the benchmark glacier concept does it work lessons from the north cascade range usa benchmark glaciers were established in many alpine areas during the 1960s as part of the international hydrological decade to represent typical mass and energy processes on glaciers in different climatic regions around the world these glaciers have received new interest in the past decade because they are used to infer the contribution of alpine glacier wastage to global sea level rise we compare south cascade glacier the benchmark glacier for the northwest contiguous usa and four other secondary glaciers against the topographic area and mass changes of 321 glaciers in the surrounding region results show that south cascade glacier is unusually large of lower slope and much larger area and had mass losses greater than most other glaciers in the region three of the four secondary glaciers were much more typical year to year variations in mass balance were highly correlated between all five glaciers and any of these glaciers including the benchmark glacier could be used to infer temporal mass variations in the region however the use of south cascade glacier to estimate area mass losses for the region would result in overestimating the area mass changes by a factor of three local differences in the magnitude of annual glacier mass balance control cumulative mass changes and area changes there appears to be no way to select a representative glacier a priori and knowledge of changes over the region is required therefore there may be great uncertainty in estimates of sea level rise from the wastage of alpine glaciers based on the benchmark approach we recommend re evaluation of regional glacier mass changes inferred from benchmark glaciers in critical regions

role of geological inheritance in australian beach morphodynamics the australian coast contains 10 685 beaches which occupy 49 of the 30 000 km coast and average 1 37 km in length their relatively short length is largely due to the presence of bedrock calcarenite and laterite which form boundaries to many of the beaches as well as occurring as rocks reefs and islands along and off the beaches this geological inheritance plays a major role in australian beach systems determining their length and through wave refraction and attenuation influencing beach location shape type morphodynamics and circulation which in turn influence sediment transport and the backing dune and barrier systems this paper uses a database covering every australian beach to review the role of headlands rocks and reefs on australian beaches major effects are the short average beach length reduction in breaker height resulting in lower energy beach types wave refraction resulting in increased beach curvature the presence of topographic rips on moderate and higher energy beaches and megarips during high wave conditions and the interruption of and or trapping of longshore sand transport leading to beach rotation

spatially integrated geodetic glacier mass balance and its uncertainty based on geostatistical analysis application to the western svartisen ice cap norway estimates of glacier mass balance using geodetic methods can differ significantly from estimates using direct glaciological field based measurements to determine if such differences are real or methodological there is a need to improve uncertainty estimates in both methods in this paper we focus on the uncertainty of geodetic methods and describe a geostatistical technique that takes into account the spatial correlation of the elevation differences when calculating spatially averaged elevation changes we apply this method to the western svartisen ice cap norway using elevation differences from the surrounding bedrock derived from stereophotogrammetry we show that the uncertainty is not only dependent on the standard error of the individual elevation differences but is also dependent on the size of the averaging area and the scale of the spatial correlation to assess if the geostatistical analysis made over bedrock is applicable to glacier surfaces we use concurrent photogrammetrical and laser scanning data from bedrock and a range of glacier surfaces to evaluate the dependency of the geostatistical analysis on the surface type the estimated geodetic mass balance and its uncertainty is 2 6 0 9 m w e for the period 1968 85 and 2 0 2 2 m w e for 1985 2002

identifying and mapping very small 0 5 km2 mountain glaciers on coarse to high resolution imagery small mountain glaciers are an important part of the cryosphere and tend to respond rapidly to climate warming historically mapping very small glaciers generally considered to be 0 5 km2 using satellite imagery has often been subjective due to the difficulty in differentiating them from perennial snowpatches for this reason most scientists implement minimum size thresholds typically 0 01 0 05 km2 here we compare the ability of different remote sensing approaches to identify and map very small glaciers on imagery of varying spatial resolutions 30 0 25 m and investigate how operator subjectivity influences the results based on this analysis we support the use of a minimum size threshold of 0 01 km2 for imagery with coarse to medium spatial resolution 30 10 m however when mapping on high resolution imagery 1 m with minimal seasonal snow cover glaciers 0 05 km2 and even 0 01 km2 are readily identifiable and using a minimum threshold may be inappropriate for these cases we develop a set of criteria to enable the identification of very small glaciers and classify them as certain probable or possible this should facilitate a more consistent approach to identifying and mapping very small glaciers on high resolution imagery helping to produce more comprehensive and accurate glacier inventories

instruments and methods glaciological and volumetric mass balance measurements error analysis over 51 years for glacier de sarennes french alps the mass balance of glacier de sarennes french alps has been measured since 1949 using the glaciological method based on core and ablation stake data and area extrapolations to find the overall glacier balance the cumulative balance obtained in this way is very dependent on systematic errors that can increase linearly with the number n of measurement years whereas random errors rise with the volumetric balance method based on aerial photogrammetry provides results whose errors do not depend on the number of years this method was used to test field measurements for the period 1952 2003 and gives a mass balance of 32 30 1 04 m w e compared to 34 89 1 15 m w e based on field data the discrepancy between the two methods is discussed on the basis of a careful error analysis moreover the possibility of using the volumetric method to detect biases in field measurements is evaluated in terms of two types of errors the number and locations of measurement sites required to account for all the spatial and temporal variabilities of the mass balance is discussed by variance analysis methodological implications and recommendations are presented to provide mass balance measurements of the best possible accuracy

glacier mass balance of norway 1961 2010 calculated by a temperature index model glacier mass balance in norway is only observed over a small portion 1 between 2000 and 2010 after four decades of zero to slightly positive annual mass balances

geologically constrained morphological variability and boundary effects on embayed beaches abstract headlands rock outcrops and engineering structures impact beach and nearshore dynamics of coastal embayments inducing boundary effects that constrain the lateral and vertical beach variability this study analyses morphological change in six embayed beaches with diverse levels of exposure to wave action and various degrees of geological control in the mesotidal coast of southwestern portugal the aim is to identify whether geological boundaries constrain the morphological behaviour of embayed beaches and assess whether their effects can be decoupled from datasets of morphological change topographic data obtained over a two year period on each of the six embayments were analysed using empirical orthogonal functions eof to decompose temporal and spatial variability in the datasets first and second mode eigenfunctions were explored using time variable linear correlation analysis with several nearshore parameters that include hydrodynamic variables sedimentary and geometric characteristics of each embayment in order to derive forcing response relationships our results demonstrate that natural geological boundaries constrain the morphological behaviour of embayed beaches producing conspicuous alongshore variability in all embayments localised responses induced by lateral and vertical boundary interference with beach and nearshore dynamics include beach rotation topographically controlled rip circulation and restrained profile fluctuation spatial decoupling in cross and longshore responses is accompanied by a temporal decoupling in response times both of which are slower in more constrained embayments from 1 day in exposed embayments to 1 week or more in the most sheltered ones normalised wave power was correlated at the 99 confidence level with the primary mode of morphological variability at most embayments which represent 67 to 94 of the variance in the datasets this correlation stresses the importance of combined parameterization of wave and tide forcing in process response relations between hydrodynamics and morphological change for mesotidal coastal environments lateral and vertical geological boundaries exert their effects fundamentally by restraining longshore sediment transport inducing cellular surf zone circulation and by impacting cross shore sediment transport it is postulated that decreasing sediment abundance and substrate depth intensify vertical boundary effects while higher indentation and wave obliquity enhance the effects of lateral boundaries

