holocene glacial activity and climatic variations in the swiss alps reconstructing a continuous record from proglacial lake sediments cores recovered from proglacial lake silvaplana swiss alps were investigated to examine the influence of holocene glaciers on lacustrine sedimentation during times of glacial activity in the catchment the sedimentation in the lake is dominated by the input of silt and clay sized material delivered by glacial meltwaters the deposition of fine grained material and the formation of varves reflect the existence of glaciers in the catchment and can therefore be used for the reconstruction of glacial history sedimentation rates are up to nine times higher in the varved than in the non varved sediments indicating significantly higher erosion rates under glaciated catchment conditions glacial varves were deposited in lake silvaplana during glacial retreat in the latest pleistocene and early holocene until 9400bp non varved deposits having a higher organic content and coarser grain sizes accumulated at lower rates when glacial activity was absent or negligible within the catchment between 9400 and 3300 bp

holocene history of fire vegetation and land use from the central pyrenees france located on a mountain pass in the west central pyrenees the col d ech peat bog provides a holocene fire and vegetation record based upon nine 14c ams dates we aim to compare climate driven versus human driven fire regimes in terms of frequency fire episodes distribution and impact on vegetation our results show the mid holocene 8500 5500 cal yr bp to be characterized by high fire frequency linked with drier and warmer conditions however fire occurrences appear to have been rather stochastic as underlined by a scattered chronological distribution wetter and colder conditions at the mid to late holocene transition 4000 3000 cal yr bp led to a decrease in fire frequency probably driven by both climate and a subsequent reduction in human land use on the contrary from 3000 cal yr bp fire frequency seems to be driven by agro pastoral activities with a very regular distribution of events during this period fire was used as a prominent agent of landscape management

a chronology of holocene and little ice age glacier culminations of the steingletscher central alps switzerland based on high sensitivity beryllium 10 moraine dating abstract the amplitude and timing of past glacier culminations are sensitive recorders of key climate events on a regional scale precisely dating young moraines using cosmogenic nuclides to investigate holocene glacier chronologies has proven challenging but progress in the high sensitivity 10 be technique has recently been shown to enable the precise dating of moraines as young as a few hundred years in this study we use 10 be moraine dating to reconstruct culminations of the steingletscher a small mountain glacier in the central swiss alps throughout the holocene the outermost recorded positions of steingletscher most likely occurred in the early holocene and appear nearly synchronous with glacier culminations reported from other regions in the alps a late holocene position corroborates the evidence for a significant glacier advance of similar extent to that of the little ice age lia 3 kyr ago finally fourteen boulders from different moraines yield 10 be ages between 580 and 140 years with analytical precisions mostly 10 dating steingletscher advances during the lia because these lia 10 be ages are in stratigraphic order we tentatively distinguish four lia glacier culminations about 1470 ce 1650 ce 1750 ce and 1820 ce which are in good agreement with existing independent records during the lia in the swiss alps these findings illustrate the high potential of the 10 be moraine dating method to directly link paleo glacier chronologies to historical records and thus present day glacier evolution

holocene coastal glaciation of alaska holocene uctuations of the three cirque glaciers on the seward peninsula and ve groups of tidewater and land terminating glaciers along the northernmost gulf of alaska provide a proxy record of late holocene climatic change furthermore the movements of the coastal glaciers were relevant to late holocene native american migration the earliest expansion was recorded about 6850 yr bp by hubbard glacier at the head of yakutat bay in the gulf of alaska however its down fjord advance to the bay mouth was delayed until 2700 bp similarly expansions of the icy bay bering and mccarty glaciers occurred near their present termini by 3600 3000 bp compatible with marked cooling and precipitation increases suggested by the alaskan pollen record decrease in glacier activity 2000 bp was succeeded by advances of gulf coastal glaciers between 1500 and 1300 bp correlative with early medieval expansions across the northern hemisphere a medieval optimum encompassing at least a few centuries prior to ad 1200 is recognized by general retreat of land terminating glaciers but not of all tidewater glaciers little ice age advances of land based glaciers many dated with the precision of tree ring cross dating were centered on the middle 13th or early 15th centuries the middle 17th and the last half of the 19th century a d strong synchrony of these events across coastal alaska is evident 2000 elsevier science ltd all rights reserved

lateglacial holocene environmental changes in the mediterranean alps inferred from lacustrine sediments this study investigates sediment cores from the mediterranean alpine lakes located in upvalley cirques upper than 1700 metres a s l using sedimentological palynological and geomorphological studies in order to document environmental changes following the last phase of glacier retreat these results are considered in the framework of the deglaciation characterized from 16 sediment cores from high altitude lakes and mires including 104 14c ages and geomorphological studies of the mediterranean alps considering each sediment core proxy as an independent observation i e comparisons between 14c ages and palynostratigraphy between 14c ages and lithostratigraphy between palynostratigraphy and lithostratigraphy these data are aimed at contributing to a better understanding of the timing of postglacial environmental changes the 14c ages combined with pollen biostratigraphy indicate that the deglaciation of cirque catchments is dated between 14 500 and 13 000 cal bp i e during the lateglacial interstadial greenland interstadial 1e the sixteen lacustrine and mire sediment records are systematically characterized by three units from bottom to top organic poor blue clay beige to light brown silty clay and organic rich dark brown gyttja lithotype during the younger dryas lakes located below 2300 m a s l were ice free and their pollen record indicates steppe conditions the sedimentary facies also informs on the timing of glacial dominated processes the onset of organic rich gyttja is dated at 11 000 cal bp suggesting the last influence of cirque glaciers in these lakes at the beginning of the holocene the timing of the onset of this organic rich unit differs in sites 2000 years probably due to an altitudinal and exposure gradient of the glacial cirques the presence of gyttja from 11 000 cal bp to present indicates biogenic infilling lake for all the holocene even though the literature have indicated rock glacier advances occurred during the holocene subboreal and lia in the south of the alps no significant sedimentological patterns related to glacier fluctuations are recorded in lake vens the glacier fluctuations in the mediterranean alps are concomitant with those dated in the non mediterranean alps thus suggesting a main common climate forcing however the increase in terrigenous sediment inputs since 1800 cal bp is mainly due to human activities

late pleistocene climate change and landscape dynamics in the eastern alps the inner alpine unterangerberg record austria drill cores from the inner alpine valley terrace of unterangerberg located in the eastern alps of austria offer first insights into a pleistocene sedimentary record that was not accessible so far the succession comprises diamict gravel sand lignite and thick fine grained sediments additionally cataclastic deposits originating from two paleo landslide events are present multi proxy analyses including sedimentological and palynological investigations as well as radiocarbon and luminescence data record the onset of the last glacial period wurmian at unterangerberg at 120 110 ka this first time period correlated to the mis 5d was characterised by strong fluvial aggradation under cold climatic conditions with only sparse vegetation cover furthermore two large and quasi synchronous landslide events occurred during this time interval no record of the first early wurmian interstadial mis 5c is preserved during the second early wurmian interstadial mis 5a the local vegetation was characterised by a boreal forest dominated by picea with few thermophilous elements the subsequent collapse of the vegetation is recorded by sediments dated to 70 60 ka i e mis 4 with very low pollen concentrations and the potential presence of permafrost climatic conditions improved again between 55 and 45 ka mis 3 and cold adapted trees re appeared during interstadials forming an open forest vegetation mis 3 stadials were shorter and less severe than the mis 4 at unterangerberg and vegetation during these cold phases was mainly composed of shrubs herbs and grasses similar to what is known from today s alpine timberline the unterangerberg record ended at 45 ka and or was truncated by ice during the last glacial maximum

the rhone glacier was smaller than today for most of the holocene we present the development and application of the novel in situ cosmogenic 14 c 10 be chronometer to recently exposed proglacial bedrock of the rhone glacier switzerland results show that during the holocene the glacier was smaller than today for 6500 2000 yr and larger than today for 4500 2000 yr this pattern is consistent with limited data from other techniques for glaciers in the alps and scandinavia but in contrast to glaciers from the southern alps of new zealand emphasizing the high sensitivity of large mountain glaciers to small climate changes the 14 c 10 be chronometer also shows that abrasion rates beneath the rhone glacier increased with ice speed

discovery of early holocene wood and peat on the forefield of the pasterze glacier eastern alps austria during recent years a number of fragments of pinus cembra and larix decidua as well as peat were found in front of the tongue of the pasterze glacier in the eastern alps these were washed out by the stream from under the present ice the wood originates from trees which reached ages of upto 400 years or more radiocarbon dating shows them to come from the early holocene they indicate that between cal bc 8100 and cal bc 6900 the pasterze glacier was smaller than at present the pasterze glacier advanced around cal bc 6900 a lump of peat shows that around cal bc 6300 at the latest the pasterze glacier was again smaller than today the radiocarbon age of the fulvic acid fraction of thepeat suggests that growth could have continued until cal bc 5430 5080 further wood samples dated to around cal bc 4800 and cal bc 3800 show that at these times the pasterze glacier was smaller than at present the pasterze glacier had a relatively limited extent over long periods inthe early holocene thus mostly favou

late pleistocene holocene surface processes and landscape evolution in the central swiss alps abstract the european alps are a geomorphologically active region and experience a number of gravity driven hillslope processes soil and landscape formation in the alps has consequently undergone several minor and major traceable changes of developmental trajectories during the holocene soil development is hypothesised to be often non linear with time and characterised by stages of progressive and regressive evolution caused by upbuilding formation profile deepening and erosion profile shallowing several cold and warm climate phases are identified during the holocene but it is largely unknown which effects these might have had on slope processes by using datable moraines 10 be and mires 14 c we have constructed a temporal framework for these processes using the geochemical imprint of mires in the alpine setting of the goschener valley of the central swiss alps we reconstructed general mostly erosional landscape processes for the last ca 10 ka as this is the type locality for the goschener cold phase we assumed that this phase goschener cold phase i and ii 1 5 and 2 5 ka bp should have left easily recognizable traits after deglaciation 11 12 ka bp soil evolution was progressive beginning around 8 ka bp we detect a distinct increase in erosion here together with a vegetation change towards tundra vegetation and the highest measured rates of carbon sequestration other phases of high geomorphic activity were recognised ca 5 6 ka bp 4 ka bp and to a lesser extent 1 3 ka ago the cold phase at 5 6 ka bp corresponds to a less distinct change in vegetation and lessened erosion human impact is increasingly obvious since about 2 4 ka bp which overlaps with the goschener cold phase nonetheless erosion processes were not extraordinarily high during this period and a climate effect cannot be distinguished we detect evidence of increasing human disturbance regressive soil evolution for about the last 1 ka we also detect an increase in dust flux during the last ca 4 5 ka presumably due to the landscape change s in the sahara during this time

