the current state of knowledge about shatter cones introduction to the special issue shatter cones are a fracture phenomenon that is exclusively associated with shock metamorphism and has also been produced in the laboratory in several shock experiments the occurrence of shatter cones is the only accepted meso to macroscopic recognition criterion for impact structures shatter cones exhibit a number of geometric characteristics orientation apical angles striation angles sizes that can be best described as varied from case to case possible links between geometric properties with impact or crater parameters have remained controversial and the lack of understanding of the mechanism of formation of shatter cones does not offer a physical framework to discuss or understand them a database of shatter cone occurrences has been produced for this introduction paper to the special issue of meteoritics and planetary science on shatter cones distribution of shatter cones with respect to crater size and lithology suggests that shatter cones do not occur in impact craters less than a few kilometers in diameter with a few currently questionable exceptions all pertinent hypotheses of formation are presented and discussed several may be discarded in light of the most recent observations the branching fracture mechanism and the interference models proposed respectively by sagy et al 2002 and baratoux and melosh 2003 require further evaluation new observations experiments or theoretical considerations presented in this special issue promise an important step forward based on a renewed effort to resolve the enigmatic origin of these important features

analyzing rockfall activity 1600 2002 in a protection forest a case study using dendrogeomorphology for the first time dendrogeomorphology has been used to investigate spatial and temporal variations of rockfall activity in a protection forest we report results of 564 cores from 135 severely injured larix decidua mill trees on the west facing taschgufer slope swiss alps while trees sampled reached an age of 297 years on average the oldest one attained breast height in ad 1318 for reasons of sample depth the analysis was limited to the period 1600 2002 in total we reconstructed 741 growth disturbances gd during the last four centuries impacts were most commonly found in trees located in the southern part of the slope where gd recurred more than once per decade in contrast trees in the northern part were less frequently disturbed by rockfall and define recurrence intervals of more than 150 years throughout the last four centuries rockfall has caused gd to the trees sampled on the taschgufer slope most frequently in the form of low magnitude high frequency events in addition we identified one high magnitude low frequency event in 1720 which displaced the forest fringe of the northern sector a considerable distance downslope and eliminated an entire forest stand to analyze past rockfall activity we introduce a brateq defined as the number of impacts per meter width of all tree surfaces sampled per decade results clearly demonstrate that this rockfall brateq continually decreased in both sectors after the large 1720 rockfall event significantly low rockfall bratesq can be observed during the 1850s 1960s and 1970s in the northern and during the 1820s in the southern sector in contrast high rockfall bratesq were identified during the 1870s and 1990s in the northern and during the 1770s in the southern sector reconstructed data further show that the forest recolonizing the southern sector after the 1720 event gradually improved its protective function reducing bratesq by a factor of 13 between the 1740s and the 1990s in the recent past bratesq oscillated around 0 7 gd 1 meter width 1 10 years 1 in the well established forest of the northern sector the efficacy of the protective forest was temporarily reduced by the rockfalls in 1720 resulting in increased rockfall bratesq since then the protective

a minimum sample size required from schmidt hammer measurements the schmidt hammer is a useful tool applied by geomorphologists to measure rock strength in field conditions the essence of field application is to obtain a sufficiently large dataset of individual rebound values which yields a meaningful numerical value of mean strength although there is general agreement that a certain minimum sample size is required to proceed with the statistics the choice of size i e number of individual impacts was usually intuitive and arbitrary in this paper we show a simple statistical method based on the two sample student s t test to objectively estimate the minimum number of rebound measurements we present the results as 1 the mean and median solutions each providing a single estimate value and 2 the empirical probability distribution of such estimates based on many field samples schmidt hammer data for 14 lithologies 13 81 samples for each with each sample consisting of 40 individual readings have been evaluated assuming different significance levels the principal recommendations are 1 the recommended minimum sample size for weak and moderately strong rock is 25 2 a sample size of 15 is sufficient for sandstones and shales 3 strong and coarse rocks require 30 readings at a site 4 the minimum sample size may be reduced by one third if the context of research allows for higher significance level for test statistics interpretations based on less than 10 readings from a site should definitely be avoided copyright 2009 john wiley sons ltd

the rock elm meteorite impact structure wisconsin geology and shock metamorphic effects in quartz the rock elm structure in southwest wisconsin is an anomalous circular area of highly deformed rocks 6 5 km in diameter located in a region of virtually horizontal undeformed sedimentary rocks shock produced planar microstructures pms have been identified in quartz grains in several lithologies associated with the structure sandstones quartzite pebbles and breccia two distinct types of pms are pres ent p1 features which appear identical to planar fractures pfs or cleavage and p2 features which are interpreted as possible incipient planar deformation features pdfs the latter are uniquely produced by the shock waves associated with meteorite impact events both types of pms are oriented parallel to specific crystallographic planes in the quartz most commonly to c 0001 11 batchmode documentclass fleqn 10pt legalpaper article usepackage amssymb usepackage amsfonts usepackage amsmath pagestyle empty begin document overline 2 end document 2 and r z 10 batchmode documentclass fleqn 10pt legalpaper article usepackage amssymb usepackage amsfonts usepackage amsmath pagestyle empty begin document overline 1 end document 1 the association of unusual structurally deformed strata with distinct shock produced microdeformation features in their quartz bearing rocks establishes rock elm as a meteorite impact structure and supports the view that the presence of multiple parallel cleavages in quartz may be used independently as a criterion for meteorite impact preliminary paleontological studies indicate a minimum age of middle ordovician for the rock elm structure a similar age estimate 450 400 ma is obtained independently by combining the results of studies of the general morphology of complex impact structures with estimated rates of sedimentation for the region such methods may be applicable to dating other old and deeply eroded impact structures formed in sedimentary target rocks

understanding the responses of sea surface temperature to the two different types of el nino in the western north pacific abstract in this study we examine the physical processes of the response of sea surface temperature sst in the western north pacific to the two different types of el nino the central pacific el nino and the eastern pacific el nino while a center of anomalous warm sst is observed in the eastern tropical pacific in the case of the eastern pacific el nino it is located in the central tropical pacific for the central pacific el nino we investigate the detailed sst response in the kuroshio extension region where the anomalous sst is warm cool in the central pacific el nino eastern pacific el nino during the boreal fall and winter we diagnose the sst tendency to identify the roles of the surface net heat fluxes and ekman transport during the fall and winter the atmospheric teleconnections over the north pacific are quite different between the two types of el nino which might be due to changes in atmospheric diabatic forcing in relation to rainfall in the tropical pacific our results suggest that the physical processes which are responsible for the western north pacific sst in response to the two different types of el nino are basically similar that is ekman heat transport plays a key role in warming and cooling of the sst anomalies in the kuroshio extension region in the central pacific el nino and eastern pacific el nino respectively in contrast the net surface heat fluxes act to weaken the sst anomalies this result indicates that changes in the anomalous atmospheric circulation over the north pacific which is directly associated with ekman currents at the upper levels are important to determine the responses of sst in the kuroshio extension region to the two types of el nino

detection of illegal mine voids using electrical resistivity tomography the case study of raniganj coalfield india abstract unauthorised coal mining activities may result in development of hidden hollows rat holes galleries goafs shafts etc which pose great threats of land subsidence fire water flooding leading to severe environmental hazards health problems and safety issues to the local people present study deals with delineation and mapping of unauthorised coal mine voids galleries over an abandoned old mine around khudia open cast mine nirsa raniganj coalfield india electrical resistivity tomography ert study comprising wenner schlumberger dipole dipole and gradient arrays has been carried out along three parallel profiles over the affected area further joint inversion of all combined arrays has also been carried out using 2 5d resistivity inversion program to combine the relative advantages of all the arrays for producing superior results 2d ert sections have been generated for the filtered data sets with a constant quality factors and two different current thresholds the best results have been obtained from joint inversion of all combine arrays for the filtered data with higher current threshold the observed resistivity anomalies are well correlated with the depth of coal seam occurrences as observed in the borehole litholog of nearby area finally a geoelectric model of four unauthorised coal mine galleries has been established with their extension and orientation over the study area the results demonstrate the suitability of the ert technique through joint inversion of all combined arrays for characterization of illegal coal mine workings

geomorphological pedological and dendrochronological signatures of a relict landslide terrain mt garbatka kamienne mts sw poland abstract in the kamienne mountains the largest concentration of apparently relict landslides in the sudetes range occurs on the northern slopes of mt garbatka mass movements re shaped two adjacent slope hollows and a wide depositional area is located down the valley the main landslide body is nearly 1 km long and 200 300 m wide its flattened surface morphology and the occurrence of large dispersed allochtonous boulders in the distal part suggests a flow like movement initiated by shallow translational slides in the upper slopes the thickness of colluvium determined by an ert survey may reach 10 m geomorphic signatures of mass movement are subdued suggesting that considerable time has elapsed since the origin of the landslide and that large scale mass movements are likely pre holocene in age this is consistent with the results of an extensive soil survey within the landslide body and on the surrounding slopes similarity of soil properties and well developed horizonation of profiles both within the landslide and outside it shows that no major disturbance has taken place during the soil formation period dendrogeomorphological research in turn yielded evidence of numerous growth disturbances recorded in tree rings of norway spruce growing on the landslide body these signals are interpreted that the slope surface is not entirely stable under current environmental conditions flow or creep of landslide material is not very likely given the characteristics of cover materials and it is hypothesized that dendrochronological signals develop in response to ground deformation through piping and throughflow landslide hazard in the valley below mt garbatka appears low at present but to claim complete stability would be premature

