No description available.

Deteriorating climate in the period leading up to the Last Glacial Maximum (LGM) 20,000 years ago caused global sea levels to fall to a lowstand of 125m below modern levels. This resulted in the recession of the Sicilian palaeoshoreline by up to 150km and the emergence of vast tracts of coastal lowland. Following climate amelioration and deglaciation, rising sea levels inundated these formerly exposed areas. The earliest indication of a modern human presence on Sicily comes from Fontana Nuova, in the southeast of the island. The timing of this occupation, on the basis of cross-dating of Aurignacian lithic typology, is about 37,000 BP – a time when sea levels around the Sicilian coastline were some 40-80m lower than at present. The oldest scientifically-dated human remains come from Addaura Caprara, dated to 15,643–15,177 cal BP. Some archaeologists interpret the evidence as suggesting a brief, solitary visit to the island at around 37,000 BP followed by a gap of some 20,000 years before the establishment of a permanent presence during the 16th millennium BP. Others dismiss the veracity of the evidence from Fontana Nuova and hold that Sicily was never settled until some considerable time after the LGM. Until late 20th-century studies demonstrated the attractions of coastal ecotones, absence of evidence was sometimes interpreted as a rejection of coastal landscapes by Upper Palaeolithic and Mesolithic hunter-gatherers. My thesis will argue that Sicily was not uninhabited for 20,000 years or more but that any evidence for human coastal presence throughout prehistory is potentially submerged. I consider the attractions of coastlands for early modern humans. I discuss the physical background to glaciation and deglaciation resulting in sea-level change. By combining data on absolute sea-level change with evidence for terrestrial displacement resulting from tectonic forces, I have determined relative sea-level change affecting the coastlines of Sicily from 37,000 BP until the Iron Age (ending c750 BC). The results have been combined with digital bathymetric data within an ESRI ArcMap GIS program to produce a series of maps at archaeologically-significant dates. The very areas that are now recognised as being attractive to modern humans will be shown to be submerged today. With reference to modern scientific techniques and their application by specialists in a variety of locations, I shall demonstrate that the successful recovery of submerged archaeological evidence is achievable. I shall also consider a number of phenomena revealed by my field observations that have conspired to conceal or destroy the coastal archaeological record, the absence of such evidence being used illegitimately to support claims for an unpopulated island. These phenomena include natural catastrophes such as earthquakes and related tsunamis, volcanic activity and landslides. Additionally, coastline modification resulting from river estuary migration, and anthropogenic impacts will be considered.

No description available.

The increasing interest in the use of palacoenvironmental indicators and in particular diatoms to reconstruct past changes in sea level has highlighted the need for a more precise methodology that (a) provides quantitative reconstructions, and (b) is applicable to a wide range of sedimentary environments. Despite the widespread and increasing recent interest in the use of diatoms as indicators of estuarinep alaeoenvironmentsa nd sea-levelc hange,e xisting interpretative models, basedo n simple classification of taxa into freshwater, brackish or marine forms, provide only _qualitative estimates of past conditions. Resulting palaeoenvironmental reconstructions are at best crude, offering some indication of past mean sea level height, and at worst erroneous, as they fail to consider the effect of post-mortem transport and other taphonomic processes. This study aims to address these problems for the coast of Britain by developing a more robust quantitative method for using diatoms as indicators of estuarine palaeoenvironments and sea-level change. More specifically, it aims to develop a quantitative predictive model (transfer function) that relatesd iatom assemblagec omposition to salinity, habitat, depositional environment and tidal level around the coast of Britain. This is done through the collection and analysis of a training data set of diatom assemblagesa nd environmental variables (salinity class, elevation, grain size, habitat type and sediment organic content) from 25 sites around the coast of Britain. Qualitative and quantitative relationships within the diatom assemblagesa nd between the diatom assemblagesa nd coastale nvironmentalv ariables are explored using TWINSPAN and canonical correspondencea nalysisr espectively. The key environmental variables driving diatom assemblagesin the intertidal environment are shown to be elevation, salinity and sediment particle size. Habitat type and site location also explain a significant amount of variation in the diatom data, suggestingr egional differences in diatom assemblagesn ot accounted for by geornorphological and sedimentological differences between sites. The final transfer function for inferring normalised tidal height has a root mean squared error (RMSE) of 0.26, and a squared correlation (1-2) between observed and diatom-inferred normalised tidal height of 0.61. Corresponding error estimates under cross-validation by leave-one-out are 0.34 and 0.35 for RMSEjack and rjack 2 respectively. The poor performance of the model in comparison to published regional transfer functions is concluded to be due to the mergt:i In g of data from a large number of sites over a large geographical area. Such merging - has apparently introduced a large amount of noise into the diatom / elevation relationship, and is probably related to the increased heterogeneity and interaction of sediment typeý and elevation, and to the observed regional overprint in the diatom assemblages. Analogue matching to infer Sample habitats from the diatom data performs with a success Z): rate of 59%. Further merging of the habitat types based on ecologically similarities increases the success rate to 82%. The correct scale of trade off between coverage of palaeoenvironments, fossil diatom species 4): and reduction of regionality in the modem training dataset is an issue that needs further research before this model may be applied to core material to assist in palaeoenvironmental reconstructions.

