigenous input during glacial times compared to the holocene in addition the kerogen analyses suggest that much of the glacial om is reworked at least 50 of spores and pollen grains and 40 of dinoflagellate cysts the holocene sediments in contrast contain mainly marine om which is exceptionally well preserved during the deglaciation terrigenous input was generally high due to large meltwater fluxes whereby discrepancies between different proxies call for additional influences such as the change in distance to the river mouth local productivity changes and hydrodynamic particle sorting it is possible that kerogen particles and the terrigenous biomarkers studied here represent distinct pools of land derived om with inputs varying independently

rapid least squares inversion of apparent resistivity pseudosections by a quasi newton method1 a fast inversion technique for the interpretation of data from resistivity tomography surveys has been developed for operation on a microcomputer this technique is based on the smoothness constrained least squares method and it produces a two dimensional subsurface model from the apparent resistivity pseudosection in the first iteration a homogeneous earth model is used as the starting model for which the apparent resistivity partial derivative values can be calculated analytically for subsequent iterations a quasi newton method is used to estimate the partial derivatives which reduces the computer time and memory space required by about eight and twelve times respectively compared to the conventional least squares method tests with a variety of computer models and data from field surveys show that this technique is insensitive to random noise and converges rapidly this technique takes about one minute to invert a single data set on an 80486dx microcomputer

development of tongue shaped and multilobate rock glaciers in alpine environments interpretations from ground penetrating radar surveys abstract rock glaciers occur as lobate or tongue shaped landforms composed of mixtures of poorly sorted angular to blocky rock debris and ice these landforms serve as primary sinks for ice and water storage in mountainous areas and represent transitional forms in the debris transport system accounting for 60 of all mass transport in some alpine regions observations of active flowing alpine rock glaciers indicate a common association between the debris that originates from cirque headwalls and the depositional lobes that comprise them the delivery of this debris to the rock glacier is regulated primarily by the rate of headwall erosion and the point of origin of debris along the headwall these factors control the relative movement of individual depositional lobes as well as the overall rate of propagation of a rock glacier in recent geophysical studies a number of alpine rock glaciers on prins karls forland and nordenskioldland svalbard norway and the san juan mountains of southwest colorado usa have been imaged using ground penetrating radar gpr to determine if a relationship exists between the internal structure and surface morphology results indicate that the overall morphologic expression of alpine rock glaciers is related to lobate deposition during catastrophic episodes of rockfall that originated from associated cirque headwalls longitudinal gpr profiles from alpine rock glaciers examined in this study suggests that the difference in gross morphology between the lobate and tongue shaped rock glaciers can be attributed primarily but not exclusively to cirque geometry frequency and locations of debris discharge within the cirque and the trend and magnitude of valley gradient in relation to cirque orientation collectively these factors determine the manner in which high magnitude debris discharges which seem to be the primary mechanism of formation accumulate to form these rock glaciers

the application of δ13c toc and c n geochemistry of mangrove sediments to reconstruct holocene paleoenvironments and relative sea levels puerto rico abstract we assessed the use of 13c toc and c n values of bulk sedimentary organic matter om to reconstruct paleoenvironmental and relative sea level change from mangrove environments in puerto rico the modern distribution of 13c toc and c n values was described from 63 vegetation and 59 surface sediment samples collected from three sites containing basin and riverine mangrove stands and was compared to microfossil foraminiferal and thecamoebian assemblages four vertically zoned environments were identified tidal flat 13c 18 6 2 8 toc 10 2 5 7 c n 12 7 3 1 mangrove 13c 26 4 1 0 toc 33 9 13 4 c n 24 3 6 2 brackish transition 13c 28 8 0 7 toc 40 8 11 7 c n 21 7 3 7 and freshwater swamp 13c 28 4 0 4 toc 42 8 4 8 c n 17 0 1 1 these environments had distinct 13c toc and c n values with the exception of the brackish transition and freshwater swamp zones that were difficult to distinguish on a geochemical basis alone the foraminiferal assemblages were complicated by a group that did not show a relationship to elevation due to the presence of calcareous foraminifera occurring above mean higher high water mhhw likely resulting from washover or transport by storms however the ratio of foraminifera to thecamoebians f t along with 13c toc and c n values refines the distinction between brackish and freshwater environments using linear discriminant analysis we applied the 13c toc c n and f t distributions to a 1 7 m core containing a continuous sequence of rhizophora mangle peat which began accumulating at 1650 1930 ce together microfossils 13c toc and c n values and the core chronology from 137cs and radiocarbon dating revealed that sediments in the core likely accumulated in response to anthropogenic sediment delivery making it unsuitable for relative sea level reconstruction we caution that in the absence of detailed litho bio chemo or chrono stratigraphic analyses as presented here care should be taken in interpreting sea level histories derived from single dates on mangrove peats

estimation of sediment trapping behind check dams using high density electrical resistivity tomography abstract check dams are very important structures for torrent control areas throughout the world measuring the sediment deposition behind check dams is thought to be an effective method of estimating the sediment yield of small catchments in this study we employed a high density electrical resistivity system to detect sediment at six check dams distributed in the hilly and gully area of the loess plateau a total of 11 lines were arranged with 60 electrodes along each line the resultant resistivity data were inverted into subsurface structures using least squares inversion techniques the results indicate that the sediment bottom can been identified using an electrical resistivity contour method using trenches boreholes and drillings to calibrate the calculated values the accuracy of the high density electrical resistivity tomography method was found to be quite high 95 7 the bulk density increases with the sediment deposit depth and can reach a maximum of 1 6 g cm 3 geometric methods considering three shapes v shaped u shaped and trapezoidal were used to estimate the profile area of the check dams the v shaped geometric method showed high accuracy this study provides a four step approach based on high density electrical resistivity tomography and a geometric method to estimate sediment yield for check dam controlled catchments this methodology enables the measurement of the total sediment yield including both the suspended and bedload sediment transport from an ungauged catchment