stratigraphic evidence for multiple holocene advances of lillooet glacier southern coast mountains british columbia holocene lateral moraines in the coast mountains of british columbia are commonly composed of multiple drift units related to several glacier advances in this paper we document lateral moraine stratigraphy at lillooet glacier in the southern coast mountains five tills separated by laterally extensive paleosols and layers of large woody debris were found in three cross sectional exposures through the northeast lateral moraine and two shallow gullies incised into its steep proximal face eighteen new radiocarbon ages constrain the timing of five separate advances of lillooet glacier 1 prior to 3000 14 c years bp 2 3000 14 c years bp 3 2500 14 c years bp 4 1700 to 1400 14 c years bp and 5 during the little ice age lia after 470 14 c years bp the lillooet glacier chronology is broadly synchronous with other glacier records from the coast mountains these records collectively demonstrate climate variability at higher frequencies during the late holocene than is apparent from many paleoecological reconstructions reconstructions of glacier fluctuations are often hampered by poor preservation of landforms that predate the extensive lia advances of the latest holocene our results highlight the potential of lateral moraine stratigraphy for reconstructing these earlier events

holocene glacier change in the silvretta massif austrian alps constrained by a new 10be chronology historical records and modern observations abstract mountain glaciers are important water resources in alpine regions and are sensitive to climate change reconstructing glacier oscillations improves our understanding of the amplitude and the frequency of climate variability and resolves time periods when the climate system was in transition from glacial to interglacial conditions at the beginning of the holocene and from a naturally controlled system to an anthropogenically influenced system in the course of industrialization with this study we contribute a new holocene mountain glacier chronology from the eastern european alps the study area the ochsental in the silvretta massif features pronounced holocene moraine ridges and is an important catchment for hydropower production we present 18 new 10be exposure ages of bedrock outcrops n 2 and boulders n 16 we complement the 10be glacier chronology with historical records and instrumental time series and correlate it with pre existing climate proxy records for capturing ice margin positions at different times during the holocene the ochsental chronology is compared to cosmogenic nuclide moraine records across the european alps to provide an alpine wide perspective on the transition from the younger dryas yd c 12 9 to 11 7 ka to the holocene c 11 7 ka to present results show that glaciers in the ochsental stabilized at the position of a preserved holocene moraine c 9 9 0 7 ka after retreating from their late glacial position this holocene moraine formation interval is concurrent with a cold spell detected in some climate proxy records in the swiss and austrian alps the central european cold phase 1 ce 1 glaciers were presumably much smaller during the mid holocene and readvanced to a position close to the preserved early holocene moraine during the little ice age lia c 1250 to 1850 ce lia 10be ages range from 390 20 yrs to 135 5 yrs and point to multiple advances within this time period with most robust evidence for a culmination during the 18th century the 10be record and the historical glacier records overlap and are remarkably consistent which demonstrates that 10be surface exposure dating produces reliable ages even for young glacial deposits within the last c 170 years ochsentaler glacier has retreated c 2 3 km which highlights the impact of recent warming on alpine mountain glaciers

lake level fluctuations at lake bourget eastern france around 4500 3500 cal a bp and their palaeoclimatic and archaeological implications on the basis of sedimentological analysis of two cores taken at chatillon lake le bourget northern french pre alps and well dated by radiocarbon dates in addition to tree ring dates obtained from an archaeological layer this paper presents a high resolution lake level record for the period 45003500 cal a bp the collected data provide evidence of a complex palaeohydrological climatic oscillation spanning the ca 43003850 cal bp time interval with major lake level maxima at ca 4200 and 40503850 cal a bp separated by a lowering episode around 4100 cal a bp the lake level highstands observed at chatillon between 4300 and 3850 cal bp appear to be synchronous with i a major flooding period recorded in deep cores from the large lakes le bourget and bodensee and ii glacier advance and tree line decline in the alps such wetter and cooler climatic conditions in west central europe around 4000 cal a bp may have been a nonlinear response to decrease and seasonal changes in insolation they may also provide a possible explanation for the general abandonment of prehistoric lake dwellings north of the alps between 4360 and 3750 cal a bp

a mid european decadal isotope climate record from 15 500 to 5000 years b p oxygen isotope ratios of precipitation delta18op inferred from deep lake ostracods from the ammersee southern germany provide a climate record with decadal resolution the record in detail shows many of the rapid climate shifts seen in central greenland ice cores between 15 000 and 5000 years before the present b p negative excursions in the estimated delta18op from both of these records likely reflect short weakenings of the thermohaline circulation caused by episodic discharges of continental freshwater into the north atlantic deviating millennial scale trends however indicate that climate gradients between europe and greenland changed systematically reflecting a gradual rearrangement of north atlantic circulation during deglaciation

surface exposure dating of moraines in the kromer valley silvretta mountains austria evidence for glacial response to the 8 2 ka event in the eastern alps 10 be dating of a pronounced glacier advance kromer stadial in the western part of the silvretta mountains western austria yielded ages ranging from 8010 360 to 8690 410 years with a mean age for moraine stabilization of 8410 690 years hence the kromer stadial which was previously considered as early preboreal may represent the glacier response to the early phase of the 8 2 ka event as it is recorded in the greenland ice cores the glacier advanced to a position beyond its little ice age lia limit the end moraines are situated 750 1000 m downvalley from the glacier ends in 1850 the corresponding drop of the equilibrium line altitude relative to the lia datum was 75 m the glacier advance was followed by a period of glacier recession and rock glacier development in total the climatic fluctuation may have lasted for about 500 200 years the age and duration of the climatic fluctuation is in good accordance with the misox cold phase and ce 3 climatic fluctuation as recorded in switzerland climate during the kromer stadial was characterized by more humid conditions than today along the northern fringe of the alps and slightly negative to moderately positive changes in precipitation in the central part of the austrian alps summer temperatures changes were most likely in the order of i to 0k mean annual temperature was 1 5k to 2k lower than today at least during the second phase of the climatic fluctuation

holocene glacier fluctuations a global overview of glacier advances and retreats grouped by regions and by millennia for the holocene is compiled from previous studies the reconstructions of glacier fluctuations are based on 1 mapping and dating moraines defined by 14 c tcn osl lichenometry and tree rings discontinuous records time series and 2 sediments from proglacial lakes and speleothems continuous records time series using 189 continuous and discontinuous time series the long term trends and centennial fluctuations of glaciers were compared to trends in the recession of northern and mountain tree lines and with orbital solar and volcanic studies to examine the likely forcing factors that drove the changes recorded a general trend of increasing glacier size from the earlyemid holocene to the late holocene in the extra tropical areas of the northern hemisphere nh is related to overall summer temperature forced by orbitally controlled insolation the glaciers in new zealand and in the tropical andes also appear to follow the orbital trend i e they were decreasing from the early holocene to the present in contrast glacier fluctuations in some monsoonal areas of asia and southern south america generally did not follow the orbital trends but fluctuated at a higher frequency possibly triggered by distinct teleconnections patterns during the neoglacial advances clustered at 4 4e4 2 ka 3 8e3 4 ka 3 3e2 8 ka 2 6 ka 2 3e2 1 ka 1 5e1 4 ka 1 2e1 0 ka 0 7e0 5 ka corresponding to general cooling periods in the north atlantic some of these episodes coincide with multidecadal periods of low solar activity but it is unclear what mechanism might link small changes in irradiance to widespread glacier fluctuations explosive volcanism may have played a role in some periods of glacier advances such as around 1 7e1 6 ka coinciding with the taupo volcanic eruption at 232 5 ce but the record of explosive volcanism is poorly known through the holocene the compilation of ages suggests that there is no single mechanism driving glacier fluctuations on a global scale multidecadal variations of solar and volcanic activity supported by positive feedbacks in the climate system may have played a critical role in holocene glaciation but further research on such linkages is needed the rate and the global character of glacier retreat in the 20th through early 21st centuries appears unusual in the context of holocene glaciation though the retreating glaciers in most parts of the northern hemisphere are still larger today than they were in the early and or mid holocene the current retreat

holocene glaciation and climate evolution of baffin island arctic canada abstract lake sediment cores and cosmogenic exposure ce dates constrain the pattern of deglaciation and evolution of climate across baffin island since the last glacial maximum lgm ce dating of erratics demonstrates that the northeastern coastal lowlands became ice free ca 14 ka as the laurentide ice sheet lis receded from its lgm margin on the continental shelf coastal lakes in southeastern baffin island started to accumulate sediment at this time whereas initial lacustrine sedimentation was delayed by two millennia in the north reduced organic matter in lake sediment deposited during the younger dryas chron and the lack of a glacial readvance at that time suggest cold summers and reduced snowfall ice retreated rapidly after 11 ka but was interrupted by a widespread readvance of both the lis and local mountain glaciers 9 6 ka cockburn substage a second readvance occurred just before 8 ka during a period of unusually cold summers corresponding to the 8 2 ka cold event in the greenland ice sheet most local glaciers were behind their present margins before 7 ka and in some instances much earlier although the foxe dome of the lis continued to slowly retract toward the present day barnes ice cap throughout the holocene pollen in lake sediments is rare and dominated by exotic sources prior to 12 ka subsequently grass tundra became established followed by modern tundra vegetation ca 8 ka with subtle changes in pollen assemblages in the late holocene lake primary productivity peaked in the early holocene before terrestrial vegetation or marine surface waters reached their apparent thermal maxima lacustrine marine and glacial proxies all reflect significant late holocene cooling the onset of neoglaciation is well dated in lacustrine records at ca 6 ka with intensification after 2 5 ka the expansion of local glaciers during the little ice age represents the most extensive advance since 7 ka we suggest that the replacement of atlantic surface waters by cold low salinity arctic ocean water coupled with the steady reduction of summer insolation resulted in a significant positive sea ice feedback that produced a larger late holocene summer temperature depression over the baffin region than in the pacific sector of the arctic