The aim of the research was to provide new sea-level index points,with the intention of identifying any cross-channel similarities and comparing the results to geophysical models of relative sea-level change. The research successfully provided new sea-level index points from the Pevensey levels, East Sussex; the Canche Estuary, Pas de Calais and the Somme Estuary, Picardie, which were validated using stratigraphic pollen,diatom,foraminiferal snd AMS radiocarbon dating analysis. The results pointed to the presence of a coastal barrier thoughout the mid-Holocene at Pevensey and the Somme which complicated the pattern of coastal sedimentation observed at these sites. A clear pattern of barrier de-stabilisation can be seen to take place either side of the Channel c.3000 years cal BP. A cross-channel comparison identified three similar transgressive events either side of the English Channel, c. 5500, 3000 and 2200 cal years BP. The observed results from each site were then compared to the predicted data( Lambeck pers.comm) .in order to determine whether the observational data could be used to validate the modelled data. The comparisons showed that for the sites in south east England the modelled data tended to over-predict sea-level rise for the mid-t o late- Holocene whereas the model tended to under-predict sea-level rise for the sites in northern France. The new observational data which the research provided could be used to further validate Lambeck's (1990,1997) geophysical model. The effects of local coastal processes, such as tidal range, crustal subsidence and barrier-dynamics were used to aid the comparisons between the pattern of sediment deposition and thus the sea-level signals. These findings suggested that reconstructions should be restricted to sites at an estuary-sized scale.

Coastal saltmarshes are vital ecosystems because (a) they physically buffer the land against storms and flooding from the sea and (b) ecologically they are high-productivity systems in estuaries and marine coastlines that shelter and support fish and bird populations. Saltmarshes are highly sensitive to sea level change. Any saltmarshes are now threatened by rising sea level, but how they will respond and at what rate is unclear. Managing saltmarshes is therefore necessary, but requires a good understanding of their development in order to predict how they might respond to sea level change. Current management practice in the UK is mainly managed realignment landward and future scenarios are predicted with computer models. Both use the hypothesis of facilitation succession, whereby saltmarsh progrades seawards. An alternative hypothesis is saltmarsh development by transgression landward due to rising sea level. This thesis critically examines how saltmarshes have developed under different sea-level change regimes in order to gain an insight into how they are likely to be affected by future sea level rise. Using established micropalaeontological techniques, Foraminifera tests and Ostracoda shells were extracted from sediment cores taken from saltmarshes representing a range of sea level change histories during the Holocene. Sampling of modern environments allowed saltmarsh vegetation zones to be characterised by foraminiferal and ostracod assemblages which were then used to reconstruct the development of saltmarshes over time as preserved in the cores. Sediment layers in the cores were dated using three techniques: Optically Stimulated Luminescence (OSL), radio carbon (14C) and 137Cs / 210Pb. The latter hypothesis is supported in southern England where marine transgression caused saltmarshes to migrate landwards, in contradiction to the facilitation succession hypothesis. In Scotland saltmarshes advanced seawards but due to a marine regression. Future studies should explore the applicability of these findings to saltmarshes outside the British Isles.

