palaeoglacial and palaeoenvironmental conditions of the gangdise mountains southern tibetan plateau as revealed by an ice free cirque morphology analysis abstract cirque morphology can be used to indicate patterns of palaeoglaciations and palaeoclimate many cirque morphological analyses have been conducted worldwide but only a few studies focus on the tibetan plateau tp in this study we mapped 1652 ice free cirques in the western central and eastern sectors of the gangdise mountains southern tp we calculated the cirque size shape and topography and categorized them into fifteen lithological units to study their morphological parameters results show that cirque size decreases from west to east implying that the western sector frequently developed cirque type glaciers or was eroded by dynamic glaciers during the initial period of cirque development bedrock type can also explain the difference in cirque size in the three sectors as the dominating bedrocks of the cirques in the western sector are relatively soft the relatively small l w ratios for the cirques in the western sector implies the important effect of widening on cirque planar enlargement in this sector the decreasing trend of l h and w h ratios and the increasing trend of a3d a2d ratios from west to east imply the importance of deepening for the cirques in the eastern sector moreover the different bedrock types may be attributed to the different cirque shapes the ne facing bias for the cirques reveals the impact of solar radiation this implies that the gangdise mountains were characterized by a relatively low cloudiness during the ablation season the e bias for the cirques in the eastern sector reveals that the indian summer monsoon was not strong

accounting for permafrost creep in high resolution snow depth mapping by modelling sub snow ground deformation abstract snow depth estimation derived from high resolution digital elevation models dems can lead to improved understanding of the spatially highly heterogeneous nature of snow distribution as well as help us improve our knowledge of how snow patterns influence local geomorphic processes slope deformation processes such as permafrost creep can make it challenging to acquire a snow free dem that matches the sub snow topography at the time of the associated snow covered dem which can cause errors in the computed snow depths in this study we illustrate how modelling changes in the sub snow topography can reduce errors in snow depths derived from dem differencing in an area of permafrost creep to model the sub snow topography a surface deformation model was constructed by performing non rigid registration based on b splines of two snow free dems seasonal variations in creep were accounted for by using an optimization approach to find a suitable value to scale the deformation model based on in situ snow depth measurements or the presence of snow free areas corresponding to the date of the snow covered dem this scaled deformation model was used to transform one of the snow free dems to estimate the sub snow topography corresponding to the date of the snow covered dem the performance of this method was tested on an active rock glacier in the southern french alps for two surveys dates which were conducted in the winter and spring of 2017 by accounting for surface displacements caused by permafrost creep we found that our method was able to reduce the errors in the estimated snow depths by up to 33 an interquartile range reduction of 11 cm compared to using the untransformed snow free dem the accuracy of the snow depths only slightly improved root mean square error decrease of up to 3 cm greater reductions in error were observed for the snow depths calculated for the date that was furthest i e the winter survey in time from the snow free dem additionally we found that our approach to scaling the deformation model has promising potential to be adapted for monitoring seasonal variations in permafrost creep by combining in situ snow depth measurements with high resolution surface deformation models

cirques in the sierra de guadarrama and7 somosierra mountains iberian central system shape size and controlling factors the guadarrama and somosierra mountain ranges form the eastern sector of the iberian central system and hosted numerous glaciers during the late pleistocene mis2 glaciation was of low intensity with glaciers of small sizes strongly controlled by the climatic context and the topography this study analyses the shape size distribution and location of 96 cirques existing in these mountain ranges in addition to the standard morphometric parameters and controlling factors altitude aspect and lithology used in most studies additional factors were considered here in relation to the pre glacial relief and fracture network the data were obtained and processed using arcgis 10 4 and relations between the parameters and controlling factors were evaluated using statistical methods the results indicate that most are simple cirques tending to isometry with low vertical incision capacity considerable variation in size and predominantly east facing in the context of the iberian peninsula and other european mountains these cirques are among the most isometric the lowest in height and present the least overdeepening the development of these cirques has generally been the result of random combination of various factors thus i the largest cirques are located at intermediate altitudes with the headwall located on the main divides at former torrential valley heads or at the headwalls of fracture corridor valleys and are north facing ii the longest cirques are located at former torrential valley heads on metamorphic bedrock i e schists slates and on uniform slopes finally the prevailing eastern aspects are explained by topoclimatic factors and are in agreement with previous studies which have proposed a circulation weather type cwt model throughout the iberian peninsula during the last glacial period similar to its current configuration