holocene fire regime changes from multiple site sedimentary charcoal analyses in the lourdes basin pyrenees france one lake and three peat bogs from the lourdes glacial basin france were used for macrocharcoal analyses and fire frequency reconstruction over the entire holocene 11700 years the chronology was based upon thirty three 14c ams dates comparison of the distribution of both charcoal accumulation rate char and fire return intervals showed that charcoal accumulation significantly differs between the lake and the peat bogs but that frequency calculation overcomes the disparity between these site types a composite frequency was built from the four individual records to assess regional versus local variability and fire regime controls by comparisons with regional fire activity holocene climatic oscillations and vegetation history the millennial variability can be depicted as follows relatively high frequency between 8000 and 5000 cal a bp up to 5 fires 500 yrs relatively low frequency between 5000 and 3000 cal a bp down to 0 fires 500 yrs and an increase between 3000 and 500 cal a bp up to 4 fires 500 yrs from 8000 to 5000 cal a bp fire frequency displays strong synchrony between sites and appears to be mostly driven by increased summer temperature characterizing the holocene thermal maximum htm on the contrary during the last 3000 years fire frequency was heterogeneous between sites and most probably human driven however higher frequency at the millennial scale during the mid holocene strongly suggests that the perception of human driven fire regime depends on the strength of natural controls

holocene optimum events inferred from subglacial sediments at tschierva glacier eastern swiss alps abstract this study investigates the subglacial sedimentary archive at tschierva glacier eastern swiss alps subfossil wood remains found at the retreating glacier tongue indicate that their emergence results from recent transport from an upvalley basin a confluence basin like structure was found to exist by georadar measurements underneath the present glacier in combination with high resolution age determinations based on dendrochronology and radiocarbon dating it is implied that a retreated tschierva glacier allowed vegetation growth and sediment accumulation in that basin three periods of glacier recession were detected which occurred around 9200 cal yr bp from 7450 to 6650 cal yr bp and from 6200 to 5650 cal yr bp these periods are called holocene optimum events hoe accordingly an equilibrium line rise 220 m compared to the reference period from 1960 to 1985 was inferred from digital elevation models of former glacier extents since glacier mass balance depends on summer june july august temperature and precipitation an equilibrium line altitude ela rise of 220 m implies a summer temperature increase of about 1 8 c assuming unchanged precipitation during the dated hoe alternative calculations point to probable temperature increase in a broad interval between 1 0 c taking into account a precipitation change of 250 mm a to 2 5 c with 250 mm a precipitation change supporting earlier paleotemperature estimates it is proposed that higher mean summer insolation caused a stronger seasonality during the mid holocene as compared to late holocene conditions

combined use of relative and absolute dating techniques for detecting signals of alpine landscape evolution during the late pleistocene and early holocene article i nfo a combination of three relative and two absolute numerical dating techniques applied on nine soil profiles in an alpine environment located in val di rabbi trentino northern italy was used to improve the investigation methodology of alpine sites in response to climate change and to reconstruct the chronology of late pleistocene and early holocene landscape evolution the degree of podzolisation clay mineral evolution and the element mass balances of each site were investigated furthermore the stable fraction of the soil organic matter som was extracted with 10 h2o2 and 14 c dated the age of the organic residues was compared with the age of charcoal fragments found in one of the studied soils and with the age of rock boulders obtained by surface exposure dating sed with cosmogenic 10 be numerical dating and weathering characteristics of the soils showed a fairly good agreement and enabled a relative and absolute differentiation of landscape elements the combination of 14 c dating of som and sed indicated that deglaciation processes in val di rabbi were already far advanced by around 14000 cal bp and that glacier oscillations affected the highest part of the region until about 9000 cal bp the development of clay minerals is time dependent and reflects weathering intensity we found a close link between secondary clay minerals like smectite or vermiculite and soil age as obtained by the dating of the organic residues after the h2o2 treatment calculated element mass balances strongly correlated with the ages derived from 14 c measurements old soils have lost a major part of base cations up to 75 compared to the parent material fe and al which indicates a continuous high weathering intensity results of the chemical and mineralogical analyses were in good agreement with numerical dating techniques showing the dynamics of an alpine landscape within a relatively small area the combination of relative and absolute dating techniques is a promising tool for the reconstruction of landscape history in high elevation alpine areas on siliceous substrates

neoglaciation in the southern coast mountains of british columbia chronology prior to the late neoglacial maximum moraine stratigraphy and morphology radiocarbon dates from klinaklini franklin tiedemann gilbert and bridge glaciers and related information from elsewhere in the coast mountains are used to construct a chronology for glacier fluctuations the garibaldi phase of glacier expansion 6000 5000 14c years bp at the end of the early holocene xerothermic interval is indicated by overridden tree stumps the mid neoglacial tiedemann advance 3300 1900 14c years bp is represented by moraines till and meltwater sediments at three glaciers but only tiedemann glacier attained its greatest holocene extent at this time late neoglacial expansion commenced before 900 14c years bp and continued without notable interruption until glaciers achieved their maximum post pleistocene expansion during the eighteenth and nineteenth centuries evidence for the garibaldi and tiedemann events is scarce within the coast mountains because of the more extensive late neoglacial advance however correlative advances have been

the 8 2 ka event calendar dated glacier response in the alps evidence for an 8 2 ka event related advance for an alpine glacier was missing for a long time in the light of dendrochronological analyses for tree remains found in front of the mont mine glacier swiss alps we present evidence for such an advance related to the 8 2 ka event calendar dates established for dozens of tree remains place this glacier advance 8175 yr before a d 2000 therefore this 8 2 ka advance response of the mont mine glacier terminated a nearly millennial long retreat period with a glacier always shorter than today

high frequency holocene glacier fluctuations in new zealand differ from the northern signature understanding the timings of interhemispheric climate changes during the holocene along with their causes remains a major problem of climate science here we present a high resolution 10be chronology of glacier fluctuations in new zealand s southern alps over the past 7000 years including at least five events during the last millennium the extents of glacier advances decreased from the middle to the late holocene in contrast with the northern hemisphere pattern several glacier advances occurred in new zealand during classic northern warm periods these findings point to the importance of regional driving and or amplifying mechanisms we suggest that atmospheric circulation changes in the southwest pacific were one important factor in forcing high frequency holocene glacier fluctuations in new zealand

combining glaciological and archaeological methods for gauging glacial archaeological potential abstract recent climate changes have led to an increase in the exposure of archaeological remains in frozen environments due to the melting of glaciers and ice patches and the thawing of permafrost in some cases the discovery of glacial archaeological findings has occurred due to chance in order to avoid the risk of losing exceptional often organic cultural remains due to decomposition systematic and predictive methods should be employed to locate areas of high glacial archaeological potential here we merged archaeological and glaciological methods to create a new type of archaeological prediction model in the field of glacial archaeology locational analysis and glaciological modelling were used to highlight current and future areas of archaeological potential in the pennine alps located between switzerland and italy future glacier area was calculated in 10 year increments until 2100 by 2090 93 of glacier area is expected to have disappeared the results from the final model glaciarch provide new insights into future glacial archaeological prospection in the pennine alps by narrowing down a study region of 4500 km 2 into several manageable square kilometre sites

10 be exposure dating of the timing of neoglacial glacier advances in the ecrins pelvoux massif southern french alps alpine glacier variations are known to be reliable proxies of holocene climate here we present a terrestrial cosmogenic nuclide tcn based glacier chronology relying on 24 new be 10 exposure ages which constrain maximum neoglacial positions of four small to mid sized glaciers rateau lautaret bonnepierre and etages in the ecrins pelvoux massif southern french alps glacier advances marked by mainly lateral moraine ridges that are located slightly outboard of the little ice age lia c 1250 1860 ad maximum positions were dated to 4 25 0 44 ka 3 66 0 09 ka 2 09 0 10 ka c 1 31 0 17 ka and to 0 92 0 02 ka the 4 2 ka advance albeit constrained by rather scattered dates is to our knowledge exposure dated here for the first time in the alps it is considered as one of the first major neoglacial advance in the western alps in agreement with other regional paleoclimatological proxies we further review alpine and northern hemisphere mid to high latitude evidence for climate change and glacier activity concomitant with the 4 2 ka event the 2 1 ka advance was not extensively dated in the alps and is thought to represent a prominent advance in early roman times other neoglacial advances dated here match the timing of previously described alpine neoglacial events our results also suggest that a neoglacial maximum occurred at etages glacier 0 9 ka ago i e during the medieval climate anomaly mca c 850 1250 ad at rateau glacier discordant results are thought to reflect exhumation and snow cover of the shortest moraine boulders overall this study highlights the need to combine several sites to develop robust neoglacial glacier chronologies in order to take into account the variability in moraine deposition pattern and landform obliteration and conservation

calendar dated glacier variations in the western european alps during the neoglacial the mer de glace record mont blanc massif holocene glacier records from the western european alps are still sparse although a number of sites are well suited to constraining pre and early little ice age lia glacier advances the present study provides the first dendrochronologically based and calendar dated neoglacial glacier chronology for the mont blanc massif french alps it is based on the analysis of over 240 glacially buried pinus cembra subfossil logs and wood remains found either embedded in till or as detrital material in the mer de glace right lateral moraine only a few of the samples were found to be formally in situ but we show that some logs were virtually in situ not rooted but showing little or no evidence of reworking and could be used to accurately reconstruct past glacier margin behavior in space and time uncertainties regarding the other samples may relate to original growth location and or to outer wood decay the resulting dates followed by a were therefore considered maximum limiting ages for glacier advances the main burial events interpreted as glacier advances occurred between ca 1655 and 1544 bc between ca 1230 and 1105 bc between ca 1013 and 962 937 bc at ca 802 777 bc after 608 bc between 312 and 337 ad between ca 485 ad and 606 ad between 1120 and 1178 ad between ca 1248 and 1278 1296 ad and after 1352 ad these advances predate the late lia maxima known from historical sources the magnitude of the advances gradually increased to culminate in three near neoglacial maxima during the 7th 12th and 13th centuries ad followed by a first lia neoglacial maximum in the second half of the 14th century ad the pattern of neoglacial events described here is coherent with central and eastern alpine glacier chronologies this indicates marked synchronicity of late holocene glacier variability and forcing at a regional scale although occasional differences could be detected between western and eastern records the mer de glace record also confirms the link between the timing of sediment erosion in a high elevation glaciated alpine catchment and subsequent deposition in the sub alpine lake bourget

