deep seated gravitational slope deformations related landslides and tectonics abstract deep seated gravitational slope deformations and their relationships with tectonic deformation of rocks is considered to examine the viewpoint of tectonics as a causative factor in slope deformation first a distinction is made between the different types of deep seated gravitational slope deformation then the geomorphological and structural effects of the different macrostructural deformations induced by tectonics on the scale of the whole deforming ridge is briefly discussed finally some case studies that represent either verified or possible cases of gravity deformation in response to tectonic activity are used as illustration

time constraints for the evolution of a large slope collapse in karstified mountainous terrain of the southwestern crimean mountains ukraine abstract deep seated gravitational deformations are significant denudational agents of rock slopes at the margins of karstified plateaus of the crimean mountains ukraine the aim of this article is to study long term evolution of a giant rock slope failure close to the black sea coast in the southwestern tip of the mountains near foros town the failure evolved in highly anisotropic limestones overlying plastic flysch layers where the main headscarp follows a strike slip fault we tested a new chronological strategy based on 14 c and u th series dating of speleothems from unroofed caves exposed in the headscarp area of the slope failure this approach made it possible to state maximum age of the slope collapse in individual parts of the deformed slope obtained results indicate that extension of discontinuities together with their karstification can be traced to 300 ka bp whereas evolution of the main headscarp started 110 ka bp and since then it has propagated in the eastward direction the youngest slope failure in the easternmost part of the studied collapse is of late holocene age our study indicates that conditions for large rock slope failures in carbonate areas can be prepared by speleogenesis or combined effects of propagation of cracks and their solution based expansion furthermore large rock slope failures can be important factors for the genesis of unroofed caves

integrated geophysical and geomorphological approach to investigate the snowmelt triggered landslide of bosco piccolo village basilicata southern italy abstract most of basilicata region in the southern italian apennines is characterized by landslides often developing in clayey marly formations many events have been triggered by extreme rainfall or snowmelt the most important happened on february march 2005 at bosco piccolo 5 km far from potenza this landslide developed subsequently to rapid snowmelt occurred during alternating short periods of high temperatures and intense and continuous snowfalls this complex landslide affected 4 ha of surface and reached a maximum depth of 20 m inducing damage and collapse of about 80 of the buildings in the village an integrated multidisciplinary approach has been adopted to study the landslide a multitemporal aerial photo interpretation and detailed geomorphological surveys have been carried out combined electrical resistivity tomography ert and self potential sp measurements have been performed and calibrated with boreholes stratigraphy such an integrated approach allowed us to partially reconstruct the geometry of the investigated body and to evaluate the effectiveness of drainage system planned for the area

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

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

synoptic scale characteristics and atmospheric controls of summer heat waves in china summer heat waves with persistent extreme high temperatures have been occurring with increasing frequency in recent decades these extreme events have disastrous consequences for human health economies and ecosystems in this study we examine three summers with intense and protracted heat waves the summers of 2003 2006 and 2013 with high temperatures located mainly in southeastern southwestern and eastern china respectively the synoptic scale characteristics of these heat waves and associated atmospheric circulation anomalies are investigated in the early heat wave episode of 2003 a heat center was located in the southeast coastal provinces during the first 20 days of july the maximum southward displacement of the east asian jet stream eajs induced anticyclonic anomalies to the south associated with southwestward intensification of the western north pacific subtropical high wnpsh and extreme high temperatures were found only to the south of the yangtze river in the later episode a poleward displacement of the eajs and an enhanced wnpsh over the midlatitudes of eastern china resulted in a heat dome over the region and the heat wave extended northward to cover a larger area of eastern china the coupling between the westward enhanced wnpsh and poleward displaced eajs was found in the east china heat wave of 2013 as well but the area of high temperatures reached far to the north in august 2013 with below normal temperatures located in a small region of south china in the 2006 southwestern drought and heat wave extreme poleward displacement of the eajs associated with extraordinary westward extension of the wnsph resulted in further blocking of the moisture supply from the southwest monsoon large scale moisture deficiencies dry conditions and downslope winds were common features of all investigated heat wave episodes but in 2006 low level heat lows associated with a well mixed layer due to intensive daytime heating and atmospheric turbulence were emphasized

impact of the quasi biweekly oscillation over the western north pacific on east asian subtropical monsoon during early summer 1 the impact of quasi biweekly oscillation qbwo over the western north pacific on east asian summer monsoon easm is investigated the life cycle of qbwo is divided into eight phases defined by the two leading principal components pc1 and pc2 of an empirical orthogonal function analysis subtropical rainfall shows significant changes with a northwestward propagation of convection from equatorial regions to the south china sea scs the most significant variations occur in qbwo phases 3 and 4 enhanced convection over scs and phases 7 and 8 reduced convection over scs the east asia mei yu significantly decreases in qbwo phases 3 and 4 but increases in phases 7 and 8 the qbwo influences easm through modulating the subtropical monsoon flow and extratropical circulation the response of lower tropospheric atmosphere to qbwo shows a northwestward propagation and a downstream wave train that extends northward into the western north pacific modulating the scs monsoon trough and the easm flow associated with moisture transportation the mid tropospheric extratropical circulation and the western pacific subtropical high also show obvious changes accompanying qbwo evolution resulting in circulation patterns associated with cold air activity moreover changes with qbwo are found in the upper tropospheric east asian westerly jet stream and the south asian high and these changes contribute to upper level divergence over subtropical east asia

experimental investigation on progressive deformation of soil slope using acoustic emission monitoring abstract the deformation process of soil slopes observed during a landslide can have progressive characteristics which can be quantified through acoustic emission ae monitoring a model test is designed based on the geological model of a translational landslide and experiments are conducted to reproduce the three stage deformation process of a soil slope the deformation process of progressive landslides is described using equations and an entire loading process is realized using a programmable logic controller plc the maximum velocity of a sliding body is measured to be approximately 6 mm s with the final displacement exceeding 210 mm the ae deformation and mechanical measurements of the entire process are compared to comprehensively evaluate the evolution behavior of progressive soil landslides the experiments demonstrate that ae rates can linearly quantify slope velocity as well as help quantify slope acceleration a copper tube and an aluminum tube are compared as different waveguides and the quantitative relationship between the ae and deformation obtained by the active copper waveguide is found to be more distinct the experiments also show that the acceleration of a slope can be effectively used as a discriminant index of progressive landslides which has the potential to be applied in field monitoring

