coupling patterns between para glacial and permafrost degradation responses in antarctica the recently deglaciated environments in maritime permafrost regions are usually affected by very active paraglacial processes elephant point is an ice free area of 1 16 km2 located in the sw of livingston island south shetland islands antarctica between 1956 2010 the retreat of the ice cap covering most part of this island has exposed 17 3 of the land surface in this peninsula two geomorphological units were identified in this new ice free area a moraine extending from the western to the eastern coastlines and a relatively flat proglacial surface the glacier in 1956 sat in contact with the northern slope of the moraine but its accelerated retreat in parallel to the warming trend recorded in the antarctic peninsula left these areas free of glacier ice subsequently the postglacial evolution was controlled by the relaxation phase typical of paraglacial systems the typology and intensity of geomorphological processes show a significantly different dynamics between the southern and northern slopes of the moraine this pattern is related to the different stage of paraglacial adjustment in both slopes in the southern side on coarser sediments pronival ramparts debris flows and alluvial fans are distributed with a low to moderate activity of slope processes in the northern side mass wasting processes are extremely active on fine grained unconsolidated sediments ice rich permafrost is being degraded by thermokarst processes landslides and mudflows transfer large amounts of sediments down slope the surface affected by retrogressive thaw slumps in the moraine has been quantified in 24 172 m2 which accounts for 9 6 of its surface the abundance of kettle lakes is also indicative of the degradation of the ground ice paraglacial processes are expected to continue in the moraine and proglacial area in the near future although their intensity and duration will depend on the magnitude and rate of future climate trends in the northern antarctic peninsula copyright 2015 john wiley sons ltd

the holocene deglaciation of the byers peninsula livingston island antarctica based on the dating of lake sedimentary records the process of deglaciation in the antarctic peninsula region has large implications for the geomorphological and ecological dynamics of the ice free environments however uncertainties still remain regarding the age of deglaciation in many coastal environments as is the case in the south shetland islands this study focuses on the byers peninsula the largest ice free area in this archipelago and the one with greatest biodiversity in antarctica a complete lacustrine sedimentary sequence was collected from five lakes distributed along a transect from the western coast to the rotch dome glacier front limnopolar chester escondido cerro negro and domo lakes a multiple dating approach based on 14c thermoluminescence and tephrochronology was applied to the cores in order to infer the holocene environmental history and identify the deglaciation chronology in the byers peninsula the onset of the deglaciation started during the early holocene in the western fringe of the byers peninsula according to the basal dating of limnopolar lake ca 8 3 cal ky bp glacial retreat gradually exposed the highest parts of the cerro negro nunatak in the se corner of byers where cerro negro lake is located this lake was glacier free since at least 7 5 ky during the mid holocene the retreat of the rotch dome glacier cleared the central part of the byers plateau of ice and escondido and chester lakes formed at 6 cal ky bp and 5 9 ky respectively the dating of the basal sediments of domo lake suggests that the deglaciation of the current ice free easternmost part of the byers peninsula occurred before 1 8 cal ky bp

the early holocene sea level rise the causes anatomy and consequences of the early holocene sea level rise ehslr are reviewed the rise of ca 60m took place over most of the earth as the volume of the oceans increased during deglaciation and is dated at 11 650 7000 cal bp the ehslr was largely driven by meltwater release from decaying ice masses and the break up of coastal ice streams the patterns of ice sheet decay and the evidence for meltwater pulses are reviewed and it is argued that the ehslr was a factor in the ca 8470 bp flood from lake agassiz ojibway patterns of relative sea level changes are examined and it is argued that in addition to regional variations temporal changes are indicated the impact of the ehslr on climate is reviewed and it is maintained that the event was a factor in the 8200 bp cooling event as well as in changes in ocean current patterns and their resultant effects the ehslr may also have enhanced volcanic activity but no clear evidence of a causal link with submarine sliding on continental slopes and shelves can yet be demonstrated the rise probably influenced rates and patterns of human migrations and cultural changes it is concluded that the ehslr was a major event of global significance knowledge of which is relevant to an understanding of the impacts of global climate change in the future

seismicity and tectonics of the south shetland islands and bransfield strait from a regional broadband seismograph deployment 1 we investigate the tectonics of the south shetland trench and bransfield strait by performing a detailed study of local seismicity during 1997 1999 we deployed seven land seismometers and 14 ocean bottom seismometers in the south shetland island region the data we obtained indicate a high level of local seismicity mb 2 5 and we accurately located 150 earthquakes many of the earthquakes occur at locations and depths indicative of ongoing subduction in the south shetland trench a focal mechanism for the largest event in the forearc indicates shallow angle thrusting the maximum depth of seismicity is 65 km but the majority of the events are shallower than 30 km these seismic results are consistent with recent magnetic gps and multichannel seismic reflection data that suggest continued subduction at a very slow rate the south shetland trench thus represents an extreme end member of hot subduction resulting from slow convergence of young lithosphere and the absence of intermediate depth earthquakes is consistent with thermal assimilation of the slab at shallow depths we have located many earthquakes associated with volcanism and rifting in bransfield strait a swarm of events near a submarine volcano suggests current magmatic activity a normal faulting focal mechanism in the northeastern part of the strait gives evidence of extension earthquakes associated with rifting in the northeastern portion of the strait are clustered along well established rifts but the seismicity is much more diffuse to the southwest this observation is consistent with other evidence that extension has propagated from northeast to southwest

polar gravel beach ridge systems sedimentary architecture genesis and implications for climate reconstructions south shetland islands western antarctic peninsula abstract the sedimentary architecture of polar gravel beach ridges is presented and it is shown that ridge internal geometries reflect past wave climate conditions ground penetrating radar gpr data obtained along the coasts of potter peninsula king george island show that beach ridges unconformably overlie the prograding strand plain development of individual ridges is seen to result from multiple storms in periods of increased storm wave impact on the coast strand plain progradation by contrast is the result of swash sedimentation at the beach face under persistent calm conditions the sedimentary architecture of beach ridges in sheltered parts of the coast is characterized by seaward dipping prograding beds being the result of swash deposition under stormy conditions or aggrading beds formed by wave overtopping by contrast ridges exposed to high energy waves are composed of seaward as well as landward dipping strata bundled by numerous erosional unconformities these erosional unconformities are the result of sediment starvation or partial reworking of ridge material during exceptional strong storms the number of individual ridges which are preserved from a given time interval varies along the coast depending on the morphodynamic setting sheltered coasts are characterized by numerous small ridges whereas fewer but larger ridges develop on exposed beaches the frequency of ridge building ranges from decades in the low energy settings up to 1600 years under high energy conditions beach ridges in the study area cluster at 9 5 7 5 5 5 and below 3 5 m above the present day storm beach based on radiocarbon data this is interpreted to reflect distinct periods of increased storminess and or shortened annual sea ice coverage in the area of the south shetland islands for the times around 4 3 c 3 1 1 9 ka cal bp and after 0 65 ka cal bp ages further indicate that even ridges at higher elevations can be subject to later reactivation and reworking a careful investigation of the stratigraphic architecture is therefore essential prior to sampling for dating purposes

the analysis of beach profile changes using dean s method and empirical orthogonal functions abstract sea bottom changes in the cross shore direction have been analysed the cross shore profile as a major factor of beach configuration has been presented schematically as a superposition of a basic curve reflecting the mean layout and slope of the shore given by dean s function y a 2 3 and superimposed various bars troughs berms etc depicting local characteristic features of the profile the local features of the profile have been analysed by use of one 1 d and two dimensional 2 d empirical orthogonal functions on the basis of field observations and measurements the parameter a has been presented as a function of time three time scales have been distinguished short seasonal and long term with respect to which more or less regular changes of the parameter a occur the modified parameter a was applied to two different field sites namly lubiatowo baltic sea poland and gold beach black sea bulgaria it has been found that in extreme cases the parameter a can vary in time by a factor of two or more for the same grain size distribution

two dimensional reduced physics model to describe historic morphodynamic behaviour of an estuary inlet abstract understanding medium to long term morphodynamic change is important for sustainable coastal and estuary management this paper analyses morphodynamic change of a complex estuary inlet which is subjected to multiple environmental drivers and proposes a reduced physics model to explain the historic medium term morphodynamic change of the inlet the analysis shows that even though the estuary inlet undergoes multiscale morphological change the changes that take place over a timescale of several years are more significant and important the reduced physics model suggests that this simplified modelling approach is able to recognise principal historic morphodynamic trends in the estuary however the length and quality of the inlet bathymetry data set limits the applicability of the models and the quality of model outputs

slab breakoff a model for syncollisional magmatism and tectonics in the alps slab breakoff is the buoyancy driven detachment of subducted oceanic lithosphere from the light continental lithosphere that follows it during continental collision in a recent paper davies and von blanckenburg 1994 have assessed the physical conditions leading to breakoff by quantitative thermomechanical modeling and have predicted various consequences in the evolution of mountain belts breakoff will lead to heating of the overriding lithospheric mantle by upwelling asthenosphere melting of its enriched layers and thus to bimodal magmatism breakoff will also lead to thermal weakening of the subducted crustal lithosphere thereby allowing buoyant rise of released crustal slices from mantle depths in this paper we present a test of this model in the tertiary evolution of the european alps in the alps both basaltic and granitoid magmatism occur between 42 and 25 ma following the closure of oceanic basins by subduction and continental collision the granitoids are now well established to result from mixing of basalt with assimilated continental crust to identify the tectonically crucial origin of the partial mantle melts we have compiled all published geochemical and isotopic data of numerous mafic dykes occurring throughout the whole alpine arc their trace element and isotopic composition suggests that they have been formed by low degree melting of the mechanically stable lithospheric mantle we see no evidence for melting of asthenospheric mantle it was thus not decompressed to depths shallower than 50 km once initiated rapid lateral migration of slab breakoff will result in a linear trace of magmatism in locally thermal weakened crust this explains why all alpine magmatic rocks intruded almost synchronously along a strike slip fault the periadriatic lineament a compilation of ages from penninic high pressure rocks subducted to depths of up to 100 km shows that subduction took place at circa 55 40 ma followed by uplift at 40 35 ma from the short time interval between their uplift and the onset of magmatism we infer that both processes have been induced by the breakoff the slab breakoff model fulfills its predictions in the case of the alps and therefore supports the assumptions made in the theoretical model on a geological basis we believe that the characteristic association of magmatic activity with the return of high pressure rocks to the surface allows the identification of this process in the earth s mountain belts