downscaled precipitation applied in modelling of mass balance and the evolution of southeast vatnajokull iceland simulations of the post little ice age evolution of three outlet glaciers of southeast vatnajokull iceland skalafellsjokull heinabergsjokull and flaajokull are presented a coupled shallow ice approximation ice flow and degree day mass balance model is applied that is calibrated with a 14 year record of in situ mass balance measurements the measured mass balance cannot be realistically represented by constant horizontal and vertical precipitation gradients high resolution 1 km precipitation fields derived from downscaled orographic atmospheric circulation models of precipitation are required to capture the spatial variation of the winter mass balance the observed ice volume around 1890 15 30 larger than in 2000 can be simulated with 1 c lower temperatures and a 20 reduction in the annual precipitation relative to the reference climate period 1980 2000 the sensitivity of each glacier s annual balance to a change in temperature is 1 51 to 0 97 m w e a 1 c 1 and 0 16 to 0 65 m w e a 1 for a 10 increase in precipitation a steady state experiment applying a step increase in temperature of 2 c 3 c and precipitation increase of 10 results in a 50 80 90 decrease in ice volume

influence of upper air conditions on glaciers in scandinavia a simple model using once daily us national centers for environmental prediction us national center for atmospheric research ncep ncar re analysis upper air values estimates winter balance summer balance and net balance at ten glaciers in norway and two in sweden with 0 37 r 2 0 90 the october may arctic oscillation ao an index of sea level pressure slp in the northern hemisphere correlates with winter balance and net balance with 0 09 r 2 0 82 lower than the model in all but 3 of the 24 cases the october may north atlantic oscillation nao an slp gradient in the north atlantic has lower correlations than the ao for all but 5 of the 24 cases at all ten glaciers with records beginning before 1987 net balance became more positive after 1988 owing mainly to increased winter balance with summer balance changing little although winter temperatures increased they were still well below freezing so the rain snow division of the precipitation was only slightly affected increase in winter balance was due to increased precipitation caused by a change in atmospheric circulation resulting in more frequent westerly flow concurrent with the warming at 850 hpa westerly flow is 2 5 c warmer than easterly flow westerly flow warmed by 0 3 c easterly by 0 7 c both the ao and nao with which winter balance is positively correlated at all 12 glaciers were more positive after 1988

investigations on intra annual elevation changes using multi temporal airborne laser scanning data case study engabreen norway key issues of glacier monitoring are changes in glacier geometry and glacier mass as accurate direct measurements are costly and time consuming the use of various remote sensing data for glacier monitoring is explored one technology used and described here is airborne laser scanning the method enables the derivation of high quality digital elevation models dems with a vertical and horizontal accuracy in the sub metre range between september 2001 and august 2002 three laser scanner data acquisition flights were carried out covering the whole area of engabreen norway and corresponding well to the measurement dates for the mass balance year 2001 02 the data quality of the dems is assessed e g by comparing the values with a control area which has been surveyed independently or gps ground profiles measured during the flights for the whole glacier surface elevation change and consequently volume change is calculated quantified and compared with traditional mass balance data for the same time interval for the winter term emergence submergence velocity is determined from laser scanner data and snow depth data and is compared with velocity measurements at stakes the investigations reveal the high potential of airborne laser scanning for measuring the extent and the topography of glaciers as well as changes in geometry area volume

an insight into headland sand bypassing and wave climate variability from shoreface bathymetric change at byron bay new south wales australia abstract the headland sand bypassing mechanisms in the eastern australian longshore sand transport system are investigated at cape byron in response to wave climate variability the mechanisms are interpreted from shoreface bathymetric change between surveys in 1883 2002 and 2011 ce they involve a split in the sand transport to follow a nearshore path along the inner bar and a cross embayment path connecting the up coast and down coast outer bars the relative magnitude of the net sand transported via the two pathways is controlled by a rotation in directional wave conditions two bypassing mechanisms were interpreted i a predominantly cross embayment transport during unimodal east southeast wave climate such as those interpreted for the period prior to 1883 and ii a split transport between the inner nearshore and cross embayment paths during a bimodal dominant south south easterly and sub dominant east north easterly wave climate such as in the 2000s the net sand transport bypassing cape byron was dominated by a connected outer bar system prior to 1883 and conversely a stronger inner bar system during the 1960s to 2000s this is manifest in the 10 rotation in seabed morphology and shoreline planforms these changes are in accordance with decadal climate variability described by the interdecadal pacific oscillation ipo the switching between headland sand bypassing mechanisms on interannual to decadal timescales determines the geometry of the bypass strand with the downcoast littoral zone and has important implications for understanding the shoreline rotation and the application of the headland bay beach concept to predicting planform curvature in open compartments

identifying storm impacts on an embayed high energy coastline examples from western ireland abstract large sections of the western irish coast are characterised by a highly compartmentalised series of headland embayment cells in which sand and gravel beaches are backed by large vegetated dune systems exposure to modally high energy swell renders most of these beaches dissipative in character a mesotidal range c 3 5 4 5 m exists along much of the coast analysis of instrumental wind records from three locations permitted the identification of a variety of storm types and the construction of storm catalogues few individual storms were recorded at all three stations indicating a lack of regional consistency in storm record of the total storms recorded only a small percentage are potentially damaging onshore directed and even fewer span a high tide and thus potentially induce a measurable morphological response at the coast through a combination of historical records meteorological records field observations and wave modelling we attempt to assess the impact of storms quantifiable records of coastal morphology maps air photos and beach profiles are few in number and do not generally record responses that may be definitely attributed to specific storms numerical wave simulations and observations at a variety of sites on the west irish coast however provide insights into instantaneous and medium term decadal storm responses in such systems we argue that beaches and dunes that are attuned to modally high energy regimes require extreme storms to cause significant morphological impact the varying orientation of beaches a spatially nonuniform storm catalogue and the need for a storm to occur at high water to produce measurable change impart site specific storm susceptibility to these embayments furthermore we argue that long period wave energy attenuation across dissipative shorefaces and beaches reduces coastal response to distant storms whereas short period locally generated wind waves are more likely to cause major dune and beach erosion as they arrive at the shoreline unrefracted this apparently variable response of beach and dune systems to storm forcing at a decadal scale over a coastline length of 200 km urges caution in generalising regarding regional scale coastal responses to climatic change

storms shoreface morphodynamics sand supply and the accretion and erosion of coastal dune barriers in the southern north sea abstract the coast of the southern north sea is bound by dune barriers that have developed adjacent to a shallow storm and tide dominated shoreface comprising numerous shore parallel to sub shore parallel tidal sand banks the banks evolve under the joint control of tide wave and wind induced shore parallel currents which tend to stretch them eventually leading to bank division and to shoaling and breaking storm waves which tend to drive them ashore the banks thus modulate the delivery of storm wave energy to the coast redirect currents alongshore and are the sand sources for the accretion of coastal dunes foredune accretion occurs where major sand banks have migrated shoreward over the last centuries to be finally driven ashore and weld under the impact of storm waves morphological changes in the bank field can impact on shoreline stability through dissipation or enhanced shoreward transmission of storm wave energy and effects on radiation stress particularly when waves are breaking over the banks where banks are close to the shore mitigation of offshore sediment transport especially during storms can occur because of gradients in radiation stress generated by the complex 3d bank structure these macro scale mechanisms involve embedded meso scale interactions that revolve around the mobility of sand waves mobility of beach bars and troughs and foredune mobility and micro scale processes of bedform mobility in the subaqueous and intertidal domains and of swash and aeolian beach dune sand transport these embedded interactions and the morphodynamic feedback loops illustrate the importance of synchroneity of sand transport from shoreface to dune on this coast large stretches of the foredunes show either signs of stability or mild but chronic erosion furthermore a demonstrated lack of a clear relationship occurs between storminess and coastal response over the second half of the 20th century the present situation may be indicative of conditions of rather limited sand supply from offshore notwithstanding the abundance of sand on the nearby shallow shoreface except in areas where a nearshore storm driven tidal sand bank has become shore attached apart from the important influence of shoreface sand banks and of wave bank interactions foredune accretion and erosion also depend on various context controls that include individual storm characteristics wind speed and incidence relative to the shore tidal stage during storms and direct human intervention on the shore through foredune and beach management the bewildering variability inherent in these intricately related parameters may also explain the poor relationship between storminess and barrier shoreline change and will still continue to render unpredictable the response of shores to individual storms