temporal change of glaciers area and geomorphometric parameters in parbati valley himachal pradesh india temporal change in the glacier coverage is analyzed for the period between 1962 and 2003 in parbati valley himachal pradesh it is observed that the total glacier cover has been decreased by 17 ranging between 8 and 100 for individual glacier the pattern of de glaciation shows a high degree of shrinkage in outer zone of parbati valley while least shrinkage is observed in the inner valley the present study is conducted to establish relationship between glacio geomorphic parameters and glaciers shrinkage pattern to predict the future glacier cover in warming scenario a systematic change is observed for glacio geomorphic parameters associated with temporal change in glacier cover it is observed that mean and minimum elevation slope relief and duration of insolation have changed substantially maximum elevation plan profile curvatures and aspect have shown less change from 1962 to 2003 a correlation matrix between glacio geomorphic parameters for glaciers between 1962 and 2003 shows that the recent glaciers are much more controlled by terrain characteristics than that in the recent past

characteristics of the displacement of a landslide with shallow sliding surface in a heavy snow district of japan the displacement of a landslide with shallow sliding surface in a heavy snow district was automatically monitored for over 4 years by a newly developed displacement gauge meteorological properties meltwater and or rainfall mr water equivalent of snow and other factors were simultaneously observed pore water pressure was monitored but only for a limited period of time since the displacement of the landslide was too large statistical analyses showed that maximum daily displacements of each year were observed not in snow melting periods but immediately before or at the beginning of a snow cover period there are three types of annual variation pattern with peaks in mid november to mid december mid april and mid july the variation pattern of displacement from the beginning of march to the beginning of june showed the least total displacement of those three types therefore snow cover is likely to affect the displacement of a landslide detailed investigation of the landslide displacement during snow cover periods showed that the rate of displacement slowed as the snow cover deepened meaning a decrease in mr and increase in water equivalent of snow the displacement ratio for the unit antecedent mr effect during snow cover periods dropped when the snow started to accumulate on the ground in all 4 years the reduction was likely attributable to snow load since it was found to have a negative logarithmic relation with the water equivalent of snow changes in pore water pressure and the relationship between pore water pressure and displacement during the snow cover periods differed from those in the other periods therefore the displacement of a landslide that has a shallow sliding surface in a snowy region was considered to be affected by snow accumulation conditions especially water equivalent of snow

snowline depression in the tropics during the last glaciation five primary methods have been used to reconstruct pleistocene snowlines or equilibrium line altitudes elas in the tropics 23 53n 23 53s during the last glaciation but each has inherent errors that limit the accuracy of the results additional potential errorsin determiningela depression involveestimates of modernsnowline altitude datingresolution topographicreconstructionof former glaciers orographic e ects the presence of rockfall debris on glaciers and calculation of regional ela gradients eustatic sea level lowering during the last glaciation is an additional factor in uencing estimates of ela depression ela in cases where modern snowline lies above a mountain summit only a minimum value for ela can be obtained at 12 tropical sites in africa the americas to 103s latitude and paci c islands estimates of average ela range from 440 to 1400m but most fall in the range of 800 1000m mean 1 900 135m in a regional study of ela depression in the southern tropical andes 8 223s an average ela of ca 920 250m has been reported based on the assumption that glacier mass balance was controlled solely by ablation season temperature and assuming a full glacial temperature lapse rate of 63c km depression of mean annual temperature in glaciated alpine areas was ca 5 4 0 83c if adjusted for a sea level fall of 120m at the glacial maximum this value is reduced to 4 7 0 83c the gure is based on the unlikely assumption that accumulation on alpine glaciers has been invariant nevertheless it is similar to values of temperaturedepresson 5 6 43c for the last glaciationobtainedfrom variousterrestrial sites but contrasts with tropical sea surface temperature estimates that are only 1 33c cooler than present 2001 elsevier science ltd all rights reserved

a younger dryas plateau icefield in the monadhliath scotland and implications for regional palaeoclimate a record of younger dryas glaciation in scotland is well established however the role of the monadhliath a significant plateau area extending over 840 km2 in central scotland has never been investigated systematically we present the first systematic glacial geomorphological mapping across the whole region which has led to the identification of hitherto unrecorded glacial and associated landforms the spatial distribution of these landforms indicates that the last phase of glaciation in the area was that of a local plateau icefield in addition a clear morphostratigraphical signature provides a strong indication that the icefield dates to the younger dryas 12 9 11 7 ka which is supported by numerical ages in the southeast of the study area based on the geomorphological evidence and 2d glacier surface profile modelling a 280 km2 icefield is reconstructed a novel approach is introduced to quantify plateau icefield thickness for equilibrium line altitude ela and palaeoprecipitation calculations resulting in greater overall data confidence compared to traditional reconstruction methods the ela for the whole icefield is calculated to be 714 25 m whilst the elas of individual outlet glaciers range from 560 m in the west to 816 m in the east demonstrating a significant w e precipitation gradient across the region during the younger dryas these elas compare well with those calculated for younger dryas ice masses reconstructed in neighbouring regions and are in good agreement with overall precipitation patterns suggested for scotland during this time whilst the total amount of precipitation calculated from these elas is highly dependent on the method used irrespective of this the study suggests a more arid younger dryas climate in the region compared to the present day