relative sea level curves for the south shetland islands and marguerite bay antarctic peninsula this paper presents preliminary relative sea level curves for the marguerite bay region and for the south shetland islands the marguerite bay curve is constrained by both new and previously published 14c dates on penguin remains and shells and on two isolation basins dating back to 6500 14c yr bp extrapolation back to the marine limit yields a minimum deglaciation date for marguerite bay of ca 9000 14c yr bp analysis of beach clasts suggests that there was a period of increased wave activity perhaps related to a reduction in summer sea ice extent between ca 3500 and ca 2400 14c yr bp the curve for the south shetland islands is derived entirely from published 14c dates from isolation basins and on whalebone penguin bone and seal bone the curve shows an initial relative sea level fall which was interrupted by a period in the mid holocene when relative sea level rose to a highstand of between 14 5 and 16 m above mean sea level amsl before falling again

late quaternary environmental changes in marguerite bay antarctic peninsula inferred from lake sediments and raised beaches the antarctic peninsula is one of the fastest warming regions on earth but its palaeoenvironmental history south of 63 latitude is relatively poorly documented relying principally on the marine geological record and short ice cores in this paper we present evidence of late quaternary environmental change from the marguerite bay region combining data from lake sediment records on horseshoe island and pourquoi pas island and raised beaches at horseshoe island pourquoi pas island and calmette bay lake sediments were radiocarbon dated and analysed using a combination of sedimentological geochemical and microfossil methods raised beaches were surveyed and analysed for changes in clast composition size and roundness results suggest a non erosive glacial regime could have existed on horseshoe island from 35 780 38 650 33 380 or 32 910 34 630 31 370 cal yr bp onwards there is radiocarbon and macrofossil evidence for possible local deglaciation events at 28 830 29 370 28 320 cal yr bp immediately post dating antarctic isotopic maximum 4 and 21 110 21 510 20 730 interpolated cal yr bp coinciding with or immediately post dating antarctic isotopic maximum 2 the holocene deglaciation of horseshoe island commenced from 10 610 11 000 10 300 cal yr bp at the same time as the early holocene temperature maximum recorded in antarctic ice cores this was followed by the onset of marine sedimentation in the narrows pourquoi pas island before 8850 8480 9260 cal yr bp relative sea level high stands of 40 79 m above present at pourquoi pas island and 40 55 m above present at calmette bay occurred sometime after 9000 cal yr bp and suggest that a thicker ice sheet including grounded ice streams was present in this region of the antarctic peninsula than that recorded at sites further north isolation of the narrows lake basin on pourquoi pas island shows relative sea level in this region had fallen rapidly to 19 41 m by 7270 7385 7155 cal yr bp chaetoceros resting spores suggest high productivity and stratified surface waters in the narrows after 8850 9260 8480 cal yr bp and beach clasts provide evidence of a period of increased wave energy at approximately 8000 yr bp lake sediment and beach data suggest an extended period of regional warming sometime between 6200 and 2030 cal yr bp followed by the onset of neoglacial conditions from 2630 and 2030 cal yr bp in narrows lake and col lake 1 respectively diatom and 13c vs c n and macrofossil evidence suggest a potential increase in the number of birds and seals visiting the narrows lake catchment sometime after 2100 2250 2000 cal yr bp with enhanced nutrient enrichment evident after 1150 1230 1080 cal yr bp and particularly from c 460 540 380 cal yr bp a very recent increase in gomphonema species and organic carbon in the top centimetre of the narrows lake sediment core after c 410 490 320 cal yr bp and increased sedimentation rates in the col lake 1 sediment core after c 400 490 310 cal yr bp may be a response to the regional late holocene warming of the antarctic peninsula

statistical analysis and forecasts of long term sandbank evolution at great yarmouth uk abstract a data driven model has been developed to analyse the long term evolution of a sandbank system and to make ensemble predictions in a period of 8 years the method uses a combination of empirical orthogonal function eof analysis to define spatial and temporal patterns of variability jack knife resampling to generate an ensemble of eofs a causal auto regression technique to extrapolate the temporal eigenfunctions and straightforward statistical analysis of the resulting ensemble of predictions to determine a forecast and associated uncertainty the methodology has been applied to a very demanding site which includes a curved shoreline and a group of mobile nearshore sandbanks the site is on the eastern coast of the uk and includes the great yarmouth sandbanks and neighbouring shoreline a sequence of 33 high quality historical survey charts reaching back to 1848 have been used to analyse the patterns and to predict morphological evolution of the sandbank system the forecasts demonstrate an improved skill relative to an assumption of persistence but suffer in locations where there are propagating features in the morphology that are not well described by eofs

a geological constraint on relative sea level in marine isotope stage 3 in the larsemann hills lambert glacier region east antarctica 31 366 33 228 cal yr bp abstract in this paper we present geological evidence from the larsemann hills lambert glacier amery ice shelf region east antarctica of marine sediments at an altitude of c 8 m a s l as revealed by diatom pigment and geochemical proxies in a lake sediment core the sediments yielded radiocarbon dates between c 26 650 and 28 750 14c yr bp 31 366 33 228 cal yr bp this information can be used to constrain relative sea level adjacent to the lambert glacier at the end of marine isotope stage 3 these data are compared with the age and altitude of marine isotope stage 3 marine deposits elsewhere in east antarctica and discussed with reference to late quaternary ice sheet history and eustatic sea level change

late holocene relative sea level rise and the neoglacial history of the greenland ice sheet in west greenland early and mid holocene relative sea level rsl fall was replaced by late holocene rsl rise during the neoglacial after 4 3 cal ka bp thousand calibrated years before present here we present the results of an isolation basin rsl study completed near to the coastal town of sisimiut in central west greenland rsl fell from 14 m above sea level at 5 7 cal ka bp to reach a lowstand of 4 0 m at 2 3 1 2 cal ka bp before rising by an equivalent amount to present differences in the timing and magnitude of the rsl lowstand between this and other sites in west and south greenland record the varied interplay of local and non greenland rsl processes notably the reloading of the earth s crust caused by a neoglacial expansion of the greenland ice sheet gis and the subsidence associated with the collapse of the laurentide ice sheet forebulge this means that the timing of the sea level lowstand cannot be used to infer directly when the gis advanced during the neoglacial the rise in late holocene rsl is contrary to recently reported bedrock uplift in the sisimiut area based on repeat gps surveys this indicates that a belt of peripheral subsidence around the current ice sheet margin was more extensive in the late holocene and that there has been a switch from subsidence to uplift at some point in the last thousand years or so

reproduction of estuarine bathymetry by means of a process based model western scheldt case study the netherlands abstract the current study aims to investigate the processes governing the evolution of major morphological features in alluvial estuaries as well as their morphodynamic interaction with the geometry by means of a 3d morphodynamic process based numerical model delft3d the main hypothesis is that channel shoal patterns evolve through the interaction between tidal movement the available sediments and the tidal basins geometry once such a system is not disturbed too much by extreme events stable morphological patterns will emerge that compare well with observed features starting from a flat bed and imposing the western scheldt geometry model results show two distinct time scales i e channel shoal pattern formation within decades and a slow longitudinal profile development continuing for centuries the developing channel shoal patterns reflect major morphological features observed in the western scheldt estuary using the 1998 bathymetry as a reference we applied different indicators and techniques to evaluate the model performance over time namely visual comparison hypsometries brier skill score bss mean basin depth and longitudinal profiles sensitivity analysis shows that trends in development are similar for different model parameter settings like introducing salt fresh water density differences or variations in sediment grain size and sediment transport formulation varying river discharge and including non erodible layers dredging and dumping activities and 3d hydrodynamics led to occasional improvements the geometry is an important governing factor for pattern development applying an erodible geometry reveals a timescale for geometric adaptation that is much longer than the pattern development timescale within the basin model runs including highly schematized extreme conditions suggest that extreme events play a limited role the main conclusion of the study is that the interaction between tidal forcing and basin geometry plays a major role in the development of morphological features in an alluvial tidal basin such as the western scheldt a process based model taking into account these major forcing mechanisms can predict such features with significant skill the bathymetries generated in this study may form the basis for further studies considering for example the impact of sea level rise on estuarine morphodynamic development or a rapid assessment of estuarine bathymetry in the absence of measured data

patterns of isostatic land uplift during the holocene evidence from mainland scotland preliminary results of a lengthy and detailed investigation into middle and late holocene raised shorelines in mainland scotland indicate that three shorelines are sufficiently widely distributed to permit an examination of their extent and of the patterns of uplift which they indicate the shorelines are the storegga tsunami shoreline reached at c 7100 14c years bp at the culmination of the main postglacial transgression and the blairdrummond shoreline reached after the main postglacial shoreline at c 2000 4200 14c years bp at the time of a tsunami believed to have been caused by the second storegga submarine slide the main postglacial shoreline reached at c 5800 6850 14c years bp the main postglacial shoreline previously believed to be the highest holocene raised shoreline in scotland is now believed to be overlapped around the periphery of the uplifted area by the later blairdrummond shoreline isobase models based upon quadratic trend surface analysis of available comparable height dat

