rapid stepwise onset of antarctic glaciation and deeper calcite compensation in the pacific ocean the ocean depth at which the rate of calcium carbonate input from surface waters equals the rate of dissolution is termed the calcite compensation depth at present this depth is 4 500 m with some variation between and within ocean basins the calcite compensation depth is linked to ocean acidity which is in turn linked to atmospheric carbon dioxide concentrations and hence global climate1 geological records of changes in the calcite compensation depth show a prominent deepening of more than 1 km near the eocene oligocene boundary 34 million years ago 2 when significant permanent ice sheets first appeared on antarctica3 4 5 6 but the relationship between these two events is poorly understood here we present ocean sediment records of calcium carbonate content as well as carbon and oxygen isotopic compositions from the tropical pacific ocean that cover the eocene oligocene boundary we find that the deepening of the calcite compensation depth was more rapid than previously documented and occurred in two jumps of about 40 000 years each synchronous with the stepwise onset of antarctic ice sheet growth the glaciation was initiated after climatic preconditioning7 by an interval when the earth s orbit of the sun favoured cool summers the changes in oxygen isotope composition across the eocene oligocene boundary are too large to be explained by antarctic ice sheet growth alone and must therefore also indicate contemporaneous global cooling and or northern hemisphere glaciation

stratigraphical and δ13c records of permo carboniferous platform carbonates south china responses to late paleozoic icehouse climate and icehouse greenhouse transition abstract little attention has been focused on the stratigraphical imprints of the late paleozoic ice age on the equatorial eastern paleo tethys an integrated study of biostratigraphy microfacies and stable carbon isotope stratigraphy was carried out on pennsylvanian middle guadalupian carbonates of the gongchuan section in the bama platform south china it records seven cooling and two warming pulses in the pre kungurian interval comparing with ice proximal stratigraphical records and far field indirect proxies in lower latitudes a kungurian negative 13 c excursion from 4 4 at the base of the kungurian to 1 6 recorded only in the subequatorial belt is documented here it is followed by a global positive 13 c trend reaching 5 3 near the cisuralian guadalupian boundary seven third order shallowing upward cycles are reported for the first time from the kungurian succession the duration of each cycle is estimated to ca 1 myr these cycles are interpreted as being of glacioeustatic origin and mainly driven by long period modulations of obliquity 1 2 myr under major p co 2 decreasing condition this interpretation is supported by recent climate ice sheet modeling and cenozoic glaciation studies which argue that astronomical forcing will be amplified by large magnitude perturbations in the carbon cycle when only localized ice centers persist our results emphasize the need for integration of sedimentological and paleoclimatological proxies in elucidating the dynamics of the deglacial phases of the late paleozoic ice age

contemporary changes of the channel pattern and braided gravel bed floodplain under rapid small valley glacier recession scott river catchment spitsbergen abstract after the little ice age high latitude proglacial river catchments have been observed to transition to paraglacial conditions through the activation of fluvial processes and changes in the river valley and channel forms this project provides an analysis of contemporary changes in the morphology of the valley bottom and channel development of the proglacial scott river catchment nw part of the wedel jarlsberg land sw spitsbergen based on observations conducted during the 2009 2013 melt seasons almost half of the catchment area of 10 km2 is occupied by a valley glacier currently in the stage of rapid recession the processes driving the development of the glacier free valley floor are determined by 1 long term factors such as geological structure glaciotectonics or the morphogenesis of the terminoglacial zone 2 medium term factors including climatic changes and changes in the extent of the glacial terminus and hydrological regime and 3 short term factors such as weather driven flooding events geological factors determined the development of two valley narrowings and a clear division of the valley floor into three morphological zones the upper gorge in the terminal moraine rampart distinguishes the wide up to 700 m upper section of the valley bottom dominated by an outwash plain where the river system is fed by small tributaries the lower valley gorge dissecting the elevated marine terrace separates the middle section of the braided river floodplain from the mouth section alluvial fan the geomorphological field mapping of the valley floor and riverbed was conducted using geodesic and hydrometric measurements with high resolution survey techniques based on the global positioning system gps the detail measurements of the scott river valley and channel were carried out at representative cross sections and longitudinal profiles in various parts of the catchment because of the dominance of the glacial alimentation regime changes in the discharge rate and bedload transport regime are influenced by the glacial ablation rate which determines the variability of channel morphology and the contemporary development of the valley bottom the upper section of the valley is dominated by a multiple channel braided system fed by sub and supraglacial waters while in the middle section the development pattern changes from a meandering single thread channel to a multiple channel wandering system to a multiple channel braided system the current valley bottom is almost entirely occupied by a braided river floodplain and multiple channel river bed changes in the channel system are related to periods of snowmelt and the related flooding after the retreat of the snow cover the channels are highly stable as their spatial pattern is usually transformed during several days of ablation or ablation precipitation flood flows in the river s mouth section the channel returns to a single thread meandering pattern before transitioning to a multiple channel distribution system and finally to a single thread straight channel the river below the ebb in the storm bank develops a subaqual prodelta

disturbances in coarse bedload transport in a high mountain stream channel system western tatras poland abstract bedload transport measurements in the formerly glaciated chocholowski catchment located in the western tatras in poland were performed in the period 1975 to 2018 measurement of bedload displacement allowed to determine the role of bedload transport disturbances in both system connectivity and sediment transfer bedload transport occurred as many as triggered up to several times a year the longest distances were observed during rain on snow events between 12 m in headwaters and over 100 m in the fluvial valley bedload became activated along the entire length of the channel system 10 5 km every 2 to 5 years when the stream discharge exceeded 10 m3 s 1 with an average of 1 25 m3 s 1 in such situations bedload dynamics increased downstream and stream power was sufficient to overcome local barriers i e boulder and log steps downstream increases in bedload dynamics may become disturbed and inverted by sudden snowmelt and locally heavy rainfall these types of events caused the dynamics of bedload transport to be 190 to 320 greater in the upper part of the studied catchment and to decline in the downstream direction over a distance of 7 km to yield an attenuation effect the same pattern was observed in local tributaries where the dynamics of bedload transport were 200 higher in the upper part and attenuation was observed along a distance of 1 5 km in the downstream direction all events of this type cause seasonal disturbances in bedload transport however the greatest effect on bedload dynamics was produced by natural deforestation a 16 decrease in forest cover causes a fluvial system disequilibrium manifested in an intensification of hydro geomorphologic processes and formation of new landforms

spatial variations of surface water chemistry and chemical denudation in the erdalen drainage basin nordfjord western norway abstract this study conducted over an investigation period of six years 2004 2010 focuses on spatial variation in chemical components of drainage water from sub areas within a confined drainage basin of 79 5 km 2 erdalen drainage basin inner nordfjord western norway for detection of spatial diversity and relation to environmental factors the erdalen drainage basin is homogenously composed of gneisses which is reflected in a homogenous relative as a percentage chemical composition of surface water across the entire drainage basin system at the same time the mean annual tds values of surface water sampled in creeks draining defined subsystems within erdalen show a rather high spatial variability the main controls of this spatial variability are i differences in slope deposit regolith thickness ii differences in slope angle iii differences in areal regolith cover iv differences in vegetation cover v differences in snow cover and ground frost conditions and vi differences in elevation m a s l altogether the mean annual tds values in erdalen are rather low which can be explained by i the shallow thickness of regolith across the very steep drainage basin ii the small percentage of surface areas showing a significant cover of regolith iii the cool climate in the fjord landscape of western norway and iv the weathering resistance of the predominant gneisses within erdalen the annual chemical denudation rates in erdalen are in a similar range of magnitude to rates published for numerous other cold environment catchments worldwide despite the rather low mean annual tds values chemical denudation is a comparably important and spatially very variable denudational process and should therefore not be neglected when studying slope development as well as slope and catchment wide denudation rates and mass budgets in this kind of steep mountainous cold climate drainage basins

