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Long-term monitoring along the Irish Sea coast of Britain at Formby has identified hundreds of animal and human footprints in 31 discrete sediment beds. A new programme of radiocarbon dating shows that the Formby footprints span at least 8,000 years of the Holocene Epoch from the Mesolithic period to Medieval times. In a landscape largely devoid of conventional archaeology and faunal records, we show how species data from the footprint stratigraphy document long-term change in both large mammal diversity and human behaviour. The footprint beds record shifting community structure in the native fauna through an era of profound global change. As sea levels rose rapidly in the Early Holocene, men, women and children formed part of rich Mesolithic intertidal ecosystems from ~9,000 to 6,000 cal BP, with aurochs, red deer, roe deer, wild boar, beaver, wolf and lynx. Doggerland was reclaimed by the sea in this period. In the agriculture-based societies that followed, after 5,500 cal BP human footprints dominate the Neolithic period and later beds, alongside a striking fall in large mammal species richness. Stacked footprint beds can form multimillennial records of ecosystem change with precise geographical context that cannot be retrieved from site-based fossil bone assemblages.

‘Peoples of the Arctic’ focuses on the 4 million people that live north of the Arctic Circle, providing an important distinction between indigenous and settler residents, as over 1 million indigenous peoples live in the eight Arctic states. Archaeological evidence suggests that the first people in the Arctic arrived about 40,000 years ago as there were Upper Palaeolithic hunting communities in north-eastern Siberia. There is considerable diversity of indigenous peoples that have called the Arctic home. Arctic demographers predict that more and more Arctic peoples will be based in towns and cities, but in the Russian and North American Arctic there will still be dispersed and small-scale settlements. Indigenous peoples of the Arctic are culturally, economically, and politically active in all the Arctic states.

The Arctic: A Very Short Introduction provides an account of the Arctic, its physical environment, and its people. The Arctic is demanding global attention as it warms, melts, and thaws in a manner that threatens not just its 4 million inhabitants, but the whole planet. The reduction of the Arctic to its changing environment would ignore the complexities of the region and its potential. This VSI explores key issues facing the region today, from geopolitics to global warming. It examines the causes and effects of cultural, physical, ecological, political, and economic change in the Arctic, and considers its uncertain future.

‘Exploration and exploitation’ reviews the history of Arctic exploration and exploitation, which owes a great deal to early European encounters with the 'New World'. This topic includes the earliest Viking settlement of Greenland to a succession of European explorers and expeditions that were designed to search for the Northwest Passage. The Hudson's Bay Company (HBC), which specialized in fur trading, was integral to the early exploitation of the Canadian north since it was chartered in May 1670. The history and presence of industrial-scale mining in the Arctic over the last 300 years also played an important part. The term 'Arctic paradox', used by Arctic observers, describes a series of contradictory pressures facing the region—managing resources, promoting sustainable development, and ensuring that indigenous and northern communities are beneficiaries from any form of resource-led development.

‘Arctic ecosystems’ highlights the treeless landscapes that fringe the Arctic Ocean, in which the diversity of plants is low, nutrient supply is limited, and soil depth is constrained by permafrost. The aim is to capture some of the key characteristics of the Arctic biome in the past and present. How do ecosystems function in the northern high latitudes? How have they responded to the recent environmental change? Arctic vegetation is grouped into twenty-one provinces based on various characteristics including relative uniformity of species and number of endemics. High fluctuation in animal populations is a key feature of the Arctic biome.

‘The physical environment’ describes the Arctic as the polar opposite of the Antarctic continent as it is an ocean semi-enclosed by land. The rocks of the Arctic record key periods in Earth history. The Arctic environment has had an interesting path of evolution. Why is the Arctic cold today? The polar latitudes actually receive less solar energy than the rest of the Earth's surface. What is the key role of sea ice in the Arctic climate system? How does sea ice decline impact upon the Arctic Ocean? The Greenland ice sheet, high latitude glaciers, and the importance of permafrost in the far north are also important topics related to the physical environment.

‘The Arctic carbon vault’ describes the large share of Earth's organic carbon sequestered in the frozen ground and within the shelf sea sediments of the Arctic Ocean. The organic carbon stock of the permafrost is roughly equivalent to half of total global soil carbon. A cold Arctic with extensive permafrost is an effective long-term carbon sink as carbon is safely locked away as long as permafrost is maintained. Giant craters appeared on the Yamal peninsula. The thawing permafrost leads to the formation of thermokarst lakes, which are frozen bodies of water held in subsidence depressions created by the thawing of ground ice. Well-preserved carcasses of extinct ice age beasts, including woolly mammoths and cave bears, have been recovered from the thawing permafrost.

