This study discusses the extent to which hunter-gatherer mobility strategies are changed by abrupt climate change events by monitoring changes in lithic assemblage compositions through the Pleistocene/Holocene Transition, from ca. 14,000 cal BP to 10,000 cal BP in northwest Europe, with a focus on the Younger Dryas Stadial event, which occurred around 12,900 cal BP to 11,700 cal BP. A set of predicted archaeological indicators were formed from existing theoretical models, based largely on Binford’s logistical and residential mobility model, with the expectation that a more residential mobility strategy would be used by hunter-gatherer-populations during warmer climatic phases (i.e. the Allerød and Preboreal) and a more logistical mobility strategy would be used during cold climatic phases (i.e. the Younger Dryas). The lithic assemblages from sites across northwest Europe were then compared with these expectations in order to determine if a shift from a more residential strategy to a more logistical strategy can be seen from the lithic record. Additionally, a further comparative dataset was collected from south Europe in order to determine if there were differences in the response to the Younger Dryas at lower latitudes where the impact of this event is assumed to be less severe. The results found that in northwest Europe there is evidence to suggest there was indeed a shift from a more residential strategy during the warm Allerød interstadial to a more logistical strategy during the Younger Dryas Stadial, and the adoption of a more residential strategy with the return of warmer conditions during the Preboreal. However, it appears that the Preboreal Interstadial shows significant differences between the Allerød Interstadial, with the Preboreal sharing more characteristics in common with the Younger Dryas. This has been interpreted as a response to the unstable climatic conditions reported from the environmental evidence in this region during the Preboreal, which may have limited the ability of hunter-gatherer populations to return to similar levels of residential mobility seen during the Allerød. The south Europe dataset provides evidence that the lesser impact of the Younger Dryas at lower latitudes brought about a more muted response by hunter-gatherer populations to this event when compared with the northwest. However, there appears to be a reversal of that seen in the northwest, with more logistically mobile populations during the Allerød and especially the Preboreal, and more residentially mobile populations during the Younger Dryas. This is despite the environmental evidence showing a very similar environmental response to the northwest, with a distinct opening of the landscape during the Younger Dryas. The apparent difference in mobility strategies appear to be more related to the available faunal species within a region and their behaviour within their environment rather than directly to the climate. In the south, species such as red deer and ibex are the main source of faunal subsistence throughout the Pleistocene/Holocene Transition, unchanged by shifts in temperature and environment, but the way in which hunter-gatherers would hunt such species would be expected to change in more wooded environments compared with more open environments. If we compare this with the northwest, there is evidence of a distinct change from hunted prey, such as red deer, during the Allerød and Preboreal, to reindeer and horse during the Younger Dryas (although faunal preservation is poor in this region). With this shift to a more mobile prey species, along with a harsher, more open environment it may be more suitable to practise a more logistical strategy. Additionally, the instability of the Preboreal may have also changed the environment on a smaller scale, which would have required the hunting of warmer climate prey in shifting local environments, much like that of the Younger Dryas in south Europe. This might explain the differences seen between the Allerød and the Preboreal. Overall, there appears to be strong evidence supporting the theory that colder, harsher climates promote a more logistically mobile response from hunter-gatherer populations as seen in the northwest of Europe, and that there was a more muted, different response to the Younger Dryas in the lower latitudes of south Europe. However, it is the opinion here that changes in human mobility are not controlled directly be climatic conditions, rather controlled by the available major prey species and their behaviour in changing environments.

Nuclear power plays a crucial role in energy supply in the world: around 15% of the electricity generated worldwide is provided from nuclear stations avoiding around 2.5 billion tonnes of CO2 emissions. As of January 2016, 442 reactors that generated 380+ GW were in operation and 66 new reactors were under construction. The seismic design of new nuclear power plants (NPPs) has gained much interest after the high-profile Fukushima Dai-ichi accident. In the UK, a tectonically stable continental region that possesses medium-to-low seismic activity, strong earthquakes capable of jeopardising the structural integrity of NPPs, although infrequent, can still occur. Despite that no NPP has been built in Great Britain after 1995, a New Build Programme intended to build 16 GW of new nuclear capacity by 2030 is currently under way. This PhD project provides a state-of-the-art framework for seismic probabilistic safety assessment and risk control of NPPs in Northwest Europe with particular application to the British Isles. It includes three progressive levels: (i) seismic input, (ii) seismic risk analysis, and (iii) seismic risk control. For seismic input, a suitable model to rationally define inputs in the context of risk assessments is proposed. Such a model is based on the stochastic simulation of accelerograms that are compatible with seismic scenarios defined by magnitude 4 < Mw < 6.5, epicentral distance 10 km < Repi < 100 km, and different types of soil (rock, stiff soil and soft soil). It was found to be a rational approach that streamlines the simulation of accelerograms to conduct nonlinear dynamic analyses for safety assessments. The model is a function of a few variables customarily known in structural engineering projects. In terms of PGA, PGV and spectral accelerations, the simulated accelerograms were validated by GMPEs calibrated for the UK, Europe and the Middle East, and other stable continental regions. For seismic risk analysis, a straightforward and logical approach to probabilistically assess the risk of NPPs based on the stochastic simulation of accelerograms is studied. It effectively simplifies traditional approaches: for seismic inputs, it avoids the use of selecting/scaling procedures and GMPEs; for structural outputs, it does not use Monte Carlo algorithms to simulate the damage state. However, it demands more expensive computational resources as a large number of nonlinear dynamic analyses are needed. For seismic risk control, strategies to control the risk using seismic protection systems are analysed. This is based on recent experience reported elsewhere of seismically protected nuclear reactor buildings in other areas of medium-to-low seismic activity. Finally, a scenario-based incremental dynamic analysis (IDA) is proposed aimed at the generation of surfaces for unacceptable performance of NPPs as function of earthquake magnitude and distance. It was found that viscous-based devices are more efficient than hysteretic-based devices in controlling the seismic risk of NPPs in the UK. Finally, using the proposed scenario-based IDA, it was found that when considering all controlling scenarios for a representative UK nuclear site, the risk is significantly reduced ranging from 3 to 5 orders of magnitude when using viscous-based devices.