gis analysis to assess landslide susceptibility in a fluvial basin of nw sicily italy abstract landslide hazard assessment effected by means of geostatistical methods is based on the analysis of the relationships between landslides and the spatial distributions of some instability factors frequently such analyses are based on landslide inventories in which each record represents the entire unstable area and is managed as a single instability landform in this research landslide susceptibility is evaluated through the study of a variety of instability landforms landslides scarps and areas uphill from crown the instability factors selected were bedrock lithology steepness topographic wetness index and stream power index the instability landform densities computed for all the factors which were arranged in unique condition unit allowed us to derive a total of three prediction images for each landslide typology the role of the instability factors and the effects generated by the use of different landforms were analyzed by means of a bivariate analysis of the relationships between factors and landslide density b predictive power validations of the prediction images based on a random partition strategy the test area was the iato river basin north western sicily whose slopes are moderately involved in flow and rotational slide landslides 219 and 28 respectively the area is mainly made up of the following complexes numidian flysch clays 19 1 terravecchia sandy clays 5 1 terravecchia clayey sands 3 0 3 and san cipirello marly clays 9 0 the steepness parameter shows the highest landslide density in the 11 19 class for both the typologies 8 1 even if the density distributions for rotational slides are right asymmetric and right shifted we obtained significant differences in shape when we used different instability landforms unlike scarps and areas uphill from crowns landslide areas produce left asymmetric and left shifted density distributions for both the typologies as far as the topographic wetness index is concerned much more pronounced differences were detected among the instability landforms of rotational slides in contrast the flow landslides produce normal like density distributions the latter and the rotational slide landslide areas produce the highest density values in the class 5 5 6 7 despite an abrupt decreasing trend starting from the first class 3 2 4 4 which is generated by the density values of the rotational slide scarps and areas uphill from crowns the stream power index at the foot of the slopes which was automatically derived using a gis procedure shows a positive correlation with the landslide densities marked by the maximum classes 4 8 6 0 for flows and 6 0 7 2 for rotational slides the validation procedure results confirmed that the choice of instability landform influences the results of the susceptibility analysis furthermore the validation procedure indicates that a the predictive models are generally satisfactory b scarps and zones uphill from crown areas are the most diagnostically unstable landforms for flow and rotational slide landslides respectively

onset and timing of deep seated gravitational slope deformations in the eastern alps italy abstract a previously unrecognised complex of deep seated gravitational slope deformations dsgsd extends 20 km along upper venosta valley in the eastern alps italy mt watles exhibits spectacular features indicative of dsgsds including double ridges trenches and counterscarps the slope deformation occurs along a nappe boundary now corresponding to the schlinig normal fault is also conditioned by recent faults marked by shallow earthquakes and shows glacial paraglacial controls on slope evolution the mt watles dsgsd is a complex deep seated compound slide along a basal shear zone involving the schlinig fault gravitational reactivation of ne trending fractures formed gravitational scarps counterscarps and half grabens in the upper slope whereas the lower part of the slope partially collapsed although our work indicates the importance of the schlinig fault and recent fracturing on slope failure the trigger seems to be postglacial debuttressing of the valley walls radiocarbon dating of peat deposits within one of the major counterscarps indicates that slope deformation started during the lateglacial period and continued during the holocene in several slope sectors

geomorphology and weathering characteristics of erratic boulder trains on tierra del fuego southernmost south america implications for dating of glacial deposits abstract erratic boulder trains ebts are a useful glacial geomorphological feature because they reveal former ice flow trajectories and can be targeted for cosmogenic nuclide exposure dating however understanding how they are transported and deposited is important because this has implications for palaeoglaciological reconstructions and the pre exposure and or erosion of the boulders in this study we review previous work on ebts which indicates that they may form subglacially or supraglacially but that large angular boulders transported long distances generally reflect supraglacial transport we then report detailed observations of ebts from tierra del fuego southernmost south america where their characteristics provide a useful framework for the interpretation of previously published cosmogenic nuclide exposure dates we present the first comprehensive map of the ebts and analyse their spatial distribution size and physical appearance results suggest that they were produced by one or more supraglacial rock avalanches in the cordillera darwin and were then transported supraglacially for 100 s of kilometres before being deposited rock surface weathering analysis shows no significant difference in the weathering characteristics of a sequence of ebts previously hypothesized to be of significantly different age i e different glacial cycles we interpret this to indicate that the ebts are much closer in age than previous work has implied this emphasises the importance of understanding ebt formation when using them for cosmogenic nuclide exposure dating

using multiple logistic regression and gis technology to predict landslide hazard in northeast kansas usa abstract landslides in the hilly terrain along the kansas and missouri rivers in northeastern kansas have caused millions of dollars in property damage during the last decade to address this problem a statistical method called multiple logistic regression has been used to create a landslide hazard map for atchison kansas and surrounding areas data included digitized geology slopes and landslides manipulated using arcview gis logistic regression relates predictor variables to the occurrence or nonoccurrence of landslides within geographic cells and uses the relationship to produce a map showing the probability of future landslides given local slopes and geologic units results indicated that slope is the most important variable for estimating landslide hazard in the study area geologic units consisting mostly of shale siltstone and sandstone were most susceptible to landslides soil type and aspect ratio were considered but excluded from the final analysis because these variables did not significantly add to the predictive power of the logistic regression soil types were highly correlated with the geologic units and no significant relationships existed between landslides and slope aspect