the effect of sea breeze on beach morphology surf zone hydrodynamics and sediment resuspension abstract beach morphodynamic processes were investigated over part of a sea breeze cycle on a microtidal low wave energy sandy beach in southwestern australia prior to the onset of the sea breeze offshore winds with speeds less than 5 m s prevailed during the sea breeze alongshore winds with speeds higher than 10 m s were experienced the sea breeze induced pronounced changes to the nearshore morphodynamics which were similar to that of a storm event 1 root mean square wave height increased from 0 3 to 0 5 m 2 zero upcrossing wave period decreased from 8 to 4 s 3 mean cross shore flows reached velocities of 0 2 m s directed offshore and 4 the longshore current increased in strength from 0 05 to 1 0 m s before the sea breeze sediment resuspension typically occurred during isolated high wave events associated with the passage of wave groups flux coupling between the wave oscillatory currents and the suspended sediment jaffe b e sternberg r w sallenger a h 1984 the role of suspended sediment in shore normal beach profile changes proc 19th int conf coastal engineering asce pp 1983 1996 induced net onshore suspended sediment transport resulting in beachface accretion and a steepening of the foreshore profile in contrast during the sea breeze sediment resuspension was almost continuous the suspended sediment load increased six fold and as a consequence the longshore suspended sediment transport rate increased by a factor of 100 during the sea breeze cross shore transport was directed offshore and primarily associated with mean offshore flows this resulted in erosion of the beachface and deposition in the surf zone and consequently a flattening of the beach profile the suspended sediment load was strongly related to the shields parameter defined for the combined action of waves and currents investigation of the suspended sediment profiles indicated that the degree of vertical mixing parameterised by the sediment diffusion coefficient increased with distance from the bed in addition the sediment diffusion coefficient exhibited a large temporal variation ranging between 0 005 and 0 018 m2 s the variability in the sediment diffusion coefficient is possibly due to changes in the sea bed morphology

ice stream initiation duration and thinning on james ross island northern antarctic peninsula predicting the future response of the antarctic ice sheet to climate change requires an understanding of the ice streams that dominate its dynamics here we use cosmogenic isotope exposure age dating 26al 10be and 36cl of erratic boulders on ice free land on james ross island north eastern antarctic peninsula to define the evolution of last glacial maximum lgm ice in the adjacent prince gustav channel these data include ice sheet extent thickness and dynamical behaviour prior to 18 ka the lgm antarctic peninsula ice sheet extended to the continental shelf edge and transported erratic boulders onto high elevation mesas on james ross island after 18 ka there was a period of rapid ice sheet surface lowering coincident with the initiation of the prince gustav ice stream this timing coincided with rapid increases in atmospheric temperature and eustatic sea level rise around the antarctic peninsula collectively these data provide evidence for a transition from a thick cold based lgm antarctic peninsula ice sheet to a thinner partially warm based ice sheet during deglaciation

assessing the link between coastal morphology wave energy and sea ice throughout the holocene from antarctic raised beaches post glacial rebound has preserved beaches across many ice free parts of the antarctic coastline these beaches typically contain gravel to boulder sized deposits and are built by high magnitude waves five new ages from the western antarctic peninsula were added to a compilation of 282 published ages from antarctic beaches a reduced compilation based solely on those ages that date beach formation is used to assess variations in beach formation throughout the holocene around antarctica we suggest the clustering of beach ages centered at 0 8 and 2 4 ka in the antarctic peninsula 1 5 3 6 and 6 0 ka in the ross sea and a broad peak from 2 7 to 6 3 ka in east antarctica indicates periods of heightened wave exposure leading to increased beach formation measurements of clast roundness from raised beaches show more rounded material is coincident with periods of heightened beach formation providing an independent means of assessing wave climate a comparison of periods of increased beach formation with available sea ice proxies suggests beach formation is synchronous with reduced sea ice conditions and thus higher wave climate as the presence or absence of sea ice determines open water conditions the factors that control sea ice directly influence antarctic coastal evolution

reconstructing the alps carpathians dinarides as a key to understanding switches in subduction polarity slab gaps and surface motion palinspastic map reconstructions and plate motion studies reveal that switches in subduction polarity and the opening of slab gaps beneath the alps and dinarides were triggered by slab tearing and involved widespread intracrustal and crust mantle decoupling during adria europe collision in particular the switch from south directed european subduction to north directed wrong way adriatic subduction beneath the eastern alps was preconditioned by two slab tearing events that were continuous in cenozoic time 1 late eocene to early oligocene rupturing of the oppositely dipping european and adriatic slabs these ruptures nucleated along a trench trench transfer fault connecting the alps and dinarides 2 oligocene to miocene steepening and tearing of the remaining european slab under the eastern alps and western carpathians while subduction of european lithosphere continued beneath the western and central alps following the first event post late eocene nw motion of the adriatic plate with respect to europe opened a gap along the alps dinarides transfer fault which was filled with upwelling asthenosphere the resulting thermal erosion of the lithosphere led to the present slab gap beneath the northern dinarides this upwelling also weakened the upper plate of the easternmost part of the alpine orogen and induced widespread crust mantle decoupling thus facilitating pannonian extension and roll back subduction of the carpathian oceanic embayment the second slab tearing event triggered uplift and peneplainization in the eastern alps while opening a second slab gap still present between the eastern and central alps that was partly filled by northward counterclockwise subduction of previously unsubducted adriatic continental lithosphere in miocene time adriatic subduction thus jumped westward from the dinarides into the heart of the alpine orogen where northward indentation and wedging of adriatic crust led to rapid exhumation and orogen parallel escape of decoupled eastern alpine crust toward the pannonian basin the plate reconstructions presented here suggest that miocene subduction and indentation of adriatic lithosphere in the eastern alps were driven primarily by the northward push of the african plate and possibly enhanced by neutral buoyancy of the slab itself which included dense lower crust of the adriatic continental margin

biota and geomorphic processes as key environmental factors controlling soil formation at elephant point maritime antarctica abstract we examined the main soil forming factors affecting the soil composition soil properties and the associated soil forming processes at elephant point a small ice free environment in the south shetland islands maritime antarctica for this purpose we collected twenty soil samples from each of ten different sites distributed along a linear transect running from the coast to the front of the rotch dome glacier the samples were obtained from surface layers 0 10 cm and at depth 40 50 cm although collection was limited in the moraine area by the permafrost table we determined ph electrical conductivity size particle distribution total organic carbon total nitrogen and total concentrations of al fe ca and p for physical and chemical characterization of the samples we also analysed the samples to determine the bioavailability of nutrients and fe al and p partitioning and finally examined them by isotopic 15n and x ray diffraction xrd analysis the results of the analyses revealed two clear geochemical environments corresponding to the two most extensive geomorphological units in this peninsula moraine and marine terraces soils from the moraine were characterized by alkaline reaction and high quantity of minerals with a low degree of crystallinity whereas soils from the marine terraces showed acid reaction high concentration of organometallic complexes and a high diversity of phosphate minerals taranakite minyulite struvite hydroxylapatite and leucophosphite which seem to be generated by phosphatization of faecal matter deposited by seabirds and seals consequently biota activity is the most relevant soil differentiating factor in the marine terraces which add organic matter and activate geochemical cycles on the other hand geomorphic processes strongly affected by physical weathering processes such as glacial abrasion by grinding process frost shattering and wind abrasion are the main soil forming factors in moraine these forces break up the parent material transform it and translocate the products formed

the marine record of deglaciation of the south shetland islands antarctica since the last glacial maximum abstract the marine geological record of the glacial retreat history of the south shetland islands is derived from the integration of seismic data core lithofacies radiocarbon ages and geomorphological data from two study areas on the northern shelf we present one of the first published multibeam bathymetric images of the seafloor this new image combined with descriptions of new and existing short sediment cores and high resolution seismic data from the continental shelf north of king george island are used to map a grounding zone wedge that marks the minimum seaward extent of the south shetland ice cap during the last glacial maximum seismic data multibeam bathymetry and sediment cores from maxwell bay on the opposite side of king george island are used to provide further spatial constrains on the history of grounding and retreat of the ice cap along the southern margin of the south shetland islands during the last glacial maximum the south shetland ice cap extended onto the outer continental shelf some 50 km north of its present location the ice grounded on the shelf in troughs in present water depths of almost 400 m it had a minimum thickness of 570 m and was also grounded in the deepest part of fjords and straits between the islands to the south the ice cap extended seaward of the mouths of fjords and straits to the steep northern boundary of the bransfield strait sediment eroded from the fjords and straits was deposited in prominent fans that extend into the bransfield strait and show evidence for an ice shelf that covered the bransfield strait during the last glacial maximum a long drill core shaldril in maxwell bay and several jumbo piston cores yielded carbonate material used to constrain the timing and spatial extent of glacial retreat within maxwell bay the oldest glacimarine sediments in the fjord date back to 14 1 to 14 8 ka and suggest an initial deglaciation earlier than most previous studies of the south shetland islands upper maxwell bay was ice free by 9 1 ka and most of maxwell bay proper was ice free by 5 9 ka except for the smaller tributary fjords of maxwell bay these smaller tributary fjords were ice free by 1 7 ka but may have been ice free earlier but reoccupied by a neoglacial advance that ended approximately 1 7 ka