a brief survey of gis in mass movement studies with reflections on theory and methods this paper surveys the evolution and progress of landslide studies with particular reference to the use of geographic information systems gis in setting the agenda for research the article begins with a critical discussion of the mass movement classification problem and notes that it has been thornier and more complex than it has for many other types of extreme natural phenomena the evolution of slope instability studies is charted from its descriptive field based origins to recent higher levels of understanding on the one hand there has been a shift from static to dynamic modelling of slope processes using digital simulation and computer graphics while on the other hand automated cartography gis and remote sensing have enabled regional studies at last to predominate over site based ones however gis often tends to favour inductive study design and so does the continuing emphasis on classification the low level of insight generated by inductive studies has inhibited the development of more interdisciplinary frameworks for study it has also proved difficult to reorient landslide studies to tackle slope instability problems with greater sensitivity to the stakeholders needs finally although social administrative political cultural and perceptual aspects of landslides have been neglected there are signs of a new interest in these important aspects

seasonal change in permeability of surface soils on a slow moving landslide in a heavy snow region abstract this study demonstrated seasonal changes in the topsoil permeability due to vegetation growth in summer and snow loading in winter of a landslide in a temperate snowy area of northern japan which is underlain by soft neogene sedimentary rocks the decrease in saturated hydraulic conductivity due to loading was also examined for undisturbed and remolded specimens of surface soils from the landslide using a newly developed apparatus for the consolidation permeability test infiltration capacity measured in the field increased gradually after snowmelt to a peak in midsummer and decreased exponentially with increasing snow load in winter in the laboratory experiment saturated hydraulic conductivity declined as an exponential function of loading the topsoil was permeable enough to infiltrate rainwater into the ground even for intense rain storms in summer but became less permeable under heavy snow load during winter and was not capable of full infiltration of meltwater during the snowmelt period this suggested that hortonian overland flow should occur in late winter at least patchily under the melting snowpack

cirque form and development in romania allometry and the buzzsaw hypothesis abstract a complete inventory of the 631 glacial cirques in romania and adjacent ukraine shows that they are scale specific and develop allometrically extending in length more rapidly than they deepen shape changes with size horizontal dimensions are around 700 m vertical around 300 m on each quantitative measure they form a single unimodal population with limited variation in size on a logarithmic scale cirque axial gradients 15 33 are appropriate to occupation by rotationally flowing glaciers lake basins are more common 26 on granitic rocks compared with 10 6 of all cirques geology also affects vertical dimensions and gradients the relation between subjective five grades and objective measures of cirque development is shown by an r 2 of 62 when grade is predicted from maximum gradient minimum gradient and plan closure cirques larger in horizontal dimensions have better grades cirque floors cover around 28 of cirque map area larger cirques and nested inner and outer cirques are common in ranges that rose well above the snowline and are associated with more extensive more symmetrical glaciation and more cols in size and shape romanian cirques are similar to those in england and wales they are similar in some respects to those in part of the british columbia coast mountains except for smaller vertical dimensions they may have developed only in the last few glaciations mountain ranges can be ranked by degree of glacial modification and symmetry of glaciations the buzzsaw hypothesis is applicable only in the cores of the higher ranges elsewhere summit surfaces that are essentially preglacial survive

recommendations for the compilation of glacier inventory data from digital sources modern geoinformatic techniques allow the automated creation of detailed glacier inventory data from glacier outlines and digital terrain models dtms once glacier entities are defined and an appropriate dtm is available several methods exist to derive the inventory data e g minimum maximum and mean elevation mean slope and aspect for each glacier from digital intersection of both datasets compared to the former manual methods the new grid based statistical calculations are very fast and reproducible the major aim of this contribution is to help in standardizing the related calculations to enhance the integrity of the global land ice monitoring from space glims database the recommendations were prepared by a working group and also contribute to the european space agency project globglacier the document follows the former unesco manual for the production of the world glacier inventory published in 1970 identifies the potential pitfalls and describes the differences from the former methods of compilation the online background material for this paper see http www glims org contains example scripts for calculation of each parameter and will be updated when required