10be exposure ages of a rock avalanche and a late glacial moraine in alta valtellina italian alps abstract a rock avalanche deposit was investigated in order to understand the chronological evolution of geological hazards and to evaluate the interaction of the triggering geodynamic processes in the valley val viola italian alps the deposit is situated west of the alpe dosde in a permafrost area with deep seated gravitational deformations dsgd along a tectonic line based on its geomorphologic context the rock avalanche was first interpreted as a result of slope stress release without exact timing this hypothesis was tested by measuring the 10 be exposure date of quartz from one boulder from the rock avalanche the age of 7430 460 years places the event in the early holocene the timing of the last deglaciation was constrained using the inner late glacial moraine of a moraine doublet in the valley alpe dosde situated at an altitude between 2140 and 2120 m a s l west of the rock avalanche the 10 be concentrations of quartz yield minimum exposure ages of 11 480 670 and 10 850 820 years different proposals for potential triggering factors of the rock avalanche include a melting of the local valley glacier and slope stress release in the val viola likely to play a minor role as trigger because of the time delay between the deglaciation and the rock avalanche event more likely are b enhanced crustal seismicity induced by post glacial regional isostatic glacial rebound coupled with tectonic stress or and c climate conditions with higher temperatures around 7430 460 years resulting in an upwards movement of the permafrost limit and destabilization of the rock walls

insights into the kinematics and dynamics of the luanshibao rock avalanche tibetan plateau china based on its complex surface landforms abstract complex topographic features on the surfaces of rock avalanche deposits have been regarded as important indicators for understanding avalanche kinematics and dynamics based on a combination of remote sensing data and in situ observations of surface landforms including toreva blocks transverse and longitudinal ridges ridges separated by conjugate troughs and hummocks a giant holocene rock avalanche on the tibetan plateau is recognized this work aims to understand the kinematics of this event in planview the tongue shaped rock avalanche exhibits a clear sequential distribution of various landforms the translation zone ii is characterised by toreva blocks originating from extension in subzone iii 1 of the accumulation zone iii compression related transverse ridges are well developed longitudinal ridges resulting from lateral velocity differences due to radial spreading are present in the front part of subzone iii 1 farther down ridges separated by conjugate troughs generated by a combination of compression and radial spreading are common in subzone iii 2 subzone iii 3 is characterised by abundant scattered hummocks with circular to oval shapes based on the distributions of these landforms this rock avalanche is proposed to have mainly experienced a motion featuring laminar flow with radial spreading in its distal and marginal parts during transport three distinct processes appear to have occurred in the avalanche mass from the proximal to the distal zones extension dominated sliding in zone ii compression dominated sliding in subzones iii 1 and iii 2 and rapid radial spreading in subzone iii 3

longitudinal ridges in mass movement deposits prominent longitudinal features are often reported on the surfaces of mass movement deposits however the genesis and implications of these have not hitherto been considered and herein we present preliminary observations of their occurrence both in the field and in the laboratory elongated ridges are often oriented sub parallel to the flow direction and aligned radially from the source due to debris spreading they are particularly prominent in large 106m3 rock avalanches emplaced onto deformable substrates and are also found in the proximal reaches of volcanic debris avalanches flowbands which are longer and thinner expressions of longitudinal ridges are continuous along the entire flow length and are observed in rock avalanches emplaced onto glaciers in snow and some ice avalanches in pyroclastic flows and some block and ash flows in ejecta sheets in extraterrestrial landslides and in some volcanic debris avalanches other volcanic debris avalanches and the distal areas of rock avalanches often display hummocks that are aligned radially from the source we propose that these aligned hummocks are remnants of longitudinal ridges the formation of elongate ridges and their expressions as flowbands aligned hummocks or distal lobes and digits in qualitatively similar fashion in both laboratory and field environments suggests they represent an intrinsic tendency of granular flows in a wide range of situations

forensic investigations of the cima salti landslide northern italy using runout simulations abstract over the last decades a movement has begun to reclassify deposits previously misidentified as having origins other than landsliding the reverse problem of incorrectly assigning deposits a mass movement origin however has been addressed less in the landslide community the cima salti landslide in the lake garda region of northern italy is a cautionary tale of assuming source areas and volumes it was traditionally thought to have dammed tenno lake in the middle ages and to have a volume of 20 30 mm3 we show through geological field data and simple runout simulations with the codes dan3d and shaltop which produced comparable results that the volume of the landslide was likely significantly overestimated in the past and that it most likely did not dam tenno lake as has been assumed we propose that a smaller volume landslide 2 5 mm3 was deposited on stagnant ice melting in situ in the lateglacial period a relatively minor event in the complex history of the magnone valley this interpretation emphasizes the importance of careful field investigations and assumption validation at cima salti and in a broader context it also shows the unique capacity of landslide simulation to guide field observation and discriminate mass emplacement processes