patterns of spatio temporal paraglacial response in the antarctic peninsula region and associated ecological implications abstract the antarctic peninsula ap constitutes the warmest region of antarctica although 98 of the surface is still covered by glaciers the region shows contrasting geographic and climatic properties which have conditioned past and present glacial activity this paper constitutes a review of the spatial and temporal patterns of paraglacial activity across the ap bridging the geomorphological and ecological perspectives the number and extent of ice free environments has increased since the last glacial maximum particularly during the early holocene and the 20th century following deglaciation the redefinition of coastlines and the uplift of landmasses proceeded differently in the three sectors of ap with maximum uplift in the western sector 40 m a s l the minimum on the north 20 4 m a s l and intermediate in the eastern sector 30 m there are also differences in the levels of raised beaches with the highest complexity in the northern ap 5 7 levels and the lowest in the eastern ap 3 levels the transition from glacial to periglacial conditions paraglacial stage also differed greatly between the three sectors with the absence of rock glaciers in the western sector the development almost exclusively of glacier derived rock glaciers in the eastern ap and the majority of talus derived rock glaciers in the northern ap the development of protalus lobes block streams and other periglacial features was highly dependent on the cold warm based character of individual glaciers this characteristic determines the existence or absence of permafrost following deglaciation which in turn conditions the type and intensity of geomorphic processes in newly exposed ice free areas more recently following the post 1950s regional warming there have still been important differences between the three sectors in the development of paraglacial environments permafrost degradation has occurred in newly exposed areas accelerating mass wasting and sediment redistribution and changing hydrological processes especially in the northern and western ap while sudden glacial outburst flooding has occurred in the eastern ap the most apparent major ecological response to this recent warming is greening due to vegetation expansion which is more evident where paraglacial and periglacial processes are less intense the accurate characterization of the different paraglacial responses existing in the ap enables a better understanding of future environmental responses in this climatically sensitive region where climate models forecast significant environmental change for during forthcoming decades

relative sea level history from the lambert glacier region east antarctica and its relation to deglaciation and holocene glacier readvance we present a relative sea level rsl history constrained by ams radiocarbon dated marine freshwater transitions in isolation basins from a site adjacent to the lambert glacier east antarctica the rsl data suggest an initial ice retreat between c 15 370 and 12 660 cal yr b p within this period meltwater pulse ia mwp ia between c 14 600 14 200 and 14 100 13 700 cal yr b p occurred an exceptionally large ice melting event inferred from far field sea level records the rsl curve shows a pronounced highstand of approximately 8 m between c 7570 7270 and 7250 6950 cal yr b p that is consistent with the timing of the rsl highstand in the nearby vestfold hills this is followed by a fall in rsl to the present in contrast to previous findings the isolation of the lakes in the larsemann hills postdates the isolation of lakes with similar sill heights in the vestfold hills an increase in rsl fall during the late holocene may record a decline in the rate of isostatic uplift in the larsemann hills between c 7250 6950 and 2847 2509 cal yr b p that occurred in response to a documented mid holocene glacier readvance followed by a late holocene retreat

quaternary sea level changes in western scotland abstract in recent years major advances have been made in our understanding of late quaternary sea level changes in western scotland in particular new hypotheses have been advanced to explain the ages and origins of high level rock platform fragments and high level marine shell beds certain raised shorelines in islay and jura sw argyll and wester ross have been related to former margins of the last ice sheet and are associated with drops in the lateglacial marine limit in some areas the decline in lateglacial sea level took place in association with a stationary ice margin while in others the fall in sea level occurred in conjunction with considerable ice retreat during the lateglacial interstadial relative sea level fell rapidly between ca 13 and ca 12 ka bp and thereafter more slowly until ca 11 ka bp renewed marine erosion during the cold climate of the loch lomond younger dryas stadial ca 11 10 ka bp resulted in the production of the main lateglacial shoreline which declines in altitude to the w sw and s away from the centre of glacio isostatic uplift in the w highlands the shoreline has a maximum altitude of 10 11 m o d in the oban area and passes below sea level in ne islay ardnamurchan colonsay w mull kintyre and arran during the early holocene a pronounced marine transgression took place probably culminating between 6 6 and 7 0 ka bp the culmination of the transgression is represented by the main postglacial shoreline that reaches a maximum altitude of ca 14 m in the oban area and declines gently in altitude away from the centre of glacio isostatic uplift reconstruction of the uplift isobases for this shoreline appears to indicate a slight eastward migration of the uplift centre since the younger dryas in peripheral areas of western scotland the main postglacial shoreline is not present owing to the effect of holocene submergence

timing of formation of neoglacial landforms in the south shetland islands antarctic peninsula regional and global implications abstract the timing of neoglacial advances in the antarctic peninsula ap is not yet well constrained accurate temporal reconstruction of neoglaciation in the ap is needed to better understand past glacial responses and regional and global teleconnections during the holocene here we examine all available information about neoglacial advances in the south shetland islands ssi as well as in the broader geographical context of the ap region and antarctic continent in order to shed light on the contrasting chronologies existing for neoglacial advances in these regions we focused on a case study where a detailed picture of the holocene deglaciation was already available lake sediments revealed that byers peninsula west of livingston island ssi was fully deglaciated during the holocene thermal maximum to complement this approach we identified glacially polished bedrock surfaces erratic boulders and a moraine ridge near the present front of the glacier in the se corner we applied cosmogenic ray exposure cre dating using in situ 36cl for basalt rocks and 10be for granitic rocks in i 8 samples from glacial erratic and ice rafted boulders ii 2 samples from moraine boulders iii 2 samples from polished bedrock surfaces and iv 1 sample from an erratic boulder deposited on one of these surfaces the cre dates indicate that the onset of deglaciation started around 9 9 1 2 ka with two phases of glacier expansion during the mid late holocene forming moraines at 4 1 0 5 and 1 0 0 2 ka respectively the main neoglacial advances in the ap and the ssi were mostly synchronous and coincided with cold periods as shown by other records e g glacio isostatic marine terraces marine and lake sediments in addition these periods of glacial expansion show a similar timing to those recorded in the arctic these results suggest that neoglaciation was driven by global climate forcing in both polar areas despite temporal variations at regional and local scale

facies architecture of the upper oligocene submarine smrekovec stratovolcano northern slovenia abstract the upper oligocene smrekovec volcanic complex svc represents the remains of a submarine stratovolcano which underwent early miocene tectonic dissection and large scale displacement along the periadriatic line according to the lithofacies architecture abundance and spatial distribution central medial and distal zones of the former volcano edifice have been recognized the zones extend at a distance of 0 2 km 2 5 km and 5 20 km south of the periadriatic line respectively lavas shallow intrusive bodies autobreccia peperite and hyaloclastite deposits occur mainly in the central zone which is extensively altered under hydrothermal conditions characterised by the development of zeolites mainly laumontite prehnite chlorite albite and epidote explosive volcanic activity intensified with the evolution of magma from basaltic andesitic to dacitic gas and water supported eruption fed density flows are assumed their deposits show lithofacies organisation in pyroclastic depositional units pdus similar to either volcaniclastic turbidites type 1 or thin subaqueous ignimbrites type 2 volcaniclastic debris flow deposits are developed as volcaniclastic breccia and sandy debris flow deposits the former occurs in the central and medial zones and the latter occurs in the medial zone only the most widespread lithofacies in the svc are volcaniclastic turbidite deposits three types of sedimentary unit tsu have been distinguished type 1 is 2 5 m thick and dominated by the massive division it mainly occurs in the central zone type 2 is 0 7 3 5 m thick and occurs in the central and medial zones it comprises the massive division bedded fining and thinning upward division and a horizontally wavy and cross laminated division topped by massive fine grained tuff type 3 is 0 1 1 5 m thick and mainly occurs in the distal zone the massive division is absent and thinly bedded and laminated divisions are topped by massive fine grained tuff volcaniclastic turbidites were settled from low density turbidity currents and related suspension clouds mixed volcaniclastic siliciclastic deposits are subordinate in occurrence and restricted to the distal zone they are commonly reworked by bottom currents

retreating glacier fronts on the antarctic peninsula over the past half century the continued retreat of ice shelves on the antarctic peninsula has been widely attributed to recent atmospheric warming but there is little published work describing changes in glacier margin positions we present trends in 244 marine glacier fronts on the peninsula and associated islands over the past 61 years of these glaciers 87 have retreated and a clear boundary between mean advance and retreat has migrated progressively southward the pattern is broadly compatible with retreat driven by atmospheric warming but the rapidity of the migration suggests that this may not be the sole driver of glacier retreat in this region

long term morphodynamic evolution of estuaries an inverse problem abstract a new technique for predicting long term variations in estuary morphology is developed using a morphological evolution equation that isolates diffusive and non diffusive processes in estuaries the contribution from non diffusive processes to the morphological changes of the estuary is incorporated in the governing equation by a source function the source function is derived by solving an inverse problem using historic survey data of the humber estuary uk covering a period of 150 years source functions derived for the consecutive pairs of bathymetry surveys show a significant structure persistent throughout the entire data set large scale features such as tidal channels tidal flats and linear banks in the outer estuary are persistently visible in the source function empirical orthogonal function eof analysis is used to analyse the spatial and temporal variation in the source function the first spatial eigenfunction which corresponds to the time mean value of the source function captures over 92 of the mean square of the data over 65 of the data variance is captured by the first six eigenfunctions the first temporal eigenfunction which corresponds to the mean value of the source function is almost constant as expected

holocene isostatic uplift of the south shetland islands antarctic peninsula modelled from raised beaches we present new isobases constraining the holocene isostatic uplift of the south shetland islands northern antarctic peninsula based on evidence from raised shorelines holocene shorelines were described and surveyed at fifteen sites to determine the spatial variability of relative sea level rsl change across the south shetland islands and provide new spatial rsl change corrections for the region results show that the highest shoreline is a transgressive feature correlated by geomorphological evidence on most exposed coastlines of the archipelago its surveyed height was corrected for local variability in wave energy by subtracting the measured altitude of the present day shoreline these corrected surveyed heights of the highest raised beach were modelled using quadratic polynomial trend surface analysis to constrain differing rates of regional isostatic uplift we present two isobase models of isostatic uplift since formation of the highest holocene raised beach circa 7360 7000 years ago these models suggests a maximum uplift of ca 20 m was centred on an area north of greenwich island with isobases implying an elongate zone of uplift orientated east southeast to west northwest along the spine of the island chain this corresponds well with previously published geomorphologically based estimates of palaeo ice extent and the deglaciation history of the south shetland islands and gives new context to the palaeo ice extent and glacial history of the region