down slope variation in geotechnical parameters and pore fluid control on a large scale alpine landslide abstract a geotechnical investigation has been carried out on a large volume landslide in the stambach valley on the slopes above the town of bad goisern austria undrained loading has been considered as a means of triggering a large volume debris flow the initiation of this landslide has been linked with the collapse of rock pillars from the rock face of zwerchwand onto the head of the flow the concept of pore tensions resulting from stress relief has been used to account for the time delays of up to 10 months between the loading and the reactivation of the debris flow

from the geological to the numerical model in the analysis of gravity induced slope deformations an example from the central apennines italy abstract this paper presents the findings from a study on gravity induced slope deformations along the northern slope of mt nuria rieti italy the slope extends from the village of pendenza to the san vittorino plain and hosts the peschiera river springs i e the most important springs of the central apennines average discharge about 18 m3 s detailed geological geomorphological and geomechanical surveys supported by a site stress strain monitoring system and laboratory tests led us to define the main evolutionary features of the studied phenomena based on the collected data a geological evolutionary model was developed with a view to identifying a spatio temporal correlation between relief forms jointing of the rock mass and its stress conditions the geological evolutionary model was expected to improve numerical simulations and to test our assumptions the numerical model also allowed us to simulate changes in the stress strain conditions of the rock mass and correlate them with jointing seepage as well as with site detected and site monitored forms and deformations in particular significant relations between seepage tensile stresses within the rock mass karst solution and collapse of cavities were identified

landslides and quaternary climate changes the state of the art abstract climatic factors are considered major causes and triggers of slope instability but the palaeoclimatic implications of landslides have not yet been systematically reviewed as inferred from landslides dated to the late glacial and holocene glacial interglacial transitions are the major intervals of enhanced landsliding but the length of this interval varies between distinct types of landscapes mass movements in non glaciated temperate mountain ranges arid and tropical regions and coastal areas intensified soon after the onset of the holocene alongside the warming and wetting of the climate whereas large rock slides in areas within the limits of pleistocene glaciations mostly show a millennial scale time lag with respect to glacier withdrawal although the incidence of landslides was ubiquitous throughout the holocene the mid to late holocene transition 5 4 ka was especially favourable for the origin of landslides across distinct types of landscapes indicating a strengthened role of mass movements during the culmination phases of interglacial climate optima in addition growing evidence suggests that the enhanced activity of landslides occurred during warmer interstadial conditions which is best demonstrated in the temporal coincidence of arid zone landslides with quaternary pluvials future progress in the understanding of the relationships between landslides and quaternary climate changes should benefit from the i extension of datasets of dated landslides ii geographical expansion of dating studies to regions with a lack of chronologically determined landslides e g tropics iii improvement of landslide dating strategies involving the incorporation of independent palaeoclimatic proxies and iv wider incorporation of numerical modeling within landslide dating studies

electrical imaging of sliding geometry and fluids associated with a deep seated landslide la clapiere france this paper deals with the applicability of electrical resistivity tomography ert for the recognition of large landslide structures at depths which have never previously been imaged accurately one of the most studied and instrumented deep landslides in europe is taken as an example the la clapiere landslide the first stage of the study consisted of an accurate geological mapping taking into account a morphological analysis of gravitational deformations this allowed a very fine definition of the landslide structure that could be compared with three provided ert profiles performed within the landslide body very good correlations were obtained for the determination of sub horizontal structures and associated fluid circulations it confirmed the position of the sliding surface that reached a maximum depth of 100 m forward computing was however necessary to determine the influence and then the presence of vertical discontinuities it supports the use of ert as an efficient tool for large scale landslide imaging such as deep seated landslides copyright 2010 john wiley sons ltd

evolution of the circulation anomalies and the quasi biweekly oscillations associated with extreme heat events in southern china abstractsouthern china located in the tropical subtropical east asian monsoonal region presents a unique anticyclonic cyclonic circulation pattern during extreme heat eh obviously different from the typical anticyclone responsible for eh in many other regions associated with the evolution of eh in southern china the anticyclonic cyclonic anomalies propagate northwestward over the philippines and southern china before the eh onsets the anticyclonic anomaly dominates southern china resulting in stronger subsidence over southern china and stronger southerly southwesterly flow over the western northern margins of southern china the southerly southwesterly flow transports more water vapor to the north of southern china thus together with the local stronger subsidence resulting in drier air condition and accordingly favoring the occurrence of eh conversely after the eh onsets the cyclonic component approaches southern china and offsets the high temperature the oscillations of temperature

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

topographic controls on evolution of shallow landslides in pastoral wairarapa new zealand 1979 2003 abstract this study aims to identify topographic influence on shallow landslides and their evolution during 1979 2003 in the pastoral lower north island new zealand landslide affected sites were mapped from aerial photographs and an aster satellite image the two landslide maps were overlaid in a geographic information system arcgis to detect the changes that have taken place in landslide affected areas the change map and the landslide distribution maps were overlaid with three topographic layers of slope gradient slope position and slope aspect that had been derived from a digital elevation model in arcgis the overlay analysis revealed that landslides affected area increased from 23 75 ha in 1979 to 110 97 ha in 2003 the distribution of landslide affected sites is inversely correlated with slope gradient but positively with slope position northern aspects are the most vulnerable to landsliding containing about 78 of the total affected sites moderate slope gradients suffered the most severe landsliding in the lower to middle slopes the overall magnitude and frequency of landsliding is also related to northern and eastern octants on the moderate slope gradients in the low to moderate slope positions although the same topographic setting is conducive to landsliding in both 1979 and 2003 the rate of landsliding varies with topographic setting hence topography is critical not only to landsliding but also to the evolution of sites already affected by landslides such an understanding over large spatial scales is possible only with the use of multitemporal remote sensing data and gis that are able to speed up data collection and analysis