testing the use of bulk organic δ13c δ15n and corg ntot ratios to estimate subsidence during the 1964 great alaska earthquake abstract during the m w 9 2 1964 great alaska earthquake turnagain arm near girdwood alaska subsided 1 7 0 1 m based on pre and postearthquake leveling the coseismic subsidence in 1964 caused equivalent sudden relative sea level rsl rise that is stratigraphically preserved as mud over peat contacts where intertidal silt buried peaty marsh surfaces changes in intertidal microfossil assemblages across these contacts have been used to estimate subsidence in 1964 by applying quantitative microfossil transfer functions to reconstruct corresponding rsl rise here we review the use of organic stable c and n isotope values and c org n tot ratios as alternative proxies for reconstructing coseismic rsl changes and report independent estimates of subsidence in 1964 by using 13 c values from intertidal sediment to assess rsl change caused by the earthquake we observe that surface sediment 13 c values systematically decrease by 4 over the 2 5 m increase in elevation along three 60 to 100 m long transects extending from intertidal mud flat to upland environments we use a straightforward linear regression to quantify the relationship between modern sediment 13 c values and elevation n 84 r 2 0 56 the linear regression provides a slope intercept equation used to reconstruct the paleoelevation of the site before and after the earthquake based on 13 c values in sandy silt above and herbaceous peat below the 1964 contact the regression standard error average 0 59 reflects the modern isotopic variability at sites of similar surface elevation and is equivalent to an uncertainty of 0 4 m elevation with respect to mean higher high water to reduce potential errors in paleoelevation and subsidence estimates we analyzed multiple sediment 13 c values in nine cores on a shore perpendicular transect at bird point our method estimates 1 3 0 4 m of coseismic rsl rise across the 1964 contact by taking the arithmetic mean of the differences n 9 between reconstructed elevations for sediment above and below the 1964 earthquake subsidence contact this estimate compares well with independent subsidence estimates derived from post earthquake leveling in turnagain arm and from microfossil transfer functions at girdwood 1 50 0 32 m while our results support the use of bulk organic 13 c for reconstructing rsl change in southern alaska the variability of stable isotope values in modern and buried intertidal sediment required the analysis of multiple samples to reduce error

beware intercepts interpreting compositional ratios in multi component sediments and sedimentary rocks the corganic ntotal ratio and the hydrogen index hi are commonly used to describe the bulk composition the sources and the post depositional alteration of sedimentary organic matter data from modern sediments and sedimentary rocks frequently show significant intercepts and strong linear relationships in plots of corganic vs ntotal and of s2 vs corganic for many different data sets demonstrating that the ratios are not constant across the range of organic matter contents the presence of such intercepts whose causes are well understood means that changes in corganic ntotal and hi as corganic changes cannot be used to infer different organic matter sources and or post depositional alteration or degrees of organic matter preservation of different sediment fractions moreover the strong linear regressions in such x y plots imply that the organic fraction of sediments and sedimentary rocks in any given setting or stratigraphic section generally has a uniform composition

resistivity and induced polarization surveys for slope instability studies in the swiss alps a geoelectrical investigation has been carried out in the swiss alps near the dent de nendaz within the southern part of the rhone valley in the swiss alps to delineate groundwater circulation within an unstable slope this unstable zone is characterized by a landslide area with clear scarps and hummocky ground at the bottom of the slope large scale apparent resistivity mapping provided information on the main pathways for water transport within the slope subsequently 2d resistivity and induced polarization imaging supplied details on the region of instability located at the bottom of the slope polarizable units identified in the region of instability could be linked to a clay rich unit or to local enrichment of graphite within the bedrock our results illustrate how low permeability clay graphite units and permeable water bearing units could be distinguished using a combined interpretation of resistivity and ip data in slope instability studies

stable carbon isotopes as potential sea level indicators in salt marshes north carolina usa we compared the use of 13c values and c n ratios from salt marsh sediments to reconstruct relative sea level rsl with an established approach using foraminifera analysis of bulk organic sediment and plant samples collected along transects at two sites in north carolina usa demonstrates that sediment 13c values can be used to distinguish between spartina alterniflora dominated low marsh c photosynthetic pathway 13c values from 17 6 to 16 1 and juncus roemerianus dominated high marsh c 3 photosynthetic pathway 13c values from 28 2 to 21 8 environments juncus roemerianus plants undergo little decompositional change in 13c average 0 8 although there is a clear difference between spartina alterniflora tissue and bulk organic sediments approximately 4 c n ratios on bulk organic sediment from freshwater upland and salt marsh environments converge during early diagenesis rendering them of little use in reconstructing rsl the utility of 13c values as a sea level indicator is limited by the elevational range of c4 plants making it difficult to recognize salt marsh subenvironments and improve the precision of rsl reconstructions furthermore juncus roemerianus dominated high marsh and freshwater upland sediments cannot be adequately distinguished with 13c values

the application of δ13c toc and c n geochemistry to reconstruct holocene relative sea levels and paleoenvironments in the thames estuary uk we examined the use of d 13 c toc and c n geochemistry of sedimentary organic matter to reconstruct former sea levels and paleoenvironments in the absence of suitable microfossil data the modern distribution of d 13 c toc and c n of 33 vegetation and 74 surface sediment samples collected from four coastal wetlands in the thames estuary and norfolk uk are described the d 13 c toc and c n geochemistry of sediments varied in relation to the input of in situ vascular vegetation versus allochthonous particulate organic matter and algae which was controlled primarily by tidal inundation we reviewed published and unpublished studies to produce an english database of vegetation n 257 and sediment n 132 d 13 c toc and c n geochemistry four elevation dependent environments in the database had statistically distinct d 13 c toc and c n values 1 tidal flat low marsh d 13 c 24 9 1 2 toc 3 6 1 7 c n 9 9 0 8 2 middle marsh high d 13 c 26 2 1 0 toc 9 8 6 7 c n 12 1 1 8 3 reed swamp d 13 c 27 9 0 7 toc 36 5 11 5 c n 13 9 1 2 and 4 fen carr d 13 c 29 0 0 6 toc 41 6 5 7 c n 17 4 3 1 the d 13 c toc and c n geochemistry database was applied to a holocene sediment core collected from the thames estuary to produce three new sea level index points and one limiting date illustrating the utility of d 13 c toc and c n values to reconstruct holocene relative sea levels copyright 2015 john wiley sons ltd

thermal characteristics and impact of climate change on mountain permafrost in iceland 1 this study contains the first quantitative description of mountain permafrost in iceland obtained through analysis of four ground temperature time series from recently established shallow boreholes at high altitude 900 m above sea level in central and eastern iceland permafrost is present at three of the four boreholes where temperatures range from 2 to 0 c during the data logging period 2004 2006 the thickness of the active layer at the individual sites varied between less than 2 m and more than 5 m mainly owing to differences in near surface ice content the ground temperature profiles are nonlinear with near surface temperature perturbations considered to be related to a recent warming of the ground surface at the one nonpermafrost site the insulating influence of winter snow cover is more pronounced a one dimensional heat conduction model was calibrated using ground temperature measurements and driven by surface temperature time series the model results reproduce the measured ground temperature pattern well this simplified model simulating the results of possible future climate scenarios indicates that permafrost degradation will occur at these sites within decades depending on climate scenarios chosen and subsurface ice content