effects of solution mining of salt on wetland hydrology as inferred from tree rings radial growth and concentrations of selected elements within rings were studied in white pine pinus strobus trees from a wetland in central new york approximately 5 km north of a salt solution mining field that operated from 1889 to 1988 trees seemingly document three sequential episodes of mine induced alterations of groundwater discharge irrigating the wetland during the 100 year period the radial growth of trees established before the onset of mining declined abruptly in the early 1890s and remained suppressed until about 1960 as did growth of numerous other trees that became established after the onset of mining suppressed pre 1960 radial growth coincided with the interval that surface water was injected into the saltbeds suggesting that losses of injected water to the bedrock and or unconsolidated deposits increased groundwater flow into the wetland an abrupt and sustained enhancement of radial growth beginning about 1960 indicates that the wetland became drier and thus more conducive to tree growth when injection practices were discontinued in the late 1950s despite the continued pumping of brine following the cessation of mining in the late 1980s head pressures again increased in the upper valley driving chloride enriched flow northward along regional bedding plane fractures and into the wetland large concentrations of chloride were detected within the most recently formed rings of some trees as the result of chloride enriched irrigation the radial growth of some trees declined and some trees died thus trees have preserved evidence of a century of hydrologic alterations unobtainable by other means where the effects of brine mining have not been documented previously

gravitationally induced caves and other discontinuities detected by 2d electrical resistivity tomography case studies from the polish flysch carpathians abstract widened discontinuities among them crevice type caves are characteristic phenomena of landslides in anisotropic rock massifs forming the flysch carpathians we tested the reliability of 2d electrical resistivity tomography ert in the detection of well mapped cave passages and then tried to explore new subsurface cavities in three sites of crevice type caves in the polish flysch carpathians the jaskinia miecharska jaskinia malinowska and jaskinia diabla dziura caves each comprising a different stage of mass movement development and thus being a representative case study the total of 14 ert profiles was selected while each of them was measured by several electrode arrays dipole dipole wenner and or wenner schlumberger our results show that the selection of an appropriate electrode array and spacing are crucial for the detection of subsurface cavities measurement using the dipole dipole electrode array gave best results in the detection of known structures and its interpretation seems to be most reliable in the extrapolation of non investigated areas the application of ert shows abundant occurrence of air filled voids in gravitationally deformed flysch massifs and in several places its results enable comparison with open spaces detected by speleological exploration ert enables us to identify fractures in deformed slopes before the proper failure of these slopes affected by a landslide as well as in landslides themselves fissure zones connected with trenches less dense segments of colluvial ramparts and some lithological tectonical or gravitationally induced elements of slope structures the reliability of ert detection of potential caves was verified by speleological exploration of a newly discovered cave at the jaskinia miecharska site following the ert campaign

the control of overburden thickness on resurgent domes insights from analogue models abstract resurgent doming consists of the uplift usually accompanied by volcanic activity of part of a collapse caldera analogue models were used to investigate the architecture of resurgent domes dry sand simulates the brittle crust uprising silicone located at the base of the sand pack simulates magma the deformation pattern depends mainly upon 1 the ratio aspect ratio between the thickness of the sand overburden and the width of the silicone intrusion 2 the duration of experiment for aspect ratios 1 two concentric domes develop the first formed outer dome is bordered by inward dipping reverse ring faults while the inner dome by outward dipping normal ring faults the layers inside the dome are uniformly dipping for aspect ratios 0 4 the dome shows a crestal depression surrounded by radial fractures followed by an apical extrusion of silicone the internal structure of the dome is made up of domed layers independently from the aspect ratio the duration of the experiment enhances silicone extrusion a consistent structure is observed in most resurgent domes in nature the comparison between experiments and nature suggests that two distinct resurgence modes occur mainly depending on the aspect ratio thickness width of the crust overlying the magma chamber aspect ratios 1 develop a resurgent block with uniformly dipping layers and peripheral volcanic activity ischia and pantelleria type aspect ratios 0 4 develop a resurgent dome with a crestal depression domed layers within and peripheral and internal volcanic activity valles and long valley type

integrated geophysical and geochemical study on amd generation at the haveri au cu mine tailings sw finland the haveri tailings area contains 1 5 mt of sulfide bearing waste from the au cu mine that operated during 1942 1961 geophysical and geochemical methods were used to evaluate and characterize the generation of acid mine drainage amd correlations were examined among the electrical resistivity tomography ert data the total sulfide content and concentrations of sulfide bound metals cu co fe mn ni pb and zn of tailings samples and the resistivity and geochemistry of surface water the resulting geophysical geochemical model defines an area in the vadose tailings where a low resistivity anomaly 10 ohm m is correlated with the highest sulfide content extensive sulfide oxidation and low ph average 3 1 the physical and geochemical conditions resulting from the oxidation of the sulfide minerals suggest that the low resistivity anomaly is associated with acidic and metal rich porewater i e amd the lower resistivity values in the saturated zone of the central impoundment suggest the formation of a plume of amd the natural subsoil layer silt and clay and the bedrock surface below the tailings area were well mapped from the ert data the detected fracture zones of the bedrock that could work as leakage pathways for amd were consistent with previous geological studies the integrated methodology of the study offers a promising approach to fast and reliable monitoring of areas of potential amd generation and its subsurface movement over large areas ca 9 ha this methodology could be helpful in planning drill core sampling locations for geochemical and mineralogical analysis groundwater sampling and choosing and monitoring remedial programs

application of field geophysics in geomorphology advances and limitations exemplified by case studies abstract during the last decade the use of geophysical techniques has become popular in many geomorphological studies however the correct handling of geophysical instruments and the subsequent processing of the data they yield are difficult tasks furthermore the description and interpretation of geomorphological settings to which they apply can significantly influence the data gathering and subsequent modelling procedure e g achieving a maximum depth of 30 m requires a certain profile length and geophone spacing or a particular frequency of antenna for more than three decades geophysical techniques have been successfully applied for example in permafrost studies however in many cases complex or more heterogeneous subsurface structures could not be adequately interpreted due to limited computer facilities and time consuming calculations as a result of recent technical improvements geophysical techniques have been applied to a wider spectrum of geomorphological and geological settings this paper aims to present some examples of geomorphological studies that demonstrate the powerful integration of geophysical techniques and highlight some of the limitations of these techniques a focus has been given to the three most frequently used techniques in geomorphology to date namely ground penetrating radar seismic refraction and dc resistivity promising applications are reported for a broad range of landforms and environments such as talus slopes block fields landslides complex valley fill deposits karst and loess covered landforms a qualitative assessment highlights suitable landforms and environments the techniques can help to answer yet unsolved questions in geomorphological research regarding for example sediment thickness and internal structures however based on case studies it can be shown that the use of a single geophysical technique or a single interpretation tool is not recommended for many geomorphological surface and subsurface conditions as this may lead to significant errors in interpretation because of changing physical properties of the subsurface material e g sediment water content in many cases only a combination of two or sometimes even three geophysical methods gives sufficient insight to avoid serious misinterpretation a good practice guide has been framed that provides recommendations to enable the successful application of three important geophysical methods in geomorphology and to help users avoid making serious mistakes

warm pool and cold tongue el nino events as simulated by the gfdl 2 1 coupled gcm recent studies report that two types of el nino events have been observed one is the cold tongue ct el nino which is characterized by relatively large sea surface temperature sst anomalies in the eastern pacific and the other is the warm pool wp el nino in which sst anomalies are confined to the central pacific here both types of el nino events are analyzed in a long term coupled gcm simulation the present model simulates the major observed features of both types of el nino incorporating the distinctive patterns of each oceanic and atmospheric variable it is also demonstrated that each type of el nino has quite distinct dynamic processes which control their evolutions the ct el nino exhibits strong equatorial heat discharge poleward and thus the dynamical feedbacks control the phase transition from a warm event to a cold event on the other hand the discharge process in the wp el nino is weak because of its spatial distribution of ocean dynamic field the positive sst anomaly of wp el nino is thermally damped through the intensified evap orative cooling

characteristic variations of sea surface temperature with multiple time scales in the north pacific abstract temporal evolution and spectral structure of sea surface temperature sst anomalies in the north pacific over the last 37 years are investigated on the three characteristic time scales shorter than 24 months hf 24 60 months es and longer than 60 months dc the leading empirical orthogonal function eof for the dc time scale is characterized by a zonally elongated monopole centered at around 40 n 180 the leading eof for the hf time scale is somewhat similar to that for the dc time scale although there are two centers of action with the same polarity at the mid and western pacific the leading eof for the es time scale however exhibits a different pattern whose center of action at the mid pacific is located farther southeastward in the time evolution of the sst anomalies associated with the leading eof of the dc time scale several anomaly periods can be identified that last five years or longer the transition from a persistent period to another with the opposite polarity is gene