geomorphological debates in japan related to surface processes tectonics climate research principles and international geomorphology abstract debates contribute to the development of science and technology this is also the case with geomorphology and past geomorphological debates in countries like japan were often related to concepts and methods imported from western countries in europe and north america where advanced studies tended to be conducted applications of imported ideas often led to debates because some researchers thought the applications were successful but some others did not and indicated problems including the neglect of differences in the local environment between japan and the west therefore the history of geomorphological debates in japan is not a mere national issue but informative in discussing international exchange of geomorphological thoughts and global diversity in geomorphological environments this paper provides a review of geomorphological debates in japan with attention to geomorphic processes climates tectonics research principles and international geomorphology the examined representative debates concern 1 effects of glaciers versus mass movements and running water 2 effects of periglacial processes versus mass movements and running water 3 effects of tectonics versus climates and 4 descriptive historical geomorphology versus process geomorphology classic geomorphological studies in japan mostly published in japanese and thus not well known to international communities are introduced here the relations with international geomorphology are also discussed in relation to the progress and consequences of the geomorphological debates

onset of neoglaciation in the southern hemisphere a review of evidence documenting an early neoglacial mid holocene advance of mountain glaciers in south america and new zealand reveals that of 16 glaciers for which radiocarbon age control exists only two have associated dates that may approximate the culmination of an advance advances of the remaining glaciers are controlled only by minimum or maximum limiting ages additional dates for several new zealand glaciers are based on weathering rind measurements having large potential errors twelve of the glaciers now terminate or have terminated in lakes or in tidewater and are subject to instabilities associated with calving termini an extensive debris cover in the ablation zone of nearly half of the glaciers makes their moraine succession potentially suspect as a record of detailed climatic variation the two glaciers with seemingly reliable age control are located in valleys where large rock avalanches could affect glacier mass balance and lead to random advances or where rock avalanche deposits might easily be mistaken for moraines and tills the early neoglacial interval has been defined primarily based on this set of data the ages taken at face value suggest that the early neoglacial advance culminated between ca 5400 and 4900 cal yr ago ca 4600 4400 14c yr bp this chronology however should remain provisional until improved age control is obtained for a large population of glaciers based on closely bracketing radiocarbon dates and or an adequate number of cosmogenic isotope ages data from calving glaciers and those subject to rock avalanche activity should be avoided or assessed critically copyright 2000 john wiley sons ltd

surface exposure dating of the flims landslide graubunden switzerland abstract sixteen boulder and bedrock surfaces related to the flims landslide volume 8 12 km3 were dated with 36cl and 10be exposure ages range from 4900 250 yr to 15 440 1480 yr including corrections made due to snow cover and karst erosion ages of 11 410 590 yr and 13 340 1090 yr were obtained on bedrock surfaces outside of the landslide zone these are minima for deglaciation of segnes valley and provide constraints on possible amounts of inherited nuclides based on seven boulder ages which range from 8200 260 to 9520 990 yr a mean of 8900 700 years is calculated for the flims landslide we exclude three outliers one significantly older and two significantly younger than the others and the ages from the cassons bedrock site from the mean calculation the latter is excluded as shielding due to snow and vegetation cover is difficult to constrain there the oldest boulder on the landslide yielded an age 15440 1480 yr more than 5000 years older than any other boulder age suggesting that it included the surface of the pre slide bedrock the exposure ages are consistent with a single failure event the erratics and patches of till lying on the landslide debris must have been carried piggy back on top of the landslide rather than having been deposited by the late pleistocene vorderrhein glacier the flims rockslide is about the same age as the kofels 9800 yr and kandertal 9600 yr rockslides all three occurred during the marked transition to warmer wetter conditions during the early holocene

the ad 1717 rock avalanche deposits in the upper ferret valley italy a dating approach with cosmogenic 10be on 12 september ad 1717 a rock volume larger than 10 million m3 collapsed onto the triolet glacier mobilized a mass composed of ice and sediment and travelled more than 7 km downvalley in the upper ferret valley mont blanc massif italy this rock avalanche destroyed two small settlements causing seven casualties and loss of livestock no detailed maps were made at the time later investigators attributed accumulations of granitic boulders and irregular ridges on the upper valley floor to either glacial deposition or the ad 1717 rock avalanche or a complex mixture of glacial deposition earlier rock avalanche and ad 1717 rock avalanche origin in this study we present cosmogenic 10be exposure ages from nine boulders in the extensive chaotic boulder deposit with irregular ridges two from holocene glacier free areas and one from a little ice age moraine exposure ages between 330 23 and 483 123 a from eight of nine boulders from the chaotic deposit indicate that at least seven were deposited by the ad 1717 rock avalanche the other three boulders yielded 10be exposure ages of 10 900 400 9700 400 and 244 97 a respectively our results are in good agreement with the existing chronology from dendrochronology and lichenometry and radiocarbon analysis of wood samples but not with older 14c ages from a peat bog in the upper part of the valley based on the new age control the rock avalanche deposits cover the whole bottom of the upper ferret valley copyright 2012 john wiley sons ltd