rapid collapse of northern larsen ice shelf antarctica in january 1995 4200 square kilometers of the northern larsen ice shelf antarctic peninsula broke away radar images from the ers 1 satellite complemented by field observations showed that the two northernmost sections of the ice shelf fractured and disintegrated almost completely within a few days this breakup followed a period of steady retreat that coincided with a regional trend of atmospheric warming the observations imply that after an ice shelf retreats beyond a critical limit it may collapse rapidly as a result of perturbated mass balance

a new holocene relative sea level curve for the south shetland islands antarctica abstract precise relative sea level rsl data are important for inferring regional ice sheet histories as well as helping to validate numerical models of ice sheet evolution and glacial isostatic adjustment here we develop a new rsl curve for fildes peninsula south shetland islands ssis a sub antarctic archipelago peripheral to the northern antarctic peninsula ice sheet by integrating sedimentary evidence from isolation basins with geomorphological evidence from raised beaches this combined approach yields not only a holocene rsl curve but also the spatial pattern of how rsl change varied across the archipelago the curve shows a mid holocene rsl highstand on fildes peninsula at 15 5 m above mean sea level between 8000 and 7000 cal a bp subsequently rsl gradually fell as a consequence of isostatic uplift in response to regional deglaciation we propose that isostatic uplift occurred at a non steady rate with a temporary pause in ice retreat ca 7200 cal a bp leading to a short lived rsl rise of 1 m and forming a second peak to the mid holocene highstand two independent approaches were taken to constrain the long term tectonic uplift rate of the ssis at 0 22 0 48 m ka placing the tectonic contribution to the reconstructed rsl highstand between 1 4 and 2 9 m finally we make comparisons to predictions from three global sea level models

relative sea level history of marguerite bay antarctic peninsula derived from optically stimulated luminescence dated beach cobbles abstract calmette bay within marguerite bay along the western side of the antarctic peninsula contains one of the most continuous flights of raised beaches described to date in antarctica raised beaches extend to 40 8 m above sea level masl and are thought to reflect glacial isostatic adjustment due to the retreat of the antarctic peninsula ice sheet using optically stimulated luminescence osl we dated quartz extracts from cobble surfaces buried in raised beaches at calmette bay the beaches are separated into upper and lower beaches based on osl ages geomorphology and sedimentary fabric the two sets of beaches are separated by a prominent scarp one of our osl ages from the upper beaches dates to 9 3 thousand years ago ka as of 1950 consistent with previous extrapolation of sea level data and the time of ice retreat from inner marguerite bay however four of the seven ages from the upper beaches date to the timing of glaciation we interpret these ages to represent reworking of beaches deposited prior to the last glacial maximum lgm by advancing and retreating lgm ice ages from the lower beaches record relative sea level fall due to holocene glacial isostatic adjustment we suggest a holocene marine limit of 21 7 masl with an age of 5 5 7 3 ka based on osl ages from calmette bay and other sea level constraints in the area a marine limit at 21 7 masl implies half as much relative sea level change in marguerite bay during the holocene as suggested by previous sea level reconstructions no evidence for a relative sea level signature of neoglacial events such as a decrease followed by an increase in rsl fall due to ice advance and retreat associated with the little ice age is found within marguerite bay indicating either 1 no significant neoglacial advances occurred within marguerite bay 2 rheological heterogeneity allows part of the antarctic peninsula i e the south shetland islands to respond to rapid ice mass changes while other regions are incapable of responding to short lived ice advances or 3 the magnitude of neoglacial events within marguerite bay is too small to resolve through relative sea level reconstructions although the application of reconstructing sea level histories using osl dated raised beach deposits provides a better understanding of the timing and nature of relative sea level change in marguerite bay we highlight possible problems associated with using raised beaches as sea level indices due to post depositional reworking by storm waves

reaction of a polar gravel spit system to atmospheric warming and glacier retreat as reflected by morphology and internal sediment geometries south shetland islands antarctica sedimentary architecture and morphogenetic evolution of a polar bay mouth gravel spit system are revealed based on topographic mapping sedimentological data radiocarbon dating and ground penetrating radar investigations data document variable rates of spit progradation in reaction to atmospheric warming synchronous to the termination of the last glacial re advance lgr 0 45 0 25 ka bp the southern hemisphere equivalent of the little ice age cooling period results show an interruption of spit progradation that coincides with the proposed onset of accelerated isostatic rebound in reaction to glacier retreat spit growth resumed in the late 19th century after the rate of isostatic rebound decreased and continues until today the direction of modern spit progradation however is rotated northwards compared with the growth axis of the early post lgr spit this is interpreted to reflect the shift and strengthening in the regional wind field during the last century a new concept for the interplay of polar gravel spit progradation and glacio isostatic adjustment is presented allowing for the prediction of future coastal evolution in comparable polar settings

holocene sea level changes and glacio isostasy in the gulf of finland baltic sea abstract shoreline displacement in the eastern part of the gulf of finland during the past 9000 radiocarbon years was reconstructed by studying a total of 10 isolated lake and mire basins located in virolahti in southeastern finland and on the karelian isthmus and in ingermanland in russia study methods were diatom analyses sediment lithostratigraphical interpretation and radiocarbon dating in southeastern finland the marine litorina transgression maximum occurred ca 6500 6200 14 c yr bp 7400 7100 cal yr bp in areas of the slower land uplift rate on the karelian isthmus and in ingermanland the transgression maximum occurred ca 6400 6000 14 c yr bp 7300 6800 cal yr bp the highest litorina shoreline is located at ca 23 m above present sea level in southeastern finland whereas in the eastern part of the karelian isthmus near st petersburg it is located at ca 8 m above present sea level the amplitude of the litorina transgression in virolahti area is ca 4 m whereas on the karelian isthmus and in ingermanland the amplitude has varied between 5 and 7 m the regional differences between areas are solely due to different glacio isostatic land uplift rates the seven basins studied in this research were connected to the baltic sea basin during the litorina sea stage and their diatom and lithostratigraphical records indicate a single smooth litorina transgression

extracting decadal morphological behaviour from high resolution long term bathymetric surveys along the holland coast using eigenfunction analysis abstract the understanding and prediction of coastal behaviour over a time span of decades and alongshore stretches of tens of kilometres is important in coastal management the controlling variables for coastal behaviour on these scales are yet unknown it is hypothesised that regions exhibiting different large scale coastal behaviour lscb regions are controlled by different hydrodynamic forcings or by different sedimentological or morphological constraints or by some combination of these factors the objective of this study is to elaborate a method that effectively quantifies large scale morphological changes from a large bathymetric data set large temporal and spatial extent combined with a high resolution such to define lscb regions the method of analysis consists of a combination of the empirical eigenfunction technique and a moving window approach the method has been applied on a data set of over 14 000 nearshore profiles the data set consists of yearly soundings of the nearshore profile along a coastal stretch of 115 km length the holland coast the alongshore profile spacing is generally 250 m all profiles surveyed in the period 1963 1990 are included in the analysis application of the method on the dutch data set reveals that lscb regions indeed can be identified the sizes of the lscb regions are 5 km 15 km 20 km 32 km and 42 km differences in behaviour of the secondary morphology i e morphology other than the mean profile shape e g nearshore bars are most pronounced the change in behaviour between lscb regions generally occurs over distances as short as about 2 km the boundaries between the regions are therefore surprisingly sharp in general no clear long term trends in the development of the shape of the sub aqueous profile have been observed along the holland coast along certain stretches trends in cross shore shifting of the sub aqueous profile occurred the average shape of the sub aqueous profile seems to have no relation with the trend in cross shore shifting of the shoreline the 1 m contour the sub decadal shoreline fluctuations however are possibly related to the largescale dynamics of multiple bar systems

alteration in the irdp drill hole compared with other drill holes in iceland the overall alteration pattern in the drill hole at reydarfjordur is very similar to alteration patterns observed in icelandic geothermal areas and in low grade metamorphosed basalts in deep crustal sections elsewhere in iceland however more detail is obtained by the study of the irdp drill core than by study of drill cuttings sampled in previous drill holes in iceland a comparatively high fossil thermal gradient is obtained at reydarfjordur by a combination of mineral stability data and the observed occurence of secondary minerals this high gradient is consistent with the measured dike dilation at the drill site and the location of the drill site adjacent to a central volcano

on the formation of sand banks of finite extent we consider a model where the fluid depth depends on both horizontal coordinates quasi steady depth uniform non divergent fluid flow is governed by inertial pressure and bottom frictional forces sand transport is proportional to the cube of the instantaneous current but augmented by a down slope component and by wind wave action and sand is conserved it is found that low parallel banks grow fastest so that in an extensive spatially uniform sea previous calculations for linear banks are appropriate the inclination of banks to the tidal currents can be interpreted in terms of similarly inclined deposition bands resulting from vorticity generation and advection in flow over a small isolated hump a small bump can evolve to an equilibrium bank typically after an initial rapid extension across the tidal currents provided that sand is sufficiently restricted and particularly if some wind wave action prevents growth up to the sea surface sand banks are likely to be in a late stage of evolution when the main change is a slow lengthening as the net current and transport along the bank side slows and turns around the bank end with net deposition the equilibrium is apparently stable except when there is an overall bed slope in the direction of the tidal currents or when sand is abundant