the deglaciation history of the simplon region southern swiss alps constrained by 10be exposure dating of ice molded bedrock surfaces the deglaciation history of the swiss alps after the last glacial maximum involved the decay of several ice domes and the subsequent disintegration of valley glaciers at high altitude here we use bedrock exposure dating to reconstruct the temporal and spatial pattern of ice retreat at the simplon pass altitude 2000 m located 40 km southwest of the rhone ice dome eleven 10be exposure ages from glacially polished quartz veins and ice molded bedrock surfaces cluster tightly between 13 5 0 6 ka and 15 4 0 6 ka internal errors indicating that the simplon pass depression became ice free at 14 1 0 4 ka external error of mean age this age constraint is interpreted to record the melting of the high valley glaciers in the simplon pass region during the warm bolling allerod interstadial shortly after the oldest dryas stadial two bedrock samples collected a few hundred meters above the pass depression yield older 10be ages of 17 8 0 6 ka and 18 0 0 6 ka these ages likely reflect the initial downwasting of the rhone ice dome and the termination of the ice transfluence from the ice dome across the simplon pass toward the southern foreland there the retreat of the piedmont glacier in val d ossola was roughly synchronous with the decay of the rhone ice dome in the interior of the mountain belt as shown by 10be ages of 17 7 0 9 ka and 16 1 0 6 ka for a whaleback at 500 m elevation near montecrestese in northern italy in combination with well dated paleoclimate records derived from lake sediments our new age data suggest that during the deglaciation of the european alps the decay of ice domes was approximately synchronous with the retreat of piedmont glaciers in the foreland and was followed by the melting of high altitude valley glaciers after the transition from the oldest dryas to the bolling allerod when mean annual temperatures rose rapidly by 3 c

the provenance of sediments in the gulf of lions western mediterranean sea in this study we undertook a reconnaissance study of sediments provenance in the gulf of lions focusing over the last 16 ka we used geochemical and isotopic tracers to determine the source of sediments and give insight into the weathering conditions prevailing sediments samples were selected both onshore and offshore from the western eastern and central part of the gulf of lions we analyzed bulk sediments coarse and fine silt and clay fractions elemental and nd isotope compositions appeared to differ from one grain size fraction to another one these are interpreted in terms of zircon addition in the coarse silt fraction for the elemental concentrations and variable sources influences for the nd isotope compositions our results indicate that sediments in the gulf of lions mainly originated from the rhone river watershed although a contribution of saharan dust is seen in one sample influence of pyrenean small rivers is minor in these samples some sr isotope compositions shifts are interpreted as reflecting variable amounts of chemical weathering that are consistent with published paleoclimatic reconstructions

tracking rockglacier evolution in the eastern alps from the lateglacial to the early holocene abstract relict rockglaciers are distinctive indicators of past permafrost occurrence their lower limit is attributed to a former mean annual air temperature maat of below 2 c this study provides a comprehensive dataset of 34 10be exposure ages from boulders along two complex series of relict rockglaciers called tandl rockglaciers and norbert rockglaciers carinthia austria the lowest tandl rockglacier complex stabilised around 14 ka at an elevation of 1350 m a s l the lowest norbert rockglaciers 1580 and 1730 m a s l stabilised around 15 7 ka additionally in both study sites the low elevation relict rockglaciers interacted with glacial deposits of the local pre bolling glaciers gschnitz stadial glacier temperature lowering based on our data of the gschnitz rockglaciers ranges between 6 3 and 4 5 c compared to modern maat the cross cutting relationships of the rockglaciers and the glacial deposits together with the exposure ages of the rockglaciers indicate that these rockglaciers and therewith also permafrost developed shortly after or even simultaneously with retreat of the gschnitz stadial glaciers this is the first permafrost formation in the alpine areas after the retreat of the warm based last glacial maximum glaciers the tandl and norbert rockglacier lobes located at higher elevations up to about 2300 m a s l finally stabilised in the early holocene ages of several dated lobes lie between 12 10 ka at this time which corresponds to the egesen stadial younger dryas cold phase rockglaciers and glaciers co existed from the lowest position of the egesen rockglacier lobe at the tandl site 1700 m a s l a temperature lowering for the egesen stadial of 4 6 c was calculated this study highlights the potential of relict rockglacier deposits as an independent paleoclimate archive and their usefulness for reconstruction of past permafrost development and distribution in high mountain areas when they can be placed in a temporal framework

multicentury glacier fluctuations in the swiss alps during the holocene subfossil remains of wood and peat from six swiss glaciers found in proglacial fluvial sediments indicate that glaciers were smaller than the 1985 reference level and climatic conditions allowed vegetation growth in now glaciated basins an extended data set of swiss glacier recessions consisting of 143 radiocarbon dates is presented to improve the chronology of glacier fluctuations a comparison with other archives and dated glacier advances suggests 12 major recession periods occurring at 9850 9600 93008650 85508050 77007550 74506550 61505950 57005500 52004400 43003400 28002700 21501850 14001200 cal yr bp it is proposed that major glacier fluctuations occurred on a multicentennial scale with a changing pattern during the course of the holocene after the younger dryas glaciers receded to a smaller extent and prolonged recessions occurred repeatedly culminating around 7 cal kyr bp after a transition around 6 cal kyr bp weak fluctuations around the present level dominated after 3 6 cal kyr bp less frequent recessions interrupted the trend to advanced glaciers peaking with the prominent little ice age this trend is in line with a continuous decrease of summer insolation during the holocene

silver and lead in high altitude lake sediments proxies for climate changes and human activities abstract high altitude lake sediments are often used as archives for environmental changes and their chemical and isotopic compositions provide significant constraints on natural and anthropogenic long term changes that have occurred in their catchment area here trace element concentrations and pb isotopes are presented for two sedimentary cores from lake blanc huez in the french alps to trace the impact of climate changes and human activities over the holocene lead and ag contents are very high and clearly dominated by input from a pb ag vein located a few meters from the lakeshore a vein that also buffers the pb isotopes mining of this vein in medieval times is recorded in the corresponding lake sediments with high ag content coupled with high pb u ratio these chemical characteristics can be used to constrain the major holocene climate changes significant advances of glaciers next to the lake produced sediments with ag and pb concentration peaks and high pb u ratios due to accelerated erosion of the pb ag vein similar to the effects of the medieval mining in contrast reduced glacier activity led to the formation of organic rich sediments with high u and as contents and low pb u ratios more generally the observed combination of chemical changes could be used elsewhere to decipher environmental changes over long periods of time

quantifying geomorphic and riparian land cover changes either side of a large flood event using airborne remote sensing river tay scotland the potential of high resolution multi spectral airborne remote sensing to detect and quantify changes in channel morphology and riparian land cover are illustrated the river tay is a partially embanked wandering gravel bed river and airborne thematic mapper data which collect reflectance in the visible near mid and thermal infrared were acquired in 1992 and 1994 either side of a 1 65 recurrence interval flood event imagery was radiometrically atmospherically and geometrically corrected in order to minimise atmospheric and geometric changes between the 1992 and 1994 scenes a maximum likelihood classifier was then used on each image and change was quantitatively mapped using a classification comparison approach bathymetric mapping was undertaken by applying a lyzenga algorithm to atm bands 5 6 and 8 to account for an exponential decrease in electromagnetic radiation penetration through the water column with depth despite the magnitude of the flood event no major changes in channel position or form occurred but the change detection algorithms revealed subtle changes not observed in the field bar head accretion bar tail formation and extension bar dissection localised bank erosion and the overriding of low level vegetated islands by gravel lobes were the main forms of change on the floodplain flood embankment failures resulted in fans of sands and gravels on agricultural land more generally the study reveals the potential for using airborne remote sensing to detect change in fluvial systems and as a mutually complementary tool to field survey

mesolithic settlement and mobility patterns at high altitudes the site of staller sattel sts 4a south tyrol italy abstract this paper presents the results of an ongoing research aimed at reconstructing early mesolithic settlement strategies and mobility patterns at high altitudes of alpine area focusing on the interactions and possible mutual influence between human behavior and the geomorphological and environmental context due to the high altitude environment research had to face the effects of post depositional processes on anthropogenic remains investigations have been carried out on a terrace in the ackstall locality south of the staller sattel passo stalle italian austrian border central eastern alps covered by coniferous vegetation since the preboreal the terrace central with respect to the available resources and in a strategic position within a reconstructed route system conjoining different sites and adjacent hunting territories yielded several lithic findspots one of these the excavated open air site sts 4a lying at 2125 m a s l revealed human site frequentation dating at least between 7370 and 6590 cal bc human occupation was established on a forested soil subsequently buried indicated as paleo podzol stratigraphy micromorphology and artifact distribution this latter showing a ring shaped pattern suggest the preparation of the living space by manipulating the existing soil cover anthropogenic remains indicate on site activities as wood carving exploitation of rock crystal and chert for tool manufacture and the probable consumption of plants originating from lower altitudes several features some of which connected with fire use have been identified fuel was collected in the form of dead wood in the open larch and stone pine forests surrounding the site the comparison of multiscale data allowed to get insights on the living space of a mesolithic hunter gatherer camp integrating detailed data from the excavation of a single site with the wider territorial context investigated by surveys allowed to draw a multi facetted picture of early mesolithic lifeways and highlighted the potential of research on the ephemeral high altitude sites