Yes / Around 8150 BP, the Storegga tsunami struck North-west Europe. The size of this wave has led many to assume that it had a devastating impact upon contemporaneous Mesolithic communities, including the final inundation of Doggerland, the now submerged Mesolithic North Sea landscape. Here, the authors present the first evidence of the tsunami from the southern North Sea, and suggest that traditional notions of a catastrophically destructive event may need rethinking. In providing a more nuanced interpretation by incorporating the role of local topographic variation within the study of the Storegga event, we are better placed to understand the impact of such dramatic occurrences and their larger significance in settlement studies. / The study was supported by European Research Council funding through the European Union's Horizon 2020 research and innovation programme (project 670518 LOST FRONTIERS, https://erc.europa.eu/ https://lostfrontiers.teamapp.com/) and the Estonian Research Council grant (https://www.etag.ee; project PUTJD829).

The Sefidrud has developed a large delta in the south west of the Caspian Sea. Its delta is characterized by rapid sedimentation rate (20 mm/yr) in the delta plain and low sedimentation rate (1.67 mm/yr) in a very steep delta front. Sefidrud Delta evolution depends upon sediment supply by river and longshore current under rapid Caspian Sea Level (CSL) fluctuation and tectonic setting at the point of entry to the basin. The tectonic setting caused a very steep slope in the delta front. Sediment supply is variable and affected by river avulsion and dam construction. The CSL has undergone significant changes during the last millennium. Therefore, the Sefidrud Delta evolution during the last millennium is explained based on CSL fluctuations. This fluctuation has major impacts not only on coastal lagoons, but also more inland in wetlands when the CSL rose up to at least -21.44 m (i.e. >6 m above the present water level) during the early Little Ice Age. Although previous studies in the southern coast of the Caspian Sea have detected a high-stand during the Little Ice Age period, this study presents the first evidence that this high-stand reached so far inland and at such a high altitude. This study also examines the interdependence of different factors in the evolution of coastal lagoons as a part of delta evolution. Dam flushing operations and rapid sea–level rise (~3 m between 1977 and 1995) have accelerated the infilling of the coastal lagoon system. This rapid infilling (31 mm/yr) makes the whole system more prone to sediment encroachment in the short term. Because the lagoons are short-lived and have dynamic evolution, the impact of the Anthropocene is also visible in the delta evolution.

Shorelines, including the Inner Forth in Scotland, are facing unprecedented challenges with climate change. Rising sea levels mean that stakeholders need to work closely to deliver adaptation, such as the nature-based option of intentionally realigning shorelines landwards to give the sea more space. Drawing from workshops, interviews and surveys with citizens living on the shores of the Inner Forth, and semi-structured interviews with locally active organisations and land-owners, this thesis examines the governance context and methodological issues of citizen engagement in adaptation, with a focus on the use of participatory valuation tools. In particular, I develop citizen-oriented methodological options for integrated and deliberative valuation to address issues of inclusivity and knowledge gaps. The novelty of the deliberative valuation presented here is based on the explicit consideration of awareness gaps from both expert and local perspectives. The results show that even though emerging collaborative institutions are broadening the spectrum of stakeholders engaged in shoreline governance, they do not yet include representative groups of citizens. Empirical material presented here suggests that bridging the citizen engagement gap would potentially support the uptake of nature-based adaptation options, enhance legitimacy of decision-making processes, and bring other-regarding moral principles and biocentric values into decision-making. However, as the valuation results from the citizen workshops illustrate (in resonance with the central tenets of the Intergovernmental science-policy Platform on Biodiversity and Ecosystem Services), commonly applied valuation methods may be too narrow in their framing to capture plural values and world views. Furthermore, the ability of citizens to engage in adaptation is limited by knowledge gaps regarding the local area and the pressures it is facing. The deliberative citizen-oriented approach to valuation developed here led to the emergence of clearer priorities, improved choice model fit and participant confidence, providing empirical evidence to support the premise that deliberation builds citizens' ability to engage in adaptation. In addition to contributing empirical insights on how adaptation governance is unfolding on local scales, this thesis responds to methodological discussions on the use of valuation for citizen engagement in three main ways: 1) it demonstrates that the choice of value framings impacts the engagement outcomes; 2) it illustrates how deliberative valuation can shape citizens' attitudes towards the uptake of adaptation measures; 3) it provides evidence of the specific role that local knowledge plays in improving the outcomes of deliberative valuation.