temperature dependent residual shear strength characteristics of smectite bearing landslide soils this paper presents experimental investigations regarding the effect of temperature on the residual strength of landslide soils at slow to moderate shearing velocities we performed ring shear tests on 23 soil samples at temperatures of 6 29 c the test results show that the shear strength of smectite rich soils decreased when temperatures were relatively low these positive temperature effects strength losses at lower temperatures observed for smectite bearing soils are typical under relatively slow shearing rates in contrast under relatively high shearing rates strength was gained as temperature decreased as rheological properties of smectite suspensions are sensitive to environmental factors such as temperature ph and dissolved ions we inferred that temperature dependent residual strengths of smectitic soils are also attributed to their specific rheological properties visual and sem observations of ca bentonite suggest that slickensided shear surfaces at slow shearing rates are very shiny and smooth whereas those at moderate shearing rates are not glossy and are slightly turbulent indicating that platy smectite particles are strongly orientated at slow velocities the positive temperature effect is probably due to temperature dependent micro friction that is mobilized in the parallel directions of the sheet structure of hydrous smectite particles on the contrary the influence of micro viscous resistance which appears in the vertical directions of the lamination is assumed to increase at faster velocities our results imply that if slip surface soils contain high fractions of smectite decreases in ground temperature can lead to lowered shear resistance of the slip surface and trigger slow landslide movement

relationship between rain and or meltwater pore water pressure and displacement of a reactivated landslide abstract in order to clarify the relationship between rain and or meltwater mr pore water pressure and landslide displacement continuous monitorings were conducted at a reactivated landslide comprised mainly of weathered mudstone of tertiary in age an exponential relationship was found between the total amount of mr at each event and the amount of pore water pressure increment integrated by time impulse of pore water pressure in addition as the total mr increased the difference between the minimum and maximum values of pore water pressure for each event fluctuation range of pore water pressure also increased but the intensity of mr had little effect on the fluctuation range of pore water pressure the correlation coefficient for the fluctuation range of pore water pressure and cumulative landslide displacement and that for the impulse of pore water pressure and cumulative displacement were similar but were only 0 57 to 0 66 on the other hand the correlation coefficient for the total mr and cumulative landslide displacement was large 0 65 0 69 cumulative landslide displacement was very highly correlated with effective mr which shows the estimated water content in the ground for a half life period of 4 days and correlation coefficients were 0 89 0 92 thus the displacement characteristics of this reactivated landslide which has a long history of landsliding can be explained using the hydrological factor of water content rather than the hydraulic characteristics of pore water pressure

reconstruction of a lateglacial younger dryas mountain ice field in sutherland northwestern scotland and its palaeoclimatic implications quaternary geomorphological and geological mapping of a large area 1800 km2 in the northwestern scottish highlands has led to the reconstruction of a coherent mountain ice field approximately 45 km long and 30 km wide at its maximum extent this west sutherland ice field covered an area of 350 km2 and had a mean equilibrium line altitude of 334 m assuming that the outlet glaciers all reached their maxima simultaneously numerical dating strongly suggests a younger dryas 12 9 11 7 ka age of the mapped limits of this mountain ice field this study also shows that the area of northwestern scotland covered by younger dryas glaciers was five times larger than previously thought palaeo temperature estimates obtained from chironomid and beetle assemblages elsewhere have been used to reconstruct palaeo precipitation during the younger dryas for west sutherland using a previously published global empirical dataset annual precipitation of 2344 248 mm a 1 at sea level is inferred from our new palaeo glacier reconstruction suggesting slightly wetter conditions compared to the present day these figures are in good agreement with those reconstructed for other parts of the scottish highlands and islands and this may indicate a marked w e palaeo precipitation gradient during the younger dryas this paper goes on to discuss the wider validity of palaeo climatic reconstructions from inferred palaeo glacier geometries and presents a number of possible scottish lateglacial climate scenarios which warrant further testing copyright 2010 john wiley sons ltd