subglacial basins their origin and importance in glacial systems and landscapes closed topographic basins are found beneath contemporary ice masses and within the footprint of former ice masses in all glaciated regions we present the first integrated review of subglacial basin occurrence and formation and the implications of such basins for glaciological processes and the evolution of landscape our purpose is to motivate research in areas where understanding of basin origin and process significance is weak basins on the order of 10 102 m deep and 102 103 m long are produced by glacial erosion of subglacial rock and or sediment and are known as overdeepenings outlet and valley glaciers can overdeepen their beds far below sea level or local fluviatile base level larger basins typically in ice sheet contexts may have a pre glacial usually tectonic origin subglacial basins are important glaciologically because they require ice water and sediment to ascend an adverse subglacial slope in order to exit the glacial system the efficiency of which is dependent upon the gradient of the adverse slope and that of the ice surface basins thus influence subglacial drainage system morphology and transmissivity the thickness and distribution of basal ice and sediment layers and the mechanisms and dynamics of ice flow adverse gradients that exceed 11 times that of the ice surface may even permit the formation of subglacial lakes we speculate that in comparison to ice masses with few or no subglacial basins those with numerous or very large basins may respond to climatic changes with unexpected vigour in addition erosion rates and transport pathways of water and sediment through the glacial system and the expression of these processes in the sediment and landform record may be unexpectedly complex further our review shows that in a warming climate ice masses resting on adverse slopes will be vulnerable to rapid and potentially catastrophic retreat new lakes in subglacial basins exposed by mountain glacier retreat will present an increasing hazard and subglacial lakes may drain catastrophically on even longer time scales we speculate that the glacial excavation and post glacial filling of basins in mountainous regions should contribute importantly to climate related changes in isostasy and relief although the controls on overdeepening and their influence on other glacial and landscape processes remain uncertain we hypothesise that overdeepened glacial systems reflect an equilibrium ice bed geometry that maximises the efficiency of ice discharge improved understanding of overdeepening processes especially overdeepened bed hydrology is therefore necessary to understand fully the dynamic behaviour of valley and outlet glaciers and thus the fate of earth s largest ice masses

radiocarbon dating of palaeosol components in moraines in lapland northern sweden abstract accurate geochronologies are the key for comparison of palaeoclimate records in order to clarify problems concerning the geochronology of glacier fluctuations we dated palaeosols in moraines in the kebnekaise mountain region of swedish lapland these palaeosols already have been dated several years ago using bulk samples of the palaeosols and yielded ages of 6180 5790 and 2750 2100 cal yr bp in an attempt to evaluate the sources of contamination associated with bulk samples these soils were re dated by using coleoptera fragments cenococcum geophilum spores humic acids and woody plant tissues the new dates reveal that the two palaeosols found within the moraines represent much longer periods of time than was previously assumed soil formation periods can be distinguished for periods 7800 7580 6300 4080 2450 2000 and 1170 740 cal yr bp these age groups point to differentiated soil formation processes resedimentation bioturbation and or cryoturbation the results show that dated terrestrial macrofossils from glacial moraines indicate climate changes that are in accordance with other proxy records in northern and central scandinavia and in certain times off phase with glacier fluctuations in southern maritime norway this throws light on possible changing interaction of forcing factors during the holocene

correlation of late quaternary moraines impact of climate variability glacier response and chronological resolution abstract the last decade has seen a global surge in the number and resolution of well dated geomorphological reconstructions of mountain glacier fluctuations and former ice sheet extents this has been facilitated by the widespread deployment of large samples of terrestrial cosmogenic nuclide dating tcnd allowing more sophisticated probability analyses for reducing the statistical uncertainty of moraine ages and testing of correlations at local regional and hemispheric scales geochronological advances in the field laboratory and on model calibration have taken place in parallel with modelling of palaeoclimate based on glacier reconstructions and of glacier sensitivity to temperature and precipitation forcing in spite of these advances basic conceptual issues remain this review questions whether the technical leap forward in dating has encouraged us to over reach our interpretive limits particularly in terms of the concept and practice of correlation we propose that to enable reliable correlation glacier chronologies should first be examined for their climatic integrity spatial coherence and chronological robustness even with excellent dating interpretive complexity remains due to complex climate signals and glacier response characteristics and to erosion censoring of the landform record all are issues which must be addressed to avoid either spurious lumping correlation or splitting differentiation of glacier chronologies and thus misinterpretation of the climatic significance of reconstructed glacier advances we suggest that the reliability of correlation is no better than the weakest link in the chain of reasoning which connects climatic fluctuations with dated landforms and sediments improved dating means that poor chronological resolution is less likely to be the limiting factor for correlation but shifts the focus onto other less quantifiable sources of uncertainty these conceptual statements are exemplified with reference to holocene glacial chronologies of contrasting mid latitude environments in southern norway iceland and new zealand

circum mediterranean fire activity and climate changes during the mid holocene environmental transition 8500 2500 cal bp a mid to late holocene synthesis of fire activity from the mediterranean basin explores the linkages among fire climate variability and seasonality through several climatic and ecological transitions regional fire histories were created from 36 radiocarbon dated sedimentary charcoal records available from the global charcoal database during the mid holocene thermal maximum around 7500 4500 cal bp charcoal records from the northern mediterranean suggest an increase in fire while records from the southern mediterranean indicate a decrease associated with wetter than present summers a north south partition between 40 and 43 n latitude is apparent in the central and western mediterranean relatively abrupt changes in fire activity are observed c 5500 5000 cal bp records of holocene fire activity appear sensitive to both orbitally forced climate changes and shorter lived excursions which may be related to north atlantic cold events possibly modulated by an nao like climate mechanism in cases wh

7000 years of vegetation history and land use changes in the morvan mountains france a regional synthesis this paper aims to reconstruct the vegetation history of a middle mountain the morvan burgundy france since the neolithic i e 7000 years the results of palynological and non pollen palynomorphs npps analysis performed on 10 peat cores document the main phases of human agro pastoral practices and natural resources management which drove the formation of the cultural landscape of the morvan massif over time to document the history of human activities at a regional scale particular attention was given to the determination the characterization and the graphical depiction of phrases of human impact both the quantification of the impact of human pressure and the chronological uncertainty of the different phases identified by pollen and npp analysis were taken into account this study reveals a clear human presence during periods that were formerly poorly documented such as the onset of the neolithic period the bronze age the early iron age and the early middle ages it also sheds new light over periods for which there is better archaeological and historical knowledge such as the widespread occupation of the massif in the late iron age the cultivation of chestnut from the 11th to the 16th century and the impact of modern firewood exploitation on the forest

structure and origin of holocene cold events abstract the present interglacial the holocene spans the period of the last 11 700 years it has sustained the growth and development of modern society the millennial scale decreasing solar insolation in the northern hemisphere summer lead to northern hemisphere cooling a southern shift of the intertropical convergence zone itcz and a weakening of the northern hemisphere summer monsoon systems on the multidecadal to multicentury scale periods of more stable and warmer climate were interrupted by several cold relapses at least in the northern hemisphere extra tropical area based on carefully selected 10 000 year long time series of temperature and humidity precipitation as well as reconstructions of glacier advances the spatiotemporal pattern of six cold relapses during the last 10 000 years was analysed and presented in form of a holocene climate atlas hoclat see http www oeschger unibe ch research projects holocene atlas a clear cyclicity was not found and the spatiotemporal variability of temperature and humidity precipitation during the six specific cold events 8200 6300 4700 2700 1550 and 550 years bp was very high different dynamical processes such as meltwater flux into the north atlantic low solar activity explosive volcanic eruptions and fluctuations of the thermohaline circulation likely played a major role in addition internal dynamics in the north atlantic and pacific area including their complex interaction were likely involved

the δ18o record along the greenland ice core project deep ice core and the problem of possible eemian climatic instability over 70 000 samples from the 3029 m long greenland ice core project grip ice core drilled on the top of the greenland ice sheet summit have been analyzed for 8o a highly detailed and continuous 8o profile has thus been obtained and is discussed in terms of past temperatures in greenland we also discuss a three core stacked annual 8o profile for the past 917 years the short term 50 years variability of the annual 8o signal is found to be 1 in the holocene and estimates for the coldest parts of the last glacial are 3 or higher these data also provide insights into possible disturbances of the stratigraphic layering in the core which seems to be sound down to the onset of the eemian spectral analysis of highly detailed sequences of the profile helps determine the smoothing of the 8o signal which for the holocene ice is found to be considerably stronger than expected we suggest this is due to a process involving diffusion of water molecules along crystal boundaries in the recrystallizing ice matrix deconvolution techniques were employed for restoring with great confidence the highly attenuated annual 8o signal in the holocene we confirm earlier findings of dramatic temperature changes in greenland during the last glacial cycle abrupt and strong climatic shifts are also found within the eem sangamon interglaciation which is normally recorded as a period of warm and stable climate in lower latitudes the stratigraphic continuity of the eemian layers is consequently discussed in section 3 of this paper in terms of all pertinent data which we are not able to reconcile

extracting a climate signal from 169 glacier records i constructed a temperature history for different parts of the world from 169 glacier length records using a first order theory of glacier dynamics i related changes in glacier length to changes in temperature the derived temperature histories are fully independent of proxy and instrumental data used in earlier reconstructions moderate global warming started in the middle of the 19th century the reconstructed warming in the first half of the 20th century is 0 5 kelvin this warming was notably coherent over the globe the warming signals from glaciers at low and high elevations appear to be very similar

late glacial and holocene paleoenvironmental records in the tatra mountains east central europe based on lake peat bog and colluvial sedimentary data a summary review abstract the tatra mountains are the highest massif in the carpathian mountain arc 2655 m and represent a typical alpine landscape developed in the course of pleistocene glaciations but are not glacierized today the glacial relief of the massif offers an abundance of topographic depressions cirque overdeepenings morainic closed depressions where sedimentary sequences may potentially reveal paleoenvironmental changes that may have occurred since the glaciers retreat from the last glacial maximum position 26 18 ka we present a review of late glacial and holocene sedimentary archives from the tatra mountains collected in the polish and non polish literature the data sets 40 sites included 21 lake 13 peat bog and 6 colluvial sediment sites the entire listed sediment sequence features radiometric datings or at the very least a chronological framework is inferred from the biostratigraphy the oldest sampled sedimentary sequences were dated back to the oldest dryas and were obtained from the deepest glacial lakes located in the subalpine zone up to 1700 m shallow lakes

