The intense precipitation associated with large storms can initiate thousands of landslides and debris flows, endangering lives and cause significant damage to infrastructure. Changes to the frequency and/or intensity of storms is a predicted consequence of anthropogenically-driven climate change (Rosenzweig et al., 2007), thus predictive models of landsliding are essential for mitigating these effects. Shallow landslides that initiate in soil are particularly destructive as they often initiate rapidly moving debris flows. Physically-based shallow landslide hazard models usually estimate landsliding a function of modern hydrologic, ecologic, and soil mechanical properties (Montgomery and Dietrich, 1994; Pack et al., 2001). The flaw in this approach is that it does not account for the "memory" of previous landslides in a catchment, where landslides are unlikely to occur twice in the same location within the short window of time (<1000 years). When landslide "memory" is considered, we hypothesise two possible effects on future landsliding: (1) the likelihood that extreme rainfall will create a large landslide event is dependent on the number of large storms that have recently occurred in a catchment, and (2) storms that initiate a 1000's of landslides may have a resonance within a landscape that causes landslides to cluster in time. Accounting for the combined role of precipitation and landscape resonance is of immediate concern as we begin to make predict hazards associated with climate change. The proposed research will quantify whether landslides are clustered in time, through the collection of a novel, large, millennial-scale dataset of landslide frequency. We will analyse landslide frequency using radiocarbon found at the base of 75 hollows (local depocentres located 10's of metres above channel heads) where shallow landslides initiate. These data, in conjunction with high resolution LiDAR topographic data, will drive the creation of a unique, probabilistic, landslide hazard model that estimates landslide hazard based on both recent precipitation and the potential resonance imparted by previous storms. Our novel landslide dataset and landslide hazard model will significantly improve our ability to predict the risks posed by landslides in current and future climate scenarios.

The Antarctic continent is an important part of the Earth system, both influencing and responding to global ocean and atmospheric circulation. The ice sheet plays a major role in sea-level change and currently holds the equivalent of 70m of global sea-level rise. Monitoring change in the climate, cryosphere and biosphere of Antarctica is therefore a critical element in understanding and predicting future global change. Over the past 50 years, the climate over most of Antarctica has remained relatively stable, but the Antarctic Peninsula has experienced one of the highest rates of warming anywhere on Earth, with increases of 3oC since the 1950s, and even higher rates for winter in some locations. The rapid increase in temperature has been associated with decreased sea-ice extent, ice-shelf collapse, glacier retreat and increased ice flow rates, and changes in ecosystems on land and sea. However, the causes and context of the recent temperature changes are unclear, although it is thought that stratospheric ozone depletion and increasing greenhouse gases are both important. Current global climate models do not capture the observed changes adequately at present. A key question in understanding and attribution of Antarctic climate change is whether the recorded changes on the Peninsula are unusual compared with past natural climate variability. However, this question cannot be addressed because the instrumental records are too short and existing proxy-climate records are not suitably located to be able to trace the spatial signature of change over time. The project proposed here will exploit moss banks as a new proxy-climate archive to test three key hypotheses: 1) The recent temperature rise on the Antarctic Peninsula is unprecedented in the late Holocene. 2) The spatial pattern of variability is similar to that which occurred during previous periods of climate change. 3) Plant communities are responding to recent climate change by increases in growth rates and altered seasonal growth patterns. Moss banks are ideal deposits for reconstructing climate change over the land surface of the Antarctic Peninsula because of their location in relation to recorded temperature changes, their age, and their attributes as archives. The moss banks have accumulated peat over the past 5-6000 years at locations throughout the western Antarctic Peninsula. They are formed of only one or two species, annual growth can be traced in the surface peats and preservation of moss remains is good. We will use multi-proxy indicators of past climate (stable isotopes, measures of decay, testate amoebae and moss morphology) to reconstruct climate variability from critical locations across the observed gradient in rate of temperature change between 69o and 61o S. Although these techniques are tried and tested in more temperate regions of the world, they have not been employed in the Antarctic. We carried out pilot studies on Signy Island which show that these proxies work well for the moss banks in the Antarctic so we know that our approach will produce valuable results. Our work will also involve improving our understanding of proxy-climate relationships by a programme of surface sampling and measurement. The records will be calibrated using annually resolved records covering the period of instrumental observations. Together with records from Signy Island being produced as part of a current BAS PhD project supervised by members of the research team, emerging results from the BAS ice core at James Ross Island and some of the higher resolution ocean sediment records, our data will also provide the basis for a more complete understanding of late Holocene climate variability in the broader region, building on the BAS Past climate and Chemistry programme directed at reconstructing and understanding Holocene climate variability in the Antarctic Peninsula.