determination of the bedload transport rate in a small proglacial high arctic stream using direct semi continuous measurement abstract the article presents the results of a 34 day series of direct semi continuous measurements of the bedload transport performed during the melt season 2013 in the scott river catchment nw part of the wedel jarlsberg land spitsbergen the daily variability of the bedload transport rates and its relation to the dissolved and suspended load were analysed in two cross sections located in the lower course of a proglacial gravel bed river the bedload flux was measured by means of two 4 module sets of river bedload traps rbt in the research period a total of 34 day long samples of bedload and 34 water samples for the determination of the dissolved and suspended load were collected in each of the two cross sections 200 m apart the measurements showed longitudinal and temporal variability of bedload flux and the remaining components solutions suspensions corresponding with changes in water discharge the mean daily bedload flux qb in consecutive measurement cross sections xs amounted to 124 kg d 1 xs i and 59 kg d 1 xs ii respectively and showed high variability and an evident relationship with temperature the unequal bedload flux of the two measuring stations xs i and xs ii suggests aggradation within the alluvial fan that separates the two reaches the volume and rate of bedload flux were determined by the frequency of the occurrence of flood flows during which approximately from 59 xs i to 77 xs ii of total bedload was discharged the highest recorded daily values constituted 12 of total bedload flux through the cross section below the alluvial fan the river discharged approximately 6 million cubic meters m m3 of water 3 t of bedload lb 2238 t of suspended load ls and 613 t of dissolved load ld the relationships between the three components of the load suggest a 500 fold excess of suspended load and a 100 fold excess of dissolved load in relation to bedload flux high temporal and latitudinal variability of the bedload transport rate resulted in changes in the channel morphology and during floods also the floodplain

landscapes depositional environments and human occupation at middle paleolithic open air sites in the southern levant with new insights from nesher ramla israel abstract middle paleolithic human occupation in the levant 250 50 ka ago has been recorded in roofed cave and rockshelter and open air sites research at these different types of sites yielded different perspectives on the middle paleolithic human behavior and evolution until recently open air middle paleolithic sites in the levant were found in three major sedimentary environments fluvial lake margin and spring here we describe a unique depositional environment and formation processes at the recently discovered open air site of nesher ramla israel and discuss their contribution to understanding site formation processes in open air sites in the levant the site is 8 m thick middle paleolithic sequence osl dated to 170 80 ka that is located in a karst sinkhole formed by gravitational deformation and sagging into underground voids the sedimentary sequence was shaped by gravitational collapse cyclic colluviation of soil and gravel into the depression waterlogging in situ pedogenesis and human occupation original bedding and combustion features are well preserved in the lower archaeological sequence a rare occurrence in comparison to other open air archaeological sites this phenomenon coincides with episodes of fast sedimentation burial which also allowed better preservation of microscopic remains such as ash the upper archaeological sequence does not exhibit bedding or preservation of ash despite presence of heat affected lithic artifacts which makes it similar to other open air sites in the levant we suggest that rate of burial is the major factor that caused the difference between the upper and lower sequences the differences in the burial rate may be connected to environmental and vegetation changes at the end of mis 6 we also identified an interplay between sediment in wash and density of human activity remains i e during episodes of low natural sediment input the density of artifacts is higher relative to episodes with high rate of sediment in wash the detailed analysis of natural and anthropogenic processes at nesher ramla suggests a much wider spectrum of processes than previously reported for southern levantine paleolithic sites nesher ramla shares certain depositional and post depositional characteristics with both cave and open air sites and provides a better insight into processes which control both types of sites

environmental controls rates and mass transfers of contemporary hillslope processes in the headwaters of two glacier connected drainage basins in western norway the role of hillslopes functioning as the key elements for sediment production storage and transfers is particularly important within headwater systems in cold climate mountain landscapes that are considered to react sensitively to climate change and human impact environmental controls rates and sedimentary mass transfers of the contemporary slope processes were explored within the headwater systems of the parabolic shaped and glacier connected erdalen and bodalen drainage basins in western norway the identified relevant contemporary processes in both drainage basins include rockfalls and boulder falls snow avalanches slush flows debris flows slow mass movements and creep processes wash and chemical denudation and fluvial transport of solutes suspended sediments and bedload these denudational processes were analyzed based on an extensive geomorphic monitoring program conducted over a period of four years 2009 2012 combined with detailed geomorphological mapping and in depth studies of the most important slope processes a range of different monitoring and field techniques was applied the results show that the intensity of contemporary denudational processes in erdalen and bodalen is rather low and appears to be in a range of magnitude comparable to a number of other cold climate environments situated in the higher latitudes of the northern hemisphere the present day spatio temporal pattern of the denudational slope processes occurring in the headwater systems is controlled by a complex combination of meteorological and morphometric factors a comparison of the different denudational slope processes according to their annual mass transfers reveals the highest relative importance for rockfalls snow avalanches slope wash and chemical slope denudation in erdalen as well as for rockfalls chemical slope denudation snow avalanches and debris flows in bodalen the revealed differences between the single headwaters regarding the absolute and relative importance of the denudational slope processes are seen as a consequence of the different glacially inherited valley morphometries however due to the generally low process intensities the postglacial modification of the inherited glacial relief is altogether minor in both valleys

proglacial lakes character behaviour and geological importance proglacial lakes are ubiquitous within the quaternary record and can provide exceptional breadth and depth of palaeoenvironmental information present deglaciation is increasing the number and size of proglacial lakes around the world this study provides a synthesis of knowledge on proglacial lake character and behaviour and critically evaluates the importance of proglacial lakes from a geological perspective we show how ice marginal or ice contact lakes and other distal proglacial lakes can be distinguished from each other by geomorphological sedimentological chemical and biological characteristics the key controls on proglacial lake geomorphology and sedimentology are outlined and discussed proglacial lakes can exacerbate mountain glacier and ice sheet margin ablation via mechanical and thermal stresses but very large lakes can moderate summer air temperatures and relatively retard summer ice ablation proglacial lakes interrupt meltwater flux and are very efficient sediment traps hydrological routing and consequent geomorphological activity can be radically modified by sudden drainage of proglacial lakes and resultant glacial lake outburst floods exceptionally large proglacial lake drainages affected global ocean circulation and global climate during the quaternary overall analyses of proglacial lakes can provide a valuable insight into i patterns character and behaviour of mountain glaciers ice sheets and glaciations and ii the impacts of past present and future deglaciation