a gis based landslide susceptibility evaluation using bivariate and multivariate statistical analyses bivariate and multivariate statistical analyses were used to predict the spatial distribution of landslides in the cuyahoga river watershed northeastern ohio u s a the relationship between landslides and various instability factors contributing to their occurrence was evaluated using a geographic information system gis based investigation a landslide inventory map was prepared using landslide locations identified from aerial photographs field checks and existing literature instability factors such as slope angle soil type soil erodibility soil liquidity index landcover pattern precipitation and proximity to stream responsible for the occurrence of landslides were imported as raster data layers in arcgis and ranked using a numerical scale corresponding to the physical conditions of the region in order to investigate the role of each instability factor in controlling the spatial distribution of landslides both bivariate and multivariate models were used to analyze the digital dataset the logistic regression approach was used in the multivariate model analysis both models helped produce landslide susceptibility maps and the suitability of each model was evaluated by the area under the curve method and by comparing the maps with the known landslide locations the multivariate logistic regression model was found to be the better model in predicting landslide susceptibility of this area the logistic regression model produced a landslide susceptibility map at a scale of 1 24 000 that classified susceptibility into four categories low moderate high and very high the results also indicated that slope angle proximity to stream soil erodibility and soil type were statistically significant in controlling the slope movement

quaternary slip rate and geomorphology of the alpine fault implications for kinematics and seismic hazard in southwest new zealand glacial landforms at 12 localities in 9 river valleys are offset by the southern end of the onshore alpine fault offsets cluster at 435 1240 and 1850 m consistent with evidence for glacial retreat at 18 58 and 79 calendar ka the peak of an offset fluvial aggradation surface is correlated with the last glacial maximum at 22 ka displacement rates derived from features aged 18 22 58 and 79 cal ka are 24 2 2 2 23 2 4 9 21 4 2 6 and 23 5 2 7 mm yr respectively with uncertainties at the 95 confidence level the joint probability weighted mean and arithmetic mean of all observations pooled by rank are 23 1 1 5 23 2 1 4 and 23 1 1 7 mm yr respectively we conclude that the mean surface displacement rate for this section of the alpine fault is 23 1 mm yr with standard error in the range of 0 7 0 9 mm yr the reduction in estimated long term slip rate from 26 6 mm yr to 23 2 mm yr results in an increase in estimated hazard associated with faulting distributed across the rest of the plate boundary model dependent probabilities of alpine fault rupture within the next 50 yr are in the range 14 29 the 36 3 mm yr of total plate motion nuvel 1a is partitioned into 23 2 mm yr of alpine fault dextral strike slip 12 4 mm yr of horizontal motion by clockwise block rotations and oblique dextral reverse faulting up to 80 km southeast of the alpine fault and 5 3 mm yr of heave on reverse faults at the peripheries of the plate boundary

landslide susceptibility assessment by bivariate methods at large scales application to a complex mountainous environment statistical assessment of landslide susceptibility has become a major topic of research in the last decade most progress has been accomplished on producing susceptibility maps at meso scales 1 50 000 1 25 000 at 1 10 000 scale which is the scale of production of most regulatory landslide hazard and risk maps in europe few tests on the performance of these methods have been performed this paper presents a procedure to identify the best variables for landslide susceptibility assessment through a bivariate technique weights of evidence woe and discusses the best way to minimize conditional independence ci between the predictive variables indeed violating ci can severely bias the simulated maps by over or under estimating landslide probabilities the proposed strategy includes four steps i identification of the best response variable rv to represent landslide events ii identification of the best combination of predictive variables pvs and neo predictive variables npvs to increase the performance of the statistical model iii evaluation of the performance of the simulations by appropriate tests and iv evaluation of the statistical model by expert judgment the study site is the north facing hillslope of the barcelonnette basin france affected by several types of landslides and characterized by a complex morphology results indicate that bivariate methods are powerful to assess landslide susceptibility at 1 10 000 scale however the method is limited from a geomorphological viewpoint when rvs and pvs are complex or poorly informative it is demonstrated that expert knowledge has still to be introduced in statistical models to produce reliable landslide susceptibility maps

glacial advance and stagnation caused by rock avalanches abstract new model results show that a glacier advance caused by deposition of a rock avalanche on the ice will be followed by stagnation of the advanced ice lobe producing distributed hummocky deposits quite different from the single moraine ridges typically dated in paleoclimatic reconstructions we obtain these results using a numerical flow line glacier model with superimposed rock debris in particular our results imply that the single moraine ridge known as the waiho loop of the franz josef glacier new zealand is not the result of an advance triggered by a rock avalanche else there would be a widespread hummocky glacial stagnation deposit associated with it

the hofðaholar rock avalanche sturzstrom chronological constraint of paraglacial landsliding on an icelandic hillslope the hof aholar rock avalanche in the skagafjor ur area of northern iceland was investigated on the basis of a geomorphological analysis of its landforms and close surrounding environment thanks

multiple origins of large hummock deposits in alai valley northern pamir implications for palaeoclimate reconstructions abstract this paper interprets the origin of several of the largest hummocky landform assemblages in the alai valley northern pamir a formerly glaciated intermontane depression the vast hummocky deposits in the koman suu and achik tash river catchments are found to be of two contrasting modes of formation glacial hummocks deposited during koman and lenin glaciers withdraw and avalanche hummocks produced during catastrophic koman and lenin rock avalanches the origins of the deposits we assessed through remote and field based geomorphological mapping as well as sedimentological investigations which included clast analysis and the identification of micro scale agglomerates indicative of rock avalanche emplacement both the koman and lenin rock avalanches were large catastrophic events with run outs of 34 and 24 km respectively and a volume over 1 109 m3 each that occurred subsequent to glacier withdrawal from the area the complex conditions on the moment of the rock avalanche emplacement promoted unusual deposits geomorphology and extensive run outs the landslide landforms formed over the pre existing glacial hummocks and fluvial deposits and are geomorphologically and sedimentologically distinct from the larger glacial hummocks the reconstruction of this sequence of events has implications for how hummock dating should be interpreted this research illustrates large scale catastrophic landsliding in the glacial environment and adds to the ongoing debate about the misidentification of rock avalanche deposits as of glacial origin and their relevance to palaeoclimatological and palaeoseismological reconstructions