structural constraints on deep seated slope deformation kinematics abstract a significant sackung type deep seated slope gravitational deformation dsgsd was recognised for the first time by the authors in the middle part of valfurva east of bormio rhaetian alps italy the reconstruction of its kinematics age and state of activity is presented through a detailed description of its morphological geomechanical and structural features an integrated multi disciplinary approach was performed to achieve a clear comprehension of the phenomenon field surveys and aero photo interpretation were carried out in order to clarify the structural geological and geomorphological setting in which the dsgsd developed a kinematic conceptual model of the slope deformation was developed through the analysis of morpho structures of their significance and relationships with lithological markers and quaternary deposits after a geomechanical characterisation of the rock mass involved in the slope deformation numerical modelling was performed to verify the hypotheses made on kinematics and driving factors of the phenomenon the sackung affects pre permian metapelites metabasites and marbles belonging to the upper austroalpine basement of the campo nappe as well as late pleistocene and holocene glacial and rock glacier deposits the deformation started after the late wurmian age 15 000 11 000 years b p and continued until few centuries ago not excluding a present day low rate activity deformation consists in a large oblique sagging along a deep confined sliding surface associated with gravitational reactivation of pre existing late alpine and recent tectonic brittle structures leading to the formation of n s and wnw ese trending gravitational morpho structures the evolution of the wnw ese trending system resulting in asymmetric trenches led to progressive failure of the lower part of the slope during the last 10 000 years as testified by large paleo landslide accumulations and it is still in progress numerical modelling indicates post glacial unloading as the main triggering factor of the slope deformation the importance of this deep seated slope deformation is enhanced by the occurrence of the 30 mm 3 active ruinon landslide in the lower part of the slope such landslide is subjected to rapid evolution and threatens the valley floor establishing an important risk factor connected to human lives and socio economic activities

the recent fault scarps of the western alps france tectonic surface ruptures or gravitational sackung scarps a combined mapping geomorphic levelling and 10be dating approach abstract in the western alps some recent scarps were previously interpreted as surface ruptures of tectonic reverse and normal faults that agree with microseismicity and gps measurements our analysis shows that in fact there are hundreds of recent scarps up to 30 m high and 2 1 km long with only pure normal motions they share the same characteristics as typical sackung scarps the scarps are mainly uphill facing parallel to the ridge crests and the contour lines they are relatively short less than 2 1 km with respect to tectonic fault ruptures and organized in swarms they cut screes and relict rock glaciers with a slow commonly 1 mm year average slip rate in the aiguilles grives massif these sackung scarps clearly express the gravitational toppling of sub vertical bedding planes in hard rocks in contrast the belledonne outer crystalline massif exhibits scarps that stem from the gravitational reactivation of conjugate tectonic faults the recent faults extend to about 1600 m beneath the rognier ridge crest but are always above the valley floor the main scarp swarm is 9 2 km long and constitutes the largest sackung ever described in the western alps 10 be dating of a scarp and offset surfaces shows that 4 m slip may have occurred rapidly in less than 3800 years sometimes between the end of the glaciation and 8800 1900 years ago this dating together with the location of some faults far from the deep glacial valleys suggests that sagging might have been triggered by strong earthquakes during a post glacial period of probably enhanced seismicity the belledonne and synclinal median faults just beneath the rognier sackung could have been the sources of this seismicity

deep seated failure propagation in a fractured rock slope over 10 000 years the la clapiere slope the south eastern french alps abstract the la clapiere area tinee valley alpes maritimes france is a typical large complex unstable rock slope affected by deep seated gravitational slope deformations dgsd with tension cracks scarps and a 60 106 m3 rock slide at the slope foot that is currently active the slope surface displacements since 10 ka were estimated from 10be ages of slope gravitational features and from morpho structural analyses it appears that tensile cracks with a strike perpendicular to the main orientation of the slope were first triggered by the gravitational reactivation of pre existing tectonic faults in the slope a progressive shearing of the cracks then occurred until the failure of a large rock mass at the foot of the slope by comparing apertures variations and changes in direction between cracks of different ages three phases of slope surface displacement were identified 1 an initial slow slope deformation spreading from the foot to the top characterized by an average displacement rate of 4 mm yr 1 from 10 5 6 ka bp 2 an increase in the average displacement rate from 13 to 30 mm yr 1 from the foot to the middle of the slope until 3 6 ka bp and 3 development of a large failure at the foot of the slope with fast displacement rates exceeding 80 mm yr 1 for the last 50 years the main finding of this study is that such a large fractured slope destabilization had a very slow displacement rate for thousands of years but was followed by a recent acceleration the results obtained agree with several previous studies indicating that in situ monitoring of creep of a fractured rock slope may be useful for predicting the time and place of a rapid failure

a model study of heat waves over north america meteorological aspects and projections for the twenty first century abstractthe characteristics of summertime heat waves in north america are examined using reanalysis data and simulations by two general circulation models with horizontal resolution of 50 and 200 km several key regions with spatially coherent and high amplitude fluctuations in daily surface air temperature are identified the typical synoptic features accompanying warm episodes in these regions are described the averaged intensity duration and frequency of occurrence of the heat waves in various key regions as simulated in the two models for twentieth century climate are in general agreement with the results based on reanalysis data the impact of climate change on the heat wave characteristics in various key regions is assessed by contrasting model runs based on a scenario for the twenty first century with those for the twentieth century both models indicate considerable increases in the duration and frequency of heat wave episodes and in number of heat wave days per year during the twenty firs

a late holocene deep seated landslide in the northern french pyrenees abstract a very large deep seated landslide dsl in the northern pyrenees with over 1 4 10 9 m 3 was mapped and dated based on sedimentation rates and 10 be terrestrial cosmogenic radionuclide surface exposure cre dating our analysis on the landslide reveals the role of inherited structures in the landslide process and highlighted typical gravitational morpho structures and a small lake trapped at the toe of the landslide head scarp the rate of lake sedimentation 0 86 0 57 mm yr 1 also provided us with the approximate age of the landslide 1106 540 yr the cre dating result highlights two main slope destabilization phases then we discussed the history of dsl activity and its controlling factors information related to historic markers and the absence of particular climate markers and changes during the medieval dark ages point to a single event in ad 1380 due to a major seismic event lavedan earthquake

influence of tectonic structures on the hope slide british columbia canada abstract the hope slide which occurred on january 9 1965 involved an estimated 47 mm3 of meta volcanics and intrusive rocks previous workers reported the presence of tectonic structures faults and shear zones along the failure surface at the hope slide these tectonic features were investigated in detail to assess their effects on rock mass quality and the related implications for slope stability this paper integrates basic field and laboratory concepts from structural and engineering geology subdividing the failure area into structural domains allowed distinct discontinuity sets to be associated with specific tectonic structures the geological strength index gsi was used to estimate the rock mass damage related to the tectonic structures low gsi values were seen to outline tectonic damage zones point load tests were used to characterise the compressive strength of rocks adjacent to the tectonic structures strength anisotropy tentatively attributed to damage caused by a large shear zone was observed in greenstone samples seepage zones along the failure surface were observed preferentially along shallow discontinuities that dipped downslope and in rock masses of good quality gsi 40 an alternative morphology of the slope failure is proposed by distinguishing between the extent of the surficial damage due to the rock slope failure and the zone of failed material depletion zone for the first time a kinematic mechanism for the hope slide is proposed based on a preliminary 3 dimensional block model a pre 1965 dem was produced from estimates of material lost and gained as reported by previous workers the pre 1965 dem revealed that the tectonic structures recognised during fieldwork bounded the material that failed in the 1965 event