sources and preservation of organic matter in plum island salt marsh sediments ma usa long chain n alkanes and stable carbon isotope compositions elemental toc tn c n and stable carbon isotopic delta 13 c compositions and n alkane nc 16 38 concentrations were measured for spartina alterniflora a c 4 marsh grass typha latifolia a c 3 marsh grass and three sediment cores collected from middle and upper estuarine sites from the plum island salt marshes our results indicated that the organic matter preserved in the sediments was highly affected by the marsh plants that dominated the sampling sites delta 13 c values of organic matter preserved in the upper fresh water site sediment were more negative 23 0 0 3 as affected by the c 3 plants than the values of organic matter preserved in the sediments of middle 18 9 0 8 and mud flat sites 19 4 0 1 as influenced mainly by the c4 marsh plants the distribution of n alkanes measured in all sediments showed similar patterns as those determined in the marsh grasses s alterniflora and t latifolia and nc 21 to nc 33 long chain n alkanes were the major compounds determined in all sediment samples the strong odd to even carbon numbered n alkane predominance was found in all three sediments and nc 29 was the most abundant homologue in all samples measured both delta 13 c compositions of organic matter and n alkane distributions in these sediments indicate that the marsh plants could contribute significant amount of organic matter preserved in plum island salt marsh sediments this suggests that salt marshes play an important role in the cycling of nutrients and organic carbon in the estuary and adjacent coastal waters c 2003 elsevier ltd all rights reserved

application of stable carbon isotopes for reconstructing salt marsh floral zones and relative sea level new jersey usa we investigated use of 13c in bulk organic sediment to define the botanical origin of samples preserved in coastal sediment as a means to reconstruct relative sea level in new jersey usa modern transects at three sites demonstrated that low and high salt marsh floral zones dominated by c4 species spartina alterniflora and spartina patens were associated with sediment 13c values between 18 9 and 15 8 and occurred from mean tide level mtl to mean higher high water mhhw brackish transitional settings vegetated by phragmites australis with iva fructescens and typha sp c3 species and freshwater upland samples c3 species were characterized by bulk sediment 13c values of 27 0 to 22 0 and existed above mhhw parallel transects at one site suggested that intra site variability was not discernible the utility of 13c values for reconstructing relative sea level in new jersey is limited by an inability to differentiate between brackish sediments related to sea level and freshwater upland samples to facilitate this distinction in a 4 4 m core we used a multi proxy approach 13c values with presence or absence of agglutinated foraminifera to recognize indicative meanings for four sample types sediment with 13c values greater than 18 9 was derived from a vegetated salt marsh and formed between mtl and mhhw sediment with 13c values less than 22 0 and containing agglutinated foraminifera formed in a brackish transitional zone between mhhw and highest astronomical tide hat this is the narrowest elevational range of the four sample types and most precise sea level indicator sediment with 13c values less than 22 0 and lacking foraminifera can only constrain the upper bound of former sea level samples with intermediate values 22 0 to 18 9 formed between mtl and hat using these indicative meanings and radiocarbon dates we suggest that a transition from brackish to salt marsh 13c values recorded in the core took approximately 350 years from 1800 to 1450 cal a bp

a multi method field experiment to determine local groundwater flow in a glacier forefield we implemented multiple independent field techniques to determine the direction and velocity of groundwater flow at a specific stream reach in a glacier forefield time lapse experiments were conducted using two electrical resistivity tomography ert lines installed in a cross pattern a circular array of groundwater tubes was also installed to monitor groundwater flow via discrete salt injections both inter borehole and ert results confirmed this stream section as a losing reach and enabled quantification of the flow direction both techniques yielded advection velocities varying between 5 7 and 21 8 m day estimates of groundwater flow direction and velocity indicated that groundwater infiltrates from the stream nearby and not from the adjacent lateral moraine groundwater age estimated from radon concentration measurements supported this hypothesis despite uncertainties inherent to each of the methods deployed the combination of multiple field techniques allowed drawing consistent conclusions about local groundwater flow we thus regard our multi method approach as a reliable way to characterize the two dimensional groundwater flow at sites where more invasive groundwater investigation techniques are difficult to carry out and local heterogeneities can make single measurements unreliable copyright 2014 john wiley sons ltd

new approaches to the characterization of clay bearing densely jointed and weak rock masses various classification systems for rock masses have been used in engineering applications however these systems are not sufficient to classify clay bearing densely jointed and weak rock masses among the factors that cause this deficiency are the damaging effect of water on rocks which has not sufficiently been described in the existing classification systems this factor was allowed for by the inclusion of new parameters in the modified rock mass classification m rmr system developed in recent years the aim of this study is to make contributions to the m rmr classification system and to overcome the difficulties encountered in the classification procedure for this purpose data were collected for rock mass classification from 13 clay bearing densely jointed and weak rock masses in four regions yatagan soma baskoyak and guvenc located in the western and middle parts of turkey the discontinuity data were collected by the line survey technique and evaluated by statistical methods in addition to the uniaxial compressive strength test for the determination of the rating for intact rock strength the block punch index test was also considered as an alternative parameter and the slake durability index test and x ray diffraction analyses were performed on 104 samples collected from the studied rock masses further the weathering coefficient wc determined by schmidt hammer was considered as an alternative parameter for the determination of the rating for joint weathering as a result of statistical evaluation of data obtained from the field and laboratory studies it has been concluded that the block punch index bpi could be used as an alternative parameter for the determination of the rating for intact rock strength in the m rmr classification system it was also found that the slake durability index id determined at the fourth cycle would be a more effective approach than the second cycle index that has previously been used to express the unfavourable effect of water on the rock mass the propositions made in the present work to contribute to the m rmr system were tested in back analyses of three previously failed slopes and the performance of the system with the newly introduced improvements appeared to be satisfactory

rock glaciers and protalus landforms analogous forms and ice sources on earth and mars 1 the basic features and terminology of terrestrial rock glaciers are reviewed together with associated forms termed protalus lobes and protalus ramparts two basic models of rock glacier formation and flow invoke either the creep of ice derived from permafrost or glacial former glacial activity a third possible mechanism invokes landslide emplacement observations on terrestrial rock glaciers and similar forms suggest that the ice component can be produced via ground ice or from a glacier system finite element modeling of simple slope systems containing 1 a continuous ice layer buried by debris and 2 a mixture of ice and rigid blocks can both show creep but with very low rates especially at low temperatures possible martian examples of rock glacier and protalus lobe features are identified from candor chasma by wide angle mars orbiter camera moc imagery although the topography does not allow unambiguous interpretation some possible ways in which moc and mars orbiter laser altimeter mola and other mars orbiter data could help future interpretation of rock glaciers related protalus landforms and ice presence are discussed