development and recent activity of the san andres landslide on el hierro canary islands spain abstract extremely voluminous landslides with a long run out also known as megalandslides on oceanic volcanic islands are infrequent denudational processes on such islands at the same time they represent a major geological hazard that must be looked into to avoid negative consequences for the inhabitants of these islands their occurrence can be related to periods of intense seismo volcanic activity similar to that which occurred on el hierro island over 2011 2012 landslides on volcanic islands are studied using onshore and offshore geological geophysical and geomorphological records considering their unique triggering conditions e g lava intrusions eruptive vents magma chamber collapses previous work has pointed out similarities between specific cases of landslides on volcanic islands and deep seated gravitational slope deformations dsgsds which are typical in high mountain settings nevertheless the methodological approaches and concepts used to investigate dsgsds are not commonly applied on volcanic islands studies even though their use may provide new information about the development stage recent movements and future hazards therefore this approach for studying the san andres landslide sal on el hierro canary islands has been developed applying a detailed morphological field mapping an interpretation of digital elevation models structural measurements kinematic testing and a precise movement monitoring system the acquired information revealed a strong structural influence on the landslide morphology and the presence of sets of weakened planes acting as the sliding surfaces of the sal or secondary landslides within its body the presence of secondary landslides deep erosive gullies coastal cliffs and high on shore relative relief also suggests a high susceptibility to future landslide movement direct monitoring on the landslide scarps and the slip plane performed between february 2013 and july 2014 using an automated optical mechanical crack gauge with a precision of up to 10 2 mm detected creep movement in the order of 1 mm yr 1 with a persistent sinistral component as well as episodic horizontal and a subtle vertical movement this monitoring will continue in the future in order to verify the initial observations which instead of long term movement patterns could represent a landslide response to the period of an intense seismo volcanic activity during 2011 12

structural geology of impact craters abstract the formation of impact craters is a highly dynamic and complex process that subjects the impacted target rocks to numerous types of deformation mechanisms understanding and interpreting these styles of micro meso and macroscale deformation has proved itself challenging for the field of structural geology in this paper we give an overview of the structural inventory found in craters of all size ranges on earth and look into the structures of craters on other planetary bodies structural features are discussed here that are caused by i extremely high pressures and temperatures that occur during the initial passage of the shock wave through the target rock and projectile ii the resulting flow field in the target that excavates and ejects rock materials and iii the gravitationally induced modification of the crater cavity into the final crater form a special focus is put on the effects that low angle impacting bodies have on crater formation we hope that this review will help both planetary scientists and structural geologists understand the deformation processes and resulting structures generated by meteorite impact

the chicxulub asteroid impact and mass extinction at the cretaceous paleogene boundary the cretaceous paleogene boundary similar to 65 5 million years ago marks one of the three largest mass extinctions in the past 500 million years the extinction event coincided with a large asteroid impact at chicxulub mexico and occurred within the time of deccan flood basalt volcanism in india here we synthesize records of the global stratigraphy across this boundary to assess the proposed causes of the mass extinction notably a single ejecta rich deposit compositionally linked to the chicxulub impact is globally distributed at the cretaceous paleogene boundary the temporal match between the ejecta layer and the onset of the extinctions and the agreement of ecological patterns in the fossil record with modeled environmental perturbations for example darkness and cooling lead us to conclude that the chicxulub impact triggered the mass extinction

the north pacific climatology of winter mixed layer and mode waters abstract a climatology of the winter mixed layer in the north pacific ocean was constructed using hydrographic data from historical archives and recent observational programs including the world ocean circulation experiment the main aim was to provide better knowledge about source areas of upper water masses the authors have endeavored to preserve water properties near the frontal regions by keeping the smoothing scale as small as possible the resulting climatology shows considerable differences in the mixed layer depth and its water properties from those derived from the world ocean atlas woa maps of the potential vorticity field of the north pacific pycnocline are presented using the isopycnally averaged climatology hydrobase three distinct lateral minima of potential vorticity are identified as subtropical mode water stmw central mode water cmw and eastern subtropical mode water estmw in the western central and eastern parts of the subtropical gyre respectively the hydrobase isopy

evaluation of meteorological controls of reconstructed rockfall activity in the czech flysch carpathians the spatio temporal characteristics of rockfall activity were studied at four localities representative of old landslides in the highest part of the czech flysch carpathians moravskoslezske beskydy mountains historical activity chronology and spatial context of rockfall activity were reconstructed using dendrogeomorphic techniques and rockfall rate index rr a total of 1132 increment cores from 283 trees growing in the rockfall transport and accumulation zones enabled the dating of 989 rockfall events reconstruction of a 78 year long rr chronology suggests similar rockfall histories and trends at all study sites indicating the existence of major common factors driving rockfall dynamics in the region temporal analysis and correlation of the rr series obtained with monthly mean temperatures numbers of days with temperature transitions through 0 deg c and monthly precipitation totals show that meteorological characteristics have evident but variable influence on rockfall activity

timing of destruction of the north china craton abstract the north china craton ncc is the typical example of destruction of an ancient craton however the destruction mechanism and geodynamic controlling factors still remain enigmatic due to controversy on the timing of destruction which is the key to understanding the destruction processes based on temporal and spatial distributions of the igneous rocks and their sources and tectonic settings it is recognized that six stages of tectono magmatism occurred in the ncc during the phanerozoic i e carboniferous to early permian late permian to middle triassic late triassic jurassic early cretaceous and cenozoic among them cenozoic magmatism mainly consists of alkali basalts and is found only occasionally in the eastern ncc the first four stages of magmatism and tectonism related to the southward subduction of the paleo asian plate and the assembly of sino korean and yangtze cratons are locally distributed in limited parts of the ncc reflecting a multiple stage modification of the ncc from the late carboniferous to jurassic however the intensive development of early cretaceous magmatism extensional deformation and associated gold mineralization with significant continental crustal growth indicate that the eastern ncc was destroyed during this time period this destruction was the result of paleo pacific subduction beneath the eastern asian continent with lithospheric removal and or replacement of an ancient cratonic lithosphere by a juvenile oceanic lithosphere

teleconnections in the geopotential height field during the northern hemisphere winter abstract contemporaneous correlations between geopotential heights on a given pressure surface at widely separated points on earth referred to as teleconnections in this paper are studied in an attempt to identify and document recurrent spatial patterns which might be indicative of standing oscillations in the planetary waves during the northern hemisphere winter with time scales on the order of a month or longer a review of existing literature on the subject reveals the existence of at least four such patterns the north atlantic and north pacific oscillations identified by walker and bliss 1932 a zonally symmetric seesaw between sea level pressures in polar and temperature latitudes first noted by lorenz 1951 and what we will refer to as the pacific north american pattern which has been known to operational long range forecasters in this country since the 1950 s a data set consisting of nmc monthly mean sea level pressure and 500 mb height analyses for a 15 year period is used as a basis fo

application of electrical resistivity tomography to map lithological differences and subsurface structures eastern sudetes czech republic abstract the aim of this study is to determine the subsurface lithological variability and thickness of each metamorphic rocks unit by means of geophysical methods which were presented within the framework of sedibud research was performed on the ridge and the steep eastern slope of the orlik massif 1204 m in the hrub jesenik range of the eastern sudetes the czech republic to obtain a spatial image of a geological rock mass the non invasive and relatively rapid method of electrical resistivity tomography ert was used which resulted in the creation of six profiles using the dipole dipole and wenner schlumberger arrays as complementary methods vertical electrical sounding ves and seismic refraction tomography were chosen fifteen measuring points along two profiles obtained by vertical electrical sounding allowed the determination of the following in the vertical section layers of different resistivity and thickness at direct points in contact primarily with devonian quartzite rocks and weathered covers in a series of field studies a four layered rock mass was examined in which the first layer is of fine grained materials with medium and large size clasts the second layer is quartzite the third is gneiss and the fourth is phyllite the five profiles measured by seismic refraction tomography made it possible to draw the boundary between the studied phyllites gneisses and quartzites in addition geophysical surveys and the results of mineralogical composition analysis allowed us to determine the nature and thickness of the weathered layers present on the massif area which in the upper sections are predominantly a clayey loam partially covered with blocks the inclination of the slope is associated with an increase in the fraction of coarse material the majority of the thickness of these layers is related to the local flattened surfaces and the presence of numerous streams which contributed to the accumulation of the sediments that were also transported from the ridge area this diversity indicates notably active slope processes during the pleistocene the results confirmed the usefulness of geophysical methods to identify the geological structure of rocks with highly variable lithology with faults and folding features