structural control and types of movements of rock mass in anisotropic rocks case studies in the polish flysch carpathians abstract types of gravitational movements in the flysch carpathians are related to tectonic and lithologic anisotropy of rock massifs this article presents the main types of mass movements in the highly anisotropic flysch massifs lateral spreading and rock flow topple translational rotational and compound sliding and complex type of mass movements which are illustrated by chosen forms described using structural analysis joints faults and other structural planes orientation topple is the typical mass movement for double ridges and top trenches e g gaworzyna in the beskid s decki mts translational landslides with flat structural sliding surfaces typical for shallow forms can develop along bedding planes e g duszatyn western bieszczady mts as well as along joints opuszna gorce mts and fault planes rzeki gorce mts currently used classification of the structural landslides is applied only to translational landslides shearing zones of deep seated landslides are composed of structural sections of joints faults bedding planes and shearing elements consequently most of the carpathian landslides have developed as compound type with non circular sliding zones representing complex movements combined with various types of displacement rotation translation and or topple purely rotational movements with circular failure typical for isotropic material have developed in the flysch where thick bedded hard sandstones are underlain by plastic shales e g mt kostrza in the beskid wyspowy mts the influence of anisotropy of these rocks on sliding surface is significantly reduced and plastic type rocks stimulate rock flow development which is usually later transformed into complex landslides with predominant rotational movement e g rotational landslide with topple and flow elements on mt muronka in the beskid l ski mts compound landsliding on mt lubon wielki beskid wyspowy mts represents an antithetic rotational slide with topple and rotational type movements

morphology structure and kinematics of a rainfall controlled slow moving andean landslide peru the large slow moving landslide of maca is located in the upper colca valley southern peru a region characterized by a well pronounced rainy period and intense and recurrent sustained seismicity the landslide developed in deep lacustrine deposits has recently accelerated threatening the maca village this work aims at understanding the rupture mechanism and the causes of the recent landslide reactivation acceleration we present a multidisciplinary characterization of the maca landslide that includes i geological and morphological mapping in the field ii remote sensing analysis using an historical aerial photograph of 1955 and the pleiades satellite images 2013 iii global positioning system gps including time series of surveys over 13 years and continuous measurements over 14 months iv a geophysical campaign with deep electrical resistivity tomography profiles acquired across the landslide mass our study shows that this 60 mm3 landslide which can be classified as a clay silt compound landslide moved by 15 m between 2001 and 2014 with a large inter annual velocity variation up to a factor of 500 depending on the rainfall intensity we suggest that these dramatic changes in velocity are the result of the combination of a threshold mechanism and the short intense rainy season in peru this study reveals three main driving factors acting at different timescales i over several decades the river course has significantly changed causing the maca landslide reactivation in the 1980s due to the erosion of its toe ii at the year scale a minimum amount of rainfall is required to trigger the motion and this amount controls the landslide velocity iii transient changes in slide velocity may occur anytime due to earthquakes this study particularly highlights the non linear behaviour of the motion with rainfall copyright 2016 john wiley sons ltd

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

characterization of the groundwater response to rainfall on a hillslope with fractured bedrock by creep deformation and its implication for the generation of deep seated landslides on mt wanitsuka kyushu island abstract in this study the hydrogeological response of a hillslope affected by gravitational deformation was analyzed based on the data obtained for two observation boreholes a 10 m borehole representing a relatively superficial section of the hillslope dominated by soil and old landslide deposits and a 40 m borehole representing the bedrock aquifer for this analysis the precipitation events in the area groundwater levels of the two boreholes electrical conductivity and isotopic concentration oxygen and hydrogen of the groundwater in the boreholes and rainfall samples were measured derived from the rainfall data the antecedent precipitation index api with a 6 h half life offers a good correlation with the peaks in the groundwater levels in the bedrock aquifer the characteristics of the groundwater response suggest the existence of a single structure in the bedrock that controls the response of the hillslope the structure serves as a conduit which rapidly drives the rainfall water recharge into the bedrock evidently this process is unrelated to the superficial section represented by the observations in the 10 m borehole the structure is associated with an area of high hydraulic conductivity in the bedrock caused by the gravitational deformation in the hillslope the strong control of this structure in the hillslope s hydrogeological response makes it responsible for the hillslope s stability during high precipitation events this information is highly relevant to areas featuring the generation of several deep seated landslides under heavy rain conditions

deep seated gravitational slope deformations controlled by the structure of flysch nappe outliers insights from large scale electrical resistivity tomography survey and lidar mapping abstract the flysch nappe outliers represent a structural setting prone to the development of deep seated gravitational slope deformations dsgsds the study area of the palkovicke h rky hills represents an isolated outlier of the carpathians flysch nappes czech republic geomorphological mapping based on field surveys and interpretation of lidar data reveals the occurrence of various types of slope deformations including two dsgsds with the aim of detecting the main controlling factors of the dsgsds a multiapproach investigation combining surface and underground studies has been performed structural measurement points to a brachysynclinal structure composed of jointed and lithologically diverse strata with step like topography high resolution lidar data suggest strong tectonic disruption caused by conjugated transtensional and en echelon tectonic faults controlling the course of slope segments river valleys and landslide scarps four specific localities have been subjected to geophysical surveying kilometre scale electrical resistivity tomography ert profiles that have depths of penetration reaching the limits of the method 150 m were acquired across the gravitationally deformed nappe outlier the data show the overall structural conditions of the nappe outlier consisting of alternating lithological units affected by folds and fault zones a local subordinate anticline within the central part of the brachysynclinal structure has controlled the origin of the most morphologically pronounced dsgsds other large scale dsgsds related to the inherited fault system potentially affect the entire n nw segment of the studied elevation data integration indicate that structural conditions including lithological boundaries tectonic disruption and local folding to be the main controlling factors of the dsgsds evolution