the partitioning of the total sediment load of a river into suspended load and bedload a review of empirical data the partitioning of the total sediment load of a river into suspended load and bedload is an important problem in fluvial geomorphology sedimentation engineering and sedimentology bedload transport rates are notoriously hard to measure and at many sites only suspended load data are available often the bedload fraction is estimated with rule of thumb methods such as maddock s table which are inadequately field tested here the partitioning of sediment load for the pitzbach is discussed an austrian mountain stream for which high temporal resolution data on both bedload and suspended load are available the available data show large scatter on all scales the fraction of the total load transported in suspension may vary between zero and one at the pitzbach while its average decreases with rising discharge i e bedload transport is more important during floods existing data on short and long term partitioning is reviewed and an empirical equation to estimate bedload transport rates from measured suspended load transport rates is suggested the partitioning averaged over a flood can vary strongly from event to event similar variations may occur in the year to year averages using published simultaneous short term field measurements of bedload and suspended load transport rates maddock s table is reviewed and updated long term average partitioning could be a function of the catchment geology the fraction of the catchment covered by glaciers and the extent of forest but the available data are insufficient to draw final conclusions at a given drainage area scatter is large but the data show a minimal fraction of sediment transported in suspended load which increases with increasing drainage area and with decreasing rock strength for gravel bed rivers whereby in large catchments the bedload fraction is insignificant at 1 for sand bed rivers the bedload fraction may be substantial 30 50 even for large catchments however available data are scarce and of varying quality long term partitioning varies widely among catchments and the available data are currently not sufficient to effectively discriminate control parameters

short term geomorphological evolution of proglacial systems proglacial systems are amongst the most rapidly changing landscapes on earth as glacier mass loss permafrost degradation and more episodes of intense rainfall progress with climate change this review addresses the urgent need to quantitatively define proglacial systems not only in terms of spatial extent but also in terms of functional processes it firstly provides a critical appraisal of prevailing conceptual models of proglacial systems and uses this to justify compiling data on rates of landform change in terms of planform horizontal motion elevation changes and sediment budgets these data permit us to produce novel summary conceptual diagrams that consider proglacial landscape evolution in terms of a balance of longitudinal and lateral water and sediment fluxes throughout we give examples of newly emerging datasets and data processing methods because these have the potential to assist with the issues of i a lack of knowledge of proglacial systems within high mountain arctic and polar regions ii considerable inter and intra catchment variability in the geomorphology and functioning of proglacial systems iii problems with the magnitude of short term geomorphological changes being at the threshold of detection iv separating short term variability from longer term trends and v of the representativeness of plot scale field measurements for regionalisation and for upscaling we consider that understanding of future climate change effects on proglacial systems requires holistic process based modelling to explicitly consider feedbacks and linkages especially between hillslope and valley floor components such modelling must be informed by a new generation of repeated distributed topographic surveys to detect and quantify short term geomorphological changes

sediment transport in an alpine river before and after a dambreak flood event fluvial sediment transport in the high mountain partnach river reintal valley bavarian alps was investigated during a 10 year observation period 2001 2010 during this period the downstream reach of the partnach river was decoupled from upstream sediment throughput by a rockslide deposit until 2005 in august 2005 the dam was partially breached during a flood event resulting in renewed sediment coupling between the upstream and downstream reaches a comparison of pre and post dambreak river sediment load data showed that the dissolved load dominated sediment transport prior to august 2005 with a switch to the dominance of bedload transport post dambreak the higher post dambreak bedload rates were particularly evident during the first years after the dam failure due to significant coarse material coupling between active sediment sources undercut banks talus cones and the partnach river in the last years of the observation period 2009 and 2010 the dominance of dissolved load transport was re established copyright 2011 john wiley sons ltd

the cueva del angel lucena spain an acheulean hunters habitat in the south of the iberian peninsula the cueva del angel archaeological site is an open air sedimentary sequence remnant of a collapsed cave and part of a karst complex the faunal assemblage dominated by equus ferus large bovids and cervids has been subjected to intense anthropic actions reflecting selective predation the fauna may be correlated with european faunistic associations of the end of the middle pleistocene to the beginning of the upper pleistocene the cueva del angel lithic assemblage dominated by non modified flakes and abundant retouched tools with the presence of 46 handaxes appears to fit well within the regional diversity of a well developed non levallois final acheulean industry a preliminary 230th 234u age estimate the review of the lithic assemblage and faunal evidence would favour a chronological positioning of the site in a period stretching from the end of the middle pleistocene to the beginning of the upper pleistocene mis 11 mis 5 the acheulean lithic assemblage found at the cueva del angel fits very well with the hypothesis of a continuation of acheulean cultural traditions in the site distinct from the contemporaneous uniquely mousterian complexes witnessed in other parts of the iberian peninsula and western europe

holocene hillslope development in glacially formed valley systems in nordfjord western norway abstract large areas of the norwegian fjord landscapes are covered by hillslopes that reflect the influence of glacial inheritance from the last glacial maximum lgm the focus of this paper is two fold 1 analyze the spatio temporal variability of relevant denudational slope processes and process intensities over the holocene and 2 detect holocene modification of the glacial valley morphometry research was performed on hillslope systems within two steep parabolic shaped and glacier fed tributary valleys erdalen and bodalen located on the western side of the jostedalsbreen ice cap in western norway orthophoto delineation high resolution mapping tls detailed geomorphological information and spatial data analysis were combined with dating techniques and geophysical investigations calculated holocene rockwall retreat rates at selected slope test sites range from 0 38 to 0 67 mm yr 1 with a mean value of 0 53 mm yr 1 slightly higher values were found in erdalen with a mean rockwall retreat rate of 0 57 mm yr 1 compared to 0 50 mm yr 1 in bodalen valley wide holocene rockwall retreat rates of 0 38 0 50 mm yr 1 are consistent with other estimates of holocene rockwall retreat rates in cold mountain environments it is shown that the glacial inheritance of topography is the most important factor controlling valley development since the lgm and that sediment storage capacity is primarily conditioned by valley morphometry compared to contemporary rates the results indicate enhanced denudation activity and intensity immediately following deglaciation and during the little ice age the overall tendency of landscape development is postglacial widening of the parabolic shaped valley morphometry through rockwall retreat with associated debris accumulation beneath rockwalls as a result the glacially sculpted topography has not yet adapted to denudational processes acting under holocene environmental conditions

paleolithic caves and hillslope processes in south western samaria israel environmental and archaeological implications abstract south western samaria is emerging as a major province of paleolithic cave sites most recently discovered caves have been naturally filled with terra rossa type colluvial deposits when the hillslopes above the caves were stripped from vegetation during late quaternary times site formation processes differ significantly between caves with pit like openings such as qesem emanuel and rantis caves vs those with cliff side entrances such as shukbah tinshemet and deir kaddis caves the former favored accumulation of colluvial debris while the latter were relatively protected from these deposits caves discovered in the 20th century were mainly of the latter cliff face type while in the 21st century new discoveries commonly occur where construction works intersect previously unnoticed filled caves