feather features a low shock pressure indicator in quartz 1 feather features are a recently discovered type of microstructure in shocked quartz they occur as short parallel to subparallel lamellae with spacing similar to that of planar deformation features pdfs these lamellae are always found in combination with a planar fracture pf feather features are crystallographically controlled 0001 101 and 112 orientations are common while 103 and 102 orientations are lacking samples from the nordlinger ries and the matt wilson impact structures are compared with plane wave shock recovery experiments 16 gpa microscopic analysis of quartz grains with feather features show that their formation is linked to shearing along the associated pfs during shock deformation the generation of shear fractures with feather features in plane wave shock recovery experiments suggests a pressure range of 7 10 gpa although further constraints are needed for an upper and lower pressure limit the orientation of feather features in rock samples is suggested to be controlled by the direction of the principal axis of stress with sheared pfs at 45 angles to the axis and most feather feature lamellae aligned parallel to the axis 20 the majority of feather feature lamellae emanate from the pfs in the same direction and in experiments point in the direction from which the shock wave came on the basis of their appearance in shocked quartz grains from 26 impact craters and the current lack of reports of these features in endogenically deformed crustal rocks their uniqueness as a new type of impact induced planar microstructure alongside pdfs and pfs is proposed

reconnaissance survey of the duolun ring structure in inner mongolia not an impact structure the duolun basin which is located in inner mongolia china has been proposed to be an impact structure with an apparent rim diameter of about 70 or even 170 km the designation as an impact structure was based on its nearly circular topography consisting of an annular moat that surrounds an inner hummocky region and the widespread occurrences of various igneous rocks polymict breccias and deformed crustal rocks critical shock metamorphic evidence is not available to support the impact hypothesis we conducted two independent reconnaissance field surveys to this area and studied the lithology both within and outside of the ring structure we collected samples from all lithologies that might contain evidence of shock metamorphism as suggested by their locations especially those sharing similar appearances with impact breccias suevites impact melt rocks and shatter cones field investigation together with thin section examination discovered that the suspected impact melt rocks are actually early cretaceous and late jurassic lava flows and pyroclastic deposits of rhyolitic to trachytic compositions and the interpreted impact glass is typical volcanic glass petrographic analyses of all the samples reveal no indications for shock metamorphic overprint all these lines of evidence suggest that the duolun basin was not formed through impact cratering the structural deformation and spatial distribution pattern of the igneous rocks suggest that the duolun basin is most likely a jurassic cretaceous complex rhyolite caldera system that has been partly filled with sediments forming an annular basin followed by resurgent doming of the central area

contrasting eastern pacific and central pacific types of enso abstract surface observations and subsurface ocean assimilation datasets are examined to contrast two distinct types of el nino southern oscillation enso in the tropical pacific an eastern pacific ep type and a central pacific cp type an analysis method combining empirical orthogonal function eof analysis and linear regression is used to separate these two types correlation and composite analyses based on the principal components of the eof were performed to examine the structure evolution and teleconnection of these two enso types the ep type of enso is found to have its sst anomaly center located in the eastern equatorial pacific attached to the coast of south america this type of enso is associated with basinwide thermocline and surface wind variations and shows a strong teleconnection with the tropical indian ocean in contrast the cp type of enso has most of its surface wind sst and subsurface anomalies confined in the central pacific and tends to onset develop and decay in situ

case study of inhomogeneous cloud parameter retrieval from modis data 1 cloud parameter retrieval of inhomogeneous and fractional clouds is performed for a stratocumulus scene observed by modis at a solar zenith angle near 60 the method is based on the use of neural network technique with multispectral and multiscale information it allows to retrieve six cloud parameters i e pixel means and standard deviations of optical thickness and effective radius fractional cloud cover and cloud top temperature retrieved cloud optical thickness and effective radius are compared to those retrieved with a classical method based on the homogeneous cloud assumption subpixel fractional cloud cover and optical thickness inhomogeneity are compared with their estimates obtained from 250m pixel observations this comparison shows a fairly good agreement the cloud top temperature appears also retrieved quite suitably

dating of small gully formation and establishing erosion rates in old gullies under forest by means of anatomical changes in exposed tree roots southern poland abstract small gullies occur in forested gully systems on the undulating loess plateau in southern poland the old gully hillslopes are mainly covered with 200 year old beech trees in contrast with the surface of the summit plateau which is cultivated agricultural land beech roots are exposed in the gullies through erosion wood vessels in the root tree rings divide into early wood and late wood and after the roots are exposed start to make fewer vessels these anatomical changes in root tree rings allow us to date erosion episodes small gullies form in a different manner on the valley floor and on hillslopes in valley bottoms erosion features are often formed at some distance from one another and in time small gullies combine to form a single longer one depending on local conditions such as the hillslope profile hillslopes may exhibit headward erosion or may be eroded downwards hilllope gullies may be transformed into side valleys as a result of gradual widening and deepening dating the exposure of roots indicates that small gullies had already formed in the valley system by 1949 intensive gully erosion was recorded between 1984 and 2002 during intense precipitation in 1984 and of particular note during the extraordinary flood of 1997 which affected all of central europe the mean rate of small gully erosion in the old gully system studied is 0 63 m year on hillslopes the mean gully erosion rate is 0 21 0 52 m year and on the valley bottoms 0 18 1 98 m year high bottom erosion rates resulted from the emergence of long gullies during the erosion episodes in 1984 and 1997 sheet flow in valley floors intensifies at times of heavy rainfall which causes long gullies to form taking into account the fact that conditions favoured erosion the rate at which the old gullies under forest were transformed should be considered slow new side gullies form slowly within the valley and it appears that if erosion progressed at the rate observed new side valleys would take a few hundred years to form

morokweng south africa a large impact structure of jurassic cretaceous boundary age geophysical petrographical and geochemical data indicate the presence of a large impact structure in the area around morokweng northwest province south africa possibly up to 340 km in diameter drill cores from the center of the structure show a thick layer of impact melt rocks with high abundances of cr ni co and the platinum group elements consistent with the presence of up to 5 of a chondritic component ion probe dating of zircons extracted from the impact melt yielded a 206 pb 238 u age of 146 2 1 5 ma and a 208 pb 232 th age of 144 7 1 9 ma these are indistinguishable from the age of the jurassic cretaceous boundary following the identification of the chicxulub impact structure of cretaceous tertiary boundary age the discovery of a second large impact structure at a previously established major chronostratigraphic boundary strengthens suggestions that large impact events have been major factors in the evolution of the earth

genesis types and evolution of crevice type caves in the flysch belt of the western carpathians czech republic abstract crevice type caves are among the least investigated natural phenomena connected with the development of slope failures these caves present complex and peculiar underground systems with their own development and resulting landforms we investigated eight caves in the czech part of the outer western carpathians to determine their genesis types and evolution crevice formation is predisposed according to the lithological tectonic and morphological characteristics of the landslide body including the position and location of bedding planes joints and faults we performed several analyses including speleological mapping evaluation of high resolution topography above the caves geophysical ert measurements and structural investigations within cave passages in accordance with these analyses various mechanisms responsible for cave development were revealed an intra bed translation is responsible for the creation of regularly shaped passages with flat ceilings toppling as well as back and horizontal rotation of rock blocks determine the specific morphology and shapes of passages a relatively novel aspect of the current study is the identification of the subsidence of massive rock wedges due to the widening of cracks all of these mechanisms control the specific morphological characteristics within crevices e g typical shapes of passages cave level ordering and ceiling types some of these processes also influence topography above the caves finally the different phases of evolution of these caves were determined

crevice type caves as initial forms of rock landslide development in the flysch carpathians crevice type caves formed along joints are very common in the polish flysch carpathians more than 600 have been recorded the caves represent accessible parts of the widened cracks which are basic initial forms of development of deep seated rock landslides structural features of four selected caves situated in different parts of the carpathians were studied in order to determine relations between joint systems and landslide formation the studies prove that the main rock scarps often represent effects of earlier propagation of the cracks cutting surfaces due to loading and unloading shearing stress the cracks are structural forms developed along joints or faults the cutting surfaces represented by cracks caves develop a long time before the main gravitational mass movements whereas the sliding surfaces shearing zones are formed or significantly modified ad hoc during the gravitational transport of rock masses occurrence of the deep initial cracks causes modification of shape of the sliding surfaces which are noncircular the mountain slopes cut by many cracks are permanently developed thus the periodic increase of activity of external factors floods downpours earthquakes etc leads to common formation of the landslides earlier prepared by crack development this model of slope evolution enables us to interpret the occurrence of the landslide phases in the holocene during which increasing of frequency of the landslides is observed

changes in the relationship in the sst variability between the tropical pacific and the north pacific across the 1998 1999 regime shift this study shows that sea surface temperature sst variability in the central to eastern tropical pacific has a strong negative correlation with that of the central to eastern north pacific in the boreal winter after the 1998 1999 regime shift this phenomenon is in contrast to before the 1998 1999 regime shift the anomalous aleutian low pressure associated with the tropical sst forcing became stronger and its center shifted to the south and to the west after 1998 1999 such a modulation caused the change in the north pacific sst response this also resulted in a close relationship between the tropical pacific and north pacific sst variability the modulation of the aleutian low pressure is primarily due to the westward shift in the location of the tropical convective heating around the dateline which occurred during 1998 1999 the results of simple atmospheric model experiments support this hypothesis that the shift in the tropical convective heating to the west is responsible for the modulation of the aleutian low pressure and the associated change in the relationship of the sst variability between the tropical pacific and north pacific these results imply that the seasonal predictability of the north pacific sst has increased since 1998 1999 due to its increased correlation with the tropical pacific sst variability

