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

late cretaceous through cenozoic strike slip tectonics of southwestern alaska abstract new geologic mapping and geochronology show that margin parallel strike slip faults on the western limb of the southern alaska orocline have experienced multiple episodes of dextral motion since 100 ma these faults are on the upper plate of a subduction zone 350 450 km inboard of the paleotrench in southwestern alaska dextral displacement is 134 km on the denali fault at least 88 94 km on the iditarod nixon fork fault and perhaps tens of kilometers on the dishna river fault the strike slip regime coincided with late cretaceous sedimentation and then folding in the kuskokwim basin and with episodes of magmatism and mineralization at 70 60 and 30 ma no single driving mechanism can explain all of the 95 million year history of strike slip faulting since 40 ma the observed dextral sense of strike slip has run contrary to the sense of subduction obliquity this may be explained by northward motion of the pacific plate driving continental margin slivers into and or around the oroclin

extensive deformations of rock slopes in southern coast mountains southwest british columbia canada extensive deformations of mountain slopes occur in crystalline intrusive rocks in the southern coast mountains of british columbia typical morphological evidence of slope movement includes extensive systems of tension cracks grabens and antislope scarps collectively referred to here as linears these landforms involve displacements along penetrative joints observed in surface exposures kinematic tests on rock structural data indicate that the observed patterns of linears are generally consistent with the feasible gravitational movements along the dominant discontinuities most sites indicate sliding as the most likely initial mode of movement followed by or accompanied by toppling and toppling induced sliding movements and do not support the view that linears are the traces of active faults

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

possible role of warm sst bias in the simulation of boreal summer monsoon in sintex f2 coupled model reasonably realistic climatology of atmospheric and oceanic parameters over the asian monsoon region is a pre requisite for models used for monsoon studies the biases in representing these features lead to problems in representing the strength and variability of indian summer monsoon ism this study attempts to unravel the ability of a state of the art coupled model sintex f2 in simulating these characteristics of ism the coupled model reproduces the precipitation and circulation climatology reasonably well however the mean ism is weaker than observed as evident from various monsoon indices a wavenumber frequency spectrum analysis reveals that the model intraseasonal oscillations are also weaker than observed one possible reason for the weaker than observed ism arises from the warm bias over the tropical oceans especially over the equatorial western indian ocean inherent in the model this warm bias is not only confined to the surface layers but also extends through most of the troposphere as a result of this warm bias the coupled model has too weak meridional tropospheric temperature gradient to drive a realistic monsoon circulation this in turn leads to a weakening of the moisture gradient as well as the vertical shear of easterlies required for sustained northward propagation of rain band resulting in weak monsoon circulation it is also noted that the recently documented interaction between the interannual and intraseasonal variabilities of ism through very long breaks vlbs is poor in the model this seems to be related to the inability of the model in simulating the eastward propagating madden julian oscillation during vlbs

developments in the characterization of complex rock slope deformation and failure using numerical modelling techniques recent advances in the characterization of complex rock slope deformation and failure using numerical techniques have demonstrated significant potential for furthering our understanding of both the mechanisms processes involved and the associated risk this paper illustrates how rock slope analyses may be undertaken using three levels of sophistication level i analyses include the conventional application of kinematic and limit equilibrium techniques with modifications to include probabilistic techniques coupling of groundwater simulations and simplistic treatment of intact fracture and plastic yield such analyses are primarily suited to simple translational failures involving release on smooth basal rear and lateral surfaces where the principle active damage mechanisms are progressive failure and or asperity breakdown level ii analyses involve the use of continuum and discontinuum numerical methods in addition to simple translation level ii techniques can be applied to complex translational rock slope deformations where step path failure necessitates degradation and failure of intact rock bridges along basal rear and lateral release surfaces active damage processes in this case comprise not only strength degradation along the release surface e g asperity breakdown but also a significant component of brittle intact rock fracture level iii analyses involve the use of hybrid continuum discontinuum codes with fracture simulation capabilities these codes are applicable to a wide spectrum of rock slope failure modes but are particularly well suited to complex translation rotational instabilities where failure requires internal yielding brittle fracturing and shearing in addition to strength degradation along release surfaces through a series of rock slope analyses the application of varied numerical methods are discussed particular emphasis is given to state of the art developments and potential use of level iii hybrid techniques d 2005 elsevier b v all rights reserved

analysis of massif fracturing during deep seated gravitational slope deformation by physical and numerical modeling abstract both 3 d physical modeling and 2 d numerical modeling were used to analyze the development of deep seated gravitational slope deformations we focused especially on the link between fracturing and morphological features such as sagging sackung physical modeling was performed by using properly scaled analogue materials as well as an original vertical accelerator device this device enables cyclic loading of the model and to advance step by step in the deformation process this technique is thus particularly well suited to analyze rupture initiation and evolution surface deformation is registered with a high resolution digital camera internal model deformation was studied by making cross sections at different experiment stages the failure of one or both mountain sides was observed with a deep seated failure zone that follows an almost circular trajectory it intersects the surface perpendicularly in the upper part other fractures are generated in the moving mass in response to its motion fracture network becomes wider and morphological features such as counterscarps are generated numerical models were performed with a 2 d finite element code named adeli we tried to reproduce physical modeling results by using the same mechanical behaviour and parameters of the analogue material the results reproduced failure initiation well but poorly described moving mass deformation furthermore rupture initiation in the 2 d numerical models occurs more easily e g for a lower acceleration value than in the 3 d physical models confirming the importance of the three dimensional analysis

a procedure for landslide susceptibility zonation by the conditional analysis method numerous methods have been proposed for landslide probability zonation of the landscape by means of a geographic information system gis among the multivariate methods i e those methods which simultaneously take into account all the factors contributing to instability the conditional analysis method applied to a subdivision of the territory into unique condition units is particularly straightforward from a conceptual point of view and particularly suited to the use of a gis in fact working on the principle that future landslides are more likely to occur under those conditions which led to past instability landslide susceptibility is defined by computing the landslide density in correspondence with different combinations of instability factors the conceptual simplicity of this method however does not necessarily imply that it is simple to implement especially as it requires rather complex operations and a high number of gis commands moreover there is the possibility that in order to achieve satisfactory results the procedure has to be repeated a few times changing the factors or modifying the class subdivision to solve this problem we created a shell program which by combining the shell commands the gis geographical research analysis support system grass commands and the gawk language commands carries out the whole procedure automatically this makes the construction of a landslide susceptibility map easy and fast for large areas too and even when a high spatial resolution is adopted as shown by application of the procedure to the parma river basin in the italian northern apennines

a paleogene flora from the upper bonnet plume formation of northeast yukon territory canada palaeontological exploration of the bonnet plume basin in northwestern yukon territory canada has revealed a late paleocene to early eocene macrofloral assemblage from a channel fill deposit the flora is typified by cosmopolitan taxa and dominated by deciduous angiosperms with the notable presence of zizyphoides ettingshausenia and corylites floras with a similar composition are known from late cretaceous through early eocene deposits in alaska and the canadian arctic archipelago where they have been interpreted as evidence for warm equable temperatures this collection represents the most diverse known paleogene plant macrofossil assemblage from the yukon territory and helps to expand our knowledge of ancient high latitude floras

mechanisms for enso phase change in a coupled gcm the mechanisms leading to el nino onset and termination in the echam4 opa coupled gcm are assessed and compared to observations and existing enso paradigms at the equator as well as off equator the patterns and timing of modeled el nino composites are in good agreement with those observed heat content of the west pacific is confirmed as a precursor to enso phase change and the present work emphasizes the role of its northern off equator part west north pacific wnp region 58 158n 1208 1708e the associated heat content changes appear to be dominated by a local ekman pumping or forced rossby waves rather than the accumulation of remotely generated free rossby waves as proposed by many theories the heat content decrease in the wnp region which triggers el nino termination is due to the negative feedback of the atmospheric gill s response to the increased equatorial sst in the east pacific in agreement with most paradigms delayed recharged west pacific oscillators the present study introduces the advection of the off equator signal to the equatorial waveguide by the mean currents of the western pacific as an additional process a similar feedback with opposite sign also seems to drive the modeled el nino onset favoring a too strong and regular biennial enso in the model this is due to the stronger than observed walker circulation that isolates the wnp region from other remote influences like monsoons the model also exhibits aborted enso events where the warming peaks in late spring instead of late autumn and is quickly terminated by the gill s negative feedback the abort event occurs too frequently in the coupled model due to too strong and too zonal a convergence zone south of the equator double itcz it bears some resemblance to the spring 1993 warming when the southern tropics were also warm the results of this paper provide additional insight into the el nino seasonal phase lock mechanisms