compositions and parageneses of secondary minerals in the onikobe geothermal system japan abstract parageneses and chemical compositions of secondary minerals in many core samples of the onikobe geothermal system japan were investigated in detail in order to evaluate the controls of geothermal waters on alterations of andesitic dacitic rocks depth zonations of secondary minerals were delineated for cazeolites as mordenite laumontite yugawaralite wairakite and clay minerals as smectite alkaline smectite chlorite smectite chlorite compositional variations with depth hence temperature are apparent for smectite chlorite and illite chlorite interstratified clay minerals but not for wairakite both prehnite and epidote at depth have fe rich compositions and become more aluminous with increasing depth the ubiquitous occurrence of pyrite and rare magnetite and the absence of hematite suggest that the onikobe system had fs2 fo2 conditions within the pyrite stability field the occurrence of abundant calcite and ca zeolites indicates that thermal waters at depth are neutral to slightly alkaline and xco2 is very low to stabilize ca al silicates this conclusion is consistent with the production of a remarkable amount of alkaline high temperature steam and thermal waters in a newly drilled production well

statistical analysis of coastal morphological data sets over seasonal to decadal time scales statistical analysis of long term morphological data on coastal sedimentary features provides important information on the processes governing these features and their evolution in space and time in this paper seasonal yearly and decadal i e long term behavior of coastal morphological features is derived from field data by using both simple and advanced statistical techniques the sedimentary features which we are especially focusing on are a nearshore bars and b large scale shoreline undulations for example longshore sand waves and nesses high quality bathymetric field data of regularly sampled cross shore profiles and shorelines were the basis of the available data sets at noordwijk beach the netherlands duck north carolina usa sylt germany lubiatowo poland and winterton uk additional data sets from argus video images see holman r a stanley j 2007 the history capabilities and future of argus coastal engineering special issue of the coastview project doi 10 1016 j coastaleng 2007 01 003 and aerial photographs were used to increase the temporal and spatial resolution of the data sets where possible the statistical methods applied include some linear and non linear techniques described by larson et al larson m capobianco m jansen h rozyfiski g southgate h n stive m wijnberg k m hulscher s 2003 analysis and modeling of field data on coastal morphological evolution over yearly and decadal time scales part 1 background and linear techniques journal of coastal research 19 4 760 775 and southgate et al southgate h n wijnberg k m larson m capobianco m jansen h 2003 analysis of field data of coastal morphological evolution over yearly to decadal timescales part 2 non linear techniques journal of coastal research 19 4 776 789 the methods proved to be useful for extracting characteristics of the coastal sedimentary features concerning length scales e g spacing and rhythmicity and temporal scales e g migration rates and evolutionary patterns however the success of the statistical analysis strongly depends on the total size of the data set characterized by the specific spatial coverage spatial resolution temporal resolution and overall length in time recent data sets from remote sensing video systems like argus often meet these requirements and are of major importance for the formulation of conceptual behavior models c 2007 elsevier b v all rights reserved less

long term morphological modeling of a tidal inlet the arcachon basin france abstract the arcachon lagoon on the french atlantic coast is a triangular shaped lagoon of 20 km on a side connected to the ocean by a 3 km wide inlet between the mainland and an elongated sand spit this tidal inlet exhibits a particularly active morphology due to locally strong tidal currents and rough wave conditions during the past 300 years minimum and maximum spatial extents of the cap ferret sand spit have varied by 8 km while one or two channels have alternately allowed circulation between the lagoon and the ocean these impressive morphological changes have never prevented regular flushing of the lagoon eventhough the spit came as close as 300 m from the coast during the 18th century according to bruun s concept of tidal inlet stability theory and engineering 1978 510 pp the balance between longshore littoral transport and the tidal prism ensures the perpetuity of the inlet process modeling was believed to give better insight into the respective roles of tides and waves in driving the long term morphological changes of the inlet a two dimensional horizontal morphodynamic model was therefore developed combining modules for hydrodynamics waves sediment transport and bathymetry updates the use of process models at a scale of decades requires a schematization of the input conditions we defined representative mean annual wave and tide conditions with respect to sediment transport i e conditions that induce the same annual transport as measured in the field driven by these representative conditions simulations run from the 1993 bathymetry show that the tide is responsible for the opening of a new channel at the extremity of the sand spit where tidal currents are the strongest while waves induce a littoral transport responsible for the longshore drift of sand bodies across the inlet one particular simulation consisted in running the model from a hypothetical initial topography where the channels are filled with sand and the entire inlet is set to a constant depth 3 m the results show the reproduction of a channel and bar system comparable to historical observations which supports the idea that the lagoon is unlikely to be disconnected from the ocean provided tide and wave conditions remain fairly constant in the following decades

towards improved empirical isobase models of holocene land uplift for mainland scotland uk a new approach to modelling patterns of glacio isostatic land uplift during the holocene in mainland scotland uk is described the approach is based upon altitude measurements at the inner margin or locally highest point of raised estuarine surfaces dated by radiocarbon assay supported by microfossil analyses 2241 altitudes have been analysed by a technique new to studies of former sea levels gaussian trend surface analysis and isobase models for four holocene shorelines the holocene storegga slide tsunami shoreline abandoned rapidly circa 7900 sidereal years bp the main postglacial shoreline abandoned during circa 6400 7700 sidereal years bp the blairdrummond shoreline abandoned during circa 4500 5800 sidereal years bp and a speculative fourth shoreline the wigtown shoreline abandoned during circa 1520 3700 sidereal years bp are shown in a series of maps the implications of the shoreline patterns for glaicio isostasy in the area are discussed it is maintained that the statistical technique used enables broad estimates to be made of nearshore sea surface change

the quaternary deposits and landforms of scotland and the neighbouring shelves a review abstract a thick sequence of quaternary sediments up to 1000 m has been deposited in the north sea basin and perhaps five major glacial episodes the first occurring prior to ca 1 8 2 1 ma bp and the last during the late devensian can be recognised between the glacial events periods of low salinity arctic marine or glacio marine sedimentation have been dominant although episodes of ameliorated climate when north atlantic drift waters had access to the north sea have been identified a number of horizons in separate boreholes have been correlated with the last interglacial oxygen isotope stage 5e and a sequence of water mass movements around the scottish coasts can be reconstructed for the last ca 125 ka on land sequences of quaternary deposits relating to several glacial and non glacial terrestrial and marine events occur in different areas but due to poor dating correlation between these sequences cannot yet be achieved in particular north east scotland has a complex glacial history with evidence for ice sheet glaciation on at least four occasions evidence from the outer hebrides north east scotland and the north sea basin indicates that the late devensian scottish ice sheet had a rather restricted extent only reaching a short distance offshore along much of the east and west coasts at this time ice free areas existed in north east scotland on the isle of lewis and probably in caithness and orkney whilst part of the outer shelf around st kilda was dry land a marine embayment extended down the east coast of scotland between the scottish and scandinavian ice sheets and independent ice caps existed on the outer hebrides and probably on shetland deglaciation of the greater part of the country took place prior to ca 13 ka bp whilst the climate was still very cold the ice retreat appears to have been orderly with stagnant ice masses being trapped only in topographically suitable locations a number of retreat stages or minor readvances occurred during the general deglaciation the firth of clyde was one of the last areas outside the highlands to be deglaciated and this occurred in a rapid possibly catastrophic fashion shortly prior to ca 13 ka bp despite the mild climate at the start of the lateglacial interstadial it is not known if there was complete deglaciation prior to the loch lomond readvance the readvance glaciers however may have started to advance during the latter part of the interstadial when declining terrestrial temperatures coincided with a period of mild marine conditions the loch lomond readvance maximum can only be dated to some time after ca 10 9 ka bp and it is likely that final ice free conditions were not achieved until the earliest holocene

recent atmospheric warming and retreat of ice shelves on the antarctic peninsula in 1978 mercer1 discussed the probable effects of climate warming on the antarctic ice sheet predicting that one sign of a warming trend in this region would be the retreat of ice shelves on the antarctic peninsula analyses of 50 year meteorological records have since revealed atmospheric warming on the antarctic peninsula2 3 and a number of ice shelves have retreated4 8 here we present time series of observations of the areal extent of nine ice shelves on the antarctic peninsula showing that five northerly ones have retreated dramatically in the past fifty years while those further south show no clear trend comparison with airtemperature data shows that the pattern and magnitude of ice shelf retreat is consistent with the existence of an abrupt thermal limit on iceshelf viability the isotherm associated with this limit having been driven south by the atmospheric warming ice shelves therefore appear to be sensitive indicators of climate change

holocene sea level change and ice sheet history in the vestfold hills east antarctica abstract a new holocene sea level record from the vestfold hills antarctica has been obtained by dating the lacustrine marine and marine lacustrine transitions that occur in sediment cores from lakes which were formerly connected to the sea from an elevation of 7 5 m 8000 yr ago relative sea level rose to a maximum 9 m above present sea level 6200 yr ago since then sea level has fallen monotonically until the present the precision of the new record makes it suitable for constraining the recent history of the ice sheet in that region using numerical models of glacio hydro isostasy simplified regional models suggest that the ice sheet margin has retreated 30 40 km since the last glacial maximum with 600 700 m of thinning occurring at the present coastline