The aim of this thesis is to understand the role of geomorphological change in the abandonment of Norse harbours in the North Atlantic. Nodes of maritime activities that were established by Norse settlers during the Scandinavian Viking Age often developed into important towns and cities. Some of these, however, disappeared for unknown reasons. Norse harbours in the North Atlantic varied in scale. They ranged from small landing beaches used by small boats for local use through to much larger anchorages handling considerable trade and being important nodes on the transatlantic trading network. Changes in coastal geomorphology necessitated a response from seafarers. In this thesis, a conceptual framework for the formation, recovery and stability of headland-dominated sandy beaches in high-energy environments is established, based on empirical observation and on the use of the MIKE21 numerical sediment transport model. Under persistent calm climatic conditions, nearshore seabed gradient is a weak control on beach formation and persistence in embayments. However, under persistent stormy conditions, nearshore sea bed gradient becomes the prominent control. Embayments with nearshore gradients of > 0.025 m/m inhibit beach recovery on a sub-annual timescale, while gradients < 0.025 m/m promote beach recovery. These ideas are assessed in the Shetland Islands, using numerical modelling, geomorphology and OSL dating on sand blow deposits. In the late Norse era beach landing sites in Unst became prone to depletion and destruction because of increased storminess. Numerical modelling (MIKE21) supports the idea that the recovery time of different sandy beaches on Unst is dependent on average nearshore slope. The beach at Sandwick has shallow nearshore gradients and recovers quickly in the face of storminess, but beach stability at Lunda Wick is more uncertain, and thus Lunda Wick represents a more problematic landing place. The Norse harbour of The Bishop's seat at Garðar in the Eastern Settlement of Greenland is assessed to evaluate the impacts of gradual long term geomorphological change on coastlines that lack soft-sediment. A high resolution, near shore bathymetric survey shows that, due to relative sea level rise of 1 m/500 years, the landing site became more difficult to access during the later period of Norse settlement and key onshore infrastructure was disrupted. The possible role of terrestrial supplies of sediment in changing the viability of landing places is assessed through an evaluation of the Norse trading centre of Gásir in northern Iceland. Geomorphological mapping and analysis of fluvial connectivity indicate that the delta on which Gásir is located is prone to aggradation from large, irregular pulses of sediment derived from landslides in the catchment. Written sources and geomorphological mapping indicate geomorphological changes around the same time that trade was shifting to the use of boats with a deeper draft. Cultural change and environmental changes would have reinforced each other in rendering the harbour site nonviable. Geomorphological forces acting on varying spatial and temporal scales have the potential to disrupt the use of landing sites. Whether environmental changes led to the abandonment of a landing site was strongly influenced by the seafarers' competence and available technology. Higher levels of competence would enable more problematic landing sites to be used, but there are limits to this adaptation. Technological changes, such as the use of larger and deeper draft boats, would have changed the geomorphic requirements for harbour sites, and thus may have led to a passive abandonment of the site over time rather than active abandonment such as that in the face of a catastrophic change of the shoreline. Coastal geomorphology was a critical factor affecting the use of Norse harbours, as it interacted with the wider cultural and economic developments in the North Atlantic realm. This thesis demonstrates that numerical sediment transport analysis is a powerful tool in coastal archaeological research as it can illuminate processes driving observable changes in the empirical record.