a deep seated compound rotational rock slide and rock spread in se spain structural control and dinsar monitoring abstract the northern slope of the sierra de aitana eastern betic cordillera is characterized by a long mountain front with a prominent eocene limestone scarp overlying ductile eocene marlstones this stratigraphic feature and the highly stepped topography produced by several normal faults favor gravitational processes such as rock avalanches rock slides and rock falls this paper reports a compound landslide comprising a rotational rock slide and slab type lateral spreading affecting these materials with blocks of volumes up to 106 m3 this lateral spread process produced singular and spectacular morphological features the simas de partagat which are trenches 20 m wide and up to 40 m deep formed by the widening of discontinuities the use of a differential sar interferometry technique for monitoring this landslide over a time span of 11 yr has revealed that velocity of movement is insignificant with rates comprised between 0 and 2 mm yr 1 and cumulative negligible displacements individual rock blocks initially located at the free face of the scarp were affected by slides at the base of the scarp descending from a few to several dozen meters along the slope blocks broke up as displacement progresses with several in different stages of evolution being recognizable along the slope differential sar interferometry shows a greater activity in the area north of compound landslide although velocity is extremely low below 16 mm yr 1 this extremely slow movement revealed by interferometry is in agreement with other geological and geomorphological evidence such as the existence of speleothems and cemented breccias against the head walls of the trenches both deposits are indicative of a long period of discontinuity widening also undisturbed debris deposits covering ancient rock slides are indicative of very slow gravitational processes characterized by long dormant periods in addition a historical picture from 1898 shows nearly negligible change in the simas de partagat over this 112 yr period

the sant agata feltria landslide marche region central italy a case of recurrent earthflow evolving from a deep seated gravitational slope deformation abstract this paper examines the evolution of a large scale earthflow located in the northern sector of the marche region central italy in this area mass movements of different typology are particularly frequent since geological and geomorphological conditions often favour slope instability among these many mass movements the one affecting the historical village of sant agata feltria has been chosen also because its evolution has been recorded in chronicles starting from ancient times in fact reactivations of the 5 4 km long earthflow crossing the village have been quoted at least 12 times starting from the 16th century even though more ancient activations have been inferred historic researches and geomorphologic analyses allowed the detailed reconstruction of the evolution and the mechanism of the phenomenon outlining its causes and delineating risk zonation in particular a deep seated gravitational movement lateral spreading marked by trenches and ponds has been recognised at the top of the landslide the earthflow has been interpreted as a more surficial side effect of the deep seated phenomenon which constitutes its source area it has also been highlighted that reactivations coincided with long lasting and intense rainfalls whilst no direct connection seems to exist with earthquakes even though the area is seismically rather active and seismic shocks could have been among the major triggering factors for the deep seated deformation the oldest and probably most catastrophic recorded event itself 1561 a d took place during the first stages of a period of severe climate that involved the whole of europe

analysis of landslide inventories for accurate prediction of debris flow source areas abstract for the generation of susceptibility maps on medium scales 1 25 000 to 1 50 000 using statistical techniques a reliable landslide inventory is needed together with factor maps used as inputs this paper compares landslide susceptibility maps obtained with the same methodology but using different landslide inventories the official italian landslide inventory geoiffi for the lombardy region and a recently mapped inventory df2001 the analysis included four main steps i preparation of debris flow inventories using both random and spatial partitions and factor maps as explanatory variables ii calculation of accountability and reliability indices for a preliminary susceptibility analysis and selection of an appropriate combination of the factor maps for detailed analysis iii evaluation and validation of the obtained susceptibility maps and iv comparison of the results and selection of the final map the study area is located in the valtellina valley in the central italian alps the analysis identified highly susceptible areas of shallow landslides that may generate debris flows it was demonstrated that more precisely delimited source areas for landslide induced debris flows produce better susceptibility maps however the improvement of these maps was relatively limited when the inventories were randomly subdivided higher improvements were observed after the subdivision of the inventories into three geographical parts with different geomorphological characteristics although the modelling showed very similar results if evaluation is made using standard techniques the spatial pattern of the susceptibility maps was highly variable and dependent on the combination of the factor maps used

the asian summer monsoon an intercomparison of cmip5 vs cmip3 simulations of the late 20th century the boreal summer asian monsoon has been evaluated in 25 coupled model intercomparison project 5 cmip5 and 22 cmip3 gcm simulations of the late twentieth century diagnostics and skill metrics have been calculated to assess the time mean climatological annual cycle interannual variability and intraseasonal variability progress has been made in modeling these aspects of the monsoon though there is no single model that best represents all of these aspects of the monsoon the cmip5 multi model mean mmm is more skillful than the cmip3 mmm for all diagnostics in terms of the skill of simulating pattern correlations with respect to observations additionally for rainfall convection the mmm outperforms the individual models for the time mean the interannual variability of the east asian monsoon and intraseasonal variability the pattern correlation of the time pentad of monsoon peak and withdrawal is better simulated than that of monsoon onset the onset of the monsoon over india is typically too late in the models the extension of the monsoon over eastern china korea and japan is underestimated while it is overestimated over the subtropical western central pacific ocean the anti correlation between anomalies of all india rainfall and nino3 4 sea surface temperature is overly strong in cmip3 and typically too weak in cmip5 for both the enso monsoon teleconnection and the east asian zonal wind rainfall teleconnection the mmm interannual rainfall anomalies are weak compared to observations though simulation of intraseasonal variability remains problematic several models show improved skill at representing the northward propagation of convection and the development of the tilted band of convection that extends from india to the equatorial west pacific the mmm also well represents the space time evolution of intraseasonal outgoing longwave radiation anomalies caution is necessary when using gpcp and cmap rainfall to validate 1 the time mean rainfall as there are systematic differences over ocean and land between these two data sets and 2 the timing of monsoon withdrawal over india where the smooth southward progression seen in india meteorological department data is better realized in cmap data compared to gpcp data

predicting landslides for risk analysis spatial models tested by a cross validation technique abstract a landslide hazard map is intended to show the location of future slope instability most spatial models of the hazard lack reliability tests of the procedures and predictions for estimating the probabilities of future landslides thus precluding use of the maps for probabilistic risk analysis to correct this deficiency we propose a systematic procedure comprising two analytical steps relative hazard mapping and empirical probability estimation a mathematical model first generates a prediction map by dividing an area into prediction classes according to the relative likelihood of occurrence of future landslides conditional by local geomorphic and topographic characteristics the second stage estimates empirically the probability of landslide occurrence in each prediction class by applying a cross validation technique cross validation a blind test here using non overlapping spatial or temporal subsets of mapped landslides evaluates accuracy of the prediction and from the resulting statistics estimates occurrence probabilities of future landslides this quantitative approach exemplified by several experiments in an area near lisbon portugal can accommodate any subsequent analysis of landslide risk