origin abundance and storage of organic carbon and sulphur in the holocene humber estuary emphasizing human impact on storage changes an organic carbon corg and sulphur s storage inventory for holocene sediments in the humber estuary is established sources of organic matter and their variation over time are identified and with chronological control the importance of estuarine sediments as corg and s stores is demonstrated humber holocene sediments are grouped into seven widespread environmental facies with statistically significant geochemical data sets 1 oak hazel fenwood ohf 2 alder carr ac appearing as peats in core 3 river channel muds or sands rcm s 4 high saltmarsh hsm 5 low saltmarsh lsm 6 intertidal mudflat itmf and 7 a sandy facies s carbon nitrogen and sulphur cns abundances show that these facies have diagnostic geochemical signatures and 13c values for bulk organic matter exhibit a range of average values 28 terrestrial peats 27 hsm and 24 5 itmf reflecting the up core transition from terrestrial peats through saltmarshes to more open marine mudflat environments as regional sea level rose chronology and average sedimentation rates are partly constrained by radiocarbon dates palaeomagnetic techniques helped define discrete sediment packages and discontinuities time gaps although the humber holocene sediment record is not continuous long term sedimentation rates about 1 mm a 1 show that sediment accretion kept pace with regional sea level rise between 6 and 2 cal ka bp this sedimentation rate combined with core evidence to allow a geographic reconstruction of the palaeo humber 3 2cal ka bp is used to calculate storage values for corg and s in the various environments of the palaeo humber comparison of the corg and s sedimentation and storage terms for the palaeo humber with modern values highlights the impacts of reclamation and commercial urban development in the estuary in the last 300 years ohf and ac peats which were the largest corg and s stores in the palaeo estuary are now absent reclaimed while saltmarshes are no longer widespread conservative calculations show a net decrease in corg deposition from about 3 2 105 tonne in the palaeo estuary to no more than 2 5 103 tonne today a 99 reduction in potential corg storage capacity the total modern yearly s deposition is approximately 2 of its value 2ka ago removal of saltmarsh and associated brackish freshwater wetland suggests that suspended sediment and associated corg and s are currently bypassing former holocene storage areas and may be impacting north sea biogeochemical cycling

postglacial sea level rise and sedimentary response in the guadiana estuary portugal spain border abstract the study of sedimentological features foraminifera and molluscan fauna in samples recovered from four rotary boreholes permitted after 14 c dating the first assessment of the post glacial transgression in guadiana river estuary the holocene sequence is underlain by coarse sediments from delta fan enclosing continental swamp deposits dated 16 980 year bp the holocene sedimentary sequence was deposited either directly on this delta fan gravels or on top of fluvial sands deposited probably between 11 000 and 10 000 yr bp an accelerated phase of the estuary infilling by clayey sediments containing the salt marsh foraminifer trochammina began ca 9800 year bp when sea level was about 39 m below present between 7500 and 7000 year bp the central part of the estuary started to accommodate coarser sediments partially introduced from the continental shelf the first phase of holocene sea level rise at a rate of 0 85 m century terminated ca 6500 year bp since then lagoonal sediments in the vicinity of the estuary have been enclosed behind sand spits and predominantly sandy sedimentation was initiated within the estuary after a second phase of slower rise at the rate of 0 3 m century which lasted until ca 5000 year bp the sea approached the present level

practical techniques for 3d resistivity surveys and data inversion1 techniques to reduce the time needed to carry out 3d resistivity surveys with a moderate number 25 to 100 of electrodes and the computing time required to interpret the data have been developed the electrodes in a 3d survey are normally arranged in a square grid and the pole pole array is used to make the potential measurements the number of measurements required can be reduced to about one third of the maximum possible number without seriously degrading the resolution of the resulting inversion model by making measurements along the horizontal vertical and 45 diagonal rows of electrodes passing through the current electrode the smoothness constrained least squares inversion method is used for the data interpretation the computing time required by this technique can be greatly reduced by using a homogeneous half space as the starting model so that the jacobian matrix of partial derivatives can be calculated analytically a quasi newton updating method is then used to estimate the partial derivatives for subsequent iterations this inversion technique has been tested on synthetic and field data where a satisfactory model is obtained using a modest amount of computer time on an 80486dx2 66 microcomputer it takes about 20 minutes to invert the data from a 7 by 7 electrode survey grid using the techniques described below 3d resistivity surveys and data inversion can be carried out using commercially available field equipment and an inexpensive microcomputer

using dc resistivity tomography to detect and characterize mountain permafrost direct current dc resistivity tomography has been applied to different mountain permafrost regions despite problems with the very high resistivities of the frozen material plausible results were obtained inversions with synthetic data revealed that an appropriate choice of regularization constraints was important and that a joint analysis of several tomograms computed with different constraints was required to judge the reliability of individual features the theoretical results were verified with three field experiments conducted in the swiss and the italian alps at the first site near zermatt switzerland the location and the approximate lateral and vertical extent of an ice core within a moraine could be delineated on the murtel rock glacier eastern swiss alps a steeply dipping boundary at its frontal part was observed and extremely high resistivities of several m indicated a high ice content the base of the rock glacier remained unresolved by the dc resistivity measurements but it could be constrained with transient em soundings on another rock glacier near the stelvio pass eastern italian alps dc resistivity tomography allowed delineation of the rock glacier base and the only moderately high resistivities within the rock glacier body indicated that the ice content must be lower compared with the murtel rock glacier

reconstructing holocene sea level using salt marsh foraminifera and transfer functions lessons from new jersey usa we present an expanded training set of salt marsh foraminifera for reconstructing holocene relative sea level change from 12 sites in new jersey that represent varied physiographic environments seven groups of foraminifera are recognized including four high or transitional marsh assemblages and a low salinity assemblage a weighted averaging transfer function trained on this dataset was applied to a dated core from barnegat bay to reconstruct sea level with uncertainties of 14 of tidal range we evaluate the transfer function using seven tests 1 leave one site out cross validation suggests that training sets of salt marsh foraminifera are robust to spatial autocorrelation caused by sampling along transects 2 segment wise analysis shows that the transfer function performs best at densely sampled elevations and overall estimates of model performance are over optimistic 3 dissimilarity and 4 non metric multi dimensional scaling evaluated the analogy between modern and core samples the closest modern analogues for core samples were drawn from six sites demonstrating the necessity of a multi site training set 5 goodness of fit statistics assessed the validity of reconstructions 6 the transfer function failed a test of significance because of the unusual properties of some cores selected for sea level reconstruction 7 agreement between reconstructed sea level and tide gauge measurements demonstrates the transfer function s utility copyright 2013 john wiley sons ltd