glacier fluctuations equilibrium line altitudes and palaeoclimate in lyngen northern norway during the lateglacial and holocene based on lacustrine and morpho stratigraphical evidence from lyngen in troms northern norway 13 marginal moraines have been mapped in front of lenangsbreene in strupskardet moraines m1 m13 are inferred to represent glacier halts or advance readvance taking place during the lateglacial and holocene the presence of collapse depressions suggests that some of them were ice cored m1 m3 a chronological framework taking into account a combination of former shorelines and related glacier meltwater channels lichenometry and ams radiocarbon dated lacustrine sediments spanning the last 20 000 cal yr bp has been established the distal glacier fed lake aspvatnet was isolated from the sea c 10 300 cal yr bp and the lacustrine sediments have been investigated by use of loss on ignition loi magnetic susceptibility water content wet and dry bulk density dbd and the magnetic parameters anhysteretic remanent magnetization arm and saturation remanent magnetization sirm there is in general good agr

annular modes in the extratropical circulation part i month to month variability the leading modes of variability of the extratropical circulation in both hemispheres are characterized by deep zonally symmetric or annular structures with geopotential height perturbations of opposing signs in the polar cap region and in the surrounding zonal ring centered near 458 latitude the structure and dynamics of the southern hemisphere sh annular mode have been extensively documented whereas the existence of a northern hemisphere nh mode herein referred to as the arctic oscillation ao has only recently been recognized like the sh mode the ao can be defined as the leading empirical orthogonal function of the sea level pressure field or of the zonally symmetric geopotential height or zonal wind fields in this paper the structure and seasonality of the nh and sh modes are compared based on data from the national centers for environmental prediction national center for atmospheric research reanalysis and supplementary datasets the structures of the nh and sh annular modes are shown to be remarkably similar not only in the zonally averaged geopotential height and zonal wind fields but in the mean meridional circulations as well both exist year round in the troposphere but they amplify with height upward into the stratosphere during those seasons in which the strength of the zonal flow is conducive to strong planetary wave mean flow interaction midwinter in the nh and late spring in the sh during these active seasons the annular modes modulate the strength of the lagrangian mean circulation in the lower stratosphere total column ozone and tropopause height over mid and high latitudes and the strength of the trade winds of their respective hemispheres the nh mode also contains an embedded planetary wave signature with expressions in surface air temperature precipitation total column ozone and tropopause height it is argued that the horizontal temperature advection by the perturbed zonal mean zonal wind field in the lower troposphere is instrumental in forcing this pattern a companion paper documents the striking resemblance between the structure of the annular modes and observed climate trends over the past few decades

geodetic mass balance of the western svartisen ice cap norway in the periods 1968 1985 and 1985 2002 the geodetic mass balance of the western svartisen ice cap in northern norway is determined in this work from photogrammetry on vertical aerial photographs taken in 1968 1985 and 2002 the existing 1968 digital terrain model dtm was generated using analogue photogrammetry and the 1985 and 2002 dtms are newly generated using digital photogrammetry the geodetic mass balance for 1968 85 is 2 6 0 8 m w e and for 1985 2002 it is 2 0 1 6 m w e the area of western svartisen decreased from 190 km 2 in 1968 to 187 km 2 in 1985 and to 184 km 2 in 2002 the outlet glacier flatisen in the southeast retreated 1700 m over the two periods the geodetic mass balance is also determined for engabreen drainage basin as 2 1 0 9 m w e for the first period and 0 3 2 4 m w e for the second the results for engabreen are compared to traditional mass balances and the large deviations cannot be explained from uncertainties determined for the geodetic method the assessed errors contributing to the uncertainty in the geodetic mass balance are elevation errors uncertainties from the applied melt correction and the use of sorge s law assuming constant snow thickness and density

coastal geomorphology and restoration abstract increases in human development of the coastal zone sea level rise and intensity of coastal storms will test the resilience of coastal systems an integrated approach is needed to describe geomorphic biologic dependencies feedbacks between processes and responses and determine how coastal systems can be maintained or restored the 2013 binghamton geomorphology symposium focused on three themes in these research areas 1 the geomorphic response of coastal landforms to changes in sea level and episodic storms 2 the way these stressors alter geomorphic biotic interactions and reduce the resilience of coastal environments and 3 the way natural and human processes are being integrated to restore or maintain dynamic geomorphic and biologic linkages this issue contains eighteen papers presented at the symposium six papers are devoted to each of these themes the papers point to the importance of ecological systems in modulating the responses to natural physical processes and in turn responding to geomorphic change and the role of humans in assisting natural processes

beach response to a fixed sand bypassing system abstract indian river inlet is located at roughly the mid point of the atlantic coast of delaware and connects the ocean to two delaware inland bays jetties constructed in 1940 have maintained the inlet for navigation purposes but have also acted as a barrier to net northerly alongshore sediment transport causing downdrift erosion a mobile land based bypassing system was initiated in 1990 in an effort to counteract this erosion beach profile data from 1985 pre bypassing until 2008 are used to investigate the effect of the sand bypassing system on beaches adjacent to the inlet the downdrift beach experienced horizontal shoreline erosion between 10 and 60 m during the pre bypassing period but accreted 10 20 m during the bypassing period the mean shoreline location on the updrift beach during bypassing is 10 20 m landward erosion of its position during the pre bypassing period empirical orthogonal function eof amplitudes from analyses performed on mean removed elevation surfaces during the periods of highest bypassed volume average of 83 of design rate showed that the influence of the bypassing system on the downdrift beach extends to about 1500 m of the inlet an eof analysis showed that different morphologic responses were evident following the initiation of bypass operations temporal variations of shoreline and beach morphology were correlated to the temporal variations in bypassing rates on the downdrift beach only the downdrift beach response was greatest near the inlet for larger bypassing volumes correlation in these instances occurred with a roughly 1 year time lag suggesting that the beach quickly redistributes the bypassed sand eof amplitude and shoreline response are weakly correlated to bypassed volumes when the system bypassed smaller volumes average of 56 of design rate of sand suggesting that there is a minimum bypassing rate regardless of yearly variability below which the effect on the downdrift beach is obscured

persistence of storm induced morphology on a modal low energy beach a case study from nw iberian peninsula abstract the morphology of low energy beaches is inherited from high energy events showing a non equilibrium state with the prevailing conditions an example of a sheltered low energy beach rodas beach nw iberian peninsula is examined in this paper the evolution of six beach profiles was analysed during three years in order to investigate the response of this beach under fair weather and storm conditions the beach presented significant morphological differences alongshore due to its geographical location with respect to the wave approach these differences determined the sediment transfer pattern longshore or cross shore sediment transport from the emerged beach towards the adjacent inner shoreface zone significant morphological changes at each profile seem to be related to the incidence of sea waves along the beach superimposed on persistent swell during winter morphological changes were recorded under high energy storms during winter whereas the recovery to prestorm conditions occurred under prevailing fair weather conditions during summer the traditional beach classification parameter relative tidal range rtr which takes into account the effect of the tide range was found unsuitable to properly classify such a mesotidal low energy beach therefore a new parameter the relative tidal range maximum rtrmax was introduced which is a modification of the commonly used rtr rtrmax uses the highest wave breaking height observed during high energy storm conditions instead of the modal wave breaking height by using this parameter the studied beach could be properly classified into the traditional beach classification models taking into account the tide range since low energy beaches generally show a morphology that is inherited from higher energy conditions than the prevailing conditions it is expected that the rtrmax will be applicable for the classification of other low energy sheltered beaches