a complete terrestrial oligocene magnetobiostratigraphy from the ebro basin spain abstract the integrated litho bio and magnetostratigraphic cross correlation of 11 continuous and correlatable sections in the southeastern ebro basin ne spain produced a complete oligocene magnetic polarity stratigraphy ranging from latest eocene to earliest miocene the magnetic polarity zonation of the different alluvial and shallow lacustrine sections has been correlated to the gpts using fossil mammals and the distinct sequence and pattern of polarity reversals the composite magnetic polarity sequence defines a continuous sequence from chron c15n to chron 6cn 2n from 34 8 to 23 7 ma late eocene early miocene in addition a few short normal and reverse polarity events that correlate to cryptochrons in the gpts are found i e in c11n 1r and c8n 1r the resulting regional magneto biostratigraphic framework based on fossil mammals is proposed to refine the dating of the european oligocene biochronological mammal paleogene units and correlate them with the standard oligocene marine stages and the north american land mammal ages the magnetochronology now established enables more precise dating of the late eocene and oligocene paleofloristic and paleofaunistic changes in southwestern europe which were coeval to ongoing global paleoclimatic and paleoceanographic changes on earth caused by high latitude cooling and ice sheet development in eastern antarctica

aspects of landslide activity in the mercantour massif and the french riviera southeastern france abstract landslides pose serious hazards in the mercantour massif and the french riviera in southeastern france the context for landslide development is a particularly favourable one both in terms of the geomorphic and structural setting of this alpine region and of the climatic hydrologic and seismic factors that trigger such failures high mountain relief and steep slopes constitute a very favourable setting for failures affecting massive basement rocks and a very heterogeneous sedimentary cover whose resistance has been weakened by weathering tectonic stresses and cambering due to gravity among trigger factors the important appears to be the precipitation regime rainfalls are commonly concentrated into short high intensity downpours or into bursts of sustained falls over periods of several days leading to soil saturation and lubrication of potential failure planes snowmelt also contributes to these lubrication processes earthquakes affecting this region are also a potentially important landslide trigger however while a lot of work has been done on the relationship between extreme climatic events and landslide activity much less is known of the trigger effects of earthquakes both the background factors that promote landslide development and the factors that trigger such failures are discussed within a time frame of landslide development progressive changes in soil strength due to weathering rock cambering and shattering processes lead to long term reduction in resistance superimposed on these progressive changes are episodic triggerings related to rainfall and snowmelt episodes or earthquakes landslides may occur as shallow low volume one time events or may be part of a progressive long term failure the former generally affect unconsolidated or clay rich sedimentary rocks especially on the coastal hillslopes of the french riviera a notable exception of a major voluminous one time event was the submarine landslide of the var delta in 1979 this landslide like numerous other smaller subaerial landslides onland was largely a result of human activities this landslide occurred following extensive modification of the var delta and notably reclamation of the steep fine grained delta front deforestation quarrying urbanisation and road network developments are various ways in which human activity has destabilized the coastal hillslopes favouring the development of numerous shallow landslides following each episode of heavy rainfall progressive landslides on the upper hillslopes of the mercantour massif have developed over long time spans order of 101 to 105 yrs and have involved more complex interactions between lithological controls slope characteristics and trigger factors the collelongue and bois de malbosc landslides have evolved into now stable failures buttressed by resistant migmatitic diorites or amphibolites the more voluminous and well monitored clapiere landslide is a relatively simple rotational landslide of the toe failure type this active landslide poses a serious to inhabitants and infrastructure in the tinee valley the importance of continued field monitoring modelling and mapping of landslides and their hazards is emphasised

south pacific origin of the decadal enso like variation as simulated by a coupled gcm 1 the hypothesis of the south pacific origin of the decadal 7 35 years enso like variation is investigated based on 200 year outputs of the echam4 opa oasis coupled gcm associated with the decadal warm cold sst anomalies in the tropical pacific an anomalous cyclonic anticyclonic circulation which is tilted in a southeast northwest direction appears in the south pacific this results in anomalous upward downward ekman pumping along the northeastern edge of the anomalous circulation and hence shallowing deepening the oceanic thermocline there such an external source of heat content tends to slowly discharge recharge the tropical ocean on the decadal timescale the above result is consistent with the observational study of luo and yamagata 2001 besides the model reproduces amazingly a high lagged correlation between the global land surface temperature and the decadal nino3 sst despite the model biases this suggests a potential prediction skill of the global warming based on the enso like decadal variation

landslide susceptibility assessment using weights of evidence applied to a study area at the jurassic escarpment sw germany a gis based model for the assessment of the landslide susceptibility in a selected area of the jurassic escarpment in the swabian alb sw germany is described using the weights of evidence method a quantitative model applied to landslides and their causative factors was created and illustrated in susceptibility maps while previous research work in this area concentrated on large scale investigations the present study was carried out at a regional level with a target scale of 1 150 000 the method is based on the assumption that future landslides will occur under the conditions similar or equal to those of past comparable landslides of the same type therefore the analysis was limited to one single type of landslides where the causative factors can be assumed as stable over a period of time due to uncertainties in the model mainly because of variances of the weights assigned to the causative factors the derived probability values representing the susceptibility for future landslides have to be considered relative however potential susceptible areas can be delineated and landslide indicators can be identified from the available data set slopes with angles from 11 to 26 composed of the oxford limestone marls as well as strongly argillaceous and silty colluvial material such as solifluction layers and colluvial cones are susceptible the main soil type of the escarpment and the other steep slopes of the swabian alb valleys are rendzinas formed in solifluction layers rendzina profiles including rock debris and clay which are superimposed on marl debris were also identified as landslide indicators these findings are in agreement with previous geomorphological studies in the same area the methodology seems to have widespread applicability beyond this local research area with the limitation that the knowledge of past landslides input to the model affects the absolute value of the final probability

landslide hazard evaluation a review of current techniques and their application in a multi scale study central italy in recent years growing population and expansion of settlements and life lines over hazardous areas have largely increased the impact of natural disasters both in industrialized and developing countries third world countries have difficulty meeting the high costs of controlling natural hazards through major engineering works and rational land use planning industrialized societies are increasingly reluctant to invest money in structural measures that can reduce natural risks hence the new issue is to implement warning systems and land utilization regulations aimed at minimizing the loss of lives and property without investing in long term costly projects of ground stabilization government and research institutions worldwide have long attempted to assess landslide hazard and risks and to portray its spatial distribution in maps several different methods for assessing landslide hazard were proposed or implemented the reliability of these maps and the criteria behind these hazard evaluations are ill formalized or poorly documented geomorphological information remains largely descriptive and subjective it is hence somewhat unsuitable to engineers policy makers or developers when planning land resources and mitigating the effects of geological hazards in the umbria and marche regions of central italy attempts at testing the proficiency and limitations of multivariate statistical techniques and of different methodologies for dividing the territory into suitable areas for landslide hazard assessment have been completed or are in progress at various scales these experiments showed that despite the operational and conceptual limitations landslide hazard assessment may indeed constitute a suitable cost effective aid to land use planning within this framework engineering geomorphology may play a renewed role in assessing areas at high landslide hazard and helping mitigate the associated risk

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

dynamics of the indian monsoon and enso relationships in the sintex global coupled model this paper uses recent gridded climatological data and a coupled general circulation model gcm simulation in order to assess the relationships between the interannual variability of the indian summer monsoon ism and the el nino southern oscillation enso the focus is on the dynamics of the ism enso relationships and the ability of the state of the art coupled gcm to reproduce the complex lead lag relationships between the ism and the enso the coupled gcm is successful in reproducing the ism circulation and rainfall climatology in the indian areas even though the entire ism circulation is weaker relative to that observed in both observations and in the simulation the ism rainfall anomalies are significantly associated with fluctuations of the hadley circulation and the 200 hpa zonal wind anomalies over the indian ocean a quasi biennial time scale is found to structure the ism dynamical and rainfall indices in both cases moreover ism indices have a similar interannual variability in the simulation and observations the coupled model is less successful in simulating the annual cycle in the tropical pacific a major model bias is the eastward displacement of the western north pacific inter tropical convergence zone itcz near the dateline during northern summer this introduces a strong semiannual component in pacific walker circulation indices and central equatorial pacific sea surface temperatures another weakness of the coupled model is a less than adequate simulation of the southern oscillation due to an erroneous eastward extension of the southern pacific convergence zone spcz year round despite these problems the coupled model captures some aspects of the interannual variability in the tropical pacific enso events are phase locked with the annual cycle as observed but are of reduced amplitude relative to the observations wavelet analysis of the model nino34 time series shows enhanced power in the 2 4 year band as compared to the 2 8 year range for observations during the 1950 2000 period the ism circulation is weakened during enso years in both the simulation and the observations however the model fails to reproduce the lead lag relationship between the ism and nino34 sea surface temperatures ssts furthermore lag correlations show that the delayed response of the wind stress over the central pacific to ism variability is insignificant in the simulation these features are mainly due to the unrealistic interannual variability simulated by the model in the western north pacific the amplitude and even the sign of the simulated surface and upper level wind anomalies in these areas are not consistent with observed patterns during weak strong ism years the ism and western north pacific itcz fluctuate independently in the observations while they are negatively and significantly correlated in the simulation this isolates the pacific walker circulation from the ism forcing these systematic errors may also contribute to the reduced amplitude of enso variability in the coupled simulation most of the unrealistic features in simulating the indo pacific interannual variability may be traced back to systematic errors in the base state of the coupled model