‘Arctic futures’ discusses the future of the Arctic that starts in the Norwegian territory of Svalbard wherein the Global Seed Vault functions as an Arctic sanctuary for the genetic diversity of crops. The Svalbard archipelago is a hotspot of Arctic amplification as rapid warming has been keenly felt by the small community. However, the environmental changes, no matter how stark and widespread, will not dampen interest in economic development and strategic posturing. Arctic states and northern peoples remain eager to improve their social and economic conditions as well as adapt to ongoing climate change. The Arctic is a haven of international peace and cooperation as the Arctic Council is cited as a governance model that others could emulate.

‘Arctic governance’ discusses how the Arctic, unlike many other parts of the world, has been spared military conflict, civil wars, and terrorism. Arctic governance involves an array of actors, legal regimes, institutional and social contexts, and strategic aspirations. In 1989, Finland approached the other seven Arctic states with a proposal for the Rovaniemi Meeting, which discusses the protection of the Arctic environment. This provided the foundation for the intergovernmental forum the Arctic Council (1996). The eight Arctic states will remain significant players in the future governance of the northern latitudes alongside indigenous peoples/permanent participants. There will always be powerful drivers that ensure that the 'global Arctic' will be prominent in multiple ways, including the role that China, the European Union, and other external states will play in shaping its future.

‘The Arctic world’ begins with the definition of the Arctic, which is understood as the land, sea, and ice lying north of the Arctic Circle set at a latitude of approximately 66.5° N. The Arctic tree line is a robust indicator of Arctic-ness as everything to the north is a landscape characterized by shrubs, dwarf trees, and lichen. Arctic warming occurs at least twice as rapidly as the global average, which is a phenomenon known as Arctic amplification. Since 1980, the warming trajectory in the Arctic has been much steeper than that of the rest of the planet.

Wastewater discharge to rivers is a controversial practice that compromises water quality, aquatic habitats and human health worldwide. Here we show how untreated wastewater laced with microplastics and raw sewage is routinely discharged into UK river flows that are too low to disperse the microplastics downstream. These ‘dry weather’ spills lead to acute microplastic contamination of river bed habitats. Many aquatic fauna feed in the benthic zone, the quality of which affects the entire riverine ecosystem. All microplastic types accumulate to high concentrations on the channel bed until flushed downstream by floods. These findings pose fundamental questions about the sustainable management of urban wastewater. Treating the wastewater would shut down the major source of microplastic fragments and microbeads in such rivers and prevent their transport to the ocean. Riverine microplastic transport is primarily partitioned between: (1) continuous transport at low concentrations of synthetic fibres from treated wastewater effluent; and (2) episodic flood-driven transport of the full microplastic assemblage entrained from contaminated channel beds. Focusing only on the buoyant non-flood microplastic load can produce highly unrepresentative assessments of riverine microplastic contamination. Climate warming and urban population growth will intensify the microplastic burden on many river ecosystems as summer baseflows decline and wastewater fluxes increase. The authors show how untreated wastewater laced with microplastics and raw sewage is routinely discharged into UK river flows that are too low to disperse the microplastics downstream. This discharge creates acute microplastic contamination of river beds that threatens biodiversity and the quality of riverine habitats.

On 26th December (Boxing Day) 2015 an exceptional flood event occurred in the Irwell catchment, UK, whilst the neighbouring Mersey catchment experienced a much more typical winter runoff event. This provided an opportunity to examine the influence of high magnitude hydrological processes on the behaviour of fine‐grained metal‐contaminated bed sediments. Forty sites across the two catchments were sampled for channel bed fine sediment storage and sediment‐associated metal (loid) concentrations prior to, and following, the flooding. Sediments were analysed for total As, Cr, Cu, Pb, and Zn, and then subjected to a 5‐step sequential extraction procedure. Despite a significant reorganisation of fine‐grained (