storm impact on the seasonal shoreline dynamics of a meso to macrotidal open sandy beach biscarrosse france abstract a three year dataset 2007 2010 of shoreline and sandbar positions derived from video observations of an open sandy beach biscarrosse france is analyzed to explore the impact of storms on the seasonal shoreline dynamics the results indicate that a clear seasonality is observed in the offshore significant wave height and in the occurrence of winter storm events that are defined as periods with significant wave height greater than 4 m lasting at least 12 h data indicate that the range of variation of the inner sandbar positions 120 m is two and a half times larger than the range of variation of the shoreline position correlation analyses suggest that the offshore conditions do not conclusively explain the position of the inner bar shoreline positions show a clear seasonal pattern displaying a stable position occurring in february and july providing evidence of seasonal recovery although analysis of storm activity indicates that the number and intensity of storms is highly variable over the three years the biscarrosse data show that rapid erosion can be observed also under moderate conditions and that beach recovery after the storm season can be relatively rapid

an equilibrium model to predict shoreline rotation of pocket beaches a novel and simple beach evolution model for estimating shoreline rotation at sandy pocket beaches is presented the model is based on the assumption that the instantaneous changes to the planview shape of the shoreline depend on the long term equilibrium planview shape two years of shoreline observations extracted from video images of three artificially embayed beaches of barcelona and hourly wave timeseries are used to validate the model numerical model results and field observations show an excellent agreement with an rmse less than 1 5 m the model successfully reproduced the shoreline response over a range of scales months and years because of its simplicity and its computational efficiency the model provides a powerful tool to understand the dynamics regulating the evolution of pocket beaches and predict temporal patterns in beach rotation

widespread and accelerating glacier retreat on the lyngen peninsula northern norway since their little ice age maximum the recession of mountain glaciers worldwide is increasing global sea level and in many regions human activities will have to adapt to changes in surface hydrology thus it is important to provide up to date analyses of glacier change and the factors modulating their response to climate warming here we report changes in the extent of 120 glaciers on the lyngen peninsula northern norway where glacier runoff is utilised for hydropower and where glacial lake outburst floods have occurred glaciers covered at least 114 km2 in 1953 and we compare this inventory with those from 1988 2001 and a new one from 2014 and previously dated little ice age lia limits results show a steady reduction in area 0 3 a 1 between their lia maximum 1915 and 1988 consistent with increasing summer air temperatures but recession paused between 1988 and 2001 coinciding with increased winter precipitation air temperatures increased 0 5 c per decade from the 1990s and the rate of recession accelerated to 1 a 1 between 2001 and 2014 when glacier area totalled 95 7 km2 small glaciers 0 05 km2 with low maximum elevations 1400 m experienced the largest percentage losses and if warming continues several glaciers may disappear within the next two decades

distributed mass balance and climate sensitivity modelling of engabreen norway department of geosciences university of oslo po box 1047 blindern no 0316 oslo norwayabstract assessing the impact of possible climate change on the water resources of glacierized areasrequires a reliable model of the climate glacier mass balance relationship in this study we simulate themass balance evolution of engabreen norway using a simple mass balance model based on dailytemperature and precipitation data from a nearby climate station ablation is calculated using adistributed temperature index method including potential direct solar radiation while accumulation isdistributed linearly with elevation the model was run for the period 1974 75 2001 02 for whichannual mass balance measurements and meteorological data are available parameter values weredetermined by a multi criteria validation including point measurements of mass balance mass balancegradients and specific mass balance the modelled results fit the observed mass balance well simplesensitivity experiments indicate a high sensitivity of the mass balance to temperature changes asexpected for maritime glaciers the results suggest further that the mass balance of engabreen is moresensitive to warming during summer than during winter while precipitation changes affect almostexclusively the winter balance

surface energy balance in the ablation zone of langfjordjokelen an arctic maritime glacier in northern norway glaciers in northern and southern norway are subject to different daily and seasonal cycles of incoming solar radiation which is presumably reflected in the importance of net solar radiation in their surface energy balance we present a 3 year continuous record from an automatic weather station in the ablation zone of the ice cap langfjordjokelen one of the most northerly glaciers of mainland norway despite its location at 708 n langfjordjokelen was found to have a maritime climate with an annual mean air temperature of 1 08c frequent cloud cover and end of winter snow depths over 3m in all three years the main melt season was may october but occasional melt events occurred on warm cloudy winter days net solar and longwave radiation together accounted for 58 of the melt energy with a positive contribution by net longwave radiation 7 the sensible and latent heat fluxes supplied the remainder of the melt energy cloud optical thickness over langfjordjokelen was larger than on two glaciers in southern norway especially in the summer months this resulted in a smaller contribution of net solar radiation to surface melt on langfjordjokelen the effect of the higher latitude on net solar radiation was found to be small

a continental hydrological assessment of a new grid based digital elevation model of australia a rectangular grid digital elevation model dem for australia with a horizontal resolution of 1 40 degree of latitude and longitude approximately 2 5 km has recently been calculated from continent wide coverages of point elevation and stream line data using an elevation gridding technique which incorporates a drainage enforcement algorithm an automated drainage basin analysis of this dem is in close agreement with existing basin analyses both for the better surveyed coastal areas with well defined relief and for large areas of low relief that make up much of the interior lake eyre basin and the murray darling basin the analysis of the arid western plateau region differs from the currently accepted analysis but is in broad agreement with a previous analysis of palaeodrainage systems based on topographic and geological information the drainage analyses is used to calculate cumulative distributions of spatially distributed hydrologically significant terrain parameters for the murray darling and derwent river basins the adequacy of the resolution of the dem for continental hydrological analyses is assessed by comparing drainage basin analyses and cumulative distributions of terrain parameters at resolutions of 1 40th and 1 20th degree of latitude and longitude

geodetic and direct mass balance measurements comparison and joint analysis this paper describes a new compilation of both direct and geodetic mass balance measurements develops a procedure to reduce diverse balance measurements over different time spans to common time spans and presents updated estimates of global average balance of small glaciers based on the enlarged compilation although geodetic measurements are fewer than direct measurements they cover four times as many balance years direct and geodetic measurements are unbiased with respect to one another but differences are often substantial the statistical procedure can be understood by imagining that an n year balance measurement is an average of a series of 1 year measurements the series is hypothetical but we can calculate the uncertainty of each of its elements if in addition to its measured average we can also estimate its standard deviation for this claim to be valid the annual series must be stationary and normally distributed with independent roughly uncorrelated elements for which there is reasonable evidence the need to know the standard deviation means that annual direct measurements from a nearby glacier or equally reliable information about variability are indispensable given this information the new methodology results in moderately more negative balances this is probably because tidewater glaciers are better represented in the geodetic data in any case the most recent published estimate of global average balance 0 8 1 0 mm a 1 of sea level equivalent for 2001 04 is now increased substantially to 1 1 1 4 mm a 1 for 2001 05

langfjordjokelen a rapidly shrinking glacier in northern norway in this paper we document changes of langfjordjokelen a small ice cap in northern norway surface mass balance measurements have been carried out on an east facing part 3 2 km 2 o f the ice cap since 1989 measurements reveal a strong thinning the balance year 2008 09 was the 13th successive year with significant negative annual balance 0 30 m w e the average annual deficit was 0 9 m w e over 1989 2009 the recent thinning of langfjordjokelen is stronger than observed for any other glacier in mainland norway maps from 1966 1994 and 2008 show that the whole ice cap is shrinking the total volume loss over 1966 2008 was 0 264 km 3 the east facing part has been greatly reduced in volume 46 area 38 and length 20 for this part over 1994 2008 the cumulative direct mass balance 14 5 m w e is less negative than the geodetic mass balance 17 7 m w e a surface mass balance model using upper air meteorological data was used to reconstruct annual balances back to 1948 and to reconstruct unmeasured years 1994 and 1995 sensitivity of annual balance to 18c warming is 0 76 m w e and to 10 increase in precipitation is 0 20 m w e