Millennial-scale climate variability in the subpolar North Atlantic is thought to be a pervasive, common feature of marine, ice core and terrestrial archives throughout the Holocene, mainly driven by changes in the Atlantic Meridional Overturning Circulation (AMOC). Strong ocean-atmosphere coupling in the North Atlantic mean that stronger (or weaker) westerlies associated with a prolonged positive (or negative) North Atlantic Oscillation (NAO) phase may have enhanced AMOC during the last millennium. We intend to demonstrate for the first time that the proposed atmospheric forcing of AMOC during the past millennium is an underlying mechanism that persists throughout the Holocene. AMOC variability plays an important role in the modulation of European (and global) climate variability through the latitudinal transfer of heat northwards via the North Atlantic Current (NAC) and there is an emerging understanding of the importance of subpolar gyre (SPG) dynamics, primarily driven by atmospheric forcing, upon the salinity of the NAC and hence the strength of AMOC. The fjordic environments of Scotland, as represented by Loch Sunart, are well-placed to capture this variability, and together with recent tephrochronological advances at this site, present a unique opportunity to underpin the chronology of regional land-ocean interactions during the Holocene. High-resolution (0.3 cm/yr) reconstructions of salinity, temperature and circulation from a 22.5m long core (MD04-2832), recovered from Loch Sunart (NW Scotland), reflect the controls of both NE Atlantic hydrology and large-scale atmospheric forcing. For example, between 5-6 kyr, MD04-2832 proxies respond to a major reorganization in atmospheric circulation4, SPG dynamics and AMOC variability. The available chronological control in these records, however, limits our ability to critically test the relative timing of these large-scale northern hemisphere synoptic climate changes. The aim of this proposal is to establish a tephra stratigraphy for MD04-2832, to underpin the precise timing of these large-scale shifts in Holocene marine climate and facilitate a comparison with proxies of atmospheric circulation recorded in Greenland ice cores and elsewhere. If the current understanding of stronger westerlies associated with a prolonged positive NAO phase linked to enhanced AMOC via SPG dynamics is correct, then we hypothesize that our marine proxy records from the west of Scotland will synchronize with large-scale changes in atmospheric circulation inferred from Greenland ice cores. Critically, given the uncertainties of existing age-control, tephra isochrones are the key to solving this chronological problem and a significant number of Holocene tephra are known from terrestrial settings in Scotland and Ireland.

Sea-level change is one of the most significant threats facing society over the next 100 years and beyond. Measurements of current sea-level change have shown that there has been a mean global sea-level rise of between 10 and 20 cm over the 20th century. A further rise in sea level of between 20 and 80 cm is predicted by AD 2100 due to future global climate change. However, such predictions of future change are subject to very large uncertainties because our understanding of the past behaviour of sea level is poor. It is essential that we quantify sea-level changes in the recent past if we are to provide more accurate and precise predictions for the future. It is clear from measurements and from sea-level reconstructions based on geological data that there has been a significant increase in the rate of sea-level rise from the 19th to the 20th century. We ask the question: Have similar accelerations of sea-level rise happened in the past? Some of our published geological reconstructions give us good reason to believe that there were pre-industrial sea-level accelerations and these require further investigation. We aim to establish the precise timing and magnitude of these rapid rises of sea level by constructing detailed 500-yr histories of sea-level changes in six sites around the North Atlantic Ocean. These records will be based on the remains of fossil plants and animals buried in coastal sediments which are excellent indicators of the past level of the sea. Timing is key, so we will use the most advanced dating methods, in particular ultra-high precision radiocarbon dating techniques, to find out when the rapid increases in sea-level rise occurred. If the changes we observe occurred in various sites at the same time, then it would imply that hitherto unknown episodes of land-based polar ice melt are responsible. There are important processes that obscure the sea-level signal derived from melting ice that may be observed in coastal sediments and tide gauges. These include changes in the density of sea water - leading to expansion/contraction - due to temperature and salinity variations and vertical movements of the coast. We will correct for these processes separately, using models and available tide-gauge and ocean temperature measurements. First, we will create a model that can calculate steric (density) changes along the coast. Measurements of ocean density are available for the past 50 years, but these were taken in the open ocean, not near the coast. Many processes operating on the continental shelves, such as tides, currents and winds, mix the water column in these areas and so using ocean records may be inaccurate. Our model will help us to predict how the water density changes at the coast following a measured change in the middle of the ocean. A second model can simulate ocean steric changes for the past 500 years, a period for which ocean density and temperature data are not available. Some additional corrections for wind, air pressure and tidal changes, are also necessary but these are relatively easy to do. Second, we need to remove the effects of long-term land movements from our records. We will do this by reconstructing sea-level trends over the last 2000-3000 years and subtracting these from the proxy reconstructions. There are also geophysical models and GPS data that can help with this correction. The 'corrected' records of sea level will be analysed to determine whether synchronous episodes of sea-level rise have occurred in the past 500 years. We believe the work is important because it will, for the first time, enable us to test whether accelerations in sea-level in the North Atlantic have occurred at the same time or not, and if they have, we can determine how big they were. These data will provide important 'baseline' constraints for future sea-level predictions.