kinematics of basin development during the transition from terrane accretion to strike slip tectonics late cretaceous early tertiary cantwell formation south central alaska the cantwell basin was formed during late cretaceous time in the suture zone between the wrangellia composite terrane and the former continental margin of southern alaska the late cretaceous 80 70 ma lower cantwell formation represents the initial fill of this basin and includes 4000 m of sedimentary rock between maastrichtian and late paleocene time 70 60 ma rocks of the lower cantwell formation were deformed by nearly eastwest trending folds and north vergent thrust faults this deformation can be linked to the northward accretion and suturing of the wrangellia composite terrane to southern alaska during late paleocene to early eocene time 60 55 5 ma at least 2750 m of volcanic rocks of the upper cantwell formation were deposited above the folded lower cantwell formation new 40ar 39ar ages for the upper cantwell formation range from 59 8 0 2 to 55 5 0 2 ma and reveal that the unconformity between the lower and upper cantwell formations represents a 10 20 million year hiatus following volcanism the cantwell formation was crosscut by northeast trending folds northwest trending normal faults north trending left lateral slip faults northeast trending reverse faults and east trending right lateral slip faults these structures are consistent with northwest southeast compression in a zone of right lateral simple shear along a fault with the same trend east northeast as that of the present mckinley strand of the denali fault system cantwell basin kinematics are compatible with an escape tectonics model for south central alaska whereby the cantwell basin was formed folded and partially uplifted during northward terrane accretion and suturing and was deformed again during the westward transfer of terranes along right lateral strike slip fault systems

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

regional and local vegetation community dynamics of the eocene okanagan highlands british columbia washington state from palynology palynofloras from the middle early to early middle eocene okanagan highlands northern washington state and southern british columbia are used to reconstruct vegetation across a broad upland eocene landscape in this preliminary report forest floristic composition is reconstructed using palynological analysis of sediments from republic washington localities of the allenby formation in the princeton region hospital hill one mile creek and summers creek road hat creek mcabee falkland horsefly and driftwood canyon british columbia wind dispersed taxa were dominant in all samples consistent with floras preserved in lacustrine and paludal depositional environments pseudolarix was dominant in five of the floras but abies falkland or ulmus republic corner lot site were dominant in individual samples for some floras betulaceae were dominant for mcabee alnus and allenby formation betula matching megafloral data for these sites some taxa common to most sites suggest cool conditions e g

climatically induced floristic changes across the eocene oligocene transition in the northern high latitudes yukon territory canada global temperature decline associated with the eocene oligocene transition resulted in extinctions of plants and animals in both marine and nonmarine environments the extensive stratigraphic exposures well preserved palynological assemblages and interbedded coal seams of the nonmarine amphitheatre formation burwash basin yukon territory provide a comprehensive record of this transition the formation spans a paleoclimatically significant interval otherwise poorly represented in high latitude deposits of the northwestern cordillera palynological data constrained by the chronologic and stratigraphic framework established for the amphitheatre formation indicate that the global temperature decline resulted in a shift from warm temperate angiosperm dominated to cooler temperate gymnosperm dominated mainly coniferous forest types this turnover is seen in the increase in the percentage of gymnosperm compared to angiosperm pollen upsection the effect of climate change is also recorded in the systematic composition of the angiosperm pollen spectra the highly diverse palynoflora of the lower amphitheatre formation is dominated by angiosperm pollen characteristic of plants favoring warm temperate climates and consistently includes pollen of broad leaved evergreen taxa in contrast the angiosperms most conspicuous in the low diversity palynoflora of the upper amphitheatre formation are characteristic of plants favoring a cooler temperate climatic setting petrographic compositional changes in the coals document the same plant community changes the floristic data also indicate that at high latitudes there may have been a change to a wetter and less seasonal climate during the overall global cooling trend

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

deep seated gravitational slope deformation dsgsd and slow moving landslides in the southern tien shan mountains new insights from insar tectonic and geomorphic analysis we investigated deep seated gravitational slope deformation dsgsd and slow mass movements in the southern tien shan mountains front using synthetic aperture radar sar time series data obtained by the alos palsar satellite dsgsd evolves with a variety of geomorphological changes e g valley erosion incision of slope drainage networks over time that affect earth surfaces and therefore often remain unexplored we analysed 118 interferograms generated from 20 sar images that covered about 900 km2 to understand the spatial pattern of the slope movements and to identify triggering parameters we correlated surface dynamics with the tectono geomorphic processes and lithologic conditions of the active front of the alai range we observed spatially continuous constant hillslope movements with a downslope speed of approximately 71 mm year 1 velocity our findings suggest that the lithological and structural framework defined by protracted deformation was the main controlling factor for sustained relief and consequently downslope mass movements the analysed structures revealed integration of a geological structural setting with the superposition of cretaceous paleogene alternating carbonatic and clastic sedimentary structures as the substratum for younger less consolidated sediments this type of structural setting causes the development of large scale gravity driven dsgsd and slow mass movement surface deformations with clear scarps and multiple crest lines triggered planes for large scale deep mass creeps and these were related directly to active faults and folds in the geologic structures our study offers a new combination of insar techniques and structural field observations along with morphometric and seismologic correlations to identify and quantify slope instability phenomena along a tectonically active mountain front these results contribute to an improved natural risk assessment in these structures

active break cycles diagnosis of the intraseasonal variability of the asian summer monsoon in this study various diagnostics have been applied to daily observed outgoing longwave radiation olr and ecmwf reanalysis era products to provide a comprehensive description of the active break cycles associated with the asian summer monsoon and to address the differing behaviour of the two dominant time scales of intraseasonal variability 10 20 days and 30 60 days composite analysis of olr based on filtered daily all india rainfall air for the 40 day 30 60 days intraseasonal mode indicates that during active phases convection is significantly enhanced over the indian continent extending over the bay of bengal maritime continent and equatorial west pacific while convection is suppressed over the equatorial indian ocean and northwest tropical pacific resulting in a quadrapole structure over the asian monsoon domain in response to this heating pattern the large scale hadley lateral and the two east west transverse tropical circulations are enhanced there is also a significant impact on the extra tropical circulation through excitation and propagation of rossby waves in contrast the 15 day mode is more regional to the monsoon domain and has a prominent east west orientation in convection only the local hadley circulation over the monsoon region is modulated by this mode the evolution of these two modes as revealed by pop principal oscillation pattern analysis shows that the 40 day mode originates over the equatorial indian ocean once formed it has poleward propagation on either side of the equator and eastward propagation into the equatorial west pacific from the equatorial west pacific northward propagation over the west pacific and westward propagation into the indian longitudes are prominent the propagative features are complex and interactive and are responsible for the quadrapole structure in convection seen from the composites the interannual variability assessed from the pop coefficient time series indicates that the 40 day mode is strong during the onset phase of the monsoon in all the years but systematic propagation over the entire season depends crucially on the activity of the oceanic tcz tropical convergence zone the pop analysis of the 15 day mode indicates that this event originates over the equatorial west pacific associated with westward propagating rossby waves amplifies over the northwest tropical pacific and modulates both the continental and oceanic tczs over indian longitudes simultaneously this mode is pronounced during the established phase of the monsoon due to the complexity in the propagational features of both the intraseasonal modes it is concluded that understanding the subseasonal variability of one regional component of the asian summer monsoon asm requires understanding the entire asm system