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

local aspect asymmetry of mountain glaciation a global survey of consistency of favoured directions for glacier numbers and altitudes abstract understanding aspect effects on present day glaciers provides essential background to the palaeoclimatic interpretation of reconstructed former glaciers or glacial cirques several factors influencing glacier mass balance vary with slope aspect these give more glaciers lower glaciers and possibly larger glaciers on favoured aspects their effects can be measured by either vector analysis of the number of glaciers with each aspect or fourier regression of glacier altitude or size against aspect both approaches are applied here to large data sets from the world glacier inventory for all available regions favoured aspect is measured by direction of the resultant vector mean and by the direction of minimum glacier altitude for 51 regions with a total of 66 084 glaciers the two directions are broadly consistent in mid latitudes and in the tropics but large differences occur in the arctic and nepal poleward aspects dominate especially in mid latitudes radiation receipt is the major factor with strong wind effects limited to areas with only moderate relief strength of asymmetry is measured by vector strength from glacier numbers or by a combination of first fourier coefficients from glacier altitudes measuring two different facets of degree of asymmetry they are essentially unrelated the fourier measure is the best estimate of local climatic asymmetry as vector strength is more influenced by topography

influences of the snow cover on landslide displacement in winter period a case study in a heavy snowfall area of japan the displacement of a relatively small reactivated landslide in a snowy area in japan was monitored over a long period the displacement rate of the landslide which was approximately of 20 mm d 1 before the formation of snow cover decelerated drastically during the continuous snow cover period every winter period possible causes included reduction in the amount of water that reached the ground surface mr meltwater and or rainwater and increase in snow load given that the actual displacement of the landslide was far below the predicted value based on the relationship between landslide displacement and mr immediately before the continuous snow cover period the deceleration of landslide displacement was more likely attributable to the increase in snow load than to the reduction in mr an investigation of the link between snow load and landslide displacement showed a negative logarithmic relationship a dynamic analysis based on the limit equilibrium method showed that snow load increases the effective normal stress and the stability of a landslide in which the mean inclination angle of the slip surface is smaller than the internal friction angle the stability of the actual slope was also analyzed by conducting soil tests on samples collected at the site and using the resultant parameters the analysis also showed that the increase in snow load increases the safety factor and reduces the landslide displacement the displacement of a relatively small landslide that has a shallow slip surface was found to be greatly influenced by snow cover

climatic effects on glacier distribution across the southern coast mountains b c canada over a distance of 150 km inland across british columbia glaciation level altitudinal threshold for glacier generation rises north eastward from 1800 m near jervis inlet to 2800m near lillooet on fraser river the methods of 0strem 1966b are revised for more detailed work from air photographs inclusion of small but active glaciers gives a glaciation level some 200 m below 0strem s from i 250 000 maps or 110 m below that from 1 50000 maps mountains which rise slightly above the altitudinal threshold invariably support glaciers only on their northerly slopes mountain crests need to be some 300 m higher before they support glaciers on most slopes this defines an all sided glaciation level since summit heights vary from 2500 to 2900 m through most of the transect considered here east and west facing glacier sources are found mainly in the coastal half south facing sources are rare outside icefields for particular mountain ranges bounded by valleys and low passes the aspects azimuths of glacier sources can be summarised by vector analysis the higher the range rises above glaciation level the more widespread the aspects represented and the weaker the resultant vector strength strengths as high as 90 are observed on landward ranges with a relatively sunny continental climate while 20 60 is found for coastal ranges where cloudiness reduces slope variations in incident solar radiation vector mean aspects throughout are close to north perennial lee drifts on icefields show that wind directions during and immediately after snowfalls are from the south or from south south west together with oro graphic details of the glaciation level this suggests that snow bearing winds come from the south rather than the west these winds reinforce radiation contrasts giving north outh asymmetry of glacier aspect even near the coast

late pleistocene glacial equilibrium line altitudes in the colorado front range a comparison of methods abstract six methods for approximating late pleistocene pinedale equilibrium line altitudes elas are compared for rapidity of data collection and error rmse from first order trend surfaces using the colorado front range trend surfaces computed from rapidly applied techniques such as glaciation threshold median altitude of small reconstructed glaciers and altitude of lowest cirque floors have relatively high rmses 97 186 m because they are subjectively derived and are based on small glaciers sensitive to microclimatic variability surfaces computed for accumulation area ratios aars and toe to headwall altitude ratios thars of large reconstructed glaciers show that an aar of 0 65 and a thar of 0 40 have the lowest rmses about 80 m and provide the same mean ela estimate about 3160 m as that of the more subjectively derived maximum altitudes of pinedale lateral moraines rmse 149 m second order trend surfaces demonstrate low elas in the latitudinal center of the front range perhaps due to higher winter accumulation there the mountains do not presently reach the ela for large glaciers and small front range cirque glaciers are not comparable to small glaciers existing during pinedale time therefore pleistocene ela depression and consequent temperature depression cannot reliably be ascertained from the calculated ela surfaces