Major environmental change associated with current global warming represents one of the biggest challenges for mankind during the 21st century. For example, ice-sheet melting in West Antarctica contributes ~11% to the present global sea-level rise of ~1.8 mm per year. A complete melting of the West Antarctic Ice Sheet (WAIS), which is likely to take several hundreds or thousands of years, would raise global sea level by ~5 m. This project aims to study the part of the WAIS that is currently showing the most dramatic indications for ice-sheet melting: the Amundsen Sea sector. Global sea level would rise by additional ~1.4 m, if the ice located in the Amundsen Sea sector would melt completely, which is possible to occur within the next two centuries. This melting would cause devastating flooding in many low-lying cities (e.g. New Orleans, London), agricultural areas (e.g. Netherlands, Bangladesh) and atolls (e.g. Maldives), with immense social, economic and ecological consequences. Until now, however, it is unclear if the melting of the WAIS has been occurring for some time and might continue long into the future, or if it is a relatively short-lived phenomenon. It is also unclear if the present WAIS melting is the result of climate warming, which has been ongoing since the end of the last ice age (~12,000 years ago), or of the mainly man-made greenhouse effect, which has influenced global climate for the last 150 years. Therefore, it is essential to study the history of the WAIS since the last ice age, which is the main scientific objective of the proposed project. In the proposed project the history of WAIS will be reconstructed by studying the sediments that make up the sea floor on the continental shelf that surrounds West Antarctica. These sediments are collected by coring several metres down into the seabed. Work that has already been done on the cores selected for this project shows that the WAIS extended far onto the shelf during the last ice age and retreated since then. The project will attempt to determine the timescale and speed of this retreat by the reliable dating of sediments in several cores. The timing of the ice retreat from a particular core site can be determined by radiocarbon dating of the organic remains of planktonic micro-organisms in the sediments. These organisms lived in the ocean waters that flooded onto the shelf as soon as the ice retreated. When the organisms died, their remains were deposited on the seafloor. Thus, their age reveals when the sediment was formed. Scientists have previously tried to date WAIS retreat from the shelf, but many of their dates are uncertain. This is because the marine sediments contain not only the remains from organisms alive shortly before sediment formation, but also much older, fossil organic remains. These remains were eroded from old sedimentary rocks in the Antarctic hinterland by the ice sheet. Glaciers transported the fossil remains and other detritus to the coast and released them into the sea, where they were deposited together with the remains of those planktonic organisms, which just have died. The fossil organic remains increase the apparent radiocarbon age of a sediment sample. The project will use an improved radiocarbon dating technique, which will overcome this problem and provide more accurate radiocarbon ages. Additionally, the project will apply another (independent) technique for dating the sediments. The intensity of the earth's magnetic field changed in a well-known pattern throughout the last 12,000 years. The project will use sophisticated methods for determining the relative variations of the magnetic intensity of the sediments: these reflect the global magnetic intensity variations. The relative magnetic intensity variations of the sediment cores can then be used to determine their age, and thus the time of ice retreat. The results of the proposed project will aid to a much more accurate prediction of future sea-level rise.