assessment of the influencing factors on subsidence at abandoned coal mines in south korea this study deals with the characteristics of subsidence and the relationships between the subsidence factors over abandoned coal mines in south korea the subsidence factors that were investigated were the dip angle and thickness of the coal bed mining depth depth of subsidence and subsidence area in 548 cases of subsidence that occurred throughout the country a close relationship between the type of subsidence and mining method was identified there was an intimate relation between the depth of subsidence and the dip angle of the coal bed while the subsidence area proved to be in proportion to the thickness of the coal bed and mining depth and was in inverse proportion to the dip angle of the coal bed

hydrocode simulations of chicxulub crater collapse and peak ring formation we use hydrocode modeling to investigate dynamic models for the collapse of the chicxulub impact crater our aim is to integrate the results from numerical simulations with kinematic models derived from seismic reflection and wide angle velocity data to further our understanding of the formation of large impact craters in our simulations we model the collapse of a 100 km diameter bowlshaped cavity formed in comprehensively fractured crustal material to facilitate wholesale collapse we require that the strength of the target be significantly weakened in the present model we achieve this using acoustic fluidization where strong vibrations produced by the expanding shock wave cause extreme pressure fluctuations in the target at times and positions where the overburden pressure is sufficiently counteracted the frictional resistance is reduced enabling the rock debris to flow our simulations produce a collapsed crater that contains most of the features that we observe in the seismic data at chicxulub in particular we observe a topographic peak ring formed as material that is originally part of the central uplift collapses outward and is thrust over the inwardly collapsing transient crater rim this model for peak ring generation has not been previously demonstrated by numerical simulations and predicts that the peak ring is composed of deeply derived material and that the stratigraphy within the peak ring is overturned c 2002 elsevier science usa

modes of interannual and interdecadal variability of pacific sst abstract the multichannel singular spectrum analysis has been used to characterize the spatio temporal structures of interdecadal and interannual variability of sst over the pacific ocean from 20 s to 58 n using the comprehensive ocean atmosphere data set from 1950 to 1993 three modes with distinctive spatio temporal structures were found they are an interdecadal mode a quasi quadrennial qq oscillation with a period of 51 months and a quasi biennial qb oscillation with a period of 26 months the interdecadal mode is a standing mode with opposite signs of sst anomalies in the north pacific and in the tropical pacific the amplitude of this mode is larger in the central north pacific than in the tropical pacific this mode contributes 11 4 to the total variance it is associated with cooling in the central north pacific and warming in the equatorial pacific since around 1976 77 the qq oscillation exhibits propagation of sst anomalies northeastward from the philippine sea and then eastward along 4

regolith mass balance inferred from combined mineralogical geochemical and geophysical studies mule hole gneissic watershed south india the aim of this study is to propose a method to assess the long term chemical weathering mass balance for a regolith developed on a heterogeneous silicate substratum at the small experimental watershed scale by adopting a combined approach of geophysics geochemistry and mineralogy we initiated in 2003 a study of the steep climatic gradient and associated geomorphologic features of the edge of the rifted continental passive margin of the karnataka plateau peninsular india in the transition sub humid zone of this climatic gradient we have studied the pristine forested small watershed of mule hole 4 3 km2 mainly developed on gneissic substratum mineralogical geochemical and geophysical investigations were carried out i in characteristic red soil profiles and ii in boreholes up to 60 m deep in order to take into account the effect of the weathering mantle roots in addition 12 electrical resistivity tomography profiles ert with an investigation depth of 30 m were generated at the watershed scale to spatially characterize the information gathered in boreholes and soil profiles the location of the ert profiles is based on a previous electromagnetic survey with an investigation depth of about 6 m the soil cover thickness was inferred from the electromagnetic survey combined with a geological pedological survey taking into account the parent rock heterogeneity the degree of weathering of each of the regolith samples has been defined using both the mineralogical composition and the geochemical indices loss on ignition weathering index of parker chemical index of alteration comparing these indices with electrical resistivity logs it has been found that a value of 400 ohm m delineates clearly the parent rocks and the weathered materials then the 12 inverted ert profiles were constrained with this value after verifying the uncertainty due to the inversion procedure synthetic models based on the field data were used for this purpose the estimated average regolith thickness at the watershed scale is 17 2 m including 15 2 m of saprolite and 2 m of soil cover finally using these estimations of the thicknesses the long term mass balance is calculated for the average gneiss derived saprolite and red soil in the saprolite the open system mass transport function indicates that all the major elements except ca are depleted the chlorite and biotite crystals the chief sources for mg 95 fe 84 mn 86 and k 57 biotite only are the first to undergo weathering and the oligoclase crystals are relatively intact within the saprolite with a loss of only 18 the ca accumulation can be attributed to the precipitation of caco3 from the percolating solution due to the current and or the paleoclimatic conditions overall the most important losses occur for si mg and na with 286 106 mol ha 62 of the total mass loss 67 106 mol ha 15 of the total mass loss and 39 106 mol ha 9 of the total mass loss respectively al fe and k account for 7 4 and 3 of the total mass loss respectively in the red soil profiles the open system mass transport functions point out that all major elements except mn are depleted most of the oligoclase crystals have broken down with a loss of 90 the most important losses occur for si na and mg with 55 106 mol ha 47 of the total mass loss 22 106 mol ha 19 of the total mass loss and 16 106 mol ha 14 of the total mass loss respectively ca al k and fe account for 8 6 4 and 2 of the total mass loss respectively overall these findings confirm the immaturity of the saprolite at the watershed scale the soil profiles are more evolved than saprolite but still contain primary minerals that can further undergo weathering and hence consume atmospheric co2

radial transpression ridges a new structural feature of complex impact craters the gravity driven collapse of complex impact craters induces the mass transfer of large rock volumes in distal parts of a crater inward movements dominate whereas in the centre of an impact structure outward movements occur if the central uplift collapses the particle trajectory field is centro symmetric which signifies that the conditions for plane strain deformation are not fullfilled converging particle trajectories can be compensated either by a bulk thickening of inward sliding masses folding repetition of rock units along thrust faults plastic flow or by the formation of localised radial transpression ridges rtr at the edges of individual landslides in these transpression ridges material is uplifted to accommodate the converging mass flow different modes of uplift are possible including radial folding lateral overthrusting and the formation of positive flower structures a simple geometric model is used to estimate the amount of transpression thickening and bulk thickening of inward sliding masses on the base of volumetric considerations the existence of rtrs is confirmed by structural investigations at the siljan impact structure sweden as well as at other complex impact craters on earth

interannual and interdecadal variations of sea surface temperature in the east asian marginal seas abstract interannual and interdecadal variability of sea surface temperature sst in the east asian marginal seas eams from 1951 to 1996 are investigated and the teleconnection of the eams to the equatorial ocean is studied using empirical orthogonal function analysis and coherency analysis the eams have significant coherency with the nino 3 4 sst at 2 to 3 year periods with a phase lag of 5 9 months in the sst anomaly ssta the eams also showed a higher coherency with a 6 year oscillation with a phase lag of 18 22 months for the 6 year variability the ssta of the nino 3 4 is highly coherent with the latent and sensible heat flux anomaly of the southern east sea indicating that the variability of the southern east sea is related to that in the nino 3 4 region through the ocean atmosphere interactions the southern east sea also has a higher coherency with the east china sea cooling in the southern east sea and sudden warming in the northern east sea were found to have occurred around 1965 1966 in the records of interdecadal variability the decadal and interdecadal variabilities of the eams were found to be teleconnected to the western equatorial pacific whereas the interannual variability was highly correlated to the central equatorial pacific which is represented by nino 3 4 sst

spatial correlations of interdecadal variation in global surface temperatures we have analyzed spatial correlation patterns of interdecadal global surface temperature variability from an empirical perspective using multi taper coherence estimates from 140 yr records we find that correlations between hemispheres are significant at 95 confidence for non randomness for most of the frequency band 0 06 f 0 24 cyc yr coherence estimates of pairs of 100 yr grid point temperature data series near 5 yr period reveal teleconnection patterns consistent with known patterns of enso variability significant correlated variability is observed near 15 year period with the dominant tele connection pattern largely confined to the northern hemisphere peak to peak t 0 5 with simultaneous warming and cooling of discrete patches on the earth s surface a global average of this pattern would largely cancel