effects of storm clustering on beach dune evolution abstract impacts of storm clustering on beach dune morphodynamics were investigated by applying the state of the art numerical model xbeach to formby point sefton coast uk the adopted storm cluster was established by analysing the observed winter storms from december 2013 to january 2014 using a storm threshold wave height the first storm that occurred during this period is regarded as exceptionally intense and the occurrence of such a cluster of events is very unusual a 1d model was setup for the highly dynamic cross shore at formby point after initial calibration of the model parameters against available post storm profile data the model was used for the simulation of the storm cluster it was assumed that no beach recovery occurred between adjacent storms due to the very short time intervals between storms as a result the final predicted post storm profile of the previous storm was used as the pre storm profile of the subsequent storm the predicted evolution during each storm was influenced by the previous storms in the cluster due to the clustering effect the bed level change is not proportional to the storm power of events within the cluster as it would be in an individual storm case initially the large storm events interact with the multi bared foreshore enabling the subsequent weaker storms to influence the upper beach and lower dune system this results in greater change at the dune toe level also during less severe subsequent storms it is also shown that the usual water level threshold used to define dune erosion is over predicted by about 1 m for extreme storm conditions the predicted profile evolution provides useful insights into the morphodynamic processes of beach dune systems during a storm cluster using formby point as an example which is very useful for quantifying the clustering effects to develop tools for coastal management

a new procedure for gridding elevation and stream line data with automatic removal of spurious pits abstract a morphological approach to the interpolation of regular grid digital elevation models dems from surface specific elevation data points and selected stream lines is described the approach has given rise to a computationally efficient interpolation procedure which couples the minimization of a terrain specific roughness penalty with an automatic drainage enforcement algorithm the drainage enforcement algorithm removes spurious sinks or pits yielding dems which may be used to advantage in hydrological process studies the drainage enforcement algorithm has also been found to significantly increase the accuracy of dems interpolated from sparse but well chosen surface specific elevation data moreover it facilitates the detection of errors in elevation data that would not be detected by more conventional statistical means and forms a sound physical basis for cartographic generalization

quantifying the effects of climate and surface change on glacier mass balance when a mass balance is computed using an outdated map that computation does not reveal the actual mass change but older maps often must be used for practical reasons we present a method by which with a few additional measurements each year a mass balance computed with an outdated map can be transformed into an actual mass change this is done by taking into account the influence of changes in areal extent and changes in the surface elevation of the glacier since the map was made this method is applied to south cascade glacier washington u s a as an example the computed cumulative mass balance from 1970 to 1997 would have been 16 too negative if the 1970 map had not been updated while the actual volume change of a glacier is relevant to hydrological studies the change that would have occurred on a constant or static surface is more relevant to certain glacier dynamics problems and most climate problems we term this the reference surface balance and propose that such a balance which deliberately omits the influence of changes in area and surface elevation is better correlated to climatic variations than the conventional one which incorporates those influences

evolution of the norwegian plateau icefield hardangerjokulen since the little ice age the maximum little ice age lia glacier extent provides a significant baseline to assess long term glacier change and to place currently observed rates of glacier recession in a broader temporal

the effects of storm clustering on beach profile variability abstract impacts of storms in reshaping coastlines are well known also the far greater impact of clusters of storms where storms occur at close succession has been noted in a number of previous studies in this paper we analyse and discuss the storm wave climate and the beach profile response to clusters of storms at narrabeen beach new south wales australia narrabeen beach is subjected to frequent storms all year round and the beach undergoes substantial variability as a result the impact of storm clusters with closely spaced individual storms reaching the beach is investigated by combining historic measurements of beach profile surveys and numerical modelling of storm induced beach change our analysis of storm power index of storm clusters and its correlation with the change in beach width reveals that the strengths of single storms in a storm cluster alone are not the reason for beach change but time interval between successive storms and the post storm recovery speed of the beach concerned also play important roles we have quantified and compared beach erosion return levels resulting from single storms and storm clusters it was found that beach erosion volumes resulting from storm clusters with two or more storms resemble potential beach erosion volumes induced by single storms of far higher return periods

an 1899 glacier inventory for nordland northern norway produced from historical maps glaciers depicted on old maps reveal their historical extents before the advent of aerial and satellite remote sensing digital glacier inventories produced from these maps can be employed in assessments of centennial scale glacier change this study reconstructs the 1899 covering the period 1882 1916 glacier extent in nordland northern norway from historical gradteigskart maps with an emphasis on examining the accuracy of the mapped glaciers glacier outlines were digitised from georectified scans of the analogue maps in a raster graphics editor and were subsequently inventoried in a gis the accuracy of the historical glacier extent was established from written descriptions and landscape photographs created during the original field surveys and further validated against independent glacier outlines of 1 the maximum little ice age extent derived from geomorphological evidence and 2 the 1945 extent derived from vertical aerial photographs an overall uncertainty of 17 is associated with our inventory nordland s glaciers covered an area of 1712 291 km2 in 1899 by 2000 total ice cover had decreased by 47 807 137 km2 at a rate of 6 10 a 1 80 14 km2 10 a 1 the approach presented here may serve as a blueprint for future studies intending to derive glacier inventories from historical maps

svalbard glacier elevation changes and contribution to sea level rise 1 we compare satellite altimetry from the ice cloud and land elevation satellite icesat 2003 2007 to older topographic maps and digital elevation models 1965 1990 to calculate long term elevation changes of glaciers on the svalbard archipelago results indicate significant thinning at most glacier fronts with either slight thinning or thickening in the accumulation areas except for glaciers that surged which show thickening in the ablation area and thinning in the accumulation areas the most negative geodetic balances occur in the south and on glaciers that have surged while the least negative balances occur in the northeast and on glaciers in the quiescent phase of a surge cycle geodetic balances are related to latitude and to the dynamical behavior of the glacier the average volume change rate over the past 40 years for svalbard excluding austfonna and kvitoya is estimated to be 9 71 0 55 km3 yr 1 or 0 36 0 02 m yr 1 w equivalent for an annual contribution to global sea level rise of 0 026 mm yr 1 sea level equivalent

glacier change in norway since the 1960s an overview of mass balance area length and surface elevation changes in this paper we give an overview of changes in area length surface elevation and mass balance of glaciers in mainland norway since the 1960s frontal advances have been recorded in all regions except the northernmost glaciers in troms and finnmark storsteinsfjellbreen lyngen and langfjordjokelen more than half of the observed glaciers 27 of 49 had marked advances in the 1990s the glaciological mass balance values for the period 1962 2018 where 43 glaciers have been measured show great inter annual variability the results reveal accelerated deficit since 2000 the most negative decade being 2001 2010 some years with a positive mass balance or less negative after 2010s can be attributed to variations in large scale atmospheric circulation a surface elevation change and geodetic mass balance were calculated for a sample of 131 glaciers covering 817 km 2 in the 1960s and 734 km 2 in the 2010s giving an area reduction of 84 km 2 or 10 the sample covers many of the largest glaciers in norway and they had an overall change in surface elevation of 15 5 m for the 50 year period converted to a geodetic mass balance this gives a mean mass balance of 0 27 0 05 m w e a 1