Throughout the last cold stage, the North Atlantic region was punctuated by abrupt climate shifts and atmospheric processes propagated their effects to adjacent continents. During Heinrich Stadials, the ocean was chilled by icebergs calved from the great ice sheets. The impact of multiple temperature and precipitation regime changes on Late Pleistocene mountain glaciers and landscape development is poorly understood. Here we analyse 1,118 cosmogenic exposure ages—spanning the last 100,000 years—from glacial landforms on three continents across the Mediterranean. We evaluate their geomorphological context and stratify the record by depositional setting and geographical region. The database includes 300 dated moraines. We show that, despite cold temperatures, Heinrich Stadial aridity caused negative glacier mass balance and repeatedly stalled glacier growth across the Mediterranean. In contrast, relatively warm and humid climates between Heinrich Stadials favoured positive glacier mass balance, resulting in region-wide glacier growth and moraine formation. Our analysis supports climate model simulations of repeated and widespread Heinrich Stadial aridity in the Mediterranean basin during the last cold stage. Heinrich Stadials also saw enhanced supply of coarse debris from valley sides. The cumulative geomorphological impact of these climate shifts saw the largest moraines form at the culmination of the glacial cycle. Mountain glacier growth around the Mediterranean repeatedly stalled during cold, dry Heinrich Stadials, according to an analysis of cosmogenic isotope-dated glacial landforms from across the region.

Catastrophic events such as debris flows and big floods are important agents of landscape change in steepland mountain environments. These events can be prominent in paraglacial settings as well as those that are tectonically active. Since such catastrophic events pose a significant natural hazard in deglaciating modern settings (e.g. Haeberli et al. 2017), it is useful to better understand analogous events in the recent geological past.The Tamatert Valley, near the village of Imlil, on the northern slopes of Jebel Toubkal (4167 m a.s.l.) in the High Atlas, holds a valuable record of Quaternary landscape change. The steepland Tamatert Valley was glaciated during the Pleistocene (Hughes et al. 2018) and lies on the major Tizi n’Test Fault Zone.More than 200 well rounded basalt mega-boulders (>2m b axis) have been mapped in the Tamatert Valley catchment (9 km2). Many of the boulders are larger than 5 m (b axis). The mega-boulders are found in the active channel of the Tamatert River, stranded above the modern channel, and embedded in valley-fill deposits. A preliminary chronological framework, combining cosmogenic exposure and luminescence dating, points to deposition of these boulders in the Late Pleistocene. The boulders are porphyritic basalt and lithologically distinct from the local diorite/granite bedrock. They were transported by a catastrophic flood or debris flow over a distance of more than 3 km from the glaciated basalt source area.Serendipitously, a debris flow producing a similarly extensive deposit of boulders (up to 3 m b axis) occurred in the neighbouring Mizane Valley in September 2019. Mapping of this modern deposit allows direct comparison with the Late Pleistocene event. Together, these provide valuable insights into the geomorphological significance of high magnitude, large boulder transit events in glaciated, steepland river catchments in the High Atlas. Haeberli, W., Schaub, Y. & Huggel, C. 2017. Increasing risks related to landslides from degrading permafrost into new lakes in de-glaciating mountain ranges. Geomorphology, 293, 405–417Hughes, P.D., Fink, D., Rodés, Á., Fenton, C.R. & Fujioka, T. 2018. Timing of Pleistocene glaciations in the High Atlas, Morocco: New10Be and36Cl exposure ages. Quaternary Science Reviews, 180, 193–213

The timing and extent of mountain glaciation during the Late Pleistocene shows considerable variability around the world. Identifying the nature and timing of glaciation is important for understanding landscape evolution and changing climatic conditions (precipitation and temperature). In the Balkans, glaciers were actually larger during the Middle Pleistocene when large ice caps formed in several mountain ranges including the Dinaric Alps, Montenegro, and the Pindus Mountains, Greece. Glaciations younger than Marine Isotope Stage 6 were characterised by smaller ice masses with glaciers mainly restricted to the highest mountains. The behaviour of Late Pleistocene glaciers in this region influenced the timing of sediment and meltwater delivery to river systems; the migration of modern humans across Europe; and the dynamics of biological refugia. However, dating control is limited for Late Pleistocene glaciers in the Balkans.Here we report new in-situ 36Cl terrestrial cosmogenic nuclide exposure ages from moraine boulders sampled in the Velika Kalica valley, in the Durmitor massif, Montenegro. This valley was targeted because it contains the Debeli Namet glacier - the last remaining glacier in Montenegro. We have sampled 25 limestone boulders from 5 moraines situated down-valley of the current glacier at altitudes between 1650–2000 m. AgCl targets for 36Cl assay were prepared at The University of Manchester and 36Cl concentrations were measured on the SIRIUS 6MV accelerator at the Centre for Accelerator Science at the Australian Nuclear Science and Technology Organisation. At the last local glacial maximum, the Debeli Namet glacier extended almost 3 km beyond its current position. These 36Cl analyses are part of a wider regional Mediterranean study, totalling >50 new exposure ages, which also includes Mount Tymphi in the Pindus Mountains, NW Greece. The project will address both a significant spatial and temporal gap in Mediterranean glacial chronologies by targeting the hitherto undated Late Pleistocene glacial record. The work in Montenegro will also shed light on the nature of Holocene glaciation in the Balkans.