empirical investigation and characterization of surface subsidence related to block cave mining abstract for guidance on relationships between caving depth and surface subsidence a comprehensive database was developed after an exhaustive search of published data from cave mining operations from around the world the distribution of data was found to largely focus on caving angles and macro deformations very little empirical data exists on the extent and magnitudes of smaller surface displacements the data clearly show that caving induced surface deformations tend to be discontinuous and asymmetric due to large movements around the cave controlled by geologic structures rock mass heterogeneity and topographic effects the data also show that as undercut depth increases for a given extraction volume the magnitude and extent of the caved zone on surface decreases however numerical modeling indicates that this is only the case for macro deformations and the extent of smaller displacements actually increases as a function of undercut depth the results presented caution against relying on existing empirical design charts for estimates of caving induced subsidence where small strain subsidence is of concern as the data being relied upon does not properly extrapolate beyond the macro deformations i e caving angles that make up the majority of the observations the findings also suggest that the extent and magnitudes of subsidence may be underestimated if the analysis adopted neglects the influence of geological structures and assumes symmetrical surface displacements above the undercut

lithology landscape structure and management practice changes key factors patterning vineyard soil erosion at metre scale spatial resolution in vineyards soil erosion is controlled by complex interactions between geomorphological and anthropogenic factors leading to intra plot spatial topsoil heterogeneities that are observed at a 1 m scale this study explores the relative impacts of slope lithology historical landscape structure and present day management practices on soil erosion on vineyard hillslopes the selected plot is located in the monthelie vineyard hillslopes cote de beaune france where intensive erosion occurs during high intensity rainfall events soil erosion quantification was performed at a square metre scale using dendrogeomorphology for the same plot planted in 1972 an initial erosion map was drawn in 2004 with a second map being produced in 2012 these two maps combined with lithology and slope data the evolution of landscape structure and the evolution of management practices allow the driving factors of water erosion to be assessed from the 2004 erosion map we observed that the spatial distribution of erosion for the thirty year period after planting was mainly controlled by lithology and historical landscape structure whatever the slope by subtracting 2004 data from the 2012 data and thus evaluating erosion over the last decade we discovered that the erosion rate had increased significantly that spatial distribution of erosion had changed and is now basically controlled by slope steepness and present day vineyard management practices erosion patterns for the last decade show that the impact of historical landscape structure is gradually declining this study shows that it is crucial to take into account the pre plantation history of vineyard plots and management practices to further increase our understanding of the spatial distribution of erosion on vineyard hillslopes

hailar crater a possible impact structure in inner mongolia china abstract hailar crater a probable impact structure is a circular depression about 300 m diameter in inner mongolia northeast china with broad elevated rims the present rim to floor depth is 8 20 m regional geological background and geomorphological comparison suggest that this feature is likely not formed by surface processes such as salt diapir karst aeolian glacial or volcanic activity its unique occurrence in this region and well preserved morphology are most consistent with it being a cenozoic impact crater two field expeditions in 2016 and 2017 investigated the origin of this structure recognizing that 1 no additional craters were identified around hailar crater in the centimeter scale digital topography models that were constructed using a drone imaging system and stereo photogrammetry 2 no bedrock exposures are visible within or adjacent to the crater because of thick regolith coverage and only small pieces of angular unconsolidated rocks are present on the crater wall and the gently sloped crater rim suggesting recent energetic formation of the crater 3 most samples collected from the crater have identical lithology and petrographic characteristics with the background terrain but some crater samples contain more abundant clasts and silicate hydrothermal veins indicating that rocks from depths have been exposed by the crater 4 no shock metamorphic features were found in the samples after thin section examinations and 5 a systematic sample survey and iron detector scan within and outside of the crater found no iron rich meteorites larger than 2 cm in size in a depth of 30 cm although no conclusive evidence for an impact origin is found yet hailar crater was most likely formed by an impact based on its unique occurrence and comparative geomorphologic study we suggest that drilling in the crater center is required to verify the impact origin where hypothesized melt bearing impactites may be encountered

deep seated gravitational slope deformations in the highest parts of the czech flysch carpathians evolutionary model based on kinematic analysis electrical imaging and trenching deep seated gravitational slope deformations dsgsds played an important role during the quaternary evolution of mountain ridges formed by anisotropic flysch rocks of the outer western carpathians owc four dsgsd affected ridges in the highest part of the czech sector of the owc have been subjected to multidisciplinary investigation involving mapping structural and kinematic analysis geoelectrical imaging trenching and dating all the studied dsgsds are strongly predisposed by regional structural fabric given by the intersection of bedding planes joint sets and faults performed research suggests high diversity of mechanisms leading to the origin of individual dsgsds the area of a single dsgsd can be affected by various types of movements such as sackung lateral spreading toppling or incipient sliding electrical imaging and trenching revealed that besides these mechanisms anisotropic flysch massifs formed by thick bedded sandstones are strongly exposed to subsurface opening of air filled voids related to widened crevices such a process is driven by deep seated creep and translational sliding of sandstone beds upon plastic claystones whose strength has been reduced to residual values of the angle of internal friction performed radiocarbon and osl dating revealed that some of the studied dsgsds originated in the holocene period particularly in the atlantic and subboreal chronozones

genesis and geomorphic evolution of the velke pinky stopes in the zlatohorska highlands eastern sudetes montanogenic landforms are commonly viewed as hazards by society but they are also holders of specific and uncommon morphology with unique dynamics that act as remarks on landscape history the velke pinky stopes in the zlatohorska highlands eastern sudetes are naturally revitalized post mining landforms with long term geoecological succession their genetic origin is diverse but recent processes such as deep seated slope deformations rockfalls and ground subsidence have resulted in a distinct morphology dominated by rock walls and the accumulation of blocks and debris wedges this morphology predisposes the stopes to become the core area of the most recent dynamic geomorphic activity within the wider relatively homogenous area by dendrogeomorphic techniques we identified more than 20 rockfall events within three of the stopes with increased activity since the 1980s only the 1991 and 2006 events were identical for all three stopes we obtained the years of exposures from 10 roots revealing the ground subsidence and opening of tension cracks or even the lateral retreat of the flanks of minor depressions the schmidt hammer test revealed the most recent and fresh gravitational activity in one of the stopes a relationship between the superficial morphology and underground structure was proven by electrical resistivity profiling compared to the previous studies engaged with the abandoned mines we presented how complex their evolution can be our study brings new information about the historical development of anthropogenic relief forms moreover our results suggest that standard research approaches can be successfully applied for development analysis of these specific forms

the schmidt hammer in rock material characterization the schmidt hammer provides a quick and inexpensive measure of surface hardness that is widely used for estimating the mechanical properties of rock material however a number of issues such as hammer type normalization of rebound values specimen dimensions surface smoothness weathering and moisture content and testing data reduction and analysis procedures continue to influence the consistency and reliability of the schmidt hammer test results this paper presents a a critical review of these basic issues and b the results of tests conducted on granitic rocks of various weathering grades in the light of the conclusions of this review it was found that a very good correlation exists between l and n hammer rebound values and that both hammers are fairly sensitive to the physical properties particularly to dry density though less so to effective and total porosities the n hammer producing a lesser scatter in the data proved to be more efficient than the l hammer in predicting uniaxial compressive strength and young s modulus the exponential form of the correlation curves was found to reflect microstructural changes during the course of weathering and the differences in the probing scales or mechanisms in the means of measuring these mechanical properties and could be generalized to other crystalline igneous rocks the possibility of predicting weathering grades from rebound values was also explored the changes in the rebound values during multiple impacts at a given point produced a better indication of the weathering grade than a single impact value it was concluded that increasing the impact energy and plunger tip diameter should significantly reduce the scatter in coarse grained weathered rocks and hence improve the reliability of the schmidt hammer as a rock material characterization tool

analysis of year to year variation of water temperature along the coast of the japan sea abstract mean monthly records of coastal sea surface temperature data csst obtained from stations along the japanese coasts of the japan sea and from those in the related seas for the period 1941 1984 were analyzed by using various methods of time series analysis for the purpose of clarifying the nature of the year to year variations of the state of the japan sea the year to year variations in the japan sea were found to be closely related to those in the east china sea and in the western north pacific specific results are as follows 1 a sudden cooling in the early 1960 s occurred in the southern stations of the japan sea and continued to the end of the analyzed data 2 variations with about a 6 year periodicity were observed at most stations and were especially dominant in the southern stations of the japan sea 3 these variations could be traced back to the kuroshio region of the east china sea 4 variations with about a 10 year periodicity were also observed in the northern stations of the japan sea

the number of impact craters on earth any room for further discoveries abstract only 128 impact craters exposed at earth s surface have been found so far while new craters are discovered occasionally taking into account the permanent consumption of craters by erosion we present the first estimate on the number of impact craters that should be present at earth s surface our study yields no evidence for any systematic incompleteness in the available inventory of the craters larger than about 6 km in diameter exposed at the surface in contrast more than 90 craters in the diameter range from 1 km to 6 km should still be waiting to be discovered and even more than 250 between 0 25 km and 1 km diameter the transition from a probably complete inventory above 6 km to a strongly incomplete record at smaller sizes may be related to the difference between simple and complex craters beyond these results on the terrestrial crater record our findings tentatively suggest that erosion rates on the 10 to 100 million year scale may be closer to present day erosion rates than previously assumed