holocene glacier fluctuations and climate changes in the southeastern part of the russian altai south siberia based on a radiocarbon chronology abstract this study investigates glacier dynamic and climatic variations in the southeastern part of the russian altai se altai during the last 7000 years recent glacier retreats and ice melting in moraines has led to exhumation of organic material allowing the possibility of radiocarbon dating we report here 57 new radiocarbon dates from wood remains buried by moraines and from proglacial forefields from peat layers and lacustrine sediments that cover moraines from dead trees at the upper tree limit and from rock glaciers on trough slopes from six glacial valleys in the north chuya range se altai such a numerous dataset for the vast but unified in neotectonic and climatic conditions area is presented for the first time the history of research in the altai together with 62 previously published radiocarbon ages mainly of fossil soils and peat layers in the foot of the ranges in se altai they form the basis for understanding the relative magnitudes and timing of the most important glacial and climatic events of se altai new data refute the traditional concept of the russian altai holocene glaciations as a consecutive retreat of the late wurm glaciers and argue their complete degradation at the head of trough valleys at least 7000 cal years bp moraine complexes of three holocene glacial stages are morphologically expressed in trough valleys of the north chuya range they correlate with three identified periods of glacial advances from 4900 to 4200 cal years bp akkem stage from 2300 to 1700 cal years bp historical stage and in the 13th 19th centuries little ice age lia or aktru stage the coincident extremes of lowering temperature and increasing precipitation during the akkem stage led to abrupt glacier advances and forming of the most remote moraine complexes downstream in the valleys following glacier advances had distinctly smaller magnitudes in addition to the radiocarbon data the time limits of the historical stage were defined more precisely using dendrochronological and archaeological data from scythian burials of pazyryk culture in se altai repeated forest regrowth in the presently glaciatiated area indicates significant retreat or even complete glacier degradation during interstage warming the decreases of glacier length in the following stages argues for intensification of aridity in the se altai during the second half of the holocene the thermal minimum in the middle of 19th century the greatest in the last millennium did not positively influence the mass balance of glaciers which also supports this conclusion

a chironomid based holocene summer air temperature reconstruction from the swiss alps we developed a quantitative chironomid july air temperature inference model based on surface sediments from 81 swiss lakes and applied it to the holocene subfossil chironomid record of hinterburgsee a small subalpine lake in the northern swiss alps present day mean july air temperature of 11 3 c after smoothing to reduce the high between sample variability of inferred temperatures the reconstruction indicates july air temperatures of 10 4 10 9 c at the end of the younger dryas of 11 9 12 8 c during the early and mid holocene 11500 4000 cal bp and slightly lower temperatures of 11 5 12 0 c during the late holocene 3500 1000 cal bp a warming trend inferred for the past millennium is most likely an artifact of human impact on hinterburgsee s chironomid fauna rather than a genuine temperature signal the most prominent climatological events during the holocene were two periods of lower temperatures at c 10700 10500 cal bp and 8200 7700 cal bp and an abrupt shift to a cooler late holocene cl

time constraints for post lgm landscape response to deglaciation in val viola central italian alps abstract across the northern european alps a long tradition of quaternary studies has constrained post lgm last glacial maximum landscape history the same picture remains largely unknown for the southern portion of the orogen in this work starting from existing 10be exposure dating of three boulders in val viola central italian alps we present the first detailed post lgm reconstruction of landscape i e glacial periglacial and paraglacial response south of the alpine divide we pursue this task through schmidt hammer exposure age dating shd at 34 sites including moraines rock glaciers protalus ramparts rock avalanche deposits and talus cones in addition based on the mapping of preserved moraines and on the numerical shd ages we reconstruct the glacier extent of four different stadials including egesen i 13 1 1 1 ka egesen ii 12 3 0 6 ka kartell 11 0 1 4 ka and kromer 9 7 1 4 ka whose chronologies agree with available counterparts from north of the alpine divide results show that equilibrium line altitude depressions elas associated to younger dryas and early holocene stadials are smaller than documented at most available sites in the northern alps these findings not only support the hypothesis of a dominant north westerly atmospheric circulation during the younger dryas but also suggest that this pattern could have lasted until the early holocene shd ages on rock glaciers and protalus ramparts indicate that favourable conditions to periglacial landform development occurred during the younger dryas 12 7 1 1 ka on the valley slopes above the glacier as well as in newly de glaciated areas during the early holocene 10 7 1 3 and 8 8 1 8 ka the currently active rock glacier started to develop before 3 7 0 8 ka and can be associated to the lobben oscillation four of the five rock avalanches dated in val viola cluster within the early holocene in correspondence of an atmospheric warming phase by contrast the timing of the main val viola rock avalanche 7 7 0 3 ka during the holocene thermal optimum suggests a possible causal linkage to permafrost degradation overall schmidt hammer proved to be an effective inexpensive and versatile tool for improving the spatial resolution of val viola post lgm landscape history starting from existing numerical age constrains

holocene glacier history from alpine speleothems milchbach cave switzerland abstract mountain glaciers and their sediments are prominent witnesses of climate change responding sensitively to even small modifications in meteorological parameters even in such a classical and thoroughly studied area as the european alps the record of holocene glacier mass balance is only incompletely known here we explore a novel and continuous archive of glacier fluctuations in a cave system adjacent to the upper grindelwald glacier in the swiss alps milchbach cave became partly ice free only recently and hosts holocene speleothems four coeval stalagmites show consistent petrographic and stable isotopic changes between 9 2 and 2 0 ka which can be tied to abrupt modifications in the cave environment as a result of the closing and opening of multiple cave entrances by the waxing and waning of the nearby glacier during periods of holocene glacier advances columnar calcite fabric is characterized by 18 o values of about 8 0 indicative of speleothem growth under quasi equilibrium conditions i e little affected by kinetic effect related to forced degassing or biological processes in contrast fabrics formed during periods of glacier minima are typical of bacterially mediated calcite precipitation within caves overlain by an alpine soil cover moreover 18 o values of the bacterially mediated calcite fabrics are consistent with a ventilated cave system fostering kinetic fractionation these data suggest that glacier retreats occurred repeatedly before 5 8 ka and that the amplitudes of glacier retreats became substantially smaller afterwards our reconstruction of the upper grindelwald glacier fluctuations agrees well with paleoglaciological studies from other sites in the alps and provides a higher temporal resolution compared to traditional analyses of peat and wood remains found in glacier forefields

holocene climate variability although the dramatic climate disruptions of the last glacial period have received considerable attention relatively little has been directed toward climate variability in the holocene 11 500 cal yr b p to the present examination of similar to50 globally distributed paleoclimate records reveals as many as six periods of significant rapid climate change during the time periods 9000 8000 6000 5000 4200 3800 3500 2500 1200 1000 and 600 150 cal yr b p most of the climate change events in these globally distributed records are characterized by polar cooling tropical aridity and major atmospheric circulation changes although in the most recent interval 600 150 cal yr b p polar cooling was accompanied by increased moisture in some parts of the tropics several intervals coincide with major disruptions of civilization illustrating the human significance of holocene climate variability c 2004 university of washington all rights reserved

climate at the equilibrium line of glaciers the relationships between temperature precipitation and radiation on glacier equilibrium lines are investigated using 70 glaciers for which the mass balance and meteorological observations have been carried out for sufficiently long periods it is found that the characteristic climate at glacier equilibrium lines can be described using the summer 3 months temperature in a free atmosphere annual total precipitation and the sum of global and long wave net radiation all of these are measured at or very near the equilibrium line altitudes then it is shown how the shift of the equilibriumline will occur as a result of a climatic change finally the effect of the shift of the equilibrium line on the annualmean specific mass balance is analytically derived and compared with observations the present results make it possible to identify the altitudes in climate models where glacierization should begin and to evaluate the mass balance changes as a result of possible future changes in the climate

latest pleistocene and holocene glacier variations in the european alps in the alps climatic conditions reflected in glacier and rock glacier activity in the earliest holocene show a strong affinity to conditions in the latest pleistocene younger dryas glacier advances in the alps related to younger dryas cooling led to the deposition of egesen stadial moraines egesen stadial moraines can be divided into three or in some cases even more phases sub stadials moraines of the earliest and most extended advance the egesen maximum stabilized at 12 2 1 0 ka based on 10be exposure dating at the schonferwall tyrol austria and the julier pass outer moraine switzerland final stabilization of moraines at the end of the egesen stadial was at 11 3 0 9 ka as shown by 10be data from four sites across the alps from west to east the sites are piano del praiet northwestern italy grosser aletschgletscher central switzerland julier pass inner moraine eastern switzerland and val viola northeastern italy there is excellent agreement of the 10be ages from the four sites in the earliest holocene glaciers in the northernmost mountain ranges advanced at around 10 8 1 1 ka as shown by 10be data from the kartell site northern tyrol austria in more sheltered drier regions rock glacier activity dominated as shown for example at julier pass and larstig valley tyrol austria new 10be dates presented here for two rock glaciers in larstig valley indicate final stabilization no later than 10 5 0 8 ka based on this data we conclude the earliest holocene between 11 6 and about 10 5 ka was still strongly affected by the cold climatic conditions of the younger dryas and the preboreal oscillation with the intervening warming phase having had the effect of rapid downwasting of egesen glaciers at or slightly before 10 5 ka rapid shrinkage of glaciers to a size smaller than their late 20th century size reflects markedly warmer and possibly also drier climate between about 10 5 ka and 3 3 ka conditions in the alps were not conducive to significant glacier expansion except possibly during rare brief intervals past tree line data from kaunertal tyrol austria in concert with radiocarbon and dendrochronologically dated wood fragments found recently in the glacier forefields in both the swiss and austrian alps points to long periods during the holocene when glaciers were smaller than they were during the late 20th century equilibrium line altitudes ela were about 200 m higher than they are today and about 300 m higher in comparison to little ice age lia elas the larstig rock glacier site we dated with 10be is the type area for a postulated mid holocene cold period called the larstig oscillation presumed age about 7 0 ka our data point to final stabilization of those rock glaciers in the earliest holocene and not in the middle holocene the combined data indicate there was no time window in the middle holocene long enough for rock glaciers of the size and at the elevation of the larstig site to have formed during the short infrequent cold oscillations between 10 5 and 3 3 ka small glaciers less than several km2 may have advanced to close to their lia dimensions overall the cold periods were just too short for large glaciers to advance after 3 3 ka climate conditions became generally colder and warm periods were brief and less frequent large glaciers for example grosser aletschgletscher advanced markedly at 3 0 2 6 ka around 600 ad and during the lia glaciers in the alps attained their lia maximum extents in the 14th 17th and 19th centuries with most reaching their greatest lia extent in the final 1850 1860 ad advance