control of slope deformations in high seismic area results from the gulf of corinth observatory site greece abstract the northern coast of the peloponnesus greece is characterized by high seismic activity related to the gulf of corinth opening with an extension rate of 16 mm y 1 studies presented in this paper focus on the characterization of links between tectonic and slope deformations on the panagopoula slope located on the southern coast the approach is centred on qualitative and quantitative data acquisition based on geological and geomorphological investigations geophysical imagery by electrical resistivity tomography and slope displacement monitoring firstly we highlight two different types of slope deformation on panagopoula a superficial landslide affecting weathered limestone and a large scale deformation without global failure expressed in the field tectonic features play a major role in these two dynamic processes taking into account the strong geometrical link between the inherited fractures and gravitational scarps mapped in the field secondly the displacements survey network distributed on both sides of a significant fault crossing the slope allows the quantification of slope displacements underlying two components i a gravitational sliding n010 along the slope and ii a supposed tectonic component n240

influence of structural framework on mountain slope deformation in the maiella anticline central apennines italy abstract relationships between tectonic framework and gravity driven phenomena have been investigated in an area of the central apennines italy characterised by high relief the north south half dome shaped maiella anticline lies in the easternmost part of the apennine fold and thrust belt its backlimb is bordered by the caramanico fault a normal fault with a maximum downthrown of about 3 5 km that separates the western slope of the maiella massif from the caramanico valley the southwestern maiella area is affected by deep seated gravitational slope deformation indicated by major double crest lines down hill and up hill facing scarps a pattern of crossing trenches bulging at the base of slopes and the presence of different types of landslide and talus slope deposits the onset and development of deep seated gravitational slope deformations and the location of quaternary massive rockslope failures have been strongly influenced by the structural framework and tectonic pattern of the anticline deep seated gravitational slope deformation at mt macellaro mt amaro ridge has developed along the maiella western reverse slope in correspondence with the anticline axial culmination it is bordered at the rear by a nnw sse oriented dextral strike slip fault zone and has an e w direction of rock mass deformation closer to the southern plunging area of the anticline gravity driven phenomena show instead a n s and nw se direction influenced by bedding attitude 3d topographic models illustrate the relationship between deep seated gravitational slope deformation and massive rockslope failures the campo di giove rock avalanche a huge quaternary failure event was the result of an instantaneous collapse on a mountaine slope affected by a long term gravity driven deformation

analysis of lateral rock spreading process initiation with a numerical modelling approach the first erosional front of the south eastern alps has been affected by several deep seated landslides the movements affected a jurassic limestone sequence underlain by an upper trias unit keuper mainly composed of marl and clays horst and graben like structures newly formed gravitational faults outflow and other field evidence suggest that such movements are consistent with lateral rock spreading processes an example of such processes is the la marbriere slope where field investigations have revealed that three distinct zones corresponding to three evolutionary stages of movement exist the question is what are the structural and mechanical modifications undergone by the slope between those evolution stages to tackle this question numerical models based on a 2d cross section of the la marbriere slope have been performed results show that to fit the structural evidence of the precollapse situation elasto plastic behaviour of the trias keuper unit is needed the transition between the precollapse and fresh post collapse situations requires a modification of the mechanical behaviour of the trias keuper unit to burger type resulting in the formation of antithetic and synthetic gravitational faults producing a graben like structure

electrical resistivity tomography technique for landslide investigation a review abstract in the context of in situ geophysical methods the electrical resistivity tomography ert is widely used for the near surface exploration of landslide areas characterized by a complex geological setting over the last decade the technological improvements in field data acquisition systems and the development of novel algorithms for tomographic inversion have made this technique more suitable for studying landslide areas with a particular attention to the rotational translational and earth flow slides this paper aims to present a review of the main results obtained by applying ert for the investigation of a wide spectrum of landslide phenomena which affected various geological formations and occurred in different geographic areas in particular significant and representative results obtained by applying 2d and 3d ert are analyzed highlighting the advantages and drawbacks of this geophysical technique finally recent applications of the time lapse ert tl ert for landslide investigation and the future scientific challenges to be faced are presented and discussed

are sackungen diagnostic features of de glaciated mountains abstract deep seated gravitational slope deformations dsgsds with characteristic sackung landforms e g double crests trenches uphill facing scarps and toe bulging are considered by some researchers to be diagnostic features indicating past mountain glaciations however an extensive literature review on sackung features throughout the world reveals that in some regions paraglacial processes are not the causes of such phenomena sackungen occur across a diverse spectrum of mountain types with different morphoclimatic histories including regions that have never experienced glaciation to reinforce that sackungen may originate independently of glaciation we also include two case studies from the western carpathians czech republic and slovakia which are supported by detailed geomorphic mapping trenching and absolute dating 10 be 14 c and osl on the ond ejnik ridge outer western carpathians czech republic sackungen occur in the mid holocene in the medium high mountains which are beyond the pleistocene glacial limits on the salatin mt tatra mts slovakia the sackungen which occur in formerly glaciated terrain date between 7 5 and 4 2 ka bp representing a 4 ka time lag after the disappearance of glaciers this suggests that the direct link between the ice retreat and the onset of sackung formation is not obvious even in the case of the once glaciated mountain range although paraglacial stress release is undoubtedly one of the crucial causes of sackung genesis in many mountain regions it is not the only important mechanism therefore despite occurring in numerous de glaciated mountains sackung features cannot be considered as proof of past mountain glaciations e g during analysis of extra terrestrial settings

slope monitoring an application of time lapse electrical resistivity imaging method in bukit antarabangsa kuala lumpur slope monitoring study using 2 d electrical resistivity imaging method was conducted on a slope where a massive landslide occurred in december 2008 in bukit antarabangsa kuala lumpur malaysia the main objective of the study is to determine the subsurface resistivity distribution of the study area and to map the risk potential zone of landslide in the future to detect the changes in the subsurface resistivity distribution due to variation in water saturation in the subsurface time lapse electrical resistivity imaging method was applied in this study repeated measurements of electrical resistivity over chosen lines at different times were done to monitor the changes in the subsurface resistivity distribution the results obtained from the time lapse electrical resistivity shows that there are significant changes in the subsurface resistivity distribution during different periods locations of possible slope failure are identified along the slope and are divided into zone 1 and zone 2 weak zones are characterized by the large proportion of high water saturation zones and low resistivity values which are highly affected by the supply of water into the subsurface as well as the properties of the subsurface materials these particular regions are more susceptible towards slope failure as high water content will ease the movement of soil in the subsurface thus proper mitigation must be done at the problematic zones to prevent the occurrence of slope failure in the future