climatic implications of cirque distribution in the romanian carpathians palaeowind directions during glacial periods the many glacial cirques in the mountains of romania indicate the distribution of former glacier sources related to former climates as well as to topography in the transylvanian alps southern carpathians cirque floors rise eastward at 0 714 m km 1 and cirque aspects tend ene confirming the importance of winds from some westerly direction there is a contrast between two neighbouring ranges the fa ga ras where the favoured aspect of cirques is ene and the iezer where the tendency is stronger and to nne this can be explained by the iezer mountains being sheltered by the fa ga ras which implies precipitation bearing winds from north of west at times of mountain glaciation palaeoglaciation levels also suggest winds from north of west which is consistent with aeolian evidence from pleistocene dunes yardangs and loess features in the plains of hungary and south western romania in northern romania including ukrainian maramures the influence of west winds was important but sufficient only to give a northeastward tendency in cirque aspects this gave stronger asymmetry than in the transylvanian alps as the northward solar radiation incidence tendency in these marginally glaciated mountains was less diluted by wind effects cirque floors in northern romania are lower also in northeast facing cirques in general cirque aspects result from several factors and the mean tendency is not downwind but is displaced from poleward by wind and by minor effects copyright 2010 john wiley sons ltd

the new remote sensing derived swiss glacier inventory i methods a new swiss glacier inventory is to be compiled from satellite data for the year 2000 the study presented here describes two major tasks 1 an accuracy assessment of different methods for glacier classification with landsat thematic mapper tm data and a digital elevation model dem 2 the geographical information system gis based methods for automatic extraction of individual glaciers from classified satellite data and the computation of three dimensional glacier parameters such as minimum maximum and median elevation or slope and orientation by fusion with a dem first results obtained by these methods are presented in part ii of this paper kaab and others 2002 thresholding of a ratio image from tm4 and tm5 reveals the best suited glacier map the computation of glacier parameters in a gis environment is efficient and suitable for worldwide application the methods developed contribute to the u s geological survey led global land ice measurements from space glims project which is currently compiling a global inventory of land ice masses within the framework of global glacier monitoring haeberli and others 2000

mass balance and equilibrium line altitudes of glaciers in high mountain environments abstract the mass balance characteristics of glaciers in high mountain environments complicate the relationship between glacier equilibrium line altitudes elas and climatic variables such as precipitation and air temperature therefore methods of ela reconstruction employed in low relief environments are commonly not applicable in high mountains or require some modification we review the concept of the ela with reference to the mass balance of a range of glacier types found in high mountain regions we examine the applicability of several commonly used methods of ela reconstruction for different glacier types and propose some general principles to guide the choice of appropriate methods

glaciers in the polar urals russia were not much larger during the last global glacial maximum than today abstract 10 be exposure dates from boulders indicate that the chernov moraines located only 1 km beyond the chernov glacier in the polar urals russia were formed during the time of the last global glacial maximum lgm six samples from large boulders on the moraine yielded a mean age of 21 5 2 3 std error kyr the distinct semicircular usa moraine is located beyond the western flank of the urals boulders in the valley between the chernov and usa moraines yielded some spread in 10 be ages but four out of seven yielded ages 50 60 kyr we conclude that the usa and chernov moraines represent the maximum glacier extent during marine isotope stages mis 4 and 2 respectively the exceptionally small extent of the lgm glacier is explained with a dry lgm climate but also with the fact that present day cirque glaciers in the polar urals are extremely favoured by topographical factors such as leeward accumulation and shadowing mountain walls advantages which decrease when the glaciers grow

measurement of landslide displacements using a wire extensometer a continuous recording of landslide displacements is often required in order to better understand the complex relationship between the triggering factors and the dynamics of the movement in this paper we discuss the performance of the borehole wire extensometer and the interpretation of its results the analysis for the case of a translational slide shows that the displacements measured with the wire extensometer are systematically smaller than the movements observed at the ground surface a relationship between the wire readings and the horizontal component of the landslide movement has been established by means of three equations representing different stages of the wire displacement within the borehole the applicability of these equations and the interpretation of the wire extensometer readings have been successfully checked at two landslide sites vallcebre in the eastern pyrenees and alvera in the dolomites

experimental evidence for shallow slow moving landslides activated by a decrease in ground temperature in order to understand the trigger mechanism of slow moving landslides occurring in the early cold season from late autumn to winter we investigated the effect of temperature on the shear strength of slip surface soils displacement controlled and shear stress controlled box shear experiments were performed on undisturbed slip zone soils under residual strength conditions test results conducted at temperatures from 9 to 25 c showed remarkable shear strength reductions with decreasing temperature creep like slow shear displacements were induced by a decrease in temperature these temperature dependent shear behaviors are attributed to the rheological properties of hydrous smectite that dominantly compose the soil material along the failure surface our experimental results imply that ground temperature conditions influence slope instability especially for shallow landslides occurring in smectite bearing rock areas