estimating paleorecharge and paleoclimate from unsaturated zone profiles unsaturated zone solute and isotope profiles may be interpreted in terms of past changes in recharge rate in cases where water movement can be approximated by piston flow a model is presented which describes water movement in terms of piston flow below a surface mixing layer below the mixing layer diffusion and dispersion occur in the liquid phase in the case of solutes and in both the liquid and gas phases in the case of isotopically labeled water climatic events of 4 5 years duration may be preserved in the unsaturated zone for more than 50 years if the recharge rate is greater than approximately 20 mm yr 1 longer term fluctuations in climatic conditions century scale might be preserved for over 1000 years provided the recharge rate is greater than approximately 2 mm yr 1 and the unsaturated zone is sufficiently deep profiles from cyprus and northern senegal appear to record changes in recharge rate over periods up to 400 years the profiles are well correlated with known variations in rainfall and fluctuations in lake levels the model provides limiting conditions to be applied to the interpretation of profiles

evidence for a rock avalanche origin for the hillocks moraine otago new zealand abstract a landform in otago new zealand previously interpreted as a glacial deposit has been investigated described and reinterpreted as a rock avalanche deposit the hillocks is a conspicuous cluster of small conical hills on the dart river floodplain the landform is protected under a local bylaw because of its identification as an outstanding example of a glacial kame deposit however the geological and geomorphological setting and the deposit morphology sedimentology and lithology suggest that it was formed by a large c 22 5 10 6 m 3 rock avalanche subsequent to glacial retreat and that the deposit temporarily dammed the dart river valley relative age dating evidence suggests that it is at least several hundred years old but younger than ca 7500 b p this work highlights the problem of paleoclimatic reconstructions using moraines as indicators of regional climate events despite similarities in form and in some cases sedimentology by applying an understanding of landslide initiation runout and depositional process we demonstrate that it is possible to distinguish the deposits produced by landslides from those produced by glacial deposition

near synchronous interhemispheric termination of the last glacial maximum in mid latitudes isotopic records from polar ice cores imply globally asynchronous warming at the end of the last glaciation however 10be exposure dates show that large scale retreat of mid latitude last glacial maximum glaciers commenced at about the same time in both hemispheres the timing of retreat is consistent with the onset of temperature and atmospheric co2 increases in antarctic ice cores we suggest that a global trend of rising summer temperatures at the end of the last glacial maximum was obscured in north atlantic regions by hypercold winters associated with unusually extensive winter sea ice

quaternary moraines vs catastrophic rock avalanches in the karakoram himalaya northern pakistan a history and conception of glacial events for the central karakoram himalaya proposed some 80 years ago by giotto dainelli are largely accepted today however certain deposits identified as terminal moraine complexes marking glacial episodes were actually emplaced by rock avalanches in the skardu and shigar intermontane basins of baltistan at least 15 rock avalanche events were previously mapped as moraine or till criteria used for distinguishing these catastrophic landslide deposits emphasize homogeneous lithology of rubble and matrix clast shape facies characteristics the large scale unity of emplacement and morphological relations to valley topography the deposits of three events at katzarah satpura and the north end of shigar valley have been reconstructed in detail thick supraglacial debris does not result in similar deposits extensive valley fills river terraces large sediment fans and lacustrine sediments formerly attributed to late glacial conditions are reinterpreted as postglacial events involving rock avalanches that interrupted fluvial development existing reconstructions of glaciations are left in doubt especially late glacial events in the central karakoram as are the roles assigned to karakoram main indus valley and western himalayan ice

evidence for a landslide origin of new zealand s waiho loop moraine the waiho loop moraine has been interpreted as evidence for younger dryas cooling in southern new zealand but recent dating and climatological studies have questioned this idea a detailed analysis of the sedimentology of the moraine suggests it was formed after a large landslide onto the franz josef glacier triggered a glacial surge independent of climate forcing

a mass movement origin for cirques the glacial process of cirque initiation whereby small initial hillslope hollows grow by nivation until snow can form glacier ice and ice motion then enlarges the hollow to a fully developed cirque appears to have difficulty explaining the creation of large cirques in the time available during quaternary glaciations at the rates at which glaciers are reported to erode rock and in rapidly uplifting mountain ranges it also has difficulty explaining the striking proliferation of cirques in fiordland south island new zealand an area of harder rock and less glaciation than the nearby cirque poor area of south westland here we show that cirques can be initiated as large deep seated often coseismic rock slope failure source area depressions in which snow may accumulate to form cirque glaciers which can then remove detritus from smooth and enlarge the cirque we present an example of a classically shaped cirque that has never held a glacier we show that many similarities between the locations sizes and shapes of rock slope failure source area depressions and cirques are understandable on this basis as is the occurrence of cirques in presently aseismic intraplate locations and their relative paucity in actively uplifting ranges the extent to which cirques may be of mass movement origin has implications for their value as palaeoclimatic indicators copyright 2006 john wiley sons ltd