vegetation responses to climatic variability in the swiss southern alps during the misox event at the early mid holocene transition sedimentary pollen charcoal and plant macrofossil analyses with high resolution and precision suggest a strong shift in vegetation composition during the early to mid holocene transition in the upper mountain belt at piano mire 1439m above sea level a s l ticino switzerland forests were dominated by abies alba during the early holocene prior to ca 8000cal a bp abrupt collapses of a alba at ca 7800 7400cal a bp enabled the expansion of the light demanding pioneer betula afterwards a alba populations regained their previous abundance in the forests within the dating uncertainties of our record we assume that a unique combination of wet and cold years between 8400 and 7500cal a bp led to repeated lethal disadvantages for abies our record of abies oscillations is in good biostratigraphic agreement with the record that has been used to define the misox cold event pian disignano 1540m a s l whichhas been previouslycorrelated withthe8200cal a bp event giventhe ageestimatesoftheabiescollapsesinourwell datedrecord ourresultssuggestthatadditionaleffortsare needed to understand the linkage between the misox and the 8200cal a bp event they imply a high sensitivity of mountain vegetation far below the tree line 800m to holocene climatic changes of about 28c in annual air temperature copyright 2010 john wiley sons ltd

postglacial rebound promotes glacial re advances a case study from the european alps introductionmanyorogensworldwidewerestronglyglaciated duringthelast glacial max imum lgm prominent examplesinclude the new zealand alps thenorth americancordillera thesouth ern andes and the european alps ehlersandgibbard 2004 theintenseglaciationoftheeuropeanalpsduringthe lgm is particularly well con strained owing to a wealth of geomor phological and sedimentological datacollected e g favre 1884 ja ckli 1970 van husen 1987 de beaulieuet al 1991 as indicated by theposition of moraines and erratic boul ders the lgm ice reached far into thealpine foreland haeberli 1991 theice surface in the central alps isconstrained by trimlines which arelocated at a maximum altitude of 2800 m florineth and schlu chter 1998 kelly et al 2004 the meanthickness of the ice cap was estimatedto be 500 m in the swiss alps ja ckli 1970 it has long been suspected thatmelting of the huge lgm ice masscaused a considerable postglacial re bound of the alps e g ja ckli 1965 using a combination of an analyticalhalf space model for the alpine litho sphere and a simple cylinder shapedlgm ice mass gudmundsson 1994 predicted that post lgm reboundpresumably contributes signi cantlyto the present day uplift rate of 1mma

reconstruction of former glacier equilibrium line altitudes based on proglacial sites an evaluation of approaches and selection of sites abstract various approaches are used to record variations in glacier activity and equilibrium line altitudes elas based on proglacial sites lacustrine and terrestrial these approaches are based on a conceptual model of glacier meltwater induced sedimentation in which the minerogenic nonorganic component of the sediments is related to the occurrence of a glacier in the catchment the principal coupling to former glacier activity and elas is common for these approaches however different methods and techniques may complement each other and both possibilities and limitations are demonstrated site selection for reconstructing variations in glacier activity elas is evaluated and critical factors are discussed rerouting of glacier meltwater streams across local watersheds in combination with proglacial sites gives a distinct on off signal for former glacier activity elas together with representative lateral moraines of known age local watersheds are important for calibrating reconstructed glacier activity elas based on a chain of proglacial lakes based on the modern analogue principle various proxies can record whenever glaciers existed in a catchment in a chain of proglacial lakes with different sensitivity to record variations in glacier activity elas these proxies can be calibrated against independent records for one site approaches however variations in glacier activity elas depend on the interpretation and sensitivity of the proxies used

holocene glacier history of bjornbreen and climatic reconstruction in central jotunheimen norway based on proximal glaciofluvial stream bank mires abstract holocene variations of bjornbreen smorstabbtinden massif west central jotunheimen are reconstructed from the lithostratigraphy of two alpine stream bank mires flooded episodically by meltwater the approach uses multiple sedimentological indicators weight loss on ignition mean grain size grain size fractions bulk density moisture content and magnetic susceptibility an a priori model of overbank deposition of suspended glaciofluvial sediments a detailed chronology based on 56 radiocarbon dates and a little ice age sedimentological analogue rapid late preboreal deglaciation was indicated by immigration of betula pubescens by 9700 cal bp an interval of at least 3000 years in the early holocene when glaciers were absent was interrupted by two abrupt episodes of glacier expansion around the time of the finse event the first at ca 8270 7900 cal bp bjornbreen i event and the second at ca 7770 7540 cal bp bjornbreen ii event neoglaciation began shortly before ca 5730 cal bp with gradual build up to the maximum of the bjornbreen iii event at ca 4420 cal bp later maxima occurred at ca 2750 cal bp bjornbreen iv event and at 1300 1260 1060 and 790 cal bp all within the bjornbreen v event glaciers were smaller than today and possibly melted away on several occasions in the late holocene ca 3950 1410 and 750 cal bp minor maxima also occurred at ca 660 and 540 cal bp within the late mediaeval warm period and the early little ice age respectively the little ice age maximum was dated to 213 25 bp ca 205 cal bp the relative magnitudes of the main glacier maxima were determined erdalen event little ice age event bjornbreen vi bjornbreen i finse event bjornbreen ii bjornbreen v bjornbreen iv bjornbreen iii these episodic events of varying magnitude and abruptness were used in conjunction with an independent summer temperature proxy to reconstruct variations in equilibrium line altitude ela and a holocene record of winter precipitation since the preboreal ela varied within a range of about 390 m and winter precipitation ranged between 40 and 160 of modern values winter precipitation variations appear to have been the main cause of these century to millennial scale holocene glacier variations

synchronous holocene climatic oscillations recorded on the swiss plateau and at timberline in the alps eight synchronous pre roman cold phases were found at 9600 9200 8600 8150 7550 6900 6600 6200 5350 4900 4600 4400 3500 3200 and 2600 2350 radiocarbon years bp by reconstructing past climate at two sites on the swiss plateau and at timberline in the alps the cooling events during the early and mid holocene represent temperature values similar to today and apparently the onset of cooling events represents a deviation from today s mean annual temperature of about 1 c and is triggered at a 1000 year periodicity at wallisellen langachermoos 440 m a former oligotrophic lake near zurich the correlation between sum mertime lake levels and the seed production of the amphi atlantic aquatic plantnajas flexilis was used to reconstruct lake levels over a 3000 year period during the first part of the holocene at lake seedorf on the western swiss plateau 609 m the sedimentological palynological and macrofossil record revealed fluctuations of lake levels for the complete holocene from lago basso in the

book reviewmoraines and varves origin genesis classification ch schluchter editor a a balkema rotterdam 1979 441 pp dfl 85 00 u s 45 00

holocene glacier variations in central jotunheimen southern norway based on distal glaciolacustrine sediment cores abstract sediment cores from two glacier fed lakes are used to reconstruct a continuous record of glacier variations since about 10 000 cal bp in the smorstabbtinden massif of central jotunheimen southern norway particular attention is paid to the century to millennial scale pre little ice age glacial signal based on an estimated temporal resolution of 55 and 25 yr cm 1 for bovertunsvatnet and dalsvatnet respectively visible lithostratigraphic variations organic content loss on ignition calcium carbonate content magnetic susceptibility and grain size fractions especially the fine silt are used as proxy indicators of glacier presence and extent in the lake catchments following deglaciation the early holocene was characterized by generally small glaciers until a major advance the finse event peaking at approximately 8200 cal bp from 7900 to at least 5300 cal bp glaciers appear to have been absent from central jotunheimen there is evidence of glacier expansion between about 2400 and 1600 cal bp the bovertun i event and between about 1400 and 800 cal bp the bovertun ii event before reduced glacier extent during the mediaeval warm period finally the most extensive neoglacial maximum occurred during the little ice age after 500 cal bp in addition to providing a record of the broad pattern of climatically forced holocene glacier variations periodicities at 110 140 200 285 and about 500 yr have been identified uncertainties remain concerning the precise timing of events glacierization and deglacierization detection thresholds a possible mid to late holocene 5300 2500 cal bp neoglacial build up of small glaciers and shorter term decadal to century scale variations in glacier size for which more proximal sites are required

lake bourget regional erosion patterns reconstruction reveals holocene nw european alps soil evolution and paleohydrology abstract two well dated ca holocene long sedimentary sequences from deepest parts of lake bourget provide new insights onto the evolution of erosion patterns at a regional scale in nw european alps the combination of high resolution geochemistry xrf core scanning calibrated by 150 punctual measurements and isotope geochemistry nd of the terrigenous fraction permitted the reconstruction not only of the intensity but also the type physical erosion vs chemical weathering and the location prealpine massifs vs high crystalline massifs of dominant erosion processes those data point the persistency of weak erosion fluxes from 9600 to 5500 cal bp due both to a dry climate and the growing sheltering effect of soils that rapidly progressed between 9600 and 8000 cal bp soils then reached a steady state before being destabilised around 4400 cal bp probably in response to human impact the human impact then reached a sufficient intensity to change erosion patterns at a regional scale but did not result in a significant increase of the regional terrigenous flux the following enhancement of erosion processes occurred around 2700 cal bp it was first paced by changing climatic conditions but probably reinforced by human impact during late iron age antiquity period over the long term trend the lake bourget record pinpoints an evolution of paleohydrological conditions in the alps dominated by dry conditions from 9500 to 4400 cal bp and a subsequent drift toward wetter conditions that culminated during the so called little ice age ca 1350 1900 ad in such a context the current dry conditions in european alps appear out of trend at high resolution 17 periods of enhanced hydrological activity highlight the rapid climatic changes that are typical of the holocene

the use of hypsometry to indicate long term stability and response of valley glaciers to changes in mass transfer a simple equation is derived relating the net mass balance and hypsometric curves of a steady state valley glacier it is used to examine how valley shape is linked to disparate extents and responses of glaciers subjected to similar climatic conditions examples are given which show that area based indices e g aar for estimating the equilibrium line altitude ela may be subject to a substantial built in variance because they implicitly rely upon similarity of glacier shape and regimen over a region if accurate topographic maps are available the equation may be used to infer the regimen of modern glaciers in the form of a dimensionless ratio of net mass balance gradients alternatively if similar information is available concerning regional glacier regimen disparate extents and responses may be collectively utilized to estimate values of ela or to infer climatic influence taking glacier hypsometry into account