geophysical mapping of ground ice using a combination of capacitive coupled resistivity and ground penetrating radar northwest territories canada 1 the nature and distribution of ground ice are two of the most unpredictable geological variables in near surface deposits characterized by continuous permafrost subsurface information about ground ice distribution and structure can be obtained either by invasive and environmentally destructive techniques like drilling and excavation or by noninvasive low impact geophysical methods in this study coordinated measurements by two complementary geophysical tools capacitive coupled resistivity ccr and ground penetrating radar gpr were used to map ground ice in a variety of locations in the mackenzie delta region of the western canadian arctic both ccr and gpr systems are highly portable especially on snow covered surfaces and very effective in collecting data under winter conditions when cold ground temperatures ensure that nearly all liquid water is frozen and signal penetration is enhanced ccr and gpr readily detect stratigraphic differences including the contacts between massive ice deposits and enclosing sediments gpr is widely used in permafrost research but ccr has been used in only a few studies this is the first study to combine results from both systems by collecting complementary data sets along coincident transects we demonstrate that when combined these data increase the quality and interpretation of subsurface information beyond what could be determined by either of the instruments alone the complementary nature of these two geophysical tools facilitated the detection and mapping of massive ground ice ice rich sediments ice wedges thermokarst and basic stratigraphic relationships this study breaks new ground by documenting the benefits of using these techniques together in permafrost investigations

on the sedimentological origin of down core variations of bulk sedimentary nitrogen isotope ratios 1 the bulk sedimentary nitrogen isotopic composition of two cores from nearby sites on the northern slope of the south china sea site 17940 and ocean drilling program odp site 1144 differs by up to 2 during the last glacial period given their close proximity both core sites are located in the same biogeographic zone and nutrient regime and it is thus unlikely that this offset is due to a true gradient in surface ocean conditions in an attempt to resolve this offset we have investigated the possible effects of two sedimentological parameters that can affect bulk sedimentary 15n namely the variable contribution of inorganic n to bulk n in the sediment and the grain size dependence of bulk 15n we find that neither effect singly or in combination is sufficient to explain the significant 15n offset between the two down core records by elimination the most likely explanation for the observed discrepancy is a different origin of both the organic and inorganic nitrogen at each site this study adds to the growing body of evidence highlighting the complex nature and origin of the sedimentary components in sediment drifts such as odp site 1144

bedrock detection using 2d electrical resistivity imaging along the peikang river central taiwan article i nfo we use the two dimensional 2d electrical resistivity imaging eri method to detect the contact between sediment and bedrock in a modern fluvial system we performed eight 2d electrical resistivity surveys along the peikang river in kuohsing area central taiwan with a pole pole array of 1 m electrode spacing to produce a spatial resolution of about 1 m the resistivity data were inverted into subsurface electrical structures using the least squares inversion techniques then the contact between the bedrock and sediment was found by using an image processing technique called laplacian edge detection led which represents an objective approach in interpreting various geophysical images numerical modeling demonstrates that isoresistivity lines are not in good agreement with the hypothetical interfaces between the bedrock and sediment but the zero lines of the laplacian operation are strikingly accurate our results indicate a well defined boundary in the resistivity structure that can be used to estimate the quantity of sediments covering bedrock thus highlighting the utility of this technique in studies of landscape evolution sediment transport and sediment budgets

the palaeoenvironments of coastal lagoons in the southern baltic sea i the application of sedimentary corg n ratios as source indicators of organic matter abstract c n ratios of organic matter sources in coastal lagoons and their drainage areas in the southern baltic sea region are investigated to determine the origin of organic matter i e terrigenous or marine in the sediments of the lagoons these ratios are compared with 13c values in the area terrestrial plants in the study area show c n ratios between 10 and 85 whereas aquatic macrophytes have values in the range of 6 to 44 peat and shore vegetation have c n ratios between 15 and 16 and plankton shows values close to 6 in conjunction with 13c values the c n ratios in the sediments allow the reconstruction of the holocene palaeoenvironments and palaeoecology in the lagoons oder estuary and greifswalder bodden distinct stages in the development of the water bodies resulting from sea level changes in the region can be derived post glacial lake stages with sandy sedimentation lacustrine phases with high autochthonous productivity terrestrial stages with peat formation sedimentation as a result of marine transgression and brackish sedimentation after the formation of sand spits and barrier islands the application of corg ntot ratios instead of corg norg does not have any significant influence on the interpretation of the data and may thus be used in the coastal sediments of the southern baltic sea after having applied the test procedures presented in this study

holocene relative sea level movements along the north norfolk coast uk abstract relative changes in holocene sea level are reconstructed from foraminiferal assemblages in seven cores recovered from the intertidal zone of north norfolk eastern england a total of 33 radiocarbon and infra red stimulated luminescence dates provide a detailed chronological framework for these changes a transfer function approach developed from modern uk foraminiferal datasets establishes a series of 21 new sea level index points for this coastline which are combined with 18 existing index points and a further number of limiting values errors associated with changing tidal ranges through the holocene are reduced by adopting recently developed tidal models for this period this new approach allows the use of foraminiferal assemblages to be extended from the upper saltmarsh environment traditionally used for sea level studies to lower elevations in the tidal frame and include clastic detrital sediments the results confirm the previously observed trend of continuously rising sea levels in this area during the last 10 000 years which is consistent with a glacial isostatic adjustment model relative sea level rsl rises from an observed minimum of approximately 13 50 m od at about 7500 cal bp to approximately 4 0 m at about 5300 cal bp which equates to a mean rise of c 4 3 mm yr 1 subsequently rsl rose gradually to present levels although there is evidence that a minor reverse in this trend occurred between 4000 and 2000 cal bp when sea level fell by about 1 m to c 3 5 m the rate of land subsidence for north norfolk is 0 54 0 03 mm yr 1 inverse of late holocene sea level rise

using foraminiferal transfer functions to produce high resolution sea level records from salt marsh deposits maine usa quantitative analyses of foraminiferal distributions along the coast of maine are used to provide transfer functions for reconstruction of sea level changes from fossil foraminiferal assemblages the indicative meaning of fossil assemblages is most accurately predicted by a training set that incorporates live and dead foraminifera and that uses flooding duration not height as the predictor variable sea level records are produced for two sites in maine usa a middle marsh site in scarboro and a high marsh site in machiasport these records offer temporal resolution of five to seven years and span the past century they are compared with instrumental data from a nearby tidal station to assess their accuracy strong correlations are found between the geologic records and the observational data in particular between the foraminiferal record from machiasport and the tide gauge record from eastport r2 0 83 p 0 005 thus a foraminifera based transfer function approach offers great potential for reso