global variations of local asymmetry in glacier altitude separation of north south and east west components north south and east west differences in firn line altitude equilibrium line altitude or middle altitudes of glaciers can be separated by regression on the cosine and sine of glacier aspect accumulation area azimuth allowing for regional trends in altitude the north south differences expected from radiation and shade effects can be reliably quantified from world glacier inventory wgi data the north south differences are greater in sunnier climates mid latitudes and steeper relief local altitude differences between north and south facing glaciers are commonly 70 320 m such asymmetry is near universal although weak in the arctic and tropics east west contrasts are less and found mainly in the tropics and areas most exposed to strong winds altitude latitude glacier gradient and height range calculable from most of the wgi data are potential controls on the degree of north south contrast as well as surrogates for climatic controls temperature precipitation radiation and cloudiness an asymmetric sine cosine power model is developed to describe the variation of north south contrast with latitude multiple regression over 51 regions shows altitude and latitude to be the strongest controls of this contrast aspect altitude analysis for former glaciers provides new evidence of cloudiness

reconstruction of little ice age glacier area and equilibrium line attitudes in the central and western himalaya abstract glacial changes during the little ice age lia in the himalayan mountains are important for understanding changes in the monsoonal and westerly climate of the so called the third pole however knowledge of these changes and their dynamics remains limited because of the region s geographical inaccessibility in addition to geopolitical reasons in this study we used high resolution three dimensional images from google earth to identify lateral and terminal moraines as delineators of paleoglacier boundaries and mapped the boundaries of both modern and lia glaciers arcgis 9 3 software was applied to map data and to calculate glacier lengths and areas modern glacier surface elevation data were derived from srtm shuttle radar topography mission records three methods the toe to headwall altitude ratio thar the toe to summit altitude method tsam and the toe to ridge altitude method tram were used to estimate equilibrium line altitude ela the transient snowlines tsl of ninety one modern glaciers were acquired using landsat 8 oli images in late summer to evaluate the reliability of the calculated elas our results showed that the total length and total area of two hundred and twenty glaciers in the central and western himalaya cwh had decreased respectively by 35 and 31 since the lia the tram method was the preferred method for the reconstruction of elas the mean depression of elas from the lia to the first decade of the 21st century as reconstructed using the tram method was 123 m the ela depression and rate of change of glacier length and glacier area displayed generally increasing trends from west to east along the central and western himalaya suggesting that the moisture was most likely transported from an easterly direction these changes were more intensive on southern than northern slopes suggesting that southerly and westerly precipitation likely increased over the same period we speculated that the cwh had been influenced by both the indian summer monsoon ism and westerlies since the lia ism moisture as in modern times was the main factor controlling the distribution of glaciers during the lia further precipitation carried by the westerlies likely intensified along southerly pathways along the cwh during the lia

acme a gis tool for automated cirque metric extraction regional scale studies of glacial cirque metrics provide key insights on the palaeo environment related to the formation of these erosional landforms the growing availability of high resolution terrain models means that more glacial cirques can be identified and mapped in the future however the extraction of their metrics still largely relies on time consuming manual techniques or the combination of more or less obsolete gis tools in this paper a newly coded toolbox is provided for the automated and comparatively quick extraction of 16 key glacial cirque metrics including length width circularity planar and 3d area elevation slope aspect plan closure and hypsometry the set of tools named acme automated cirque metric extraction is coded in python runs in one of the most commonly used gis packages arcgis and has a user friendly interface a polygon layer of mapped cirques is required for all metrics while a digital terrain model and a point layer of cirque threshold midpoints are needed to run some of the tools results from acme are comparable to those from other techniques and can be obtained rapidly allowing large cirque datasets to be analysed and potentially important regional trends highlighted