timing of the most recent neoglacial advance and retreat in the south shetland islands antarctic peninsula insights from raised beaches and holocene uplift rates abstract the timing of the most recent neoglacial advance in the antarctic peninsula is important for establishing global climate teleconnections and providing important post glacial rebound corrections to gravity based satellite measurements of ice loss however obtaining accurate ages from terrestrial geomorphic and sedimentary indicators of the most recent neoglacial advance in antarctica has been hampered by the lack of historical records and the difficulty of dating materials in antarctica here we use a new approach to dating flights of raised beaches in the south shetland islands of the northern antarctic peninsula to bracket the age of a neoglacial advance that occurred between 1500 and 1700 ad broadly synchronous with compilations for the timing of the little ice age in the northern hemisphere our approach is based on optically stimulated luminescence of the underside of buried cobbles to obtain the age of beaches previously shown to have been deposited immediately inside and outside the moraines of the most recent neoglacial advance in addition these beaches mark the timing of an apparent change in the rate of isostatic rebound thought to be in response to the same glacial advance within the south shetland islands we use a maxwell viscoelastic model of glacial isostatic adjustment gia to determine whether the rates of uplift calculated from the raised beaches are realistic given the limited constraints on the ice advance during this most recent neoglacial advance our rebound model suggests that the subsequent melting of an additional 16 22 increase in the volume of ice within the south shetland islands would result in a subsequent uplift rate of 12 5 mm yr that lasted until 1840 ad resulting in a cumulative uplift of 2 5 m this uplift rate and magnitude are in close agreement with observed rates and magnitudes calculated from the raised beaches since the most recent neoglacial advance along the south shetland islands and falls within the range of uplift rates from similar settings such as alaska

geological constraints on glacio isostatic adjustment models of relative sea level change during deglaciation of prince gustav channel antarctic peninsula the recent disintegration of antarctic peninsula ice shelves and the associated accelerated discharge and retreat of continental glaciers has highlighted the necessity of quantifying the current rate of antarctic ice mass loss and the regional contributions to future sea level rise observations of present day ice mass change need to be corrected for ongoing glacial isostatic adjustment a process which must be constrained by geological data however there are relatively little geological data on the geometry volume and melt history of the antarctic peninsula ice sheet apis after termination 1 and during the holocene so the glacial isostatic correction remains poorly constrained to address this we provide field constraints on the timing and rate of apis deglaciation and changes in relative sea level rsl for the north eastern antarctic peninsula based on geomorphological evidence of former marine limits and radiocarbon dated marine freshwater transitions from a series of isolation basins at different altitudes on beak island relative sea level fell from a maximum of c 15 m above present at c 8000 cal yr bp at a rate of 3 91 mm yr 1 declining to c 2 11 mm yr 1 between c 6900 2900 cal yr bp 1 63 mm yr 1 between c 2900 1800 cal yr bp and finally to 0 29 mm yr 1 during the last c 1800 years the new beak island rsl curve improves the spatial coverage of rsl data in the antarctic it is in broad agreement with some glacio isostatic adjustment models applied to this location and with work undertaken elsewhere on the antarctic peninsula these geological and rsl constraints from beak island imply significant thinning of the north eastern apis by the early holocene further they provide key data for the glacial isostatic correction required by satellite derived gravity measurements of contemporary ice mass loss which can be used to better assess the future contribution of the apis to rising sea levels

widespread acceleration of tidewater glaciers on the antarctic peninsula over the last half century the antarctic peninsula ap has been among the most rapidly warming regions on earth this has led to increased summer snowmelt loss of ice shelves and retreat of 87 of marine and tidewater glacier fronts tidewater glacier flow is sensitive to changes in basal water supply and to thinning of the terminus and faster flow leads directly to sea level rise the flow rates of most ap tidewater glaciers have never been measured however and hence their dynamic response to the recent changes is unknown we present repeated flow rate measurements from over 300 glaciers on the ap west coast through nine summers from 1992 to 2005 we show that the flow rate increased by similar to 12 on average and that this trend is greater than the seasonal variability in flow rate we attribute this widespread acceleration trend not to meltwater enhanced lubrication or increased snowfall but to a dynamic response to frontal thinning we estimate that as a result the annual sea level contribution from this region has increased by 0 047 0 011 mm between 1993 and 2003 this contribution together with previous studies that assessed increased runoff from the area and acceleration of glaciers resulting from the removal of ice shelves implies a combined ap contribution of 0 16 0 06 mm yr 1 this is comparable to the contribution from alaskan glaciers and combined with estimated mass loss from west antarctica is probably large enough to outweigh mass gains in east antarctica and to make the total antarctic sea level contribution positive

petrology of philippine geothermal systems and the application of alteration mineralogy to their assessment abstract philippine geothermal systems occur in the vicinity of large holocene calc alkaline volcanic complexes wells drilled in these areas encountered multiple intrusions the latest dikes are the subsurface manifestations of the youngest heat source commonly at least two hydrothermal regimes are juxtaposed in a single area with the latest being in equilibrium with the present temperature and chemical regime alteration by neutral ph water is pervasive and abundant a contact metamorphic aureole also occurs near intrusives alteration due to acid sulfate fluids is generally confined to permeable structures neutral ph alteration is divided into four zones on the basis of key clay minerals and two subzones are defined by calc silicates these are the smectite ambient to 180 c transition 180 230 c illite 230 320 c and biotite 270 340 c zones subzones are defined by epidote 250 340 c and amphibole 280 340 c the four main zones of acid alteration are kaolinite ambient to 120 c dickite kaolinite 120 200 c dickite pyrophyllite 200 250 c and pyrophyllite illite 230 320 c where relict high temperature alteration reaches the surface the area being drilled is usually the outflow zone of the present system these hydrothermal mineral assemblages are used 1 as geothermometers 2 to assist in determining the depth at which the production casing will be set during drilling 3 to estimate fluid ph and other chemical parameters 4 to predict possible corrosion and scaling tendencies of the fluids 5 as a measure of permeability and possible cold water influx into wells 6 as a guide to field hydrology and 7 to estimate roughly the thickness of the eroded overburden

late holocene relative sea levels near palmer station northern antarctic peninsula strongly controlled by late holocene ice mass changes abstract many studies of holocene relative sea level rsl changes across antarctica assume that their reconstructions record uplift from glacial isostatic adjustment caused by the demise of the last glacial maximum lgm ice sheets however recent analysis of gps observations suggests that mantle viscosity beneath the antarctic peninsula is weaker than previously thought which would imply that solid earth motion is not controlled by post lgm ice sheet retreat but instead by late holocene ice mass changes if this hypothesis is correct one might expect to find holocene rsl records that do not reflect a monotonic decrease in the rate of rsl fall but show variations in the rate of rsl change through the holocene we present a new record of late holocene rsl change from torgersen island near palmer station in the western antarctic peninsula that shows an increase in the rate of relative sea level fall from 3 0 1 2 mm yr to 5 1 1 8 mm yr during the late holocene independent studies of the glacial history of the region provide evidence of ice sheet changes over similar time scales that may be driving this change when our rsl records are corrected for sea surface height changes associated with glacial isostatic adjustment gia the rate of post 0 79 ka land uplift at torgersen island 5 3 1 8 mm yr is much higher than the rate of uplift recorded at a nearby gps site at palmer station prior to the larsen b breakup in 2002 ad 1998 2002 ad

early holocene retreat of the george vi ice shelf antarctic peninsula the recent collapse of several antarctic peninsula ice shelves has been linked to rapid regional atmospheric warming during the twentieth century new high resolution lake sediment records of holocene ice shelf behavior show that the george vi ice shelf was absent beginning ca 9595 calibrated cal yr b p but reformed by ca 7945 cal yr b p this retreat immediately followed a period of maximum holocene warmth that is recorded in some ice cores and occurred at the same time as an influx of warmer ocean water onto the antarctic peninsula shelf the absence of the ice shelf suggests that early holocene ocean atmosphere variability in the antarctic peninsula was greater than that measured in recent decades

geomorphological processes and frozen ground conditions in elephant point livingston island south shetland islands antarctica abstract elephant point is an ice free area in the sw corner of livingston island maritime antarctica the retreat of rotch dome glacier during the holocene has exposed a land area of 1 16 km2 up to 17 3 of this surface has become ice free between 1956 and 2010 a detailed geomorphological mapping of this ice free environment was conducted in late january 2014 a wide range of active periglacial landforms show that periglacial processes are widespread from the glacier to the coast four different geomorphological areas are identified proglacial environment moraine complex bedrock plateaus and marine terraces in situ measurements of the thawed soil depth show evidence of the widespread frozen ground conditions in the area field observations of permafrost exposures suggest that these frost conditions may be related to a soil permafrost regime almost down to sea level the activity of penguin colonies and elephant seals has created minor geomorphological features in the raised marine terraces here several archaeological sites related to early human colonization of antarctica were also found in natural shelters

hydrothermal zeolitisation controlled by host rock lithofacies in the periadriatic oligocene smrekovec submarine composite stratovolcano slovenia abstract hydrothermal zeolites laumontite yugawaralite analcime heulandite clinoptilolite prehnite and pumpellyite have been recognised in a succession of volcanic autoclastic pyroclastic resedimented volcaniclastic and mixed siliciclastic volcaniclastic deposits in cone building lithofacies association attaining 310 m the alteration minerals commonly change within a single normally graded depositional unit or alternate in the section on a dm to m scale according to the host rock lithofacies fine grained deposits rich in juvenile glassy pyroclasts are altered to heulandite and clinoptilolite or analcime and laumontite widely occurs in coarse grained host rocks lapilli tuff hyaloclastite breccia volcaniclastic breccia hyaloclastites and fracture systems in near vent lithofacies association attaining 420 m prehnite laumontite laumontite analcime and laumontite heulandite clinoptilolite zones developed as a result of superimposed thermal regime generated by the emplacement of an over 200 m thick sill the recognised dependence of alteration on porosity permeability and fracturing of the host rock is closely related to hydrological conditions in the stratovolcano hosted hydrothermal system with convective advective flow regime after separation of steam and gases from convecting hydrothermal fluids denser liquids outflowed intermittently preferentially through steeply inclined 20 30 high permeability layers in the stratovolcano edifice in low permeability layers the flow was slow and thermal conditions were mainly attained by conduction zeolites developed only in coarse and fine grained vitroclastic tuffs presumably by the dissolution of volcanic glass the interstratified siliciclastic siltstones tuffites and resedimented deposits with low content of glassy particles are devoid of zeolites and indicate compositional constraint on zeolitisation lava flows cooling in a submarine environment and undergoing disintegration and mingling with the enclosing water saturated sediment were individual ephemeral and spatially localised high temperature hydrothermal systems favourable for the formation of pumpellyite prehnite and laumontite