kinematics and geological constraints of the slow moving pisciotta rock slide southern italy abstract the pisciotta landslide is a slow moving deep seated rock slide in the campania region of southern italy which has damaged a provincial road several times in the last decades and currently poses a hazard to the national railway that intersects the toe of the landslide the landslide involves an oligocene turbidite series which is composed of intercalated calcarenites marls and mudrocks the principal objectives of this study were to investigate the morphological evolution of the unstable slope quantitatively analyse ground deformations and construct an engineering geological model that is consistent with the spatial features of the landslide the long term evolution of the unstable slope was assessed through the examination of available aerial photos from 1943 to 2006 kinematic analyses of the ground deformations were conducted based on observed progressive displacement of the road as evident from the topographic maps and orthophotos 1955 2006 and the bi weekly displacement survey of 50 targets distributed across the landslide area september 2006 march 2009 the engineering geological model of the landslide was reconstructed from the stratigraphic data obtained from the study of borehole data and monitoring of inclinometers as well as from geological structural and geophysical surveys the analysis of the aerial photographs revealed an early stage of deformation in 1943 which has been gradually widening since then in addition to the main scarp and the landslide flanks other significant landslide structures such as the longitudinal and transverse cracks as well as the positive or negative morphologies were monitored and mapped in the subsequent years these studies indicated a progressive erosion of the upper part of the slope and a bulging of the foot long term kinematic analysis based on the progressive displacements of the road allowed the measurement of the ground deformations from 1955 to 2009 which revealed a cumulative horizontal displacement of up to 53 m and an average velocity of 0 98 m year 1 which has increased in the recent decades in addition the recent monitoring of the ground deformations demonstrated a continuous activity with an approximately constant rate of displacement and a composite kinematic history of the landslide body through differential displacements and associated velocities the engineering geological model of the landslide was found to be controlled by specific stratigraphic and structural constraints the landslide involves a stratigraphic interval of the saraceno formation nord calabrese tectonic unit with a largely marly argillaceous composition whose structural setting displays complex folding at the mesoscale and faulting with an approximately monocline attitude of bedding and a downslope dip direction at the macroscale the left flank of the landslide rests on a normal fault

potential of electrical resistivity tomography to detect fault zones in limestone and argillaceous formations in the experimental platform of tournemire france the experimental platform of tournemire aveyron france developed by irsn french institute for radiological protection and nuclear safety is located in a tunnel excavated in a clay rock formation interbedded between two limestone formations a well identified regional fault crosscuts this subhorizontal sedimentary succession and a subvertical secondary fault zone is intercepted in the clay rock by drifts and boreholes in the tunnel at a depth of about 250 m a 2d electrical resistivity survey was carried out along a 2 5 km baseline and a takeout of 40 m was used to assess the potential of this method to detect faults from the ground surface in the 300 m thick zone investigated by the survey electrical resistivity images reveal several subvertical low resistivity discontinuities one of these discontinuities corresponds to the position of the cernon fault a major regional fault one of the subvertical conductive discontinuities crossing the upper limestone formation is consistent with the prolongation towards the ground surface of the secondary fault zone identified in the clay rock formation from the tunnel moreover this secondary fault zone corresponds to the upward prolongation of a subvertical fault identified in the lower limestone using a 3d high resolution seismic reflection survey this type of large scale electrical resistivity survey is therefore a useful tool for identifying faults in superficial layers from the ground surface and is complementary to 3d seismic reflection surveys

modeling of spatial lag in bed load transport processes and its effect on dune morphology in the present study two bed load transport models are introduced in an existing idealized dune model these allow for the modeling of the spatial lag between the sediment transport rate and bed shear stress along dune surfaces this lag is an important factor in determining transitions between bedform regimes results of the original dune model using an equilibrium transport formula are compared with 1 a new model version that directly models spatial lag with a relaxation equation and 2 a new model version including pick up and deposition processes both bed load models use mean particle step length as an important parameter which is varied to assess which value is appropriate for the dune regime laboratory experiments are simulated with the model this shows that the results are best with the pick up and deposition model version combined with a step length of 25 times the particle diameter it is furthermore shown that in principle the model is also able to wash out fully grown dunes by increasing the step length parameter see more at http ascelibrary org doi 10 1061 28asce 29hy 1943 7900 0001254 sthash to4wr5cu dpuf

temporal behavior of deep seated gravitational slope deformations a review abstract deep seated gravitational slope deformations dsgsds are slow moving hillslope scale mass movements featuring characteristic landforms such as double crested ridges and upslope facing scarps that occur in diverse landscapes throughout the world although these deformations have been studied since the 1960s significant insights to the rates of dsgsds have only been gained within the last two decades owing to progress in geochronology remote sensing and instrumental monitoring absolute age and monitoring data indicate that dsgsd movements are observable over long term 102 years and short term future research directions include constraining the lifespan of dsgsds with absolute age dating and precise high resolution monitoring of spatio temporal displacement across dsgsd bodies it is of great importance to include absolute time scales in the numerical models of dsgsds furthermore combining remote sensing techniques such as synthetic aperture radar interferometry with high resolution lidar scanning and near surface geophysics offers a promising toolkit for collecting very detailed and accurate data on the short term deformation rates of dsgsds

more intense more frequent and longer lasting heat waves in the 21st century a global coupled climate model shows that there is a distinct geographic pattern to future changes in heat waves model results for areas of europe and north america associated with the severe heat waves in chicago in 1995 and paris in 2003 show that future heat waves in these areas will become more intense more frequent and longer lasting in the second half of the 21st century observations and the model show that present day heat waves over europe and north america coincide with a specific atmospheric circulation pattern that is intensified by ongoing increases in greenhouse gases indicating that it will produce more severe heat waves in those regions in the future

rock slope movements along the mount currie fault scarp southern coast mountains british columbia rock slope movements are reported from mount currie ridge near pemberton in the southern coast mountains of british columbia the site displays linear trenches antislope scarps and tension cracks typical of mountain ridges undergoing slow deformation however the most prominent linear scarp on the ridge has been previously interpreted as a fault scarp kinematic tests on rock discontinuities demonstrate the feasibility of both toppling and plane sliding at this site ground motion vectors based on a 4 year laser electronic distance measurement edm record of slope movements are generally compatible with the results of the kinematic tests these results cast doubt on a strictly seismic interpretation of the mount currie scarp