application of refraction seismics in alpine permafrost studies a review abstract refraction seismics is a common geophysical application to investigate permafrost in alpine studies this study reviews the physical basis of the use of refractions seismics and introduces the history of its application in alpine environments seismic properties are influenced by rock or soil properties and fluid or ice effects in laboratory measurements these influences are determined and linked to mechanical properties or used for calibration of field studies in field conditions supplementary environmental factors influence the seismic properties of landforms in this paper laboratory studies of rocks from different lithologies and with different properties as well as case studies on rock glaciers moraines talus slopes and debris covered slopes are collected and influencing factors quantitatively analyzed the data demonstrate how lithology porosity and anisotropy influence p wave velocity environmental factors result in a high variation of p wave velocities in landforms however p wave velocities enable the differentiation of active layer and permafrost in rock glaciers and moraines in talus slopes and debris covered slopes p wave velocity contrasts between active layer and permafrost layer might be insufficient and require the application of additional methods for a final differentiation

a new holocene relative sea level curve for western brittany france insights on isostatic dynamics along the atlantic coasts of north western europe abstract this study presents new relative sea level rsl data that were obtained in the finistere region western tip of brittany france and the implications those data have for the understanding of the isostatic dynamics across north western europe and more specifically along the atlantic and channel coasts new stratigraphic sequences were obtained and analyzed to derive 24 new sea level index points in which 6 are basal these new data considerably increase the knowledge we have of the rsl evolution along the coasts of western brittany since the last 8 kyr b p from this new dataset rsl was estimated to rise continuously over the last 8 kyr with a major inflection at ca 6 kyr cal bp our results show large vertical discrepancies between the rsl records of brittany and south western uk with the latter plotting several meters below the new data from this comparison we suggest that the two regions underwent a very different pattern and or amplitude of subsidence during the last 8 kyr which has implications for the spatial and temporal pattern of the peripheral bulge of the european ice sheets we compared our data against predictions from glacio isostatic adjustment models gia models there are large misfits between rsl observations and the predictions of the global ice 5g vm2a peltier 2004 glac1 b tarasov and peltier 2002 tarasov et al 2012 briggs et al 2014 and regional uk models biis bradley et al 2009 bradley et al 2011 kuchar kuchar et al 2012 which can t be resolved through significant changes to the deglaciation history and size of the british irish ice sheet paleo tidal modelling corrections indicate regional changes in the tidal ranges played a negligible role in the data model misfits hence we propose that the misfits are due to some combination of i unaccounted mass loss of far field ice sheets antarctic ice sheet or laurentide ice sheet ii unresolved differences in the deglaciation history and size of the fennoscandian ice sheet or more likely iii significant lateral variations in the earth s structure across the english channel

2 d and 3 d resistivity image reconstruction using crosshole data theoretical changes in the distribution of electrical potential near subsurface resistivity anomalies have been studied using two resistivity models the results suggest that the greatest response from such anomalies can be observed with buried electrodes and that the resistivity model of a volume between boreholes can be accurately reconstructed by using crosshole data the distributive properties of crosshole electrical potential data obtained by the pole pole array method have also been examined using the calculated partial derivative of the observed apparent resistivity with respect to a small cell within a given volume the results show that for optimum two dimensional 2 d and three dimensional 3 d target imaging in line data and crossline data should be combined and an area outside the zone of exploration should be included in the analysis in this paper the 2 d and 3 d resistivity images presented are reconstructed from crosshole data by the combination of two inversion algorithms the first algorithm uses the alpha center method for forward modeling and reconstructs a resistivity model by a nonlinear least squares inversion alpha centers ex press a continuously varying resistivity model and the distribution of the electrical potential from the model can be calculated quickly an initial general model is determined by the resistivity backprojection technique rbpt prior to the first inversion step the second process uses finite elements and a linear inversion algorithm to improve the resolution of the resistivity model created by the first step simple 2 d and 3 d numerical models are discussed to illustrate the inversion method used in processing data from several field studies are also presented to demonstrate the capabilities of using crosshole resistivity exploration techniques the numerical experiments show that by using the combined reconstruction algorithm thin conductive layers can be imaged with good resolution for 2 d and 3 d cases the integration of finite element computations is shown to improve the image obtained by the alpha center inversion process for 3 d applications the first field test uses horizontal galleries to evaluate complex 2 d features of a zinc mine the second field test illustrates the use of three boreholes at a dam site to investigate base rock features and define the distribution of an altered zone in three dimensions

topographic migration of georadar data implications for acquisition and processing application of conventional elevation static corrections and migration to wavefield data recorded on irregular surfaces may result in poor reconstructions of complex subsurface features particulary poor images may be obtained at locations where the depths to target structures are comparable to undulations in the surface topography for example topographic relief of only 1 2 m may be important for the processing of georadar data we describe an algorithm that allows georadar data to be migrated directly from gently to highly irregular acquisition surfaces when applied to a variety of complicated synthetic data sets topographically migrated images are observed to be markedly superior to those produced by two standard processing schemes extensive tests demonstrate that topographic migration should be considered in regions characterized by surface gradients 10 i e dips 6 for effective topographic migration lateral and vertical coordinates of the georadar antennas should be determined to better

shallow seismic surveying of an alpine rock glacier to map the internal structure and lower boundary of an alpine rock glacier we recorded three shallow seismic profiles and drilled four 70 m deep holes through to the underlying bedrock although analysis of the seismic data using standard reflection processing schemes did not yield conclusive results because of the dominantly low frequency returned signals and the presence of strong source generated noise tomographic inversions of first arrival times were successful in mapping several critical subsurface features a thin low velocity layer of loose boulders air voids and snow was found to extend across the entire surveyed area below this layer two distinct velocity regimes superimposed on a general increase in velocity with depth were identified a broad regime of high velocities was interpreted to contain boulders with numerous ice filled voids whereas an adjacent regime of relatively low velocities was explained in terms of boulders with air and water filled voids this latter region of degrad

hazardous elements in soil and coal from the oltu coal mine district turkey abstract coal mining activities represent significant environmental concerns due to their potential influence on soils of the surrounding areas this study was carried out to characterize the soil of oltu coal mine erzurum with regard to potential pollutants associated with coal mining four different sites were selected for this study leaching potential of hazardous elements in coal samples was investigated samples were taken from each site to determine the hazardous elements in mine soils and the results were evaluated concentrations of hazardous elements in coal samples were found to be below world coal average range except cr and ni although cr ni and hg concentrations in soil samples were above the limit values only cr contamination of the soil was related to coal mine as observed in the results of the leachate derived from coal samples