dating of mining induced subsidence based on a combination of dendrogeomorphic methods and in situ monitoring abstract mining induced subsidence is a worldwide environmental problem that leads to damage to infrastructure and property thus knowledge of its past recent development is critically needed during land use planning moreover the temporal occurrence of subsidence is greatly variable with tendencies for gradual to abrupt movements subsidence rates can currently be achieved via radar interferometry but these data usually cover short time periods and are less accurate in forested areas in such cases dendrogeomorphic dating can provide chronologies of past subsidence activity in addition comparisons of tree ring based data with in situ monitoring may answer the sensitivity and reliability of dating methods in these specific conditions of continuous ground movement geomorphic mapping and dendrogeomorphic dating were performed at two forested landslide sites affected by coal mining subsidence in the upper silesian basin czech republic and the resulting chronology from one site was compared with levelling campaigns occurring from 1998 to 2015 based on 284 increment cores from 71 trees we were able to identify 7 subsidence events at the site dominated by a pioneering forest and 19 subsidence events at the site overgrown by a mature forest with the most frequent responses occurring from 1956 to 1971 and 2005 2011 the occurrence of multiple compression wood growth intervals some occurring in different directions of tree stems more than 30 of sampled trees indicated complex deformations presented by the flow like mechanism of waterlogged surfaces ongoing subsidence spreading and fragmentation of larger blocks and grabens a comparison of tree ring based chronology with in situ monitoring revealed good synchronicity with the periods of increased subsidence rates between 1 and 3 m year 1 thus indicating the high relevance of dendrogeomorphic methods for the determination of the most intense periods of ground subsidence our results show the first comparison of dendrogeomorphic methods with in situ monitoring of human induced subsidence areas and provide an alternative option for reconstructing decadal to centennial development of the affected areas

isrm suggested method for determination of the schmidt hammer rebound hardness revised version with its portable simple and affordable attributes the schmidt hammer sh is an ideal index apparatus which underlies its increasing popularity and expanding range of applications the sh rebound hardness value r is perhaps the most frequently used index in rock mechanics practice for estimating the uniaxial compressive strength ucs and the modulus of elasticity e of intact rock both in laboratory conditions and in situ the sh is also widely used for estimating the ucs of discontinuity walls and assessing the workability excavatability and boreability of rocks by mechanical means cutting polishing milling crushing and fragmentation processes in quarrying drilling and tunneling

tectonic strain changes affecting the development of deep seated gravitational slope deformations in the bohemian massif and outer western carpathians abstract this paper describes a pair of intensively studied deep seated gravitational slope deformations from the czech republic structural geological mapping and the interrogation of high resolution lidar dems have been used to reassess the extent of each slope deformation and to obtain new information about their surface morphologies electrical resistivity tomography has been used to image the subsurface structures while rod dilatometers and permanently installed mechanical extensometers have been used to define their kinematic behaviour dilatometric measurements from across a fissure the edge of the mu sk hill dsgsd show that the progressive trend has been interspersed by five periods of movement acceleration since monitoring began in 1990 while extensometric measurements from across a second fissure about 50 m from the edge of the plateau show that this discontinuity was affected by an significant period of extension from 2004 to 2006 and a significant period of compression from 2006 to 2008 these data demonstrate that the mu sk hill dsgsd is characterised by the lateral spreading of rigid sandstone blocks across a plastic marl formation at the edge of p ihrazy plateau extensometric measurements from the kn hyn mountain dsgsd show that a fault located at a depth of about 25 m below the surface is characterised by progressive dilation whereas a fault located at a depth of about 57 5 m below the surface is characterised by episodic vertical dip slip displacements both faults are affected by horizontal dextral strike slip displacements these data demonstrate that the kn hyn mountain dsgsd is characterised by translational rocksliding associated with the neotectonic uplift of the outer western carpathians the presented kinematic data have been compared to records of precipitation groundwater level earthquakes and strain changes measured by the fault displacement monitoring network eu tecnet strain changes induced by the widespread redistribution of stress through the crustal appear to represent an important and hitherto underappreciated geomorphological process affecting the development of the slope deformations at mu sk hill and kn hyn mountain future research will focus discovering whether this finding holds true for other deep seated gravitational slope deformations in different geomorphological and geological settings

tree ring analysis in the reconstruction of slope instabilities associated with earthquakes and precipitation the crimean mountains ukraine the crimean mountains in ukraine constitute a seismically active region that is abundant in various types of mass movement the limestone escarpments that rise above the black sea coast in the vicinity of the town of yalta are particularly subject to considerable rockfall landslide and debris flow processes that often endanger infrastructure and human life one of these very active slopes is the area of the ancient taraktash rockslide characterised by active block type movements lateral spreading toppling and incipient sliding rockfalls ongoing sliding activities and debris flows the aims of this study were i to employ tree ring analysis to reconstruct a record of slope instabilities mainly block type movements rockfalls landslides and debris flows within the taraktash slope deformation over a period of more than two centuries and ii to establish the degree of correlation between periods of enhanced slope activity and both historical earthquakes and climatic data the temporal frequency of significant slope processes was addressed through a tree ring analysis that took 738 increment cores from 255 crimean pine trees pinus nigra ssp pallasiana the tree ring record reveals periods of increased activity of block type movements rockfalls and landslides during the major earthquakes in 1790 1875 1927 and 1986 although the slope processes studied are predominantly driven by seismic activity their intensity and duration are also dependent on climatic factors this is especially true for landslides and debris flows which occurred mainly in years characterised by high precipitation totals

impact ejecta emplacement on terrestrial planets abstract impact cratering is one of the most fundamental processes responsible for shaping the surfaces of solid planetary bodies one of the principal characteristics of impact events is the formation and emplacement of ejecta deposits an understanding of which is critical for planetary exploration current models of ejecta emplacement however do not account for several important observations of ejecta deposits on the terrestrial planets in particular the presence of more than one layer of ejecta furthermore there is also no universal model for the origin and emplacement of ejecta on different planetary bodies we present a unifying working hypothesis for the origin and emplacement of ejecta on the terrestrial planets in which the ejecta are emplaced in a multi stage process the generation of the continuous ejecta blanket occurs during the excavation stage of cratering via the conventional ballistic sedimentation and radial flow model this is followed by the emplacement of more melt rich ground hugging flows the surface melt flow phase during the terminal stages of crater excavation and the modification stage of crater formation minor fallback occurs during the final stages of crater formation several factors will affect the final morphology and character of ejecta deposits the volatile content and cohesiveness of the uppermost target rocks will significantly affect the runout distance of the ballistically emplaced continuous ejecta blanket with impact angle also influencing the overall geometry of the deposits e g the production of the characteristic butterfly pattern seen in very oblique impacts ejecta deposited during the surface melt flow stage is influenced by several factors most importantly planetary gravity surface temperature and the physical properties of the target rocks topography and angle of impact play important roles in determining the final distribution of surface melt flow ejecta deposits with respect to the source crater this working hypothesis of ballistic sedimentation and surface melt flow provides a framework in which observations of ejecta at impact craters can be compared and placed in the context of the respective terrestrial planets

shock metamorphic features and their zoning and orientation in the precambrian rocks of the manicouagan structure quebec canada abstract the manicouagan structure of impact origin is located in eastern quebec about 300 km north of the st lawrence river the complex is of triassic age the shock deformation of the more important rock forming minerals of the autochthonous or at least parautochthonous rocks within the structure is described four zones of shock metamorphism are delineated based on the deformation features of plagioclase 1 plagioclase without planar features 2 plagioclase with planar features 3 first occurrence of plagioclase with partial isotropization and 4 first occurrence of plagioclase with total isotropization these four zones are more or less concentric and indicate a general increase in the grade of shock metamorphism towards the centre of the structure however several small areas probably underlain by allochthonous rocks appear not to fit this general picture biotite and garnet show evidence of a shock orientation of their deformation features an impact origin for the structure is favoured the impact possibly triggering volcanism

two types of el nino events cold tongue el nino and warm pool el nino abstract in this study two types of el nino events are classified based on spatial patterns of the sea surface temperature sst anomaly one is the cold tongue ct el nino which can be regarded as the conventional el nino and the other the warm pool wp el nino the ct el nino is characterized by relatively large sst anomalies in the nino 3 region 5 s 5 n 150 90 w while the wp el nino is associated with sst anomalies mostly confined to the nino 4 region 5 s 5 n 160 e 150 w in addition spatial patterns of many atmospheric and oceanic variables are also distinctively different for the two types of el nino events furthermore the difference in the transition mechanism between the two types of el nino is clearly identified that is the discharge process of the equatorial heat content associated with the wp el nino is not efficient owing to the spatial structure of sst anomaly as a result it cannot trigger a cold event it is also demonstrated that zonal advective feedback i e zonal adve

the 1873 collapse of the saint maximilien panel at the varangeville salt mine abstract the 1873 panel collapse at the varangeville salt mine lorraine france is described post accident reports as well as the experience drawn from neighbouring panels and mines proved that pillars punched the marly layers on which they rested a unique failure mechanism in the history of salt mines the database on rock mechanical behaviour is relatively small but it allows proposing credible values of the two most important mechanical parameters floor cohesion and roof stiffness numerical computations confirm that the central pillar despite its large horizontal dimensions punched the floor and that large strains may have localized in the rock mass above the panel edge allowing large scale deformation of the roof and catastrophic evolution of pillar punching