relict landslide development as inferred from speleothem deformation tectonic data and geoelectrics abstract the direct dating of pre and postfaulting dislocated calcite speleothems afforded new insight into slope failure in the tatra mountains in southern poland a multi approach study of the karstic kalacka cave non crevasse type enabled us to infer the slope deformation structure which had been poorly preserved in ground surface topography using combined methods including geomorphological and structural mapping of cave and ground surfaces paleostress analysis near surface electrical resistivity tomography ert and induced polarization methods ip uranium series dating 234u 230th calcite microtexture analysis and stable isotope 18o and 13c analysis here slope deformation began with dilation between 280 7 ka and 265 8 ka and proceeded as deep seated gravitational slope deformations the final stage consisted of dilation rejuvenation and rockfall during the latest pleistocene or holocene post 35 4 ka additionally some dilations are evident beyond the extent of the landslide detected by ert indicating further progradation of slope failure since this failure was initiated during the climatic transition from mis 9 to mis 8 stable isotope analysis of calcite flowstone layers was applied to test climate factors the correlation of calcite microtexture and 18o and 13c compositional changes with the interval of dilation activity indicates that regional environment factors chiefly an increase in precipitation probably contributed to slope destabilization

evolution stages of large deep seated landslides at the front of a subalpine meridional chain maritime alps france abstract studying long term evolution of gravitational slope evolution is a key to understanding deep seated landslide processes this paper deals with three large deep seated landslides dsls at a front of a subalpine meridional chain on the la marbriere slope near the town of grasse alpes maritimes france the geological framework controlling the stability and morphology of the dsls is associated with thick and tamped triassic layers of mudstone with gypsum overlain by highly faulted jurassic limestone gravitational deformation affects the entire slope involving a movement of about 1 1 10 8 m 3 of rock material it creates large disturbances in landscape morphology such as scarps counter slope scarps trenches and other typical gravitational morpho structures geomorphological mapping coupled with deep electrical resistivity tomography ert reveals a strong correlation between these morpho structures and inherited brittle tectonic features this observation relies on spatial and geometrical relations on the surface and at the depth of more than 150 m checked by ert between the most persistent fault and the gravitational morpho structures the specific distribution of the morpho structures on the basis of their morphological typologies and variations in the stage of evolution of three dsls provides an interpretation of their kinematics during the last 400 ka it appears that soft substratums combined with inherited persistent anisotropies are key factors in the development of the dsls indeed outflow of mudstone due to the lithostatic pressure imposed by individual limestone compartments has led to general slope subsidence then a progressive toppling of a rock mass may have led to the catastrophic rock collapse along bedding planes the evolution of the dsls can be divided into three distinct stages represented by three zones a young collapse stage zone 1 a pre collapse stage zone 2 and an old mature stage 400 ka zone 3 as the dsls occur on the same slope and in the same geological context this area offers interesting perspectives for understanding factors controlling the long term gravitational evolution of slopes

high resolution electrical imaging of fault zones abstract two dimensional numerical modelling studies of a generic conductive fault zone indicate that very closely spaced tm mode magnetotelluric mt data are capable of providing high resolution images of the fault structure the degree of resolution that is possible is largely controlled by the conductance of the overburden and is also dependent on the spacing of measurement sites in the absence of any overburden or in the case of very thin overburden the resolution is limited by the minimum electrode dipole length which is practicable as an example the results of two dimensional inversion of closely spaced data measured across the alpine fault are compared with an earlier model derived from more widely spaced measurement sites much higher resolution of the fault zone is obtained from the closely spaced data and some features of the earlier model appear to arise due to the sparseness of the data in the case of a very narrow fault zone it is shown that the mt data exhibit very little lateral variation in phase and therefore independent control of static shift is necessary

mid holocene cluster of large scale landslides revealed in the southwestern alps by 36cl dating insight on an alpine scale landslide activity abstract although it is generally assumed that the internal structure of a slope e g lithology and rock mass properties inherited faults and heterogeneities etc is preponderant for the progressive development of large scale landslides the ability to identify triggering factors responsible for final slope failures such as glacial debuttressing seismic activities or climatic changes especially when considering landslide cluster at an orogen scale is still debated highlighting in this study the spatial and temporal concordant clustering of deep seated slope failures in the external southwestern alps we discuss and review the possible causes for such wide spread slope instabilities at both local and larger alpine scale high resolution field mapping coupled with electrical resistivity tomography first allows establishing an inventory of large landslides in the southwestern alps determining their structural model precising their depth limit 100 200 m as well as the involved rock volumes 10 7 m 3 we show that they developed in the same geostructural context of thick mudstone layers overlain by faulted limestone and followed a block spread model of deformation that could evolve in rock collapse events cosmic ray exposure dating cre using both 36 cl and 10 be in coexisting limestone and chert respectively has been carried out from the main scarps of six deep seated landslides dsl and leads to landslide failure cre ages ranging from 3 7 to 4 7 ka they highlighted i mainly single and fast ruptures and ii a possible concomitant initiation with a main peak of activity between 3 3 and 5 1 ka centered at ca 4 2 ka because this region was not affected by historical glaciations events landslide triggering by glacial unloading can be excluded the presented data combined with field observations preferentially suggest that these failures were climatically driven and were most likely controlled by high pressure changes in the karstic medium in effect the chronicle of failure ages is concomitant to a well known climatic pulse the 4 2 ka climate event characterized by intense hydrological perturbations associated to the heaviest rainfall period of the entire holocene despite requiring further investigations and discussions the dating of numerous events across the entire alps during the middle holocene period suggests a potential synchronous triggering of several large scale gravitational failures induced by the mid holocene climatic transition

landslides triggered factors analysed by time lapse electrical survey and multidimensional statistical approach abstract a temporal imagery of water circulation in a landslide by electrical resistivity tomography ert was conducted to identify spatially and temporally the coupling between rainfalls consecutive water inflows in a sliding mass and induced resistivity variations this work is based on a multi scale experimental approach applied on the vence landslide south eastern france which is characterised by a sandy clay sliding mass on a marly limestone substratum mostly controlled by high rainfall events at the landslide scale historical geological and geotechnical data combined with field investigations and the interpretation of three ert allowed the definition of a geometrical model of the landslide and the calibration of the resistivity values on the basis of these results a permanent time lapse ert survey was designed on a specific part of the landslide coupled with water level acquisition piezometric levels and rain fall events results covering a three month period are showed the statistical analyses of all the physical parameters measured during the three months of investigation show that the matrix of correlations highlighted strong correlations between the rainfall piezometric elevation and the resistivity these first results show an accurate answer resistivity piezometric elevation that can be associated as a precursor of the reactivation of the landslide