insights into rock avalanche emplacement processes from detailed morpho lithological studies of the tschirgant deposit tyrol austria large rapid rockslope failures generate deposits with complex morphologies due to a number of causal and influencing factors to investigate these we conducted a detailed case study at the carbonate tschirgant deposit tyrol austria it preserved evidence of simultaneous rock sliding very large coherent hummocks and rock avalanche spreading smaller more scattered hummocks and ridges motion indicators such as longitudinal ridges furthermore pinpoint the transition between linear sliding and radial spreading the lithological distribution in the tschirgant deposit shows that it retained source stratigraphy despite being split into two accumulation lobes by a high bedrock ridge furthermore lithology had a very strong control on the final deposit morphology in that the different lithologic units form individual deposit surfaces river erosion has created fortuitous outcrops that reveal the basal rock avalanche contact the underlying valley fill sediments substrates have been intricately involved in shaping the rock avalanche morphology and where entrained highlight internal rock avalanche deformation features this study shows that intrinsic dynamic properties of granular media e g tendency for longitudinal alignments emplacement mode lithology and source predisposition runout path topography and substrates form the quintet of causal factors that shape rock avalanche morphology copyright 2015 john wiley sons ltd

geology and radiometric 14c 36cl and th u dating of the fernpass rockslide tyrol austria abstract one of the largest mass movements in the alps the fossil fernpass rockslide in the northern calcareous alps tyrol austria was dated absolutely for the first time three independent radiometric dating methods were applied to geologically individual sample sites and enabled a cross checking of the results close to the scarp front rockslide dammed torrent deposits indicate a 14c minimum age of at least 3380 3080 cal yrs bp the chronostratigraphic base of this backwater sequence has not been dated yet but is assumed to date somewhat older into the middle holocene however this coincides with two cosmogenic radionuclide 36cl ages of sliding planes at the steep and rugged scarp exposure data thus obtained are 3400 900 and 4800 1200 yrs respectively with an arithmetic mean of 4100 1300 yrs additional age data were acquired from post depositional calcareous cements which locally lithified the rockslide debris these meteoric cements contain remarkably high uranium total contents and yielded a 230th 234u minimum age of about 4150 100 yrs for the accumulation of the rockslide deposits all dating data agree well and indicate that the fernpass rockslide is of subboreal age thus the intensively structured present morphology characterised by the well known cone shaped toma hills and several lakes in the depressions is indicative of primary rockslide morphology and clearly not shaped by late glacial ice as assumed formerly

the application of gis based logistic regression for landslide susceptibility mapping in the kakuda yahiko mountains central japan as a first step forward in regional hazard management multivariate statistical analysis in the form of logistic regression was used to produce a landslide susceptibility map in the kakuda yahiko mountains of central japan there are different methods to prepare landslide susceptibility maps the use of logistic regression in this study stemmed not only from the fact that this approach relaxes the strict assumptions required by other multivariate statistical methods but also to demonstrate that it can be combined with bivariate statistical analyses bsa to simplify the interpretation of the model obtained at the end in susceptibility mapping the use of logistic regression is to find the best fitting function to describe the relationship between the presence or absence of landslides dependent variable and a set of independent parameters such as slope angle and lithology here an inventory map of 87 landslides was used to produce a dependent variable which takes a value of 0 for the absence and 1 for the presence of slope failures lithology bed rock slope relationship lineaments slope gradient aspect elevation and road network were taken as independent parameters the effect of each parameter on landslide occurrence was assessed from the corresponding coefficient that appears in the logistic regression function the interpretations of the coefficients showed that road network plays a major role in determining landslide occurrence and distribution among the geomorphological parameters aspect and slope gradient have a more significant contribution than elevation although field observations showed that the latter is a good estimator of the approximate location of slope cuts using a predicted map of probability the study area was classified into five categories of landslide susceptibility extremely low very low low medium and high the medium and high susceptibility zones make up 8 87 of the total study area and involve mid altitude slopes in the eastern part of kakuda mountain and the central and southern parts of yahiko mountain

green lake landslide and other giant and very large postglacial landslides in fiordland new zealand abstract green lake landslide is an ancient giant rock slide in gneiss and granodiorite located in the deeply glaciated fiordland region of new zealand the landslide covers an area of 45 km 2 and has a volume of about 27 km 3 it is believed to be new zealand s largest landslide and possibly the largest landslide of its type on earth it is one of 39 known very large 10 6 10 7 m 3 and giant 10 8 m 3 postglacial landslides in fiordland discussed in the paper green lake landslide resulted in the collapse of a 9 km segment of the southern hunter mountains slide debris moved up to 2 5 km laterally and 700 m vertically and formed a landslide dam about 800 m high impounding a lake about 11 km long that was eventually infilled with sediments geomorphic evidence supported by radiocarbon dating indicates that green lake landslide probably occurred 12 000 13 000 years ago near the end of the last otira glaciation the landslide is described and its geomorphic significance age failure mechanism cause and relevance in the region are discussed in relation to other large landslides and recent earthquake induced landslides in fiordland the slope failure occurred on a low angle fault zone undercut by glacial erosion and was probably triggered by strong shaking mm ix x associated with a large m 7 5 8 earthquake on the alpine fault c 80 km to the northwest geology was a major factor that controlled the style and size of green lake landslide and in that respect it is significantly different from most other gigantic landslides future large earthquakes on the alpine fault in fiordland are likely to trigger more very large and giant landslides across the region causing ground damage and devastation on a scale that has not occurred during the last 160 years with potentially disastrous effects on towns tourist centres roads and infrastructure the probability of such an event occurring within the next 50 years may be as high as 45