pebbly versus bouldery rock glaciers morphology structure and processes abstract differences in rockwall geology cause two types of rock glaciers a bouldery rock glacier having the active layer composed of matrix free boulders derived from crystalline rocks and massive limestone and a pebbly rock glacier consisting of matrix supported debris derived from less resistant shale and platy limestone such material composition controls transport processes responsible for the shape size and internal structure of the two types of rock glaciers this paper compares the major processes controlling the morphology and structure of the two types in the swiss alps based on mapping description of geological and morphological characteristics direct observation of stratigraphy and geophysical soundings of internal structure in the swiss alps pebbly rock glaciers are distinguished from bouldery rock glaciers by the clast size of 15 20 cm in the mean b axis diameter the former are fed by small scale rockfalls debris flows and solifluction whereas the latter mainly originate from large rockfalls pebbly rock glaciers are generally smaller 100 k m in bouldery rock glaciers appears to originate from snow banks buried with deposits of large rockfalls from the large source rockwall

locating and characterising groundwater storage areas within an alpine watershed using time lapse gravity gpr and seismic refraction methods unconsolidated sediments in alpine watersheds can store glacier melt and snowmelt as groundwater which helps sustain flow in mountain rivers during dry periods however the amount and distribution of groundwater storage in rugged alpine terrain is not well understood hindering our ability to predict the rate and timing of groundwater discharge into alpine streams we show how non invasive time lapse microgravity surveys can be used to gauge the spatial distribution of groundwater storage changes within a large ca 1500 1000 m moraine talus field of the lake o hara alpine watershed of the canadian rockies additional ground penetrating radar gpr and seismic refraction surveys provide complementary information on subsurface bedrock topography and reveal the location of a major northwest southeast trending depression that likely controls groundwater flow to an alpine lake contiguous with the moraine talus field repeat relative gravity measurements made on a network of 80 gravity stations over and around the moraine talus field during the summers of 2009 and 2010 reveal gravity changes of up to 25 gal although the small gravity changes associated with groundwater flowing out of storage areas are noisy significant changes are evident on the eastern side of the moraine talus field her majesty the queen in right of canada 2012

geochemistry of holocene salt marsh and tidal flat sediments on a barrier island in the southern north sea langeoog north west germany abstract the barrier islands of the southern north sea were formed during the holocenesea level rise these islands form part of a highly dynamic environment whoseevolution continues today subjected to sea level changes tides and stormevents the sedimentary record re ects processes occurring under varyingenergy conditions this article presents geochemical mineralogical anddiatom investigations carried out in the salt marsh of the east frisian barrierisland of langeoog which is re exposed to a rising sea level due tode embankment the major aim of this study is to improve the knowledge ofthe sedimentological and geochemical development of these deposits underthe in uence of sea level rise with a special focus on the geochemistry anddistribution of heavy mineral associated elements correlation diagramsbetween feo tio 2 and mno as well as ternary plots al 2 o 3 sio 2 zr ortio 2 clearly indicate the variable appearance of heavy minerals in differentlithological facies comprising marsh soil mixed and sand at and relocatedbeach sands a dominating abundance of ilmenite followed by zircon garnetsand some other heavy minerals is evidenced by scanning electron microscope energy dispersive x ray measurements the data presented here suggests thatthese geochemical proxies are useful tools for characterizing depositionalenergy conditions increasing depositional energy is evident for the lithologicalunits in the following order marsh soil mixed at sand at and relocatedbeach sand the energetic conditions during sediment deposition as well asthe sedimentary history are con rmed by diatom analyses as an additionalindependent indicator depending on source rock composition thegeochemical parameters used in this study may also help to investigatedepositional energy regimes of other siliciclastic sedimentary systems keywords depositional energy diatoms heavy minerals inorganicgeochemistry north sea salt marsh tidal at introductionthe depositional history of the barrier islands andadjacent tidal at system of the southern northsea coast was directly related to climate changesduring the holocene sea level rise the lasttransgressive cycle started in the weichselianlate glacial and continues today as evidenced bysedimentology 2012 59 337 355

three dimensional electrical conductivity and induced polarization tomography of a rock glacier three dimensional electrical resistivity and induced polarization data were collected on an unstable alpine rock glacier in val thorens vanoise massif france in addition to these field data we also performed induced polarization measurements during freeze and thaw using a soil sample and the poorly mineralized water both from this site in the tomograms the electrical conductivity and the normalized chargeability show very distinctly the presence of the rock ice mixture the chargeability itself is however quite constant over the entire investigated area with the exception of a small area associated with the presence of carboniferous rocks rich in graphite the background chargeability is close to the dimensionless number r 8x10 2 which is consistent with the prediction of the dynamic stern layer model for the polarization of porous media the theory implies that this dimensionless number r is independent on saturation and temperature in agreement with field observations a main implication of this observation is that the classical archie s law cannot be applied to describe the electrical conductivity in this type of environments with poorly mineralized pore water surface conductivity dominates the measured conductivity of the materials implying in turn that the electrical conductivity is related to both the water content and cation exchange capacity of the material we propose new equations for both the electric conductivity and the normalized chargeability in this type of environments plain language summary induced polarization is a geophysical method looking at imaging the 3d distribution of properties related to the ability of rocks to store reversibly electrical charges under the application of a primary electrical field this method has never been applied to rock glaciers a field application and a laboratory experiment demonstrate the usefulness of this method to characterize alpine rock glaciers and point up some shortcomings in the interpretation of electrical conductivity tomography done by previous authors in this type of environments

internal structure and conditions of permafrost mounds at umiujaq in nunavik canada inferred from field investigation and electrical resistivity tomography a systematic approach was used for the interpretation of the electrical resistivity tomography carried out on two permafrost mounds at umiujaq in nunavik canada to assess their internal structure and conditions prior information under the form of a geocryologic model of the permafrost mounds was integrated in the inversion of the pseudo section of apparent electrical resistivity the geocryologic model was developed from the synthesis of previous field investigations including shallow and deep sampling temperature and electrical resistivity logging and cone penetration tests performed in the permafrost mounds values of electrical resistivity were ascribed to the different layers making of the geocryologic model to define a synthetic resistivity model of the permafrost mounds used as a reference model to constrain the inversion the constrained resistivity model clearly show the presence of ice rich cores in the permafrost mounds underscored by high resistivity values in excess of 30 000 m while t