a gis based automated procedure for landslide susceptibility mapping by the conditional analysis method the baganza valley case study italian northern apennines among the many gis based multivariate statistical methods for landslide susceptibility zonation the so called conditional analysis method holds a special place for its conceptual simplicity in fact in this method landslide susceptibility is simply expressed as landslide density in correspondence with different combinations of instability factor classes to overcome the operational complexity connected to the long tedious and error prone sequence of commands required by the procedure a shell script mainly based on the grass gis was created the script starting from a landslide inventory map and a number of factor maps automatically carries out the whole procedure resulting in the construction of a map with five landslide susceptibility classes a validation procedure allows to assess the reliability of the resulting model while the simple mean deviation of the density values in the factor class combinations helps to evaluate the goodness of landslide density distribution the procedure was applied to a relatively small basin 167 km2 in the italian northern apennines considering three landslide types namely rotational slides flows and complex landslides for a total of 1 137 landslides and five factors namely lithology slope angle and aspect elevation and slope bedding relations the analysis of the resulting 31 different models obtained combining the five factors confirms the role of lithology slope angle and slope bedding relations in influencing slope stability

tertiary extensional tectonics in tuscany northern apennines italy abstract two extensional events have been recognized in the tertiary evolution of tuscany the first event occurred in the period between the late oligocene and late tortonian and caused a stretching of 120 or greater the second event occurred between the late tortonian and quaternary periods and caused a stretching not greater than 10 the first event is characterized by the exhumation of middle crust rocks and therefore by the development of core complexes the most significant structures of the first event are low angle normal faults which characterize the upper plate of the core complexes and ductile shear zones which characterize the lower plate the low angle normal faults tend to die out in the late triassic evaporite level which constitutes the main detachment of the core complexes the main structures of the second extensional event are high angle normal faults which dissect all the previous tectonic features these faults border tectonic depressions which were the site of clastic sedimentation from late tortonian to quaternary time these normal faults may tend to flatten in a seismic lozenge shaped band explained as an active extensional shear zone which is located at the brittle ductile boundary a similar explanation is given for the detachment located in the late triassic evaporite level during the first extensional event while the first extensional event is in the framework of the northern apennine post collisional evolution the second extensional event because it affects an already stretched crust could be attributed to the southern tyrrhenian opening which began during late tortonian

eastward propagating mjo during boreal summer and indian monsoon droughts improved understanding of underlying mechanism responsible for indian summer monsoon ism droughts is important due to their profound socio economic impact over the region while some droughts are associated with external forcing such as the el nino and southern oscillation enso many ism droughts are not related to any known external forcing here we unravel a fundamental dynamic process responsible for droughts arising not only from external forcing but also those associated with internal dynamics we show that most ism droughts are associated with at least one very long break vlb breaks with duration of more than 10 days and that the processes responsible for vlbs may also be the mechanism responsible for ism droughts our analysis also reveals that all extended monsoon breaks whether co occurred with el nino or not are associated with an eastward propagating madden julian oscillation mjo in the equatorial indian ocean and western pacific extending to the dateline and westward propagating rossby waves between 10 and 25 n the divergent rossby wave associated with the dry phase of equatorial convection propagates westward towards indian land couple with the northward propagating dry phase and leads to the sustenance of breaks thus the propensity of eastward propagating mjo during boreal summer is largely the cause of monsoon droughts while short breaks are not accompanied by westerly wind events wwe over equatorial western pacific favorable for initiating air sea interaction all vlbs are accompanied by sustained wwe the wwes associated with all vlb during 1975 2005 initiate air sea interaction on intraseasonal time scale extend the warm pool eastward allowing the convectively coupled mjo to propagate further eastward and thereby sustaining the divergent circulation over india and the monsoon break the ocean atmosphere coupling on interannual time scale such as el nino can also produce vlb but not necessary

deep structures of slopes connected with sandstone crags in the upland area of the świetokrzyskie holy cross mountains central poland abstract deep seated gravitational deformations of slopes are commonly observed and described in mountains but faintly manifested and thus neglected in upland areas thanks to the geophysical methods e g ert as well as detailed surface surveys and studies in caves such deformations have been discovered and described in the region of the wietokrzyskie holy cross mountains central poland which is an upland area of usually gentle slopes of a height of several tens of metres the deformations which have been studied on 20 30 m high slopes formed of sandstone series alternating with claystone siltstone and heterolithe series represent various movements from slight rotational and translational ca 1 m movements through horizontal and vertical shifts of several metres to significant dislocations of sandstone corestones embedded within the regolith forming the slopes the last mentioned structures are currently relics completely masked by subsequent slope processes and their origin should be related to specific periglacial and even sub glacial conditions of the pleistocene on the other hand as confirmed by radiocarbon dating and other mapping slight movements of relatively low slopes can even be active nowadays these deformations that occur in regions of a relatively low relief and have so far been neglected or considered to be unique are possibly even more frequent and should be studied using modern geophysical and other methods

thrust top basin formation along a suture zone cantwell basin alaska range implications for development of the denali fault system the cantwell formation consists of a lower sedimentary sequence as much as 4000 m thick and an upper volcanic sequence with a maximum thickness of 3750 m that was deposited in the cantwell basin south central alaska previous to this study the cantwell basin was interpreted as a paleogene nonmarine mainly fluvial pull apart basin that formed in response to dextral strike slip displacement on the denali fault system this study proposes that the cantwell basin formed as part of the mesozoic accretionary phase of deformation prior to the development of the cenozoic postaccretionary denali fault system our reinterpretation is based on several new lines of data 1 age new data based on palynologic analyses of 135 fine grained samples indicate that the lower cantwell formation was deposited during the late campanian and early maastrichtian on the basis of previous regional tectonic studies and this new age constraint the formation of the cantwell basin was coeval with regional late cretaceous shortening associated with accretionary tectonics in southern alaska 2 depositional systems our analysis of the cantwell formation demonstrates that sedimentation occurred mainly in stream dominated alluvial fan axial braided stream and lacustrine settings these depositional systems were strongly influenced by a southward dipping asymmetric basin floor the presence of abundant terrestrially derived organic material together with palynological assemblages that include marine dinoflagellates and the associated presence of oncolites may be suggestive of a time of marginal marine influence during the deposition of the upper part of the lower cantwell formation the late campanian to early maastrichtian timing of this possible marine influence is within the range of the bearpaw transgressive event of the cordilleran foreland basin and allows for regional stratigraphic correlation of the cantwell basin with other sedimentary basins in northwestern north america 3 structural controls on basin formation mapping of intraformational angular unconformities and progressively tilted strata along the southern margin of the cantwell basin provides direct evidence that thrust fault deformation and lower cantwell formation sedimentation were synchronous distinctive cantwell formation conglomerate clasts derived from the uplifted hanging walls of nearby thrust sheets adjacent to the southern basin margin also support a syndepositional thrusting interpretation provenance data and the concentration of proximal alluvial fan deposits along the northwestern basin margin adjacent to the hines creek fault indicate that it too was active during deposition of the cantwell formation on the basis of the new data the cantwell basin is interpreted to have formed as a thrust top basin i e piggyback basin along the late cretaceous suture zone between the accreting wrangellia composite terrane and the north american continental margin in contrast to previous studies this reinterpretation of the formation of the cantwell basin implies that the lower cantwell formation is not a synorogenic deposit directly associated with strike slip displacement along the denali fault system therefore the cantwell basin cannot be used to constrain the timing for the early development of the denali fault system