assessment of landslide susceptibility on the natural terrain of lantau island hong kong steep terrain and the high frequency of tropical rainstorms make landslide occurrence on natural terrain a common phenomenon in hong kong for example more than 800 slope failures were triggered by a rainstorm in november 1993 on lantau island hong kong maps of recent landslides interpreted from aerial photographs in combination with a geographical information system were used to evaluate the frequency and distribution of landslides with particular reference to such physical parameters as lithology slope gradient slope aspect elevation vegetation cover and proximity to drainage line all of which are considered to be influential in the occurrence of landslides a stepwise logistic regression model was obtained between landslide susceptibility and the above mentioned physical parameters the study area has been classified into five classes of relative landslide susceptibility namely very low low moderate high and very high based on this methodology

holocene glacier chronologies are high resolution global and inter hemispheric comparisons possible in the context of reconstruction of holocene glacier chronologies there has been a clear tendency during the past few decades towards imprecise use of the term high resolution furthermore it seems to be increasingly assumed that recently developed terrestrial cosmogenic nuclide dating tcnd is replacing earlier dating methods although recent glaciological knowledge clearly reveals the futility of oversimplified global and inter hemispheric correlation on the basis of few key sites such comparisons are widely attempted stimulated by the example of a recently published article relating to the southern alps of new zealand schaefer et al 2009 science 324 622 625 we highlight some related potential problems with the interpretation of holocene glacier chronologies in particular we consider 1 that the term high resolution should be applied only to decadal scale resolution or better and therefore not to tcnd based chronologies 2 that discontinuous moraine chronologies should not be ter

interactions between rock avalanches and glaciers in the mont blanc massif during the late holocene rock avalanches are common in the mont blanc massif which is bordered by valleys with large resident and tourist populations and important highways this paper combines historical data with detailed geomorphological mapping stratigraphic observation and absolute and relative dating to interpret several deposits resulting from rock avalanching onto glaciers nineteen rock falls and rock avalanches are described ranging in volume from 10 000 m3 to 10 106 m3 they occurred between 2500 bp and ad 2007 at six sites the events at three sites miage and drus glaciers and tour des grandes jorasses are characterised by short travel distances those at brenva triolet and frebouge glaciers exhibit excessive travel distances interactions between rock avalanches and glaciers are of four types i rock avalanche triggering where glacial and paraglacial controls include debuttressing of rockwalls due to glacier thinning and retreat oversteepening of rock slopes by glacial erosion and effects of glaciers on permafrost ii rock avalanche mobility in which mobility and travel distance are modified by channelling of rock avalanche debris by moraines and valleys incorporation of ice and snow often 50 for large events and irregularities on the glacier surface iii deposit sedimentology where melting of incorporated ice transforms the final deposit by reducing its thickness typically to 5 m and debris of variable thicknesses is juxtaposed in a hummocky deposit with chaotic piles of angular rock debris and iv glacier dynamics where insulating debris deposited upon a glacier produces a debris covered glacier of different dynamics and high elevated scars can favour the formation of small glaciers

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

prediction of landslide susceptibility using rare events logistic regression a case study in the flemish ardennes belgium abstract in this article a statistical multivariate method i e rare events logistic regression is evaluated for the creation of a landslide susceptibility map in a 200 km2 study area of the flemish ardennes belgium the methodology is based on the hypothesis that future landslides will have the same causal factors as the landslides initiated in the past the information on the past landslides comes from a landslide inventory map obtained by detailed field surveys and by the analysis of lidar light detection and ranging derived hillshade maps information on the causal factors e g slope gradient aspect lithology and soil drainage was extracted from digital elevation models derived from lidar and from topographical lithological and soil maps in landslide affected areas however we did not use the present day hillslope gradient in order to reflect the hillslope condition prior to landsliding the pre landslide hillslope was reconstructed and its gradient was used in the analysis because of their limited spatial occurrence the landslides in the study area can be regarded as rare events rare events logistic regression differs from ordinary logistic regression because it takes into account the low proportion of 1s landslides to 0s no landslides in the study area by incorporating three correction measures the endogenous stratified sampling of the dataset the prior correction of the intercept and the correction of the probabilities to include the estimation uncertainty for the study area significant model results were obtained with pre landslide hillslope gradient and three different clayey lithologies being important predictor variables receiver operating characteristic roc curves and the kappa index were used to validate the model both show a good agreement between the observed and predicted values of the validation dataset based on a qualified judgement the created landslide susceptibility map was classified into four classes i e very high high moderate and low susceptibility if interpreted correctly this classified susceptibility map is an important tool for the delineation of zones where prevention measures are needed and human interference should be limited in order to avoid property damage due to landslides