morphodynamic characteristics and classification of beaches in england and wales abstract the use of beach classification models has become widespread in literature in recent years beach classification models that recognise distinct modal beach states in response to environmental conditions are most widely used these models were developed largely in high energy micro to meso tidal sandy environments and subsequent attention has focussed on extending their use into other beach environments here the applicability of these traditional beach classification models to the highly diverse coastline of england and wales was assessed through collection of detailed morphodynamic characteristics of 92 beaches yielding a comprehensive multi variate data set containing morphological sedimentological and hydrodynamic information the complex and diverse study region incorporates beach morphology covering the full spectrum from reflective to dissipative and non barred to multi barred cluster analysis supplemented by mds ordination resulted in the identification of 9 distinct beach types traditional morphodynamic indices and rtr were found to be effective in discriminating between beach groups providing some support for the beach state models derived using information from australian beaches it was found that absolute wave energy wave power is important as well in controlling beach type for intermediate beaches a wave energy flux p h 2 t value of 3 kw m 1 was found to differentiate between beaches with p 3 kw m 1 and without p 1 three dimensional bar rip morphology a key component controlling recreational beach hazard levels observations presented here inform a beach classification model to be used as the basis for a national beach risk assessment programme beach classification models based on environmental parameters are by necessity simplifications and should be used as tools for understanding morphodynamic systems rather than beach type prediction

development of an antarctic digital elevation model by integrating cartographic and remotely sensed data a geographic information system based approach we present a high resolution digital elevation model dem of the antarctic it was created in a geographic information system gis environment by integrating the best available topographic data from a variety of sources extensive gis based error detection and correction operations ensured that our dem is free of gross errors the carefully designed interpolation algorithms for different types of source data and incorporation of surface morphologic information preserved and enhanced the fine surface structures present in the source data the effective control of adverse edge effects and the use of the hermite blending weight function in data merging minimized the discontinuities between different types of data leading to a seamless and topographically consistent dem throughout the antarctic this new dem provides exceptional topographical details and represents a substantial improvement in horizontal resolution and vertical accuracy over the earlier continental scale renditions particularly in mountainous and coastal regions it has a horizontal resolution of 200 m over the rugged mountains 400 m in the coastal regions and approximately 5 km in the interior the vertical accuracy of the dem is estimated at about 100 130 m over the rugged mountainous area better than 2 m for the ice shelves better than 15 m for the interior ice sheet and about 35 m for the steeper ice sheet perimeter the antarctic dem can be obtained from the authors

impact of the winter 2013 2014 series of severe western europe storms on a double barred sandy coast beach and dune erosion and megacusp embayments abstract the winter of 2013 2014 was characterized by a striking pattern of temporal and spatial extreme storm wave clustering in western europe the 110 km long gironde coast sw france was exposed to the most energetic wave conditions over the last 18 years the period was outstanding in terms of the available energy to move sediment and cause large scale erosion with the 2 month average significant wave height hs exceeding 3 6 m just below the 0 95 quantile and 4 distinct 10 year return period storms with hs 9 m these storm waves caused unprecedented beach and dune erosion along the gironde coast including severely damaged sea defences at the coastal towns at the end of the winter dune erosion scarp height was highly variable alongshore and often exceeded 10 m megacusp embayments were observed along the gironde coast with an average alongshore spacing of 1000 m in the south progressively decreasing to 500 m in the north with an average cross shore amplitude of 20 m while beach megacusps were previously observed to systematically couple to the inner bar along the gironde coast during low to moderate energy wave conditions severe storm driven megacusp embayments cutting the dune were found to be enforced and coupled to the outer crescentic bar a detailed inspection of the 1500 m long bimonthly topographic surveys of truc vert beach shows that in early january 2014 the outstanding shore normal incident storm swell hercules with hs and peak wave period tp peaking at 9 6 m and 22 s respectively triggered the formation of a localized megacusp embayment with the erosion scarp height exceeding 6 m in its centre where the dune retreat reached 30 m the subsequent storms progressively smoothed the megacusp by the end of the winter mostly through severe erosion of the megacusp horns because of the very long period 16 s

classification of beach response to extreme storms abstract extreme storms are responsible for rapid changes to coastlines worldwide during the 2013 14 winter the west coast of europe experienced a sequence of large storm induced wave events representing the most energetic period of waves in the last 60 years the southwest coast of england underwent significant geomorphological change during that period but exhibited a range of spatially variable and complex morphological responses despite being subjected to the same storm sequence here we use the 2013 14 storm response along the southwest coast of england as a natural field laboratory and explain this variability in storm response through the introduction and evaluation of a new classification of how sandy and gravel beaches respond to extreme storms cluster analysis was conducted using an unique data set of pre and post storm airborne light detection and ranging lidar data from 157 beach sites based on the net volumetric change dqnet and a novel parameter the longshore variation index lvi which quantifies the alongshore morphological variability in beach response four main beach response types were identified 1 fully exposed beaches that experienced large and alongshore uniform sediment losses dqnet 100 m3 m 1 2 semi exposed beaches that experienced medium alongshore uniform sediment losses dqnet 50 m3 m 1 3 sheltered short beaches that experienced limited net sediment change and alongshore variability in beach response and 4 sheltered long beaches that experienced considerable alongshore variability in beach response and large gross sediment change but limited net sediment change the key factors in determining the type of beach response are exposure to the storm waves angle of storm wave approach and the degree to which the beach is embayed these factors are universally applicable on many exposed coastlines worldwide so the response classification presented here is expected to be widely applicable

the influence of drainage boundaries on specific mass balance results a case study of engabreen norway mass balance measurements were initiated on engabreen an outlet glacier from the svartisen ice cap norway in 1970 the glacier boundary was defined based on where meltwater drained as the interest in engabreen was mainly hydrological however the apparent discrepancy between the calculated cumulative glacier mass balance since 1970 and changes in glacier geometry prompted a re examination of the glacier boundary the glaciological drainage boundary is defined by studying whether ice flow physically contributes to engabreen tongue and corresponds to a glacier with an area of 27 2 km 2 significantly smaller than that defined by the hydrological drainage boundary at 39 6 km 2 this glaciological drainage boundary is here named the ice flow perimeter the area difference between this and the hydrological drainage boundary is largest for the altitudinal range 1300 1400 m a s l generally the glaciological glacier is lower in mean altitude than the hydrological glacier and this affects the calculated specific mass balance using the glaciological boundary leads to reductions in mean annual winter and summer balance when spatial differences are ignored of 0 12 m w e from 2 92 to 2 80 m w e and 0 15 m w e from 2 32 to 2 47 m w e respectively the reduction in mean net balance for the period 1970 2006 is 0 27 m w e from 0 59 to 0 32 m w e which is about 50 of the calculated mass surplus in this period this illustrates that the choice of glacier outline can significantly influence the long term cumulative mass balance and that results from outlet glaciers must be interpreted with care when used for regional estimates of glacier change

a reevaluation of coastal embayment rotation the dominance of cross shore versus alongshore sediment transport processes collaroy narrabeen beach southeast australia 1 over 30 years of wave and beach survey data at collaroy narrabeen beach in southeast australia are analyzed to investigate the extent to which shoreline variability within this coastal embayment is dominated by shoreline oscillations due to cross shore sediment exchange or shoreline rotations due to alongshore exchange between the beach s extremities offshore wave data are derived from both buoy measurements and era 40 reanalysis data eof analysis of the monthly shoreline data suggests that the dominant mode of shoreline variability 60 of variability is an onshore offshore sediment exchange that is greater at the more exposed northern end of the beach than at the predominantly sheltered southern end this mode is primarily associated with variability in wave energy storms which by the nature of the wave climate of this region chiefly occurs from the south southeast the secondary mode of shoreline variability 26 of variability is a rotational signal between either end of the beach which coincides with 24 of the offshore wave climate shifting between the south southeast and east as well as changes in the wave period and wave energy storms a distinct annual cycle is identified in this rotation signal it is concluded that alongshore sediment transport processes associated with embayment rotation is more subtle than previously thought and a refined conceptual model of coastal embayment variability in this region is presented highlighting the dominance of cross shore sediment exchange processes