mountain slope deformations along thrust fronts in jointed limestone an equivalent continuum modelling approach abstract engineering geology studies of natural slope stability have rarely relied on continuum modelling of discontinuous rock mass or the use of conventional constitutive laws in fem or fdm codes the paper proposes the use of numerical modelling based on a practical equivalent continuum approach for analysing the deep seated gravitational slope deformations dsgsd observed in the thrust front area of the lepini mountains italian apennines the dsgsd phenomena affect a carbonate ridge close to the villages of san sebastiano and sgurgola inducing a significant risk this study began with the construction of engineering geology sections by distinguishing lithotechnical units on the basis of both site and geomechanical parameters considering geological and geomorphological field evidence the numerical simulations validated the assumed kinematic model of the slope these simulations aimed at estimating the instability of the affected rock masses by identifying a critical mass beyond which ongoing deformations become morphologically evident on the involved slope a ratio of the weight of a critical mass which is the minimum mass required to produce some geomorphological evidence to the weight of the mass involved in the gravitational slope deformations was calculated in order to quantitatively assess the evolutionary stage of the ongoing deformations the calculated ratio demonstrates a more advanced evolutionary stage for the slope sector near the village of sgurgola due to its particular geological setting than the one near the village of san sebastiano

analysis of the distributions of stress in natural ridge forms implications for the deformation mechanisms of rock slopes and the formation of sackung abstract stress distributions in general asymmetric ridge forms derived from 13 ridges in british columbia and colorado are modelled in two dimensions with a finite difference method in each of the 13 ridges sackung scarps tension cracks trenches can be found spatial correlations between stress concentrations and these sackungen landforms are investigated for the mean ridge forms rock mass properties for the modelled ridges are developed using the hoek brown criterion and the geological strength index gsi gravity loading and combined gravity tectonic loading on the ridge forms are considered the importance of representing in situ rock masses with an elastoplastic as opposed to elastic constitutive criterion is discussed the resulting stress distributions for the three general ridge classes indicate that different processes are responsible for the formation of sackungen landforms and slope deformations in each type of ridge

characteristics and origin of quasi biweekly oscillation over the western north pacific during boreal summer 1 this study investigates the structure energetic and origin of quasi biweekly oscillation qbwo over the western north pacific wnp using ncep reanalyses for the years 2000 2007 in the context of vorticity there appears to be a significant qbwo mode over the wnp during the summer qbwo emerges from the equatorial region and propagates northwestward its horizontal structure exhibits a slight southwest northeast tilt but mainly longitudinal elongation in the vertical the qbwo has a northwest tilt with height that gives rise to a structure of the first baroclinic mode the centers of vorticity and vertical motion near the equator show a phase lag of about one quarter wavelength consistent with the characteristics of equatorial waves whereas the cyclonic circulation is tightly coupled with anomalous convection as the wave moves away from the equator energetic analysis of the qbwo reveals that diabatic heating in the tropics and baroclinic processes in the subtropics play important roles in the generation of eddy available potential energy eape in turn the conversion from eape to eddy kinetic energy eke and the barotropic conversion are major sources for eke to compensate the loss by eke redistribution and dissipation tracing the qbwo to equatorial disturbances our results show some features of equatorially trapped n 1 rossby mode such as phase speed and group velocity this mode is generally characterized by a zonal planetary wave number of about 6 and nearly symmetric circulation about the equator a typical case from 2002 is chosen to illustrate that the origin of the qbwo is closely associated with the theoretical equatorial rossby wave

electrical resistivity tomography ert based subsurface characterisation of pakhi landslide garhwal himalayas india pakhi landslide is one of the major debris slides of retrogressive nature along national highway nh 58 corridor from rishikesh to badrinath in garhwal himalayas india the present work is the first such attempt in one of the landslides in indian himalayas and in the present case study the subsurface characterization of the landslide was carried out with an aim to correlate the subsurface lithology slip surface and geometry of the landslide using borehole investigation and electrical resistivity tomography ert techniques the results from ert survey along and across the landslide could help to delineate different strata layers thereby deciphering the probable slip surface of the landslide activity further based on the landslide model drawn from the ert interpretations it can be stated that the crown portion of the right flank is more vulnerable to sliding phenomenon and that of the left flank is more prone to erosion the results obtained from both the borehole investigation and ert techniques are observed to be in great agreement and could complement each other for subsurface detailed investigation of landslide the integration of both these techniques provides useful information about the landslide activities and defines the geometry of the landslide hence it will be quite helpful in planning mitigation strategies as well as usefulness of each of these techniques

late holocene catastrophic slope collapse affected by deep seated gravitational deformation in flysch ropice mountain czech republic the region of the flysch western carpathians is characterized by abundant deep seated gravitational slope deformations dsgsds this study deals with a detailed analysis of late holocene catastrophic collapse of a fault created slope of mountain ropice in the moravskoslezske beskydy mountains eastern czech republic the catastrophic collapse was initialized by huge compound rotational slide toppling deformation which occurs on the upper part of the studied slope and affects tectonically weakened subhorizontally inclined sandstone beds detailed geomorphological mapping accompanied by morphotectonic analysis and geophysical sounding revealed at least two historic flowslides the older event f1 affected 0 5 0 8 mm3 of bedrock and created a 1000 m long and up to 150 m wide accumulation with abundant transverse steps and a carapace like surface the landslide toe blocked an adjacent valley which led to the development of a small impoundment with 4 m thick deposits containing lacustrine peat bog floodplain and alluvial fan facies radiocarbon dating and pollen analysis indicate the valley blockage at 1 5 ka bp the other flowslide f2 of much smaller dimensions 10 000 12 000 m3 overlaid the main landslide body and according to the dating of minerogenic horizon in the impoundment may have taken place 0 3 ka bp the organisation of landforms character of slope failures and dynamic back modelling point to a likely rock avalanche or combined rock slide debris avalanche mechanism of movement this case study shows that rapid rock avalanches can operate also in mountainous terrain with moderate relief if toppling together with deep seated gravitational deformation of slopes modifies the original stable position of bedding planes