holocene dynamics of the rhone glacier switzerland deduced from ice flow models and cosmogenic nuclides abstract we describe efforts to model the holocene extent of the rhone glacier switzerland using four paleoclimate records as templates for paleo equilibrium line altitude to identify candidate driving mechanisms of glaciers in the alps we evaluate the success of each paleoclimate template by comparing cosmogenic 10 be and 14 c concentrations in pro glacial bedrock derived from modeled glacier configurations to measured values an adequate fit can be obtained using mean summer insolation for 46 5 n however use of the dongee cave china speleothem record yields the best fit by accounting for both sub millennial e g little ice age and medieval warm period and multi millennial climate variations summer insolation our result indicates that glaciers in the alps primarily responded to changes in insolation during the holocene were smaller than today during the early holocene when insolation was relatively high and became larger during the mid to late holocene superimposed on the first order insolation response were shorter sometimes large amplitude length changes in response to short lived climate events such as the medieval warm period and the lia

thermomechanical stress strain numerical modelling of deglaciation since the last glacial maximum in the adamello group rhaetian alps italy abstract deglaciated areas in the valleys of the italian alps have recently exhibited a high potential for geomorphologic hazards from diffuse deep seated gravitational deformations dsgsds caused by rock mass creep processes that can evolve into rock falls and rock avalanches a multidisciplinary approach that integrated geomorphologic surveys and stress strain numerical simulations was used to investigate the effects of the stress release that was induced by the last glacial maximum lgm in the adame valley italian alps no evidence of dsgsds has been found in this area however data are available to develop a well constrained evolutionary model of the valley deglaciation the extent and thickness of the southern extension of the adamello glacier the widest glacier in italy during its primary growth phases including those of the lgm three late glacial stages and the little ice age lia were reconstructed using glacial geological surveys and were reproduced using a finite difference stress strain sequential model spanning from the lgm to the present a thermomechanical numerical configuration was developed based on geomechanical field measurements that were collected from rock outcrops and data from laboratory tests specifically performed on intact rock samples the numerical simulations demonstrate that thermomechanical viscous behaviour cannot be neglected because the resulting strains on the slopes are significantly higher than those resulting from conventional elastoplastic behaviour the last major thermal effect in the rock masses reproduced using the model occurred from 11 5 ka until the lia the resulting displacement rates are as much as several tens of mm ka which are consistent with the absence of dsgsds in the adame valley as these rates are significantly lower than those previously obtained from dsgsds and other large landslides in the alps based on thermomechanical numerical solutions these rates should persist for the next 1000 years assuming that no variations in current climatic conditions occur

erosion under climate and human pressures an alpine lake sediment perspective we review the scientific efforts over the last decades to reconstruct erosion from continuous alpine lake sediment records we focused both on methodological issues showing the growing importance of non destructive high resolution approaches xrf core scanner as well as progresses in the understanding of processes leading to the creation of an erosion signal in lakes we distinguish continuous records from event records both provide complementary information but need to be studied with different approaches continuous regionally relevant records proved to be particularly pertinent to document regional erosion patterns throughout the holocene in particular applying the source to sink approach event based approaches demonstrated and took advantage of the strong non linearity of sediment transport in high altitude catchment areas this led to flood frequency and intensity reconstructions highlighting the influence of climate change upon flood dynamics in the mountain the combination of different record types both in terms of location high vs low elevation sedimentology high vs low terrigenous contribution and significance local vs regional is one of the main outputs of this paper it allows the establishment of comprehensive histories of nw french alps erosion but also and consequently soil dynamics and hydrological patterns throughout the holocene we also discuss the influence of glacier dynamics one of the major agents of erosion in the alps a major feature is the growing human influence upon erosion at a local scale since at least the middle of the bronze age 3500 cal bp however and according to the regional record from lake bourget only few periods of rising erosion at local scales generated a regional record that can be discriminated from wetter climatic periods among them the period between 200 bce and 400 ad appeared to be marked by a generalised rise in human triggered erosion at local scales in the northern french alps this review highlights the importance of modern high resolution and interdisciplinary studies of lake sediments in order to better understand the complex relationships between humans climate and the earth system in general we strongly argue that regional integration of data is now required to move a step further such an integration is easier with cost and time effective methods as well as after a better definition of approaches and their limits this should lead to a stronger collaboration between paleo data producers and modellers in the near future

origin and holocene geomorphological evolution of the landslide dammed basin of la narse de la sauvetat massif central france this work is the first geomorphological analysis of la narse de la sauvetat a hydromorphic basin located in the southern limagne plain french massif central which had never been studied despite its great palaeoenvironmental interest we explore the potential of its sedimentary archives to provide valuable data on holocene geomorphic dynamics and their sensitivity to local and regional hydro climatic changes in order to characterize the nature and the morphostratigraphic and pedosedimentary evolution of the basin we used an integrative approach involving geomorphological mapping hand auger stratigraphic cross sections topographic analysis based on lidar data and stereophotogrammetric reconstruction geophysical prospection and radiocarbon dating results revealed a palaeotopography fossilized under 6 m of sedimentary infilling with a clear shift from fluvial to hydromorphic conditions circa 2800 cal bce separated by a level with colluvial and lacustrine features a detailed analysis of the eastern border of the basin also suggests the existence of a former open valley in place of the current closed depression now locked in by a topographic threshold forming a dam the sedimentary aggradation of the basin started with an alluvial phase during the upper pleistocene and probably continued into the middle and late holocene consistently with regional alluvial dynamics in the early subboreal a massive landslide occurred on the western slopes of the puy de corent volcanic plateau thereby damming the valley and forming a closed depression this episode coincided with the mid holocene climatic shift and an associated phase of slope instability and increased landslides in western europe due to changing climatic conditions this depression evolved into a hydromorphic basin with several high energy hydro sedimentary episodes after 2800 cal bce however hydro sedimentary conditions gradually became more stable towards the late holocene around 500 cal ce the drainage deteriorated towards palustrine conditions and caused the formation of a marsh and its consequent evolution into a shallow lake throughout the middle ages this lake was drained in the late xviiith century the long term sedimentary record of la narse de la sauvetat sensitive to climatic instability periods of the middle holocene makes this landslide dammed basin a valuable site with an important potential to further development of palaeoenvironmental and geoarchaeological studies

early holocene glacier advance southern coast mountains british columbia canada abstract terrestrial and lake sediment records from several sites in the southern coast mountains british columbia provide evidence for an advance of alpine glaciers during the early holocene silty intervals within organic sediments recovered from two proglacial lakes are bracketed by ams 14 c dated terrestrial macrofossils and mazama tephra to 8780 6730 and 7940 6730 14 c yr bp 10 150 7510 and 8990 7510 cal yr bp radiocarbon ages ranging from 7720 to 7380 14 c yr bp 8630 8020 cal yr bp were obtained from detrital wood in recently deglaciated forefields of sphinx and sentinel glaciers these data together with previously published data from proglacial lakes in the canadian rockies imply that glaciers in western canada advanced during the early holocene the advance coincides with the well documented 8200 yr cold event identified in climate proxy data sets in the north atlantic region and elsewhere

the alps with little ice evidence for eight holocene phases of reduced glacier extent in the central swiss alps glacially deformed pieces of wood organic lake sediments and clasts of reworked peat have been collected in front of alpine glaciers since ad 1990 the palaeoglaciological interpretation of these organic materials is related to earlier phases of glacier recession surpassing that of today s shrunken glaciers and to tree growth and peat accumulation in the valleys now occupied by the glaciers glacial transport of the material is indicated by wood anatomy incorporated silt sand and gravel particles missing bark and deformed treerings a total of 65 samples have been radiocarbon dated so far and clusters of dates provide evidence of eight phases of glacier recession 9910 9550 9010 7980 7250 6500 6170 5950 5290 3870 3640 3360 2740 2620 and 1530 1170 calibrated years bp allowing for the timelag between climatic fluctuations glacier response and vegetation colonization these recession phases may lag behind climatic changes by 100 200 years

the submarine volcanic system of the errigoiti formation albian santonian of the basque cantabrian basin northern spain stratigraphic framework facies and sequences abstract the errigoiti formation located in the central domain of the basque cantabrian basin is an albian to santonian bathyal submarine volcanic system of alkali basaltic character these volcanics occurred in an extensional geodynamic context generated by the drifting of the iberian plate with respect to the european plate stratigraphic analyses reveal the facies distribution and depositional architecture of a longitudinal cross section of the errigoiti volcanic system four facies groups were distinguished sheet lavas sl derived from low viscosity lava flows at high magma discharge rate pillow lavas pl derived from intermediate viscosity lava flows at moderate discharge rate pillow breccias pb derived either from in situ fragmentation of lavas pb1 or rock falling from pillow lava slopes pb2 and stratified volcaniclastites vc derived from volcaniclast resedimentation through gravity flows either by early remobilization vc1 or post volcanic reworking vc2 the facies groups occur in a predictable repetitive succession essentially from base to top an sl pl pb vc stacking pattern this is interpreted to reflect an upward waning in the magma discharge rate five major volcanic sequences make up the errigoiti formation each comprises packages tens to hundreds of meters thick deposited during short time spans of volcanic activity separated by long time intervals of volcanic inactivity consequently boundaries between sequences are associated with marked hiatuses reworked volcaniclasts and or turbidite pelagic sedimentation analysis of lateral and vertical facies evolution enabled us to propose a depositional model consisting of three depositional environments from proximal to distal settings these are amalgamated pillow volcanoes scattered pillow volcanoes and volcanic fringe basically responding to a proximal to distal pl pb pl vc and sl vc evolution of facies associations contemporaneous fossiliferous turbidite pelagic sequences that surround the volcanic succession allow paleobathymetry to be estimated on the basis of biofacies sites with the highest rate of volcanic emission correspond to an average depth of 900 m sites with thinner volcanic pile accumulated at a minimum depth of 1100 m the facies sequence established in this work and the processes involved in its formation are comparable with the sequences and processes described in other submarine basic volcanic systems consequently the depositional model for the errigoiti formation can perhaps serve as a reference model for this type of volcanic system