estimating south cascade glacier washington u s a mass balance from a distant radiosonde and comparison with blue glacier a simple flux model using twice daily measurements of wind humid ity and temperature from standard upper air levels in a distant radiosonde estimated winter balance of south cascade glacier over 1959 98 with error 0 24 m w e correla tion between net and winter balance is strong the model estimates net balance with error 0 53 m w e over the past 40 years average net balance of south cascade glacier has been strongly negative 0 46 m w e and it has been shrinking steadily in com parison 200 km wsw at blue glacier the average balance has been less negative 0 13 m w e that glacier has undergone little change over the 40 years balance histories of the two glaciers are positively correlated r 0 54 and south cascade has been more out of balance than blue presumably because it is still adjusting to climate change since the little ice age recent warming and drying has made the net balance of both glaciers strongly negative since 1976 0 84 m w e at south cascade 0 56 m w e at blue if south cascade glacier were in balance with the 1986 1998 climate it would be about 1 4 of its present area if conditions persist retreat of both glaciers is inevitable

delineation of a complexly dipping temperate glacier bed using short pulse radar arrays we have defined the complex bed topography for a section of a small temperate glacier using 50 mhz monostatic short pulse radar data and a synthetic aperture array processing method the data were collected on a 100 m by 340 m array grid in the upper stem of gulkana glacier central alaska u s a the array processing was based on a modified three dimensional 3 d kirchhoff migration integral and implemented with a synthetic aperture approach that uses sequences of overlapping sub arrays to generate depth images in vertical planes typical sub array beam patterns are generally 5 at the 6 db level giving a flashlight like searching capability without distorting the wavelet shape the bed topography was constructed using normal reflections picked from 3 d array depth images in some instances reflections were imaged outside the data coverage area the bed surface dips steeply both parallel and transverse to the direction of ice flow the maximum observed depth is roughly 140 m the 3 d method resolved bed dips up to 45 in regions of steepest dip it improved depth accuracy by 36 compared with raw data and by 15 compared with standard two dimensional 2 d migration over 12 db of signal to noise improvement and improved spatial resolution was achieved compared to raw data and 2 d migration false bottom layering seen in the raw data and in 2 d migrations is not observed in the 3 d array results furthermore loss of bottom reflections is shown by the 3 d migration to be attributable to the dip and curvature of the reflector and not scattering losses or signal clutter from englacial inclusions

ice thickness measurements and volume estimates for glaciers in norway glacier volume and ice thickness distribution are important variables for water resource management in norway and the assessment of future glacier changes we present a detailed assessment of thickness distribution and total glacier volume for mainland norway based on data and modelling glacier outlines from a landsat derived inventory from 1999 to 2006 covering an area of 2692 81 km 2 were used as input we compiled a rich set of ice thickness observations collected over the past 30 years altogether interpolated ice thickness measurements were available for 870 km 2 32 of the current glacier area of norway with a total ice volume of 134 23 km 3 results indicate that mean ice thickness is similar for all larger ice caps and weakly correlates with their total area ice thickness data were used to calibrate a physically based distributed model for estimating the ice thickness of unmeasured glaciers the results were also used to calibrate volume area scaling relations the calibrated total volume estimates for all norwegian glaciers ranged from 257 to 300 km 3

seasonal mass balance gradients in norway previously discovered regularity in vertical profiles of net balance b n z on ten glaciers in norway also exists in profiles of both winter bw z and summer b s z seasonal balances all three profiles unlike those of many glaciers elsewhere in the world are remarkably linear variations of gradients db w dz and db s dz from year to year are small and correlate poorly with glacier total balances b w and b s glacier to glacier correlation is weak for both gradients but is strongly positive for b w and b s there are two direct consequences of these properties of the gradients that apply to both seasonal balances b w and b s first because db dz varies so little from year to year the difference in balance ab from year to year is nearly the same over the entire glacier except near the top and bottom of its altitude range therefore balance at a site near the middle of the altitude range of the glacier correlates very well with glacier total balance second this correlation combined with the strong positive correlation of balance from glacier to glacier is the reason balance at one altitude on one glacier correlates well with glacier total balance at other nearby glaciers

impacts of hurricane ike on the beaches of the bolivar peninsula tx usa abstract hurricane ike caused substantial beach erosion along the coast of the bolivar peninsula tx much of the erosion was caused by the offshore ebb flow of the ca 5 m storm surge that formed spatially discrete scour features using aerial photography and repeat lidar data we identify five types of scour features and describe the alongshore distribution in four flow environments type 1 scours are relatively small and compact features associated mainly with flow off a wide vegetated grasses shrubs trees surface across a wide beach type 2 scours are large and branching forms associated mainly with flow that was channeled by streets or gaps between structures type 3 scours are large and blocky features associated with flow off a marsh surface across a highway which removed almost all beach sands from the surface type 4 scours are elongated shore perpendicular channels associated with the same flow characteristics as type 3 scours type 5 scours are elongated shore perpendicular features sometimes branching associated with flow through gaps in a destroyed shore protection structure repeat imagery indicates that many of the features persisted for at least seven months recent aerial photography indicates that aspects of some features remained evident more than three years after ike s landfall

the response of three main beach types to tropical storms in south china abstract based on the observational data of 6 storms and 8 different beaches on the coasts of southern china the paper is concerned with the characteristics of storm effects on beaches with different morphodynamic types in south china a dissipative beach is very stable and has a weak response to tropical storms the storm induced morphological changes for this type of beach are characterized by erosion at the dune toe and minor changes on the beach face a low tide terrace beach has a strong response to storms with marked changes in the upper profile a barred beach usually experiences berm erosion swash bar smoothening and seaward bar migration during storms overwash may occur for the beach without backshore dune or protection in this paper backshore changes and the alteration of beach gradient in response to tropical storms are discussed with taking into account tidal influences a new morphodynamic parameter et is proposed in order to highlight the beach response intensity to storm action results show that the inherent morphodynamic properties have significant effects on the beach response to storm the more dissipative beach has a smaller response intensity and shows a moderate change in beach profile during a storm while a more reflective beach has a greater response intensity and changes markedly under storm conditions

ice volume changes bias estimation of mass balance measurements and changes in subglacial lakes derived by lidar mapping of the surface of icelandic glaciers icelandic glaciers cover 11 000 km2 in area and store 3600 km3 of ice starting in 2008 during the international polar year accurate digital elevation models dems of the glaciers are being produced with airborne lidar more than 90 of the glaciers have been surveyed in this effort including vatnajokull hofsjokull myrdalsjokull drangajokull eyjafjallajokull and several smaller glaciers the publicly available dems are useful for glaciological and geological research including studies of ice volume changes estimation of bias in mass balance measurements studies of jokulhlaups and subglacial lakes formed by subglacial geothermal areas and for mapping of crevasses the lidar mapping includes a 500 1000 m wide ice free buffer zone around the ice margins which contains many glacio geomorphological features and therefore the new dems have proved useful in geological investigations of proglacial areas comparison of the lidar dems with older maps confirms the rapid ongoing volume changes of the icelandic ice caps which have been shown by mass balance measurements since 1995 96 in some cases ice volume changes derived by comparing the lidar measurements with older dems are in good agreement with accumulated ice volume changes derived from traditional mass balance measurements but in other cases such a comparison indicates substantial biases in the traditional mass balance records

influence of north atlantic climate variability on glacier mass balance in norway sweden and svalbard climate variability can complicate efforts to interpret any long term glacier mass balance trends due to anthropogenic warming here we examine the impact of climate variability on the seasonal mass balance records of 14 glaciers throughout norway sweden and svalbard using dynamical adjustment a statistical method that removes orthogonal patterns of variability shared between each mass balance record and sea level pressure or sea surface temperature predictor fields for each glacier the two leading predictor patterns explain 27 81 of the winter mass balance variability and 24 69 of the summer mass balance variability the spatial and temporal structure of these patterns indicates that accumulation variability for all of the glaciers is strongly related to the north atlantic oscillation nao with the atlantic multidecadal oscillation amo also modulating accumulation variability for the northernmost glaciers given this result predicting glacier change in the region may depend on nao and amo predictability in the raw mass balance records the glaciers throughout southern norway have significantly negative summer trends whereas the glaciers located closer to the arctic have negative winter trends removing the effects of climate variability suggests it can bias trends in mass balance records that span a few decades but its effects on most of the longer term mass balance trends are minimal