lateral geomorphic connectivity in a fluvial landscape system unraveling the role of confinement biogeomorphic interactions and glacial legacies abstract the rates at which sediment from the landscape is recruited to channel networks reflect lateral geomorphic connectivity and have significant implications for biophysical river systems by strongly influencing sediment supply regime such inputs control the dynamics and characteristics of the channel as well as the associated habitat and biota the main objective of this research was to disentangle the relative importance of geomorphic and biological factors which define spatial patterns in lateral connectivity by promoting or restricting bank erosion avulsions and slope failures focusing on a forested formerly glaciated mountain basin in the interior pacific northwest we combined extensive field surveys with remote sensing data lidar aerial imagery to obtain metrics representing this complex suite of landscape characteristics the interpretation of evidence yielded by correlations between these variables a regime model and qualitative observations suggest that at a multi decadal timescale between major landscape disturbances lateral connectivity patterns in sullivan creek may be to a large extent governed by a combination of biotic factors and glacial legacies in particular forest canopy metrics were key predictors of hillslope stability as well as bank and valley floor resistance suggesting a pivotal influence of root reinforcement on the other hand instream large wood abundance was closely related to channel splitting which reflects its role in promoting channel avulsions more extensive bank erosion in reaches dominated by drift deposits appeared to indicate glacial legacies furthermore a strong association between bank erosion and colluvial inputs suggested a close coupling within the channel hillslope system lateral confinement defined as the proportion of the channel length abutting against bedrock terraces fans and roads was negatively associated with channel braiding the relationships linking confinement with bank erosion and the magnitude of colluvial inputs negative and positive association respectively were relatively weak taken together findings emerging from this research suggest that better understanding of lateral geomorphic connectivity patterns in mountain river basins similar to our study site requires that both channel processes and broader biophysical landscape system be considered

middle paleolithic sidescrapers were resharped or recycled a view from nesher ramla israel abstract the resharpening of sidescrapers is a widely discussed issue in recent middle paleolithic studies however in the levantine record the evidence for sidescraper resharpening is meager the middle paleolithic site of nesher ramla israel represents a rare case in which sidescrapers were frequently modified by removal of longitudinal spalls from their edges both parent sidescrapers and spalls long sharpening flakes lsf are abundant throughout the site s stratigraphy providing a rare opportunity for a complementary study of both artifact groups the aim of the present study is to reconstruct the life history of sidescrapers retrieved from nesher ramla we ask how the lsf removal changed the morphology of the sidescraper edge at which stage of the sidescraper life history it occurred what was the purpose of lsf removal and was it a part of a recycling system aimed at producing a new edge tool type or the maintenance of the existing tool edge the studied artifacts 100 parent sidescrapers and 60 complete lsf were sampled randomly from the most intensively occupied and richest layers of the site our results suggest that sidescraper edge modification was a well mastered and skillful process that resulted in standardized and morphologically distinct products in most cases the sidescrapers were not further retouched after the lsf removal this leads us to propose that the major goal was to transform the sidescraper into a tool with a sharp straight and flat edge the lsf removal at nesher ramla provides an exceptional case in which a simple raw edge was deliberately manufactured at the expense of the previously retouched edge this reinforces the previous assumptions that simple raw edges were often preferred over retouched ones

glacier melt runoff controls bedload transport in alpine catchments abstract research on factors affecting sediment regime in glacierized catchments under warming climates is still scarce despite its societal relevance in particular coarse bedload transport has never been quantitatively related to water runoff origin snowmelt vs glacier melt which provides important information on the role of different sediment sources glaciers vs hillslopes and channel bed drawing on data from multiple spatial and temporal scales in a paradigmatic alpine glacierized catchment we show that glacier melt flows play a key role in coarse sediment transport dynamics bedload concentration measured during glacier melt flows is up to 6 orders of magnitude larger than during snowmelt at the catchment scale and within the channel however minimal aggradation and degradation was detected over almost a decade in addition sedimentation rates at a hydropower weir inferred from flushing frequency during the last four decades are tightly associated to summer air temperature and not to precipitation trends and most of sediment export occurred in july august however sediment flushing frequency has been decreasing since the late 1990s despite very warm summers in the following decades collectively these findings indicate that sediment is dominantly sourced from within glacier covered areas and that transport rates are thus dictated by seasonal and multi annual glacial dynamics as glacier melt flows decrease due to ice mass loss our results suggest that for similar basins a progressive shift from supply limited driven by glacier activity to transport limited during rainfall induced events sediment transport will occur disrupting the current near equilibrium channel conditions

astronomical forcing in late eocene marine sediments we use an x ray fluorescence xrf core scanner to obtain records of elemental concentrations in sediment cores from ocean drilling program odp leg 171b site 1052 blake nose atlantic margin of northern florida this record spans the middle to late eocene as indicated by bio and magnetostratigraphy and displays cyclicity that can be attributed to the orbital forcing of a combination of climate ocean circulation or productivity we use the xrf counts of iron and calcium as a proxy of the relative contribution from calcium carbonate and terrestrial material to construct a new composite depth record this new composite depth record provides the basis to extend the astronomically calibrated geological time scale into the middle eocene and results in revised estimates for the age and duration of magnetochrons c16 through c18 in addition we find an apparent change in the dominance of orbitally driven changes in obliquity and climatic precession at around 36 7 ma on our new time scale long term amplitude modulation patterns of eccentricity and obliquity in the data do not seem to match the current astronomical model any more suggesting the possibility of new constraints on astronomical calculations

handaxe manufacture and re sharpening throughout the lower paleolithic sequence of tabun cave abstract in this paper we assess the evidence for on site manufacture and re sharpening of handaxes in the lower paleolithic layers of tabun cave by examining the ratio of thinning flakes the typical waste of bifacial manufacture to handaxes our study of twenty nine assemblages ranging from the acheulean to the acheulo yabrudian complex combining results from jelinek s and ronen s excavations shows that thinning flakes are scarce throughout the entire sequence results indicate that handaxes were commonly not manufactured or re sharpened in the excavated area and that these activities were most likely conducted outside the site the late lower paleolithic in various parts of eurasia and africa is characterized by high variability in lithic technology which in the case of the levant is best reflected in the acheulo yabrudian complex this study aids our understanding of variability in the levantine late lower paleolithic by adding the concept of segmentation of reduction as an integral part of late lower paleolithic lithic technology significantly in tabun cave the segmentation of reduction that characterizes handaxe manufacture differs from the patterns observed in amudian blade production and yabrudian scraper manufacture which were both regularly conducted on site the extent of variability and flexibility is thus reflected not only in the technologies employed but also in how different reduction sequences were segmented and executed across the landscape suggesting a link between technical knowledge mobility patterns and landscape exploitation

astronomical calibration age for the oligocene miocene boundary the stratotype section for the base of the miocene is at a reversed below to normal above magnetic transition that is claimed to represent magnetic chron c6cn 2n o deep sea drilling project dsdp site 522 is the only location we are aware of that unambiguously records the three normal events of c6cn we have quantitatively determined the range of the short lived nannofossil sphenolithus delphix and the lower limit of s disbelemnos in dsdp holes 522 and 522a in order to calibrate their precise relationship to the magnetostratigraphy and to confirm the completeness of the record at this site astronomical tuning of ocean drilling program odp sites 926 928 and 929 shows that s disbelemnos appears at 22 67 ma and that the entire range of s delphix is from about 22 98 ma to 23 24 ma using these ages linear interpolation in dsdp site 522 suggests that the age of c6cn 2n o and of the oligocene miocene boundary is 22 92 0 04 ma our value conservatively expressed as 22 9 0 1 ma is 0 9 m y younger than the currently accepted age of the oligocene miocene boundary and of c6cn 2n o which was assigned an age of 23 8 ma based on an estimate of 23 8 1 ma for the oligocene miocene boundary the bulk sediment carbon isotope data from dsdp site 522 is correlated to the record from benthic foraminifera at odp site 929 to refine the calibration of magnetic reversals from c6cn 1n o to c7n 2n o at dsdp site 522 on the astronomical time scale