catastrophic landslides glacier behaviour and moraine formation a view from an active plate margin the influence of large bedrock landslides rock avalanches on the behaviour of glaciers is incompletely recognised here we present an example from an active tectonic margin in south island new zealand where large earthquakes leave a significant imprint on glacial records we demonstrate that terminal moraines on the western side of the southern alps record both ordinary i e climate driven and landslide initiated glacial advances following consideration of the processes involved in rock avalanche initiated moraine construction we suggest ways of determining the nature of the advance that built the terminal moraine the implications of these observations are important in breaking the conventional linkage of individual terminal moraines with climate forcing

effects of rock avalanches on glacier behaviour and moraine formation although large rock avalanches are infrequent sediment production in active orogens is dominated by such events which may strongly influence geomorphic processes where rock avalanches fall onto glaciers they may affect glacier behaviour and moraine formation we outline the processes of rock avalanche initiation and motion and show that supraglacial deposits of rock avalanche debris have distinct sedimentological and thermal properties laboratory experiments on the effects of such debris on ice ablation are supplemented by field data from two rock avalanches in the southern alps new zealand their effects are compared with those of the thinner supraglacial debris that results from small rockfalls and melt out of englacial debris implications of rock avalanche debris cover for glacier behaviour are explored using a mass balance model of the franz josef glacier in new zealand demonstrating a likely supraglacial rock avalanche origin for the waiho loop moraine and considering the potential hazard of a large rock avalanche onto the present day glacier

statistical analysis of landslide susceptibility at yongin korea the aim of this study is to evaluate the susceptibility of landslides at yongin korea using a geographic information system gis landslide locations were identified in the yongin area from interpretation of aerial photographs field surveys and maps of the topography soil type timber cover and geology these data were collected and constructed into a spatial database using gis the factors that influence landslide occurrence such as slope aspect and curvature of topography were calculated from the topographic database texture material drainage and effective soil thickness were extracted from the soil database and type age diameter and density of timber were extracted from the forest database lithology was extracted from the geological database and land use was classified from the landsat tm satellite image landslide susceptibility was analyzed using the landslide occurrence factors by probability and logistic regression methods the results of the analysis were verified using the landslide location data the validation results showed satisfactory agreement between the susceptibility map and the existing data on landslide location the gis was used to analyze the vast amount of data efficiently and statistical programs were used to maintain specificity and accuracy the results can be used to reduce associated hazards and to plan land use and construction

landslide susceptibility mapping in the damrei romel area cambodia using frequency ratio and logistic regression models this study applied tested and compared a probability model a frequency ratio and statistical model a logistic regression to damre romel area cambodia using a geographic information system for landslide susceptibility mapping landslide locations were identified in the study area from interpretation of aerial photographs and field surveys and a spatial database was constructed from topographic maps geology and land cover the factors that influence landslide occurrence such as slope aspect curvature and distance from drainage were calculated from the topographic database lithology and distance from lineament were extracted and calculated from the geology database land cover was classified from landsat tm satellite imagery the relationship between the factors and the landslides was calculated using frequency ratio and logistic regression models the relationships frequency ratio and logistic regression coefficient were overlaid to make landslide susceptibility map then the landslide susceptibility map was compared with known landslide locations and tested as the result the frequency ratio model 86 97 and the logistic regression 86 37 had high and similar prediction accuracy the landslide susceptibility map can be used to reduce hazards associated with landslides and to land cover planning

rock avalanches on a glacier and morainic complex in haut val ferret mont blanc massif italy abstract deposits in upper val ferret mont blanc massif italy have been attributed to glacier advances and to a rock avalanche of 12 september ad 1717 we review evidence for the timing and mode of emplacement of the deposit and present a new geomorphic interpretation and relative and absolute dating to show that the ad 1717 deposit is less extensive than previously thought the landslide was deflected along one side of the valley floor preserving older slope and morainic sediments along the other side an earlier rock avalanche onto the triolet glacier occurred before ad 1000 the deposits of these landslides partly cover older moraine several kilometres downstream from the present glacier front and have affected the glacier regimen and construction of its moraines this study highlights the geomorphic impact of rock avalanches in glacierized high mountains

wisconsinan stratigraphy of the cuyahoga valley in the erie basin northeastern ohio during the wisconsinan stage ice of the cuyahoga lobe flowed southward from the erie basin through a lowland created by an ancestral cuyahoga river the paleovalley of the cuyahoga river is filled with the pre woodfordian tills and lacustrine deposits the oldest till the mogadore till overlies proglacial lacustrine deposits after retreat of mogadore ice into the erie basin ice readvanced to deposit a previously unnamed till northampton till over deltaic and lacustrine deposits of lake cuyahoga northampton ice melted back into the erie basin after depositing the core of the summit county morainic complex northampton ice then readvanced over deposits of proglacial lake independence and formed the defiance moraine aside from minor leaching of carbonates and weathering of clay minerals little evidence of the farmdalian substage exists woodfordian kent lavery and hiram tills were deposited over pre woodfordian deposits the multiple nature of the pre woodfordian tills in the cuyahoga lobe is sim