spring temperature variability relative to the north atlantic oscillation and sunspots a correlation analysis with a monte carlo implementation abstract a reconstruction of past spring temperatures was analysed and compared to long term records of the north atlantic oscillation nao and sunspots this palaeoclimate reconstruction built previously using multiple proxy evidence of historical and natural sources from southwest finland explained approx 70 of the instrumental temperature variance over a spring season february june and covered the time period from 1750 to the present correlations between the nao and sunspots appear markedly high and based on monte carlo tests statistically significant p

little ice age glacier variations in jotunheimen southern norwvay a study in regionally controlled lichenometric dating of recessional moraines with implications for climate and lichen growth rates a new approach to regional lichenometric dating is developed and applied to little ice age moraine ridge sequences on 16 glacier forelands in jotunheimen southern norway lichenometric dating curves based on the rhizocarpon subgenus are constructed independently for west central and east jotunheimen although there are differences between the subregions a composite regional moraine chronology for jotunheimen identifies 12 episodes of moraine formation in ad 1743 1750 the regional little ice age glacier maximum 1762 1771 1782 1790 1796 1802 1811 1818 1833 1838 1845 1854 1860 1868 1871 1879 1886 1898 1915 1922 and 1927 1934 spatial and temporal patterns in glacier behaviour between the subregions and between jotunheimen and the neighbouring jostedalsbreen are explained in terms of the interaction of annual to decadal variations in summer temperature and winter precipitation glacier advances and moraine formation events driven primarily by winter precipitation variations exhibit subregio

historically unprecedented global glacier decline in the early 21st century observations show that glaciers around the world are in retreat and losing mass internationally coordinated for over a century glacier monitoring activities provide an unprecedented dataset of glacier observations from ground air and space glacier studies generally select specific parts of these datasets to obtain optimal assessments of the mass balance data relating to the impact that glaciers exercise on global sea level fluctuations or on regional runoff in this study we provide an overview and analysis of the main observational datasets compiled by the world glacier monitoring service wgms the dataset on glacier front variations 42000 since 1600 delivers clear evidence that centennial glacier retreat is a global phenomenon intermittent readvance periods at regional and decadal scale are normally restricted to a subsample of glaciers and have not come close to achieving the maximum positions of the little ice age or holocene glaciological and geodetic observations 5200since 1850 show that the rates of early 21st century mass loss are without precedent on a global scale at least for the time period observed and probably also for recorded history as indicated also in reconstructions from written and illustrated documents this strong imbalance implies that glaciers in many regions will very likely suffer further ice loss even if climate remains stable

new insights into embayed beach rotation the importance of wave exposure and cross shore processes although embayed beach rotation has been viewed and modeled as an alongshore sediment transport process acting on a uniform beach profile recent research suggests a more complex response whereby alongshore variability in cross shore sediment fluxes may be more significant this study utilizes 5 years of fully three dimensional beach surveys at narrabeen collaroy beach se australia to quantify the control of alongshore nonuniform wave exposure and cross shore processes on embayed beach rotation empirical orthogonal function analysis of the alongshore variability in subaerial beach volume width and berm slope confirms that the dominant mode of subaerial beach variability is an onshore offshore sediment exchange that is strongly controlled r 0 8 by the alongshore gradient in breaker wave height and coincides with a uniform flattening steepening of the berm slope a secondary rotation like signal is observed in both the subaerial beach volume width data and significantly the berm slope this inverse flattening steepening of the berm slope between beach extremities is most likely a proxy for differing cross shore processes within the surf zone between the exposed and sheltered ends of the embayment particularly with regards to dissipation of storm wave energy by offshore sandbars and beach recovery following storms analysis of the corresponding wave data reveals two distinct time scales of wave forcing characteristic of short term erosion and longer term recovery processes a new conceptual model is presented of three differing modes of embayed beach rotation with the newly identified beach rotation mode controlled by offshore sandbars considered of particular importance at embayments where headland sheltering of oblique waves is pronounced

ice volume changes of selected glaciers in the swiss alps since the end of the 19th century the evolution of surface topography of glaciers in the swiss alps is well documented with high resolution aerial photographs repeatedly recorded since the 1960s and further back in time with topographic maps including elevation contour lines first surveyed in the mid 19th century in order to quantify and interpret glacier changes in the swiss alps time series of volume changes over the last 100 150 years have been collected the available datasets provide a detailed spatial resolution for the retreat period since the end of the little ice age the spatial distribution as well as temporal variations of the thickness change were analyzed a significant ice loss since the end of the 19th century was observed in the ablation area while the changes in the accumulation area were small we found moderate negative secular rates until the 1960s followed by steady to positive rates for about two decades and strong ice loss starting in the 1980s which has lasted until the present an evaluation of 19 glaciers revealed a total ice volume loss of about 13 km 3 since the 1870s of which 8 7 km 3 occurred since the 1920s and 3 5 km 3 since 1980 decadal mean net balance rates for the periods 1920 60 1960 80 and 1980 present are 0 29 0 03 and 0 53 m a 1 w e respectively

a generalized equilibrium model for predicting daily to interannual shoreline response coastal zone management requires the ability to predict coastline response to storms and longer term seasonal to interannual variability in regional wave climate shoreline models typically rely on extensive historical observations to derive site specific calibration to circumvent the challenge that suitable data sets are rarely available this contribution utilizes twelve 5 year shoreline data sets from around the world to develop a generalized model for shoreline response the shared dependency of model coefficients on local wave and sediment characteristics is investigated enabling the model to be recast in terms of these more readily measurable quantities study sites range from microtidal to macrotidal coastlines spanning moderate to high energy beaches the equilibrium model adopted here includes time varying terms describing both the magnitude and direction of shoreline response as a result of onshore offshore sediment transport between the surf zone and the beach face the model contains two coefficients linked to wave driven processes 1 the response factor that describes the memory of a beach to antecedent conditions and 2 the rate parameter c that describes the efficiency with which sand is transported between the beach face and surf zone across all study sites these coefficients are shown to depend in a predictable manner on the dimensionless fall velocity that in turn is a simple function of local wave conditions and sediment grain size when tested on an unseen data set the new equilibrium model with generalized forms of and c exhibited high skill brier skills score bss 0 85

equilibrium shoreline modelling of a high energy meso macrotidal multiple barred beach abstract 8 year time series of incident wave energy and monthly alongshore averaged beach surveys at the high energy meso macrotidal multiple barred truc vert beach are analysed we apply two behaviour oriented equilibrium shoreline models that relate the rate of cross shore shoreline displacement to the wave energy and the wave energy disequilibrium between the wave energy and the equilibrium wave energy that would cause no change to the present shoreline location the two models show similar skill results show that the equilibrium shoreline model concept works on meso macrotidal multiple barred beaches with similar skill when applied to non barred and or micro mesotidal beaches provided that a relevant shoreline proxy is used simulations show that truc vert beach responds predominantly at seasonal timescales rather than at individual storm frequency the first winter storms drive the most pronounced erosion events because both the wave energy disequilibrium and erosion change potential are large the best shoreline proxy at truc vert beach is the mean high water level where the inner bar and berm dynamics have little influence on the shoreline cross shore displacement implications for shoreline monitoring through video imagery on this type of beach are discussed results also reveal that the equilibrium shoreline concept can be extended to an equilibrium beach profile concept pending further improvements