orbital forcing of global change throughout the phanerozoic a possible stratigraphic solution to the eccentricity phase problem astronomers have little confidence in orbital forcing calculations on time scales beyond ten million years they are confident that the fundamental frequencies of the planetary orbits remain nearly constant on time scales of hundreds of millions of years small variations in these frequencies and chaotic behavior of certain resonance relationships however can introduce large uncertainty regarding the exact orientation of planetary orbits on time scales of tens to hundreds of millions of years we introduce a simple trigonometric series expression for eccentricity in order to evaluate effects that arise from imposing specified displacements in orientation of planetary orbits the resulting changes in the character of the calculated eccentricity time series should be a guide to stratigraphers seeking to relate orbital forcing to stratigraphic time series throughout the phanerozoic this geologic calibration of eccentricity time series in relatively old stratigraphic sequences may provide astronomers with clues to further refinement of their calculations

the use of the lateral tranchet blow technique at nesher ramla israel a new cultural marker in the levantine middle paleolithic abstract the open air middle paleolithic site at nesher ramla israel dated to the end of marine isotope stage 6 and marine isotope stage 5 is characterized by extensive use of the lateral tranchet blow technique this technique consists of the removal of an elongated thin spall along the retouched edge of the blank in nesher ramla this technique is used for producing a specific tool kit component unifacially retouched tools with a lateral tranchet blow ltb the tools with ltb were systematically produced throughout the 8 m thick middle paleolithic sequence of nesher ramla representing the major typological category in some of the layers together with tools with ltb the assemblages contain large numbers of ltb spalls here we present a detailed techno morphological analysis of the tools and spalls from nesher ramla unit iii one of the richest archaeological layers of the site our results suggest that the goal of the ltb technique at nesher ramla was to manufacture a tool with an edge that is partially retouched and partially sharp i e shaped by ltb the ltb technique employs a long knapping routine including a series of compulsory and optional steps implying non opportunistic behavior although on site use of the ltb technique is attested the fact that these tools were also often introduced to the site as finished objects further emphasizes their importance and suggests that most of them were not produced on site in response to an immediate need for sharp edges this tool type represents a new previously unreported component in the levantine middle paleolithic toolkit a comparison with other archaeological units along the 8 m thick stratigraphy of nesher ramla suggests that the ltb technique was one of the major techniques for manufacturing tools at that site and that the tools with ltb represent a cultural marker for nesher ramla hominins and possibly a new cultural marker in the levantine middle paleolithic according to a comparison of tools shaped by ltb from other geographic and temporal contexts most notably the central european keilmesser the nesher ramla tools with ltb were likely designed and used by right handed hominins in a longitudinal cutting motion

start and end of bedload transport in gravel bed streams 1 the threshold of incipient bedload motion expressed either as a critical force or as a critical water discharge is a key parameter in bedload transport prediction measuring the threshold of motion is difficult and reliable data from natural streams are rare by recording the vibrations triggered by bedload particles when moving over a steel plate mounted in the channel bed we determined the time at start and end of bedload transport in four streams where discharge is continuously monitored the threshold discharge scatters over approximately one order of magnitude for each stream reinforcing previous observations that critical discharge is characterized by a distribution of values we interpret a strong correlation between the discharge at the start of transport and the discharge at the end of transport of the previous event to reflect temporal changes in bed structure and consequent effects on the driving and resisting forces acting on the bed

continuous measurement of sediment transport in the erlenbach stream using piezoelectric bedload impact sensors we report on bedload transport observations using piezoelectric bedload impact sensors pbis an indirect method of estimating the volume of bedload transport of coarse sediment the pbis device registers vibrations produced by bedload particle diameter 20 mm and records the signal as a sum of the number of impulses per time sediment transport at the erlenbach stream has been continuously monitored with a pbis array starting in 1986 the sensor array spans the width of an entire cross section and is mounted flush with the surface of a check dam immediately upstream of a sediment retention basin we compare pbis data with long term sedimentation records obtained from repeated surveys of material stored in the sediment retention basin with artificial sediment input under controlled conditions in the field and also with laboratory experiments the rate of bedload transport is proportional to the number of impacts on the sensor per unit time the reliability of the calibration relationship increases with the length of the observation period e g for higher numbers of impacts and larger bedload volumes sediment volumes for individual flood events estimated with the pbis method are in agreement with volumes estimated using an independent empirical method based on the effective runoff volume of water the peak water discharge and the critical discharge for the onset of sediment transport copyright 2007 john wiley sons ltd

geologic constraints on the chaotic diffusion of the solar system the correlation of earth s orbital parameters with climatic variations has been used to generate astronomically calibrated geologic time scales of high accuracy however because of the chaotic behavior of the solar system two initially close calculations of earth s orbit diverge exponentially and have a large uncertainty beyond several million years in the past this chaotic behavior is related to a combination of angles in the precession motion of the orbits of earth and mars which currently is in resonance how long stays in libration critically depends on the dynamical model and initial conditions for the solar system here we show that geologic data can differentiate between astronomical solutions that do and do not exhibit a transition in since 40 ma and that sediments can thus provide a history for the evolution of we find that the chaotic transition of from libration to circulation did not occur after ca 30 ma we can thus constrain the chaotic diffusion of the solar system in the past and our results provide new and challenging constraints for astronomical models

seasonal and annual variations of surface water chemistry solute fluxes and chemical denudation in a steep and glacier fed mountain catchment in western norway erdalen nordfjord abstract conducted during an investigation period of six full years 2004 2010 this study focuses on inter and intra annual temporal variations of surface water chemistry solute fluxes solute yields and chemical denudation in a steep cold climate and glacier fed drainage basin system in the fjord landscape of western norway the selected erdalen drainage basin 79 5 km2 is considered a typical valley system of the nordfjord region in western norway and is connected to the jostedalsbreen ice cap through two outlet glaciers the mean annual chemical denudation rate in erdalen is 6631 kg km 2 yr 1 which is of a similar range of magnitude for annual chemical denudation rates as a number of other cold regions catchments worldwide inter and intra annual temporal variations of surface water chemistry solute gross concentrations solute gross yields and chemical denudation rates are clearly determined by the combined effects of inter and intra annual temporal variations of precipitation solar radiation and air temperature intra annual temporal variations of surface water total dissolved solids tds values reflect the dilution of base flow from the drainage basin by i thermally controlled snowmelt in spring april june ii thermally determined glacier melt in summer july august and iii more frequent and more intense rainfall events in autumn september november the highest monthly solute gross yields over the year comprising 43 of the total annual solute gross yield are recorded in the spring period three month period from april to june which is due to high runoff during spring snowmelt and comparably higher tds values than during major glacier melt in summer july august in autumn september november comparably high amounts of ion poor rainwater in combination with a fast surface drainage saturation overland flow of a significant share of rainwater during heavy rainfall events and lower air temperatures as well as lower solar radiation inputs lead to comparably lower tds values in surface water than are found in spring