holocene relative sea level changes in the inner solway firth abstract bio and lithostratigraphic data from four sites from the inner solway firth allow an accurate reconstruction of holocene rsl changes in the estuary radiocarbon assays give eleven new sea level index points providing a total of 24 reliable index points for the inner solway firth these data show a consistent pattern of rapid rsl rise during the early holocene culminating in a mid holocene sea level maximum then a gradual fall to the present day level detailed analysis of this dataset quantifies for the first time differential crustal movement between the north and south shores of the solway firth these data are used to test the accuracy of quantitative isostatic rebound models of lambeck and peltier and show there is good general agreement between the data and the models especially during the early holocene the models predict the mid holocene sea level peak slightly later than shown by the data c 500 and c 2000 yr this may be partly due to lack of resolution in the models and for the south solway the maximum altitude at this peak is 1 and 2 5 m too high in the two models the data are also compared to the isobase models of the main postglacial shoreline showing slight diachroneity between the north and south shore but otherwise general agreement with the postulated age and indicating that the altitude of this feature is 1 3 m higher than suggested by the models

the internal structure of rock glaciers and recently deglaciated slopes as revealed by geoelectrical tomography insights on permafrost and recent glacial evolution in the central and western alps italy france abstract ground ice of permafrost origin and sedimentary ice of glacial origin can coexist in locations where rock glaciers and glaciers interacted as well as in glacigenic sediments abandoned by a retreating glacier and subsequently exposed again to atmospheric cooling some of these geomorphological settings in the central foscagno rock glacier and western alps marinet and schiantala rock glaciers schiantala debris covered glacier maledia glacier were explored by means of geoelectrical tomographies the aim was that of inferring the presence of ice and cryologically interpreting electrical stratigraphies in order to test whether or not the internal structure of these landforms can be used for the reconstruction of recent permafrost and glacier evolution geomorphological data assisted these reconstructions and available borehole stratigraphies were used to calibrate the resistivities along with the ice debris mixture massive ice has also been found as lenses both at the apex and the front of the studied rock glaciers these lenses of sedimentary origin are thought to be transferred from a glacier snout to sectors of rock glacier and eventually embedded into the permafrost creep the scarcity of frozen debris in the mid upper part of the rock glaciers as revealed by low resistivity values can be due to the disruptive effect of the over riding glacier over the permafrost the near surface sedimentary ice masses detected along the slopes of the studied glacial cirques are interpreted as or debris covered terminations of the glaciers still visible upward or as fragments of it detached by the main bodies these ice masses are locally associated to medium high resistive sediments consistent with permafrost occurrence this indicates that the non glacial environment established during the deglaciation allowed the onset of frozen sediments formation overall the results indicate that internal structure of rock glaciers and recent deglaciated slopes can store the different climate related episodes occurred in a specific area such as those linked to the shifting between glacial to criotic condition and vice versa

flandrian sea level changes in the fenland ii tendencies of sea level movement altitudinal changes and local and regional factors stratigraphic micropalaeontologic and radiocarbon data show that since c 6500 bp the fenland has been influenced by 7 periods of positive sea level tendencies and by 6 periods of negative sea level tendencies despite the numerous problems associated with the reconstruction of past altitudes of sea level the periods of positive sea level tendencies were clearly characterised by a rise in sea level the development of transgressive overlaps and a landward movement of the coastline the periods of negative sea level tendencies were characterised by the development of regressive overlaps a seaward movement of the coastline and a reduced or negative rate of sea level rise the various altitudinal errors do not permit the incontrovertible distinction of periods of falling sea levels all changes within the fenland were not synchronous and local factors influenced the exact nature of each sea level indicator dominant regional and local factors have been identified for different areas and different time periods the chronological and spatial characteristics of the sequences within the fenland are best explained by a palaeocoastline without supratidal barriers controlling sedimentation the data indicate an average crustal subsidence in the fenland of 0 9m 1000 years since c 6500 bp and the pattern of positive and negative tendencies of sea level movement is also seen in the chronologies for north west england and north east scotland

proxy records of holocene storm events in coastal barrier systems storm wave induced markers abstract extreme storm events in the coastal zone are one of the main forcing agents of short term coastal system behavior as such storms represent a major threat to human activities concentrated along the coasts worldwide in order to better understand the frequency of extreme events like storms climate science must rely on longer time records than the century scale records of instrumental weather data proxy records of storm wave or storm wind induced activity in coastal barrier systems deposits have been widely used worldwide in recent years to document past storm events during the last millennia this review provides a detailed state of the art compilation of the proxies available from coastal barrier systems to reconstruct holocene storm chronologies paleotempestology the present paper aims i to describe the erosional and depositional processes caused by storm wave action in barrier and back barrier systems i e beach ridges storm scarps and washover deposits ii to understand how storm records can be extracted from barrier and back barrier sedimentary bodies using stratigraphical sedimentological micro paleontological and geochemical proxies and iii to show how to obtain chronological control on past storm events recorded in the sedimentary successions the challenges that paleotempestology studies still face in the reconstruction of representative and reliable storm chronologies using these various proxies are discussed and future research prospects are outlined

a rock glacier pond system nw italian alps soil and sediment properties geochemistry and trace metal bioavailability abstract rock glacier sediment transfer and ice melting can impact surface waters located downstream however there is a lack of knowledge on the influence of rock glacier dynamics on the geochemical hydrochemical and ecological characteristics of adjacent impounded surface waters in the col d olen area long term ecological research site nw italian alps an intact rock glacier terminates into a pond and solute enriched waters originating from the rock glacier flow into the pond through a subsurface hydrological window in this study we performed geophysical and ground surface temperature measurements moreover we sampled soils and sediments in different compartments of the investigated rock glacier pond system and we further sampled benthic invertebrates in the pond cold ground thermal regime ground ice presence and coarse debris cover on the rock glacier together with its lithology serpentinites influence the rock glacier geochemistry and ecology with respect to surrounding areas pond geochemistry is affected by transfer of trace metal enriched fine grained debris and meltwaters from the rock glacier enhanced bioavailability of serpentinite associated trace metals was proved with concentrations of ni and cr in benthic invertebrates up to 384 and 110 mg kg 1 d w respectively potentially exerting toxic effects on pond biota the advancing movement of the rock glacier not only has delivered sediments to the pond but it has progressively filled the valley depression where the pond is located creating a dam that could have modified the level of impounded water this process likely constituted a sediment trap in which serpentinitic rock glacier sediments could be deposited at the pond bottom with related geochemical and ecological implications this study illustrates the importance of rock glaciers in influencing the characteristics of downstream freshwater bodies and highlights the need to improve our knowledge about climate change related impacts of rock glacier dynamics on alpine headwaters