submarine fan deposystems and tectonics of a late cretaceous forearc basin along an accretionary convergent plate boundary maccoll ridge formation wrangell mountains alaska analysis of upper cretaceous sedimentary and volcanic strata in the wrangell mountains of south central alaska provides an opportunity to study the tectonics depositional systems and provenance of a forearc basin that developed along an accretionary convergent plate boundary new data from the 1150 m thick maccoll ridge formation indicate that deposition occurred during the campanian on a coarse grained submarine fan that was derived from an uplifted allochthonous terrane exposed in the hanging wall of a fault system that separated the forearc basin from the subduction complex new age controls include palynoflora indicative of a late middle to late campanian age and compatible radiometric age determinations of volcanic vitric crystal tuffs near the top of the formation which have 40ar 39ar isochron ages of 79 4 0 7 and 77 9 2 1 ma sedimentological and paleontological data show that sedimentation occurred on the inner portions of a sand and gravel rich submarine fan system evidence for this inte

structures and mechanisms of the northward propagating boreal summer intraseasonal oscillation abstract the spatial and temporal structures of the northward propagating boreal summer intraseasonal oscillation bsiso are revealed based on the analysis of both the echam4 model simulation and the ncep ncar reanalysis the bsiso structure and evolution characteristics simulated by the model bear many similarities to those derived from the ncep ncar reanalysis the most notable features are the remarkable meridional asymmetries relative to the bsiso convection in the vorticity and specific humidity fields a positive vorticity perturbation with an equivalent barotropic structure appears a few latitude degrees north of the convection center the maximum specific humidity also shows a clear northward shift in the lower troposphere two internal atmospheric dynamics mechanisms are proposed to understand the cause of the northward propagation of the bsiso the first is the vertical shear mechanism the key process associated with this mechanism is the generation of barotropic vorticity due to the couplin

landslide susceptibility mapping for a part of tectonic kelkit valley eastern black sea region of turkey considering damage to man made structures by natural hazards in turkey landslides are the second most important hazard after earthquakes for this reason a large scale study titled turkish landslide inventory project has been carried out since 1998 during this project some special susceptibility hazard and risk assessments have been performed in this study a landslide susceptibility map of a part of tectonic kelkit valley in the north of central turkey was produced employing binary logistic regression analyses to achieve the most appropriate results some sensitivity analyses were also carried out for this purpose four different data sets were constructed considering conditioning factors used and sampling strategies applied for the training data sets in this study as a consequence of the analyses the most proper outcomes were obtained by using the data set in which continuous topographical parameters and lithological dummy variables were implemented together and 50 of training data set was taken from seed cells at random correct classification percentage and root mean square error rmse values for the validation data for that case were estimated as 84 16 and 0 36 respectively this prediction capability shows that the landslide susceptibility map produced in this research paper can be used for the planning of protective and mitigation measures in the region

failure forecast for large rock slides by surface displacement measurements forecasting the failure of large rock slides is difficult because of nonlinear time dependency and seasonal effects which affect the displacements starting from the accelerating creep theory prop

susceptibility assessment of earthquake triggered landslides in el salvador using logistic regression abstract this work has evaluated the probability of earthquake triggered landslide occurrence in the whole of el salvador with a geographic information system gis and a logistic regression model slope gradient elevation aspect mean annual precipitation lithology land use and terrain roughness are the predictor variables used to determine the dependent variable of occurrence or non occurrence of landslides within an individual grid cell the results illustrate the importance of terrain roughness and soil type as key factors within the model using only these two variables the analysis returned a significance level of 89 4 the results obtained from the model within the gis were then used to produce a map of relative landslide susceptibility

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

catastrophic slope failure and its origins case of the may 2010 girova mountain long runout rockslide czech republic abstract one of the largest long runout landslides in the modern history of the czech republic originated on the southern slopes of the girova mountain outer western carpathians at the end of extreme rainfalls in may 2010 the structurally predisposed girova mountain rockslide occurred very quickly within fault weakened deeply weathered flysch bedrock its main phase during which a wedge like block collapsed in the upper part of slope lasted for a few hours the overloaded slope collapsed and its motion lasted for the following 3 days the may 2010 girova mountain rockslide is an excellent case of a recurrent long runout landslide nested within a deep seated gravitational slope deformation with a long history of late quaternary mass movements the chronology of slope failures within the studied slope was reconstructed by means of radiocarbon dating and dendrogeomorphological analysis at least one holocene long runout landslide 7 4 cal ka bp and several smaller failures 1 5 and 0 6 cal ka bp preceded this recent catastrophic failure dendrogeomorphological analysis showed that the failure had been preceded by at least 80 year long creep movement that accelerated over the years due to extreme rainfall events despite the fact that extreme precipitation of may 2010 represented the last incremental change before catastrophic collapse of the slope its main reason was gradual weakening of rock massif and concentrated creeping with some accelerated phases in the upper part of the slope deformation

improved extended reconstruction of sst 1854 1997 abstract an improved sst reconstruction for the 1854 1997 period is developed compared to the version 1 analysis in the western tropical pacific the tropical atlantic and indian oceans more variance is resolved in the new analysis this improved analysis also uses sea ice concentrations to improve the high latitude sst analysis and a modified historical bias correction for the 1939 41 period in addition the new analysis includes an improved error estimate analysis uncertainty is largest in the nineteenth century and during the two world wars due to sparse sampling the near global average sst in the new analysis is consistent with the version 1 reconstruction the 95 confidence uncertainty for the near global average is 0 4 c or more in the nineteenth century near 0 2 c for the first half of the twentieth century and 0 1 c or less after 1950

estimating the quality of landslide susceptibility models we present a landslide susceptibility model for the collazzone area central italy and we propose a framework for evaluating the model reliability and prediction skill the landslide susceptibility model was obtained through discriminant analysis of 46 thematic environmental variables and using the presence of shallow landslides obtained from a multi temporal inventory map as the dependent variable for statistical analysis by comparing the number of correctly and incorrectly classified mapping units it is established that the model classifies 77 0 of 894 mapping units correctly model fitting performance is investigated by comparing the proportion of the study area in each probability class with the corresponding proportion of landslide area we then prepare an ensemble of 350 landslide susceptibility models using the same landslide and thematic information but different numbers of mapping units this ensemble is exploited to investigate the model reliability including the role of the thematic variables used to construct the model and the model sensitivity to changes in the input data by studying the variation of the model s susceptibility estimate the error associated with the susceptibility assessment for each mapping unit is determined this result is shown on a map that complements the landslide susceptibility map prediction skill of the susceptibility model is then estimated by comparing the forecast with two recent event inventory maps the susceptibility model is found capable of predicting the newly triggered landslides a general framework for testing a susceptibility model is proposed including a scheme for ranking the quality of the susceptibility assessment

influence of large scale topography on gravitational rock mass movements new insights from physical modeling 1 gravitational slope failures and associated rock mass movements can be observed at various scales in the same area it seems obvious that the different movement scales should be interrelated but their relationships are poorly understood we address this problem using 3 d physical modeling experiments were conducted with mechanically homogeneous models with two scale topographic features a large scale corresponds to the whole mountain several kilometers and a smaller one to a part of a mountain slope one kilometer results show that large scale relief induces large scale large volume gravitational movements introduction of small scale topographic features results not only in the generation of smaller scale landslides but also in considerable changes in the deformation pattern the various scale processes occur simultaneously and affect each other to predict the evolution of a landslide it is therefore necessary to take into account the topography and deformation pattern at various scales