astronomical pacing of late cretaceous third and second order sea level sequences in the foz do amazonas basin abstract because of their relatively reduced tectonic influence post rift sedimentary successions have a propensity to preserve climatically driven cyclicity over long durations here we present an integrated cyclostratigraphic and sequence stratigraphic study of the post rift limoeiro sedimentary formation fm of the foz do amazonas basin offshore brazil which spans the entire late cretaceous epoch almost 35 myr long the principal goal of the present study is to decipher very long multi myr sedimentary cyclicities and their potential origin s in order to delineate the main controlling factors of post rift sediment sequences and packages we used gamma ray gr well log data for cyclostratigarphy and seismic data for sequence stratigraphy time series analysis of gr data shows a rich series of milankovitch frequency bands in particular long period cyclicities 405 kyr 2 4 myr 4 7 myr and 9 5 myr are detected with high fidelity seismic and sequence stratigraphic interpretation shows a striking sea level sl depositional sequence order matching the 4 7 myr orbital cyclicity inferred from cyclostratigraphy longer sl sequences interpreted in previous studies from the limoeiro fm closely match the 9 5 myr gr related orbital cycles thus we infer that the post rift limoeiro fm was deposited continuously under astronomical forcing over the late cretaceous epoch resulting in an extraordinary record of direct base and sea level responses to milankovitch climatic forcing including longer multi myr periodicities the 4 7 myr orbital component is recorded for the first time in sl sedimentary proxies thus allowing here to update sl hierarchical orders we suggest that third order and second order and suborders sl sequences were most likely paced by long period astronomical cycles 2 4 myr eccentricity and 4 7 and 9 5 myr orbital cycles respectively

continuous measurements of bedload transport rates in a small glacial river catchment in the summer season spitsbergen abstract the study on bedload transport was conducted on the gravel bed scott river catchment with a glacial alimentation regime located in the nw part of the wedel jarlsberg land spitsbergen with subpolar climatic conditions in the melt season of 2010 bedload transport rate was continuously monitored at 24 hour intervals by means of four river bedload trap devices aligned across the width of the channel the maximum bedload transport rate varied strongly at portions of the cross section from 16 to 152 kg m 1 d 1 in cross profile i c p i and 4 to 125 kg m 1 d 1 in cross profile ii c p ii the maximum channel mean bedload transport rate qa amounted to 54 kg m 1 d 1 c p i and 35 kg m 1 d 1 c p ii mean daily bedload discharge qb was estimated at a level of 97 kg day 1 c p i and 35 kg m 1 d 1 c p ii and the total bedload yield was determined at approx 4345 kg in the measurement period 2086 kg c p i 2203 kg c p ii from 13 07 to 10 08 the analysis of the relationship between channel mean bedload transport rate and water velocity or shear stress revealed a significant value of the correlation coefficient r2 0 6 discharge and rate of bedload transport were dependent on the weather and number of days with flood discharge approx 58 of the entire discharged bedload was transported during 3 violent ablation precipitation floods bedload grain size distribution was right skewed and showed moderate sorting

bedload component of glacially discharged sediment insights from the matanuska glacier alaska the flux of glacially derived bedload and the proportions of the suspended and bedload components carried by proglacial streams are highly debated published data indicate a large range from 30 to 75 in the bedload percentage of the total load two vents where supercooled subglacial meltwater and sediment are discharged were sam pled over the course of an entire melt season in order to quantify the flux of glacially delivered bedload at the matanuska glacier alaska the bedload component contributed by these vents for the one melt season monitored is negligible furthermore the bedload fluxes appear to be strongly supply limited as shown by the poorly correlated discharge bedload flux magnitude and grain size caliber thus in this case any attempt to employ a predictive quantitative expression for coarse sediment production based on discharge alone would be inaccurate a nonglaciated basin proximal to the matanuska glacier ter minus yielded higher bedload sediment fluxes and larger clast sizes than delivered by the two monitored vents such nonglaciated basins should not be overlooked as potentially major sources of coarse bedload that is reworked and incorporated into valley outwash usually subequal although bedload may range from 30 to 75 of the total clastic load establishing portable relationships between suspended load bedload and discharge would enhance our understanding of how and when glaciers erode for the melt season studied we show that bedload is 1 of the total clastic load and does not have any obvious correla tion to discharge at two of the main vents at the terminus of the matanuska glacier alas ka these observations coupled with high measured bedload component of adjacent non glaciated valleys inspire several working hy potheses for the observed origin of coarse bedload in the matanuska river downstream of the ice margin

contemporary suspended sediment dynamics within two partly glacierized mountain drainage basins in western norway erdalen and bodalen inner nordfjord abstract this paper focuses on environmental controls spatiotemporal variability and rates of contemporary fluvial suspended sediment transport in the neighboring partly glacierized and steep erdalen 79 5 km 2 and bodalen 60 1 km 2 drainage basins in the fjord landscape of the inner nordfjord in western norway field work including extended samplings and measurements was conducted since 2004 in erdalen and since 2008 in bodalen the distinct intra and inter annual temporal variability of suspended sediment transport found is mostly controlled by meteorological events with most suspended sediment transport occurring during pluvial events in autumn september november followed by mostly thermally determined glacier melt in summer july august and by mostly thermally determined snowmelt in spring april june extreme rainfall events 70 mm d 1 in autumn can trigger significant debris flow activity that can cause significant transfers of suspended sediments from ice free surface areas with sedimentary covers into main stream channels and is particularly important for fluvial suspended sediment transport in years with occurring relevant debris flow activity the total annual drainage basin wide suspended sediment yields are strongly determined by these single extreme events the proportion of glacier coverage followed by steepness of slopes and degree of vegetation cover in ice free surface areas with sedimentary covers are the main controls for the detected spatial variability of suspended sediment yields the contemporary sediment supply from glacierized surface areas and the jostedalsbreen ice cap through different defined outlet glaciers shows a high spatial variability the fact that the mean annual suspended sediment yield of bodalen is with 31 3 t km 2 yr 1 almost twice as high as the mean annual suspended sediment yield of erdalen 16 4 t km 2 yr 1 is to a large extent explained by the higher proportion of glacier coverage in bodalen 38 of the drainage basin surface area as compared to erdalen 18 of the drainage basin surface area and by a significantly higher sediment yield from the glacierized area of the bodalen drainage basin compared to the glacierized surface area in erdalen when looking at the total annual mass of suspended sediments being fluvially exported from both entire drainage basin systems the total amount of suspended sediments coming from the ice free drainage basin surface areas altogether dominates over the total amount of suspended sediments coming from the glacierized surface area of both drainage basins drainage basin wide annual suspended sediment yields are rather low when compared with yields of other partly glacierized drainage basin systems in norway and in other cold climate environments worldwide which is mainly due to the high resistance of the predominant gneisses towards glacial erosion and weathering the altogether only small amounts of sediments being available within the entire drainage basin systems the stable and nearly closed vegetation cover in the ice free surface areas with sedimentary covers and the efficiency of proglacial lakes in trapping sediments supplied by defined outlet glaciers both contemporary and long term suspended sediment yields are altogether supply limited contemporary suspended sediment transport accounts for nearly two thirds of the total fluvial transport and accordingly plays an important role within the sedimentary budgets of the entire erdalen and bodalen drainage basins