palaeoglacial and palaeoclimatic conditions in the nw pacific as revealed by a morphometric analysis of cirques upon the kamchatka peninsula abstract the distribution of glacial cirques upon the kamchatka peninsula far eastern russia is systematically mapped from satellite images and digital elevation model data a total of 3758 cirques are identified 238 of which are occupied by active glaciers the morphometry of the remaining 3520 cirques is analysed these cirques are found to show a very strong n bias in their azimuth orientation likely resulting from aspect related variations in insolation the strength of this n bias is considered to indicate that former glaciation upon the peninsula was often marginal and mainly of cirque type with peaks extending little above regional equilibrium line altitudes this is supported by the fact that s and se facing cirques are the highest in the dataset suggesting that glacier cover was rarely sufficient to allow s and se facing glaciers to develop at low altitudes the strength of these azimuth related variations in cirque altitude is thought to reflect comparatively cloud free conditions during former periods of glaciation it is suggested that these characteristics of marginal glaciation and comparatively cloud free conditions reflect the region s former aridity which was likely intensified at the global last glacial maximum and during earlier periods of ice advance as a result of the development of negative pressure anomalies over the north pacific driven by the growth of the laurentide ice sheet combined with other factors including an increase in the extent and duration of sea ice a reduction in global sea levels cooler sea surface temperatures and the localised growth of mountain glaciers there is published evidence to suggest extensive glaciation of the kamchatka peninsula at times during the late quaternary yet the data presented here appear to suggest that such phases were comparatively short lived and that smaller cirque type glaciers were generally more characteristic of the period

reconstructing glacier retreat since the little ice age in se tibet by glacier mapping and equilibrium line altitude calculation abstract temperate glaciers in the eastern nyainqentanglha range southeastern tibet are highly sensitive to climate change and therefore of particular high interest for research on late holocene changes of the monsoonal climate in high asia however because of the remoteness of the area the scarcity of empirical data and the challenges to remote sensing work posed by cloud and snow cover knowledge about the glacier dynamics and changes in this region is still very limited in this study we applied a remote sensing approach in which 1964 glaciers were mapped from a landsat etm scene and subsequently parameterized by dem supported measurements geomorphological evidence i e trimlines and latero frontal moraines were used to obtain quantitative data on the glaciers morphological characteristics and the changes since the little ice age lia maximum glacier advance statistical analysis of glacier length change revealed an average retreat of 27 and a trend toward stronger retreat for smaller glaciers an evaluation of different methods to calculate equilibrium line altitudes elas indicates that an optimized toe to ridge altitude method tram is more suitable than other methods in settings with complex topography and a lack of mass balance measurements a large number of glacier measurements are crucial for high quality of tram results and special attention has to be paid to different glacier characteristics in order to determine the best fitting tram ratio value and to test the quality of the calculated elas a remote sensing approach was applied for each investigated glacier the altitudes of transient snowlines visible in the late summer landsat scene were measured from the dem and compared to tram results the interpolated ela results show a se nw gradient ranging from 4400 to 5600 m asl and an average ela rise of 136 m since the lia because of the high spatial resolution of measurements the ela distribution reveals topographic effects down to the catchment scale specifically orographic rainfall and leeward shielding the interpretation of these patterns reveals that the eastern nyainqentanglha range is influenced by both the indian ism and east asian summer monsoon easm however the easm does not reach the western part of the study area the results indicate that the monsoonal temperate glaciers high sensitivity to climate change is driven by two double forcings owing to the coincidence of accumulation and ablation phases

potential use of time domain reflectometry for measuring water content in rock abstract quantifying water movement through bedrock materials requires a technique which can accurately measure water content at precise locations within the medium time domain reflectometry tdr is widely used to measure the water content of soil and has a measurement sensitivity which is tightly confined to the area immediately surrounding the probes this study applies tdr to the measurement of water content in rocks the technique was evaluated using sandstone and welded tuff in a series of laboratory experiments a block of each rock type was instrumented with a series of evenly spaced tdr probes each block was first saturated with water and then allowed to air dry the water content was determined gravimetrically using the tdr over a period of several weeks the results indicate that the tdr technique can be used to determine the water content of rock with an accuracy comparable with that reported for the technique used in soils

climate patterns during former periods of mountain glaciation in britain and ireland inferences from the cirque record we map glacial cirques and analyse spatial variability in their altitude and aspect to derive a long term time integrated perspective on climate patterns during former periods of mountain glaciation likely spanning multiple quaternary glaciations in britain and ireland the data reveal that although air temperatures were important exposure to moisture bearing air masses was the key factor in regulating sites of former mountain glacier formation and indicate that during such periods moisture supply was largely controlled by north atlantic westerlies with notable inland precipitation gradients precipitation decreasing inland similar to present day in places trends in cirque altitude may also reflect regional differences in the extent of cirque deepening controlled by the dimensions and dynamics of the glaciers that came to occupy them specifically comparatively deep cirques in coastal locations may reflect the former presence of dynamic fed by moisture from the north atlantic but comparatively small glaciers largely confined to their cirques by contrast decreasing cirque depth further inland may reflect the former presence of larger and or less dynamic ice masses occupying comparatively continental climatic conditions