human topographic signatures and derived geomorphic processes across landscapes abstract the earth s surface morphology in an abiotic context is a consequence of major forcings such as tectonic uplift erosion sediment transport and climate recently however it has become essential for the geomorphological community to also take into account biota as a geomorphological agent that has a role in shaping the landscape even if at a different scale and magnitude from that of geology although the modern literature is flourishing on the impacts of vegetation on geomorphic processes the study of anthropogenic pressures on geomorphology is still in its early stages topography emerges as a result of natural driving forces but some human activities such as mining agricultural practices and the construction of road networks directly or indirectly move large quantities of soil which leave clear topographic signatures embedded on the earth s morphology these signatures can cause drastic changes to the geomorphological organization of the landscape with direct consequences on earth surface processes this review provides an overview of the recent literature on the role of humans as a geological agent in shaping the morphology of the landscape we explore different contexts that are significantly characterized by anthropogenic topographic signatures landscapes affected by mining activities road networks and agricultural practices we underline the main characteristics of those landscapes and the implications of human impacts on earth surface processes the final section considers future challenges wherein we explore recent novelties and trials in the concept of anthropogenic geomorphology herein we focus on the role of high resolution topographic and remote sensing technologies the reconstruction or identification of artificial or anthropogenic topographies provides a mechanism for quantifying anthropogenic changes to landscape systems this study may allow an improved understanding and targeted mitigation of the processes driving geomorphic changes during anthropogenic development and help guide future research directions for development based watershed studies human society is deeply affecting the environment with consequences on the landscape therefore establishing improved management measures that consider the earth s rapidly changing systems is fundamental

collapses of old mines in korea abstract ground collapses over abandoned mines constitute a significant geohazard in korea recent collapses at the mookeuk chungyang and toehyun mines provide examples of the failures of rock over old stopes and of old backfill that had been placed in abandoned stopes micro seismic monitoring by borehole geophones is used to locate rockfalls within the keumgok mine in order to design appropriate remedial filling the government s mine reclamation corporation has an ongoing programme of documentation and remediation of the old mines

analysis of long term land subsidence near mexico city field investigations and predictive modeling the mexico city region has several flat plains formed on exceptionally porous 60 90 lacustrine deposits overlying a highly productive regional aquifer severe land subsidence due to consolidation of the lacustrine aquitard caused by aquifer exploitation has resulted in restrictions on pumping in the core of mexico city this has led to large increases in aquifer pumping in the outlying lacustrine plains where satellite communities are rapidly expanding the chalco basin is one of these lacustrine areas where pumping began in the 1950s and greatly increased in the 1980s the lacustrine sequence in the chalco area is significantly thicker than anywhere else in the basin of mexico averaging 100 m and reaching a maximum thickness of 300 m consequently this area is susceptible to the highest potential land subsidence effects as a result of groundwater extraction of anywhere in the basin land subsidence in the central part of the chalco basin has increased to 0 4 m yr since 1984 and by 1991 total subsidence had reached 8 m the rapid land subsidence in this area is causing the accumulation of meteoric waters during the rainy season resulting in extensive flooding of farmland this study first demonstrates a methodology for combining hydraulic data from a network of monitoring wells geotechnical data from core samples and a compilation of historical information on land surface elevation to quantify groundwater flow and land subsidence phenomena within the rapidly subsiding chalco basin then a one dimensional mathematical model is employed to develop predictions of future land subsidence under a range of pumping conditions the model permits the hydraulic properties of the aquitard to vary as transient functions of hydraulic head and porosity simulations suggest that under current pumping rates total land subsidence in the area of thickest lacustrine sediment will reach 15 m by the year 2010 if pumping is reduced to the extent that further decline in the potentiometric surface is prevented total maximum subsidence would be significantly less 10 m and the rate would nearly cease by 2010

impact of mass movements on geo and biodiversity in the polish outer flysch carpathians complex research was simultaneously done on the geological geomorphological and biocenotic features of landslide areas in the polish outer flysch carpathians the research allowed us to define the relations between the diversity of the landslide originating landforms and the biotopes occurring within them high geodiversity diversity of landforms soil and water of landslide areas allows for a mosaic network of extremely diversified natural habitats all of these natural habitats together are characterized by a specific biodiversity dependence between geo and biodiversity in landslide areas is connected with a specific co evolution which is related to the adaptation of the ecosystems to landforms comprehensive research of this relation to landslide areas would promote the necessity to protect the landslide areas unfortunately such research done in the carpathians is still sporadic the comprehensively documented landslide areas are especially valuable elements of the nature protection network within the carpathian euro region if made reasonably accessible they may be used for didactic purposes and in geotourism

large sackung along major tectonic features in the central italian alps deep seated gravitational slope deformation sackung is common in alpine mountain belts it is controlled by lithological geomorphological and structural features we describe and discuss five examples of dsgsd along the insubric line periadriatic fault in the central italian alps the five examples are different in morphology size state of activity and distribution and are located along both primary and secondary valleys we demonstrate relations between structural and gravitational features and discuss the possibility that structural has both passive and active roles in sackung development analysis of ps sar data shows that the studied examples are not active today numerical modelling demonstrates the importance of lithological and structural constraints postglacial debuttressing groundwater fluctuations and weathering on sackung triggering and development

geophysical anatomy of counter slope scarps in sedimentary flysch rocks outer western carpathians abstract a multidisciplinary geophysical survey consisting of electrical resistivity tomography ert ground penetrating radar gpr shallow seismic refraction ssr and gravity survey gs was used to investigate the counter slope scarps one of the typical manifestations of the relaxed zones of rock massifs and the possible initial stages of deep seated landslides dsls two upper parts of the extensive dsls within the moravskoslezske beskydy mountains outer western carpathians owc built by the sedimentary flysch rock were chosen as the testing sites a combined geophysical survey on the flysch rocks was performed on both localities to enhance our present findings the survey revealed that the ert is able to reliably detect underground discontinuities which are manifested at the ground surface by one of the typical landforms tension cracks trenches pseudokarst sinkholes double crested ridges and counter slope scarps previous studies suggested that bedrock discontinuities should be depicted by high resistivity features within ert surveying according to ssr and gs expected zones of weakened rock massif were not confirmed directly underneath the superficial landforms but they were shifted based on the ssr and gs measurements the depicted high contrast transitions between high and low resistivity domains within the ert profiles were newly identified as possible manifestation of bedrock discontinuities the results of gpr measurements give only limited information on the sedimentary flysch rocks due to shallow penetrating depth and locally strong signal attenuation the combined results of multidisciplinary geophysical surveying confirmed an importance of employing more than one geophysical technique for integrated interpretations of measured data integrated interpretations of the measured geophysical data provided a new insight into massif disintegration and the geomorphic origin of the landforms related to the dsl

el nino modoki and its possible teleconnection 1 using observed data sets mainly for the period 1979 2005 we find that anomalous warming events different from conventional el nino events occur in the central equatorial pacific this unique warming in the central equatorial pacific associated with a horseshoe pattern is flanked by a colder sea surface temperature anomaly ssta on both sides along the equator empirical orthogonal function eof analysis of monthly tropical pacific ssta shows that these events are represented by the second mode that explains 12 of the variance since a majority of such events are not part of el nino evolution the phenomenon is named as el nino modoki pseudo el nino modoki is a classical japanese word which means a similar but different thing the el nino modoki involves ocean atmosphere coupled processes which include a unique tripolar sea level pressure pattern during the evolution analogous to the southern oscillation in the case of el nino hence the total entity is named as el nino southern oscillation enso modoki the enso modoki events significantly influence the temperature and precipitation over many parts of the globe depending on the season the impacts over regions such as the far east including japan new zealand western coast of united states etc are opposite to those of the conventional enso the difference maps between the two periods of 1979 2004 and 1958 1978 for various oceanic atmospheric variables suggest that the recent weakening of equatorial easterlies related to weakened zonal sea surface temperature gradient led to more flattening of the thermocline this appears to be a cause of more frequent and persistent occurrence of the enso modoki event during recent decades

estimates of yet to find impact crater population on earth abstract one hundred and seventy six craters on earth are currently accepted as resulting from bolide impact this list is growing at a rate of approximately two craters per year because of new discoveries and revised interpretations here we take the subset of craters most relevant to sedimentary basin exploration and utilization phanerozoic kilometre scale craters and tackle the question of how many remain to be found in phanerozoic strata on earth a surprising range in predictions of crater numbers is obtained from published crater population functions reaching two orders of magnitude variation for craters in the range 1 5 km diameter this range in predictions is largely due to variations in treatment of impactor breakup in the atmosphere also required is quantification of the total area and timespan of phanerozoic sediment currently preserved on earth an estimate of 8 87 10 15 km 2 a is derived here together with a relatively conservative crater population function this yields a prediction of 845 craters subtracting the 131 known phanerozoic craters larger than 1 km leaves a predicted population yet to find of 714 of which 228 are larger than 2 5 km uncertainties subsets of this population and spatial distribution are also considered