the palaeogene forearc basin of the eastern alps and western carpathians subduction erosion and basin evolution scarce palaeogene sediment remnants in the eastern alps and western carpathians are interpreted as remains of a continuous forearc basin new apatite fission track geochronological data corroborate mild paleocene eocene exhumation and relief formation in the eastern alps palinspastic restoration and nine palaeogeographical maps of the eastern alps and western carpathians ranging from the paleocene to the late oligocene epoch illustrate west to east migration of subsidence in the forearc basin subsidence isochrons indicate that oblique subduction of the european plate below the adriatic plate was responsible for forearc basin migration at a rate of 8 mm a 1 the periadriatic lineament was formed as a result of shearing by oblique subduction the neogene to recent sumatra forearc basin is an analogue for the evolution of the east alpine west carpathian forearc basin

late devensian and holocene relative sea level changes in northwestern scotland new data to test existing models abstract pollen diatom lithostratigraphic and radiocarbon data from five sites in northwestern scotland provide new data from an area previously devoid of reliable and precise information on late devensian and holocene sea level changes the sites cover a range of palaeoenvironments indicative of diversity in coastal evolution since deglaciation for each site and palaeoenvironment the reference water tide level indicative range age and tendency of sea level movement of all sea level index points are quantified to enable correlation of the diverse coastal environments the data record patterns of relative sea level change and tendencies of sea level movement from 12 ka bp to 1 ka bp this is the longest and most comprehensive published record of relative sea level change from the area the information is used to test the accuracy of existing models of relative sea level change the results are only broadly consistent with a quantitative rebound model and there is significant disagreement with empirical models during the late devensian and the early holocene

morphodynamic behaviour of a mixed sand gravel ebb tidal delta deben estuary suffolk uk the morphodynamics of inlets and ebb tidal deltas reflect the interaction between wave and tidal current driven sediment transport and significantly influence the behaviour of adjacent shorelines studies of inlet morphodynamics have tended to focus on sand dominated coastlines and reference to gravel dominated or gravel rich inlets is rare this work characterises and conceptualises the morphodynamics of a meso tidal sand gravel inlet at the month of the deben estuary southeast england behaviour of the inlet and ebb tidal delta over the last 200 yr is analysed with respect to planform configuration and bathymetry the estuary inlet is historically dynamic with ebb tidal shoals exhibiting broadly cyclic behaviour oil a 10 to 30 yr timescale quantification of inlet parameters for the most recent cycle 1981 2003 indicate an average ebb delta volume of 1 x 10 6 m 3 and inlet cross sectional area of 775 m 2 bypassing volumes provide a direct indicator of annual longshore sediment transport rate over this most recent cycle of 30 40 x 10 3 m 3 yr 1 short term increases in total ebb tidal delta volume are linked to annual variability in the north to northeasterly wind climate the sediment bypassing mechanism operating in the deben inlet is comparable to the ebb delta breaching model of fitzgerald fitzgerald d m 1988 shoreline erosional depositional processes associated with tidal inlets in aubrey d g weishar l ed hydrodynamics and sediment dynamics of tidal inlets springer verlag inc new york pp 186 225 although the scales and rates of change exhibited are notably different to sand dominated systems a systematic review of empirical models of sand dominated inlet and ebb tidal delta morphodynamics e g those of o brien m p 1931 estuary tidal prisms related to entrance areas civil engineering 1 738 739 walton t l and adams w d 1976 capacity of inlet outer bars to store sand proceedings of 15th coastal engineering conference 1919 1937 gaudiano d j kana t w 2001 shoal bypassing in mixed energy inlets geomorphic variables and empirical predictions for nine south carolina inlets j coast res 17 2 280 291 shows the deben system to be significantly smaller yet characterised by a longer bypassing cycle than would be expected for its tidal prism this is attributed to its coarse grained sedimentology and the lower efficiency of sediment transporting processes c 2005 elsevier b v all rights reserved

new relative sea level curves for the southern scott coast antarctica evidence for holocene deglaciation of the western ross sea here we present new relative sea level rsl curves developed from holocene aged raised beaches along the southern scott coast of the western ross sea antarctica fifty four dates of marine shells seal skin and elephant seal remains incorporated within raised beaches during storms afford a chronology for these curves all of the curves show the same pattern and timing of rsl change within a small range of error the best dated curve suggests that final unloading of grounded ross sea ice from the southern scott coast and mcmurdo sound region occurred shortly before 6500 14c yr bp this age is consistent with glacial geological evidence that places deglaciation between 5730 and 8340 14c yr bp our data strongly suggest that grounding line retreat of the ross sea ice sheet southward through the mcmurdo sound region occurred in mid and late holocene time if this is correct then rising sea level could not have driven ice recession to the present day grounding line on the siple coast because global deglacial sea level rise was essentially accomplished by mid holocene time copyright 1999 john wiley sons ltd

reconstruction of ice sheet changes in the antarctic peninsula since the last glacial maximum this paper compiles and reviews marine and terrestrial data constraining the dimensions and configuration of the antarctic peninsula ice sheet apis from the last glacial maximum lgm through deglaciation to the present day these data are used to reconstruct grounding line retreat in 5 ka time steps from 25 ka bp to present glacial landforms and subglacial tills on the eastern and western antarctic peninsula ap shelf indicate that the apis was grounded to the outer shelf shelf edge at the lgm and contained a series of fast flowing ice streams that drained along cross shelf bathymetric troughs the ice sheet was grounded at the shelf edge until 20 cal ka bp chronological control on retreat is provided by radiocarbon dates on glacimarine sediments from the shelf troughs and on lacustrine and terrestrial organic remains as well as cosmogenic nuclide dates on erratics and ice moulded bedrock retreat in the east was underway by about 18 cal ka bp the earliest dates on recession in the west are from bransfield basin where recession was underway by 17 5 cal ka bp ice streams were active during deglaciation at least until the ice sheet had pulled back to the mid shelf the timing of initial retreat decreased progressively southwards along the western ap shelf the large ice stream in marguerite trough may have remained grounded at the shelf edge until about 14 cal ka bp although terrestrial cosmogenic nuclide ages indicate that thinning had commenced by 18 ka bp between 15 and 10 cal ka bp the apis underwent significant recession along the western ap margin although retreat between individual troughs was asynchronous ice in marguerite trough may have still been grounded on the mid shelf at 10 cal ka bp in the larsen a region the transition from grounded to floating ice was established by 10 7 10 6 cal ka bp the apis had retreated towards its present configuration in the western ap by the mid holocene but on the eastern peninsula may have approached its present configuration several thousand years earlier by the start of the holocene mid to late holocene retreat was diachronous with stillstands re advances and changes in ice shelf configuration being recorded in most places subglacial topography exerted a major control on grounding line retreat with grounding zone wedges and thus by inference slow downs or stillstands in the retreat of the grounding line occurring in some cases on reverse bed slopes

mechanisms of holocene palaeoenvironmental change in the antarctic peninsula region the antarctic peninsula is one of the three fastest warming regions on earth here we review holocene proxy records of marine and terrestrial palaeoclimate in the region and discuss possible forcing mechanisms underlying past change with a specific focus on past warm periods our aim is to critically evaluate the mechanisms by which palaeoclimate changes might have occurred in order to provide a longer term context for assessing the drivers of recent warming two warm events are well recorded in the holocene palaeoclimate record namely the early holocene warm period and the mid holocene hypsithermal mhh whereas there are fewer proxy data for the mediaeval warm period mwp and the recent rapid regional rrr warming we show that the early holocene warm period and mhh might be explained by relatively abrupt shifts in position of the southern westerlies superimposed on slower solar insolation changes a key finding of our synthesis is that the marine and terrestrial records in the ap appear to show markedly different behaviour during the mhh this might be partly explained by contrasts in the seasonal insolation forcing between these records circumpolar deep water cdw has been implicated in several of the prominent changes through the holocene but there are still differences in interpretation of the proxy record that make its influence difficult to assess further work is required to investigate contrasts between marine and terrestrial proxy records east west contrasts in palaeoclimate the history of cdw to retrieve a long onshore high resolution record of the holocene and determine the role of sea ice in driving or modulating palaeoclimate change along with further efforts to study the proxy record of the rrr and the mwp

holocene land and sea level changes in great britain analysis of more than 1200 radiocarbon dated samples that constrain relative sea levels in great britain over the past 16 000 yr provides estimates of current land level changes negative of relative sea level change maximum relative land uplift occurs in central and western scotland ca 1 6 mm yr 1 and maximum subsidence is in southwest england ca 1 2 mm yr 1 sediment consolidation arising from autocompaction as the sediment accumulates and from land drainage increases the subsidence in areas with thick sequences of holocene sediments with an average effect equivalent to at least an extra ca 0 2 mm yr 1 land subsidence but more in parts of southeast england 0 5 1 1 mm yr 1 modelled changes in tidal range during the mid to late holocene in eastern england suggest that the calculated rate of land subsidence is overestimated unless such changes are quantified the effect is most significant for large coastal lowlands the fenland and humber ca 0 5 and 0 6 mm yr 1 that were tidal embayments during the mid to late holocene