climate response to orbital forcing across the oligocene miocene boundary spectral analyses of an uninterrupted 5 5 million year my long chronology of late oligocene early miocene climate and ocean carbon chemistry from two deep sea cores recovered in the western equatorial atlantic reveal variance concentrated at all milankovitch frequencies exceptional spectral power in climate is recorded at the 406 thousand year ky period eccentricity band over a 3 4 million year period 20 to 23 4 my ago ma as well as in the 125 and 95 ky bands over a 1 3 million year period 21 7 to 23 0 ma of suspected low greenhouse gas levels moreover a major transient glaciation at the epoch boundary approximately 23 ma mi 1 corresponds with a rare orbital congruence involving obliquity and eccentricity the anomaly which consists of low amplitude variance in obliquity a node and a minimum in eccentricity results in an extended period approximately 200 ky of low seasonality orbits favorable to ice sheet expansion on antarctica

bedload transport measurements at the erlenbach stream with geophones and automated basket samplers in the erlenbach stream a pre alpine steep channel in switzerland sediment transport has been monitored for more than 25 years near the confluence with the main valley river stream flow is monitored and sediment is collected in a retention basin with a capacity of about 2000 m3 the basin is surveyed at regular intervals and after large flood events in addition sediment transport has been continuously monitored with piezoelectric bedload impact and geophone sensors since 1986 in 2008 2009 the measuring system in the erlenbach stream was enhanced by installing an automatic system to obtain bedload samples movable metal baskets are mounted on a rail at the downstream wall of the large check dam above the retention basin and they can be moved automatically into the flow to take bedload transport samples the wire mesh of the baskets has a spacing of 10 mm to sample all sediment particles coarser than this size which is about the limiting grain size detected by the geophones the upgraded measuring system permits to obtain bedload samples over short sampling periods and to measure the grain size distribution of the transported material and its variation over time and with discharge the analysis of calibration relationships for the geophone measuring system confirms findings from very similar measurements which were performed until 1999 with piezoelectric bedload impact sensors there is a linear relationship between impulse counts and bedload mass passing over the sensors findings from flume experiments are used to discuss the most important factors which affect the calibration of the geophone signal the bedload transport rates as measured by the moving baskets are among the highest measured in natural streams with values of the order of several kilograms per meter per second copyright 2012 john wiley sons ltd

assessment of sediment sources throughout the proglacial area of a small arctic catchment based on high resolution digital elevation models abstract the article presents calculations of quantitative modifications of the morphology of selected subsystems of a glacial valley through i identification of the spatial distribution of important sources of sediment ii assessment of the spatiotemporal variety of sediment volume and landform morphology and iii assessment of the role of particular subsystems in sediment distribution the study involved a comparison of the results of field measurements from 2010 to 2013 performed in the scott glacier catchment 10 1 km2 in nw wedel jarlsberg land spitsbergen the assessment of the landform surface changes was performed by means of a precise terrestrial laser scanning tls survey the applied field and post processing techniques for oblique laser scanning permitted the acquisition of digital elevation data at a resolution 0 01 m and density 500 pt m 2 this allowed the development of a detailed terrain model and balancing spatial quantitative changes in six research test areas 10 000 m2 located within two subsystems of the catchment in a cascade arrangement in the alluvial valley floor subsystem the survey covered 1 the glacier terminus 2 the intramarginal outwash plain 3 the extramarginal braid plain and 4 the alluvial fan and in the slope subsystem 5 the erosional depositional slope in the gorge through terminal moraines and 6 the solifluction slope three zones differing in terms of the spatiotemporal dynamics of geomorphic processes were distinguished within the two analysed valley subsystems in the valley floor subsystem these are i the zone of basic supply distribution throughout the melting season and ii the redeposition zone distribution particularly during floods and in the slope subsystem iii zone of periodical supply distributed mainly in periods of increased precipitation and rapid increases in temperature in summer and during snow avalanches in winter the glacier and the landforms of the channel and valley floor as well as slope sediments transported as a result of mass wasting processes and activity of the active permafrost layer constitute important sources of sediment supply over a short 3 year timescale evidence of major changes of the surface morphology slopes floodplain and channel platform resulted in varied sediment budgets the subtraction of consecutive dems of the test areas located in the alluvial valley subsystem revealed downstream spatial and volumetric differentiation from the predominance of erosion 79 of volume 43 of area to the dominance of deposition 90 91 respectively in upper part of the valley floor to erosion predominance in the central 88 95 and lower 87 82 part of valley floor the test areas located on the slope subsystem showed the opposite relationship deposition dominance 88 of volume 80 of area in the upper gorge and erosion dominance 99 99 respectively in the lower part solifluction slopes the analysis of short time repeated surveys 3 week survey where volumes were calculated following dem subtraction showed increased deposition 82 of volume 79 of area for the alluvial fan and for solifluction slopes 70 57 respectively

towards the identification of scaling relations in drainage basin sediment budgets abstract drainage basin sediment budgets concern inputs storages and outputs of sediments and solutes through monitored cross sections at the mouth of basins or at the base of individual slopes the question under consideration is whether and to what extent it is possible to transfer knowledge from one spatial scale to another the answer hinges on the question of scale invariance of a individual processes of sediment and solute transfer and b aggregate sediment budgets scale invariance of a number of hydrologic parameters has been established but in general with a few exceptions geomorphic parameters are subject to scale distortion by inference but not yet established by experimental or field evidence scale invariance of sediment budgets is improbable there is therefore a priority to explore scaling relations in sediment budgets so as to determine the precise extent of scale distortion that is present in this paper five ways of identifying scaling relations in drainage basin sediment budgets are identified 1 a fractal approach 2 a theory hierarchy approach 3 a non linear dynamic systems approach 4 a panarchy approach and 5 a hybrid approach there are no a priori bases for selection of any one of these approaches until further field research and modeling of sediment and solute fluxes has been completed

formation processes and combustion features at the lower layers of the middle palaeolithic open air site of nesher ramla israel the lower stratigraphic sequence units iii vi of the middle palaeolithic site of nesher ramla was studied using geoarchaeological methods field observations indicate that the site formed within a karst depression that was infilled by colluvium and in which intermittent human activity occurred including two layers highly rich in anthropogenic remains units iii and v infrared analysis of bones determined that black bones are carbonized and that certain white bones are calcined quantitative analysis of wood ash pseudomorphs indicates specific areas of high concentrations of ash micromorphological analysis enabled identification of two distinct features associated with ash and burnt bones one is a thinly bedded complex of blacked soil overlain by ash and charcoal and the second is a 20 cm thick massive fine grained layer of mixed ash the first feature is interpreted as an in situ hearth macroscopically similar features have not yet been analyzed the second feature is interpreted as ash in secondary position i e an ash pile midden that formed following hearth rake out activities these findings are unique considering that most middle palaeolithic open air sites in the levant are single layered and that in most evidence for hominin use of fire is scarce or absent we discuss the factors that may affect the preservation of ash in open air sites and conclude that the setting of nesher ramla in a topographic low provided relative protection from wind which prevented ash deflation and at the same time hominin activity remains were buried relatively fast which detached the ashes and combustion features from direct rainfall and from decalcifying root activity