deep seated gravitational slope deformations in western sicily controlling factors triggering mechanisms and morphoevolutionary models abstract a study of deep seated gravitational slope deformation dsgsd phenomena affecting areas of various geological and geomorphological settings in western sicily is described western sicily is underlain by a thin skinned imbricate wedge of meso cenozoic carbonate and siliciclastic rocks that formed by the stacking of several thrust nappes over the iblean foreland locally the original thrust sheets are folded and cut by high angle faults large areas of western sicily now display high relief energy due to plio pleistocene block faulting and uplifting and the quaternary morphogenetic phases are characterised by incision thereby triggering widespread dsgsds to identify controlling factors and triggering causes and to develop reliable morphoevolutionary models for the dsgsds of western sicily a geomorphological study based on field surveys and aerial photography interpretations was performed previous geomorphological data relating to well known examples of dsgsds were reconsidered leading to remarkable revisions of the interpretative models in certain cases new data were subsequently collected enabling recognition of additional dsgsd phenomena the whole body of data involves a total of 27 dsgsds affecting areas in two specific geological settings 1 areas with flat thrust surfaces where differential settlements back tilting lateral spreads in competent rocks overlying marls and clays large topples and or block type slope movements may develop and 2 areas where deep rooted carbonate units come into lateral contact with clayey marly units along high angle faults where lateral spreads in brittle homogeneous rocks sinking and or rock flows may occur these dsgsd phenomena are associated with different evolutionary stages allowing a morphoevolutionary model to be defined for the two geological conditions for these two different morphoevolutionary models the following structural features play an important role in the development of dsgsds 1 where carbonate bodies overlie clayey marly rocks triggering of the dsgsds traces back to deformation of a ductile substratum that follows the exhumation of the flat thrust planes and the underlying clayey marly rocks due to block faulting and or stream incision and 2 where homogeneous carbonate rocks hundreds of metres thick crop out the dsgsds are triggered by very high relief energy and tensile stress that follow the combined actions of quaternary block faulting and stream deepening associated with differential erosion

eocene oligocene extinction and paleoclimatic change near eugene oregon thick ash fl ow tuffs provide marker beds through fossiliferous eocene and oligocene marine and non marine sedimentary rocks near eugene oregon new mapping radiometric dating and paleomagnetic stratigraphy of these tuffs and rocks now allow dating of local fossil fl oras the comstock goshen rujada and willamette fl oras have been widely used as evidence for eocene oligocene climatic cooling and drying eocene leaves from comstock and hobart butte included such thermophilic taxa as liquidambar the early oligocene goshen fl ora lacked liquidambar but retained many thermophilic species with large leaves that have entire margins and acuminate apices drip tips in contrast fossil leaves from later oligocene rujada and willamette fl oras are small and serrate and most lack drip tips marine faunas also indicate climatic cooling and local disappearance of thermophilic molluscs such as anadara ficus and conus our dating and compilation of plant and molluscan fossil occurrences indicate a steady rise in species diversity from 46 ma to maximal diversity of thermophilic taxa at 35 34 ma then extinctions of 60 of plant species after 33 4 ma and 32 of marine invertebrates after 33 2 ma both signifi cantly postdating the eocene oligocene boundary at 33 7 ma plant diversity rebounds during the early oligocene but marine invertebrates continue to decline into the oligocene in part due to the retreat of fully marine environments from the eugene area neither these data nor evidence from coeval fossil plants and soils in central oregon support the notion of a terminal eocene event nor any other single abrupt paleoclimatic shift or extinction the eocene oligocene biotic and climatic transition was drawn out over some 6 m y abrupt forcings such as meteorite impacts or volcanic eruptions are less likely explanations for cooling and diversity decline than long term processes such as mountain building changing ocean currents or reorganization of the carbon cycle by coevolution of grasses and grazers

influence of indian ocean dipole on boreal summer intraseasonal oscillations in a coupled general circulation model 1 the role of indian ocean dipole iod on poleward propagation of boreal summer intraseasonal oscillations bsiso is examined using long simulation of a coupled ocean atmosphere general circulation model the model sintex f1 simulates the salient features of bsiso realistically it is found that coherent incoherent poleward propagation of precipitation anomalies from 5 s to 25 n are observed during negative positive iod years the probable mechanisms behind such an anomaly in poleward propagation of bsiso in contrasting iod years are identified we find that the mean structure of meridional specific humidity distribution undergoes cardinal changes in contrasting iod years which in turn influences the meridional propagation of bsiso enhanced decreased air sea interaction in negative positive iod years also supports coherent incoherent poleward propagation of bsiso anomalies this study has important implications considering the critical role of bsiso in modulating the seasonal mean summer monsoon rainfall

active folding in the algerian earthquake of 10 october 1980 a fold controlling the form of the local topography near el asnam algeria increased in amplitude at the time of the earthquake of 10 october 1980 the deformation occurred rapidly in an elastic brittle manner and not in the gradual ductile fashion in which folds are normally thought to develop

influence of deep seated gravitational slope deformations on landslide distributions a statistical approach abstract the influence of deep seated gravitational slope deformations dsgsds on the distribution of translational landslides was analyzed in the milia basin tuscany italy detailed geomorphological mapping combined with the analysis of aerial photography enabled us to build two landslide inventories one inventory including landslides before 1975 was used to create statistical models whereas the other inventory including landslides after 1975 was used to validate the models geology slope angle slope aspect distance to hydrographic elements and distance to tectonic lineaments were considered as landslide predisposing factors to quantify the importance of dsgsds as another landslide predisposing factor the dsgsd presence absence map was introduced in the stepwise statistical analysis the landslide inventory maps and factor maps were processed using a conditional analysis on all possible factor combinations to produce landslide susceptibility maps with five susceptibility classes the results indicate that the dsgsds significantly affect landslide distribution

spatial statistical modeling of shallow landslides validating predictions for different landslide inventories and rainfall events abstract statistical models that exploit the correlation between landslide occurrence and geomorphic properties are often used to map the spatial occurrence of shallow landslides triggered by heavy rainfalls in many landslide susceptibility studies the true predictive power of the statistical model remains unknown because the predictions are not validated with independent data from other events or areas this study validates statistical susceptibility predictions with independent test data the spatial incidence of landslides triggered by an extreme rainfall in a study area was modeled by logistic regression the fitted model was then used to generate susceptibility maps for another three study areas for which event based landslide inventories were also available all the study areas lie in the northern foothills of the swiss alps the landslides had been triggered by heavy rainfall either in 2002 or 2005 the validation was designed such that the first validation study area shared the geomorphology and the second the triggering rainfall event with the calibration study area for the third validation study area both geomorphology and rainfall were different all explanatory variables were extracted for the logistic regression analysis from high resolution digital elevation and surface models 2 5 m grid the model fitted to the calibration data comprised four explanatory variables i slope angle effect of gravitational driving forces ii vegetation type grassland and forest root reinforcement iii planform curvature convergent water flow paths and iv contributing area potential supply of water the area under the receiver operating characteristic roc curve auc was used to quantify the predictive performance of the logistic regression model the auc values were computed for the susceptibility maps of the three validation study areas validation auc the fitted susceptibility map of the calibration study area apparent auc 0 80 and another susceptibility map obtained for the calibration study area by 20 fold cross validation cross validation auc 0 74 the auc values of the first and second validation study areas 0 72 and 0 69 respectively and the cross validation auc matched fairly well and all auc values were distinctly smaller than the apparent auc based on the apparent auc one would have clearly overrated the predictive performance for the first two validation areas rather surprisingly the auc value of the third validation study area 0 82 was larger than the apparent auc a large part of the third validation study area consists of gentle slopes and the regression model correctly predicted that no landslides occur in the flat parts this increased the predictive performance of the model considerably the predicted susceptibility maps were further validated by summing the predicted susceptibilities for the entire validation areas and by comparing the sums with the observed number of landslides the sums exceeded the observed counts for all the validation areas hence the logistic regression model generally over estimated the risk of landslide occurrence obviously a predictive model that is based on static geomorphic properties alone cannot take a full account of the complex and time dependent processes in the subsurface however such a model is still capable of distinguishing zones highly or less prone to shallow landslides

a comprehensive mass flux scheme for cumulus parameterization in large scale models abstract observational studies indicate that a mass flux approach may provide a realistic framework for cumulus parameterization in large scale models but this approach through the introduction of a spectral cloud ensemble leads normally to rather complex schemes in this paper the question is addressed whether much simpler schemes can already provide realistic values of the thermal forcing by convection under various synoptic conditions this is done through verifying such a scheme first on data from field experiments for periods of tropical penetrative convection gate marshall islands tradewind cumuli atex bomex and extratropical organized convection sesame 79 and then in a nwp model the scheme considers a population of clouds where the cloud ensemble is described by a one dimensional bulk model as earlier applied by yanai et al in a diagnostic study of tropical convection cumulus scale downdrafts are included various types of convection are represented i e penetrative convection in c