combining impact sensor field and laboratory flume measurements with other techniques for studying fluvial bedload transport in steep mountain streams the timing and rate of fluvial bedload transport are of central importance within sediment budget studies and in many applications in river science and engineering during the years 2010 2011 and 2012 detailed field measurements with portable impact sensors as a non invasive technique for indirectly determining fluvial bedload transport intensity were conducted in two instrumented and supply limited drainage basin systems erdalen and bodalen in the fjord landscape in western norway additional field measurements with portable impact sensors were carried out in 2010 and 2011 in selected transport limited fluvial systems in the coast mountains of western canada the collected impact sensor field data were calibrated with laboratory flume experiments the data from the impact sensor field measurements in western norway and the flume experiments were combined with field data from continuous discharge monitoring repeated surveys of channel morphometry and sediment texture particle tracer measurements helley smith samplings underwater video filming and biofilm analyses the combination of methods and techniques applied provides insights into the temporal variability and intensity of fluvial bedload transport in the selected mountain streams i in the transport limited systems with generally high bedload transport rates during high discharge and with bedload material moving in clusters over the impact sensor plates impact sensor data based on a 1 s measuring interval provide the opportunity to detect the start and end of bedload transport thus to identify discharge thresholds for sediment entrainment and to roughly estimate the intensity and relative intensity of change of bedload transport during the measuring period ii in the supply limited systems with low bedload transport rates and bedload components moving separately as single particles over the impact sensor plates impact sensor data with a 1 s measuring interval allow the detection of the start and end of transport of bedload components 11 3 mm thus the identification of discharge thresholds for possible entrainment of particles the quantification of the number of particles 11 3 mm moving over the impact sensor plates during the measuring period the rough estimation of grain sizes of the particles moving separately over the impact sensor plates and the calculation of the total mass of the bedload material 11 3 mm moving over the impact sensor plates during the measuring period iii when combined with other methods and techniques helley smith sampling particle tracer measurements biofilm analyses underwater video filming which provide information on the active bedload transport channel width on discharge thresholds for possible entrainment of particles of different grain sizes and on transport rates of bedload material 11 3 mm total rates of fluvial bedload transport covering all given grain sizes of the bedload material can be calculated for the supply limited mountain streams with generally low bedload transport the higher measured annual bedload yield in bodalen 13 6 t km 2 yr 1 compared to erdalen 2 6 t km 2 yr 1 reflects a higher level of slope channel coupling in bodalen than in erdalen

using sediment impact sensors to improve the morphological sediment budget approach for estimating bedload transport rates constructing a sediment budget from morphological channel change typically measured using repeat cross sectional surveys has proven a useful technique for estimating mean bedload transport rates in gravel bed rivers we apply and suggest improvements to the approach using new data sources from an intensely monitored 5 6 km reach of an upland gravel bed river in northern england sediment impact sensors were placed in the bed to record the instantaneous passage of grains during transport events these sensors provide valuable information for the budget including 1 a downstream budget limit from which the rest of the budget can be calculated 2 estimates of sediment input from tributaries and 3 a better indication of active transport time used in the calculation of average transport rates further information collected from field studies include estimates of lateral inputs from the banks using field surveys and bank erosion pins and estimates of the variability of sediment porosity from bed grain size distributions budget calculations for different locations and time periods demonstrate large spatial and temporal variabilities in bedload transport rates over a short distance 3 km whilst some uncertainty in the new data sources remains this work highlights some limitations of the traditional budget approach and some potential solutions in particular the value of sediment impact sensors for sediment transport studies

sediment sources spatiotemporal variability and rates of fluvial bedload transport in glacier connected steep mountain valleys in western norway erdalen and bodalen drainage basins abstract contemporary fluvial bedload transport rates are still very difficult to measure and as a result of this in many sites only quantitative data on suspended and solute transport are included in sediment budget studies carried out for defined drainage basin systems the presented analysis of fluvial bedload dynamics in different defined subsystems of the glacier connected erdalen 79 5 km 2 and bodalen 60 1 km 2 drainage basins in the steep fjord landscape of western norway provides insights into i detectable relevant sediment sources ii instream channel storage of bedload material iii spatiotemporal variability and controls of bedload transport rates and bedload yields and iv the absolute and relative importance of fluvial bedload transport within the sedimentary budgets of these steep cold climate mountain valleys rockfalls snow avalanches stream channel bank erosion and fluvial transfers through small tributaries draining slope systems are relevant sediment sources for fluvial bedload transport in the main stream channels whereas the main outlet glaciers in both drainage basins are not of importance as all bedload material delivered directly from these outlet glaciers is trapped within proglacial lakes narrow valleys within both drainage basin systems are characterized by a higher intensity of slope channel coupling and display higher rates of sediment supply from slopes into the main stream channels than wider valleys snow avalanches are the most important sediment source in erdalen whereas fluvial transfers through small tributaries followed by snow avalanches are most important in bodalen longer term instream channel storage is not of great importance in the steep bodalen drainage basin but currently plays an important role within the erdalen drainage basin which is characterized by a stepped longitudinal main valley bottom profile favoring deposition of bedload material within less steep main channel reaches the mean annual bedload yields 2010 2013 are 2 4 t km 2 y 1 for the entire erdalen and 13 3 t km 2 y 1 for the entire bodalen drainage basin which are comparably low values for steep and partly glacierized drainage basin systems because of supply limited conditions the intensity of fluvial bedload transport is generally much more related to the availability of sediments than to channel discharge fluvial bedload transport accounts for about one third of the total fluvial transport and accordingly plays an important role within the sedimentary budgets of both drainage basin systems

contemporary suspended sediment transfer and accumulation processes in the small proglacial saetrevatnet sub catchment bodalen western norway a combination of different process monitoring lake sediment coring and sediment analysis methods and techniques was applied in the 17 5 km2 saetrevatnet sub catchment in the upper bodalen drainage basin nordfjord western norway in order to define hydro meteorological controls on runoff suspended sediment transfer and sediment accumulation and to determine the role of lake saetrevatnet within the drainage basin wide sediment routing system the proglacial system shows the typical seasonal and weather depended runoff variations for glacierized drainage basins significant suspended sediment transport is associated to summer glacier melt when 61 9 of the annual suspended sediment yield was recorded in 2010 as well as to single rainfall events when 19 8 of the annual suspended sediment yield was recorded in 2010 the intensity of atmospheric energy input and the frequency of heavy rainfall events were found to be critical for the rate of suspended sediment transport within the saetrevatnet sub catchment the computed annual suspended sediment yield from the proglacial area was 24 2 t km 2 which is notably lower as compared with a number of other glacierized basins worldwide delta accumulations rates from 2009 4 cm yr 1 and 2010 3 cm yr 1 as well as average annual delta advance ranging from 3 8 m to 4 6 m confirm the calculated high annual lake sedimentation rate of 1 7 cm yr 1 lake saetrevatnet 0 02 km2 currently traps about 80 85 of the sediments delivered from the upstream located glacial system highlighting the importance of small ephemeral proglacial lakes within larger valley fjord sediment routing systems