improved prediction of the indian ocean dipole mode by use of subsurface ocean observations abstractthe numerical seasonal prediction system using the scale interaction experiment frontier version 1 sintex f ocean atmosphere coupled model has so far demonstrated a good performance for prediction of the indian ocean dipole mode iod despite the fact that the system adopts a relatively simple initialization scheme based on nudging only the sea surface temperature sst however it is to be expected that the system is not sufficient to capture in detail the subsurface oceanic precondition therefore the authors have introduced a new three dimensional variational ocean data assimilation 3dvar method that takes three dimensional observed ocean temperature and salinity into account since the new system has successfully improved iod predictions the present study is showing that the ocean observational efforts in the tropical indian ocean are decisive for improvement of the iod predictions and may have a large impact on important socioeconomic activities particularly in the indian ocean rim co

gravitational spreading of mountain ridges coeval with late weichselian deglaciation impact on glacial landscapes in trollaskagi northern iceland abstract during the late weichselian deglaciation the coastal mountains of northern central iceland have experienced significant paraglacial readjustment processes in the form of conspicuous rock slope failures and deep seated gravitational slope deformation dsgsd local topographic slopes and ridges were deeply reshaped by these large scale paraglacial processes located on the eastern side of skagafjor ur one of the largest fjords of northern iceland the oslandshli arfjoll and hnjukar ridges 65 49n 19 14w exhibit geomorphic evidence of spectacular dsgds several series of dsgsd induced landforms such as crestal graben and troughs initiated by ridge top splitting were investigated over a 30 km 2 area on the basis of geomorphological mapping we recognized i a ridge top splitting event mainly controlled by glacial debuttressing induced by a minimal 300 m lowering of the glacier surface in the deildardalur valley ii a rapid late weichselian deglaciation of the deildardalur valley spanning a few thousands of years ice free stage probably reached around 14 000 years cal bp iii ridge top splitting having an influence on large scale glacial patterns by guiding and facilitating glacial erosion along ridge top grabens resulting in accelerated trough widening based on these interpretations we propose an evolutionary sequence of both the kinematic stages of the dsgsd and the late weichselian deglaciation at the valley scale this work provides new insights into i the patterns of the late weichselian deglaciation in the skagafjor ur area especially in tributary valleys of the fjord ii the timing of large scale paraglacial ridge top deformations in relation to the post lgm deglaciation and iii the influence of paraglacial dsgsd features on large scale glacial erosional patterns

mass movement geologic structure and morphologic evolution of the pizzotto greci slope calabria italy abstract deep seated mass movements of different types affect the pizzotto greci slope in northwest calabria italy the slope is carved out of phyllitic rocks capped by gneissic layers its geological structure is extremely complicated by tectonic structures that pervasively cross the slope transversely and downslope a large scale gravitational deformation of sackung type affects the slope on the upslope side a debris flow source area feeds a large fan constructed by recurrent debris flow deposits aggradation is consequently occurring along the stream at the base of the slope in order to define the internal structure of the slope for a stability slope model geological geostructural geomorphological historical and dendrogeomorphologic studies as well as direct geotechnical logs and indirect geophysical investigations have been carried out over a two year project financed by the ec environment programme the main aspects of the geological and geomorphological studies and some preliminary geotechnical data are presented here along with a conceptual model aimed at describing the relationships between the mass movements on the slope and the construction destruction stages of the fan at the base of the slope the model is based on the assumption that aggradation has a stabilising effect on the slope thus debris flow activity is reduced and consequently destruction of the fan occurs bringing the slope again towards unstable conditions the reactivation of mass movement however leads to the reconstruction of the fan and the buttressing effect at the base of the slope is restored thus the process is cyclic and self regulating

tectonic vs gravitational morphostructures in the central eastern alps italy constraints on the recent evolution of the mountain range abstract deep seated gravitational slope deformations dsgsds influence landscape development in tectonically active mountain ranges nevertheless the relationships among tectonics dsgsds and topography are poorly known in this paper the distribution of dsgsds and their relationships with tectonic structures and active processes surface processes and topography were investigated at different scales over 100 dsgsds were mapped in a 5000 km2 sector of the central eastern alps between the valtellina engadine and venosta valleys detailed lineament mapping was carried out by photo interpretation in a smaller area about 750 km2 including the upper valtellina and val venosta fault populations were also analysed in the field and their mechanisms unravelled allowing to identify different structural stages the youngest being consistent with the regional pattern of the ongoing crustal deformation finally four dsgsd examples have been investigated in detail by geological and 2d geomechanical modelling dsgsds affect more than 10 of the study area and mainly cluster in areas where anisotropic fractured rock mass and high local relief occur their onset and development is subjected to a strong passive control by mesoscopic and major tectonic features including regional nappe boundaries as well as nw se n s and ne sw trending recent brittle structures the kinematic consistency between these structures and the pattern of seismicity suggests that active tectonics may force dsgsds although field evidence and numerical models indicate slope debuttressing related to deglaciation as a primary triggering mechanism

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

occurrence and palaeoenvironmental significance of aromatic hydrocarbon biomarkers in oligocene sediments from the mallik 5l 38 gas hydrate production research well canada abstract the aromatic hydrocarbon biomarker distributions of thirty oligocene sediment samples with different lithology lignite clay and sand from the japex jnoc gsc et al mallik 5l 38 gas hydrate production research well canada were analyzed using gas chromatography mass spectrometry gc ms the compositions vary with lithology indicating a change in palaeoenvironmental conditions at the time of deposition aromatic diterpenoids of the abietane type are more abundant in the lignite samples than in the clay samples and represent a gymnosperm e g conifer dominated palaeovegetation in contrast in the clay samples aromatic triterpenoids are generally preserved as major constituents indicating angiosperm dominated vegetation the sand samples contain only minor amounts of aromatic terpenoids but show a preference for diterpenoid gymnosperm markers to recognise gymnosperm versus angiosperm dominated palaeoenvironments a new ratio termed the angiosperm gymnosperm aromatic ratio agar has been developed thus the terpenoid distribution in the deltaic sediments provides information on the compositional changes in the plant community at the mallik site lignites and the hinterland clays over time concomitantly the changing dominance in the plant communities allows an insight into varying climatic conditions during the late oligocene in the area additionally the aromatic biomarker composition has been used to assess the level of thermal maturity of the organic matter in the mallik samples and indicates a prevailing immature character

paraglacial slope adjustment since the end of the last glacial maximum and its long lasting effects on secondary mass wasting processes hauser kaibling austria abstract this study indicates the possible long lasting impacts of deep seated gravitational slope deformation dgsd on erosional and mass movement processes dgsd features are common large scale landforms in the crystalline basement rocks of the central alps of austria inactive forms are related to paraglacial nonglacial processes directly conditioned by former glaciation and deglaciation rock slope adjustment processes acting after glacier retreat towards the end of the late glacial period the near surface metamorphic bedrock of dgsd features is generally disintegrated such rock type favours erosion and the formation of small landslides field data laboratory analyses aerial photographs and gis based terrain analyses are used to describe the different geomorphic effects of an extremely disintegrated rock slope the studied dgsd hauser kaibling 13 6 km2 is located in central austria during the last glacial maximum the adjacent valley glacier reached an altitude of approximately 1900 m a s l glacier retreat in combination with the unfavourable tectono metamorphic setting caused gravity induced stresses to act subsequent sediment build up in the main valley restabilised the slope linear erosion cut a number of gullies into the lower part of the dgsd calculated mean erosional denudation rates at incised valley sections range from 0 5 to 2 6 mm a 1 since deglaciation smaller active landslides on the sides of the steep gullies draining the dgsd contribute to high denudation rates active landsliding is favoured by i fragmented rock ii steep slopes iii supply of surface and subsurface water by rain and snowmelt and iv human impact debris flows and debris charged flood events occurred frequently in the past during such events material was transported from the unstable slopes to the populated alluvial fans thus knowledge about the spatial distribution and the stage of development of dgsds active and currently inactive provides an important basis for risk management measures