Large glaciers and ice caps formed in the Mediterranean mountains during the cold stages of the Pleistocene and some small glaciers remain today. Here we review 157 outputs that include radiometric dates on glacial deposits or outwash in the Mediterranean published between 1975 and 2020. The last decade has seen a striking increase in the use of terrestrial cosmogenic nuclide (TCN) dating and this has revolutionised our understanding of the Late Pleistocene glacial record. Our meta-analysis of 1663 radiometric ages highlights much greater complexity in the timing of Pleistocene glaciation across the region than hitherto recognised. Evidence from multiple dating methods, in a range of depositional settings, confirms that the Mediterranean glacial record extends through all of the Late Pleistocene and deep into the Middle Pleistocene. Evidence of Early Pleistocene glacial activity has been recognised from outwash deposits in the Julian Alps of Slovenia. The most extensive glaciations occurred during the Middle Pleistocene: their ages have been established primarily by using 40Ar/39Ar in the Italian Apennines and U-series dating in the glaciokarst of the Balkans. The Late Pleistocene glacial geochronologies are based on optically stimulated luminescence (OSL), radiocarbon and TCN dating. TCN dating is now the dominant method for dating Late Pleistocene glacial landforms. It is now clear that glaciers were present throughout the Late Pleistocene and, in most parts of the Mediterranean, they were at or near their maximum extent before the global last glacier maximum (27.5–23.3 ka). The outwash record in river valleys downstream of the glaciated terrains confirms that glaciers were important agents of landscape change throughout this period. Deglaciation in the Mediterranean mountains was punctuated by glacier stabilisations as well as some readvances towards the very end of the Pleistocene. The deglacial trend has continued throughout the Holocene with rapid change in recent decades due to rising global temperatures. Some small glaciers remain today due to the influence of locally favourable topoclimatic factors. For much of the Quaternary Period conditions in the Mediterranean mountains involved much more extensive glaciation than recorded at any time in the Holocene.

The Mediterranean mountains were repeatedly glaciated during the Pleistocene. Glacierswere present in most of the major mountains areas from Morocco in the west to the BlackSea coast of Turkey in the east. Some mountains supported extensive ice caps and ice fieldswith valley glaciers tens of kilometres long. Other massifs sustained only small-scale ice masses,although this was the exception rather than the norm. Glaciers still exist today and there is evidencethat small glaciers were a common sight in many regions during the Little Ice Age. The Mediterraneanmountains are important for palaeoclimate research because of their position in the midlatitudesand sensitivity to changes in the climate regimes of adjacent areas including the NorthAtlantic. These mountains are also important areas of biodiversity and long-term biological changethrough the Quaternary ice age. All of this provided challenges and opportunities for Palaeolithicsocieties. This paper reviews the history of the study of glaciation in the Mediterranean mountainsfrom pioneer nineteenth century observations through to the detailed geomorphological mappingand advanced geochronological datasets of recent times. We also review the current state of knowledgeto frame the contributions presented in this volume. Lastly, this new synthesis then identifiesoutstanding research problems and assesses the prospects for new studies of glaciation in the Mediterraneanmountains.

A coarse-grained alluvial fan at Lipci in the Bay of Kotor, western Montenegro, was deposited in the Middle Pleistocene by a high-energy, steep gradient proglacial stream draining an outlet glacier on the Orjen massif. The fan apex is currently about 50 m above sea-level, but the majority (c. 60%) of this landform now lies offshore. Field mapping, sedimentological analysis and uranium-series dating were combined with a marine bathymetric survey and seismic profiling to explore the morphology and history of the entire fan complex. The Lipci fan was deposited on the margin of a large polje downstream of moraines that formed during the Middle Pleistocene (Marine Isotope Stage 12). The sea-level may have been more than 120 m lower than present during the glacial stages of the Middle Pleistocene. The sediments on the terrestrial portion of the fan are strongly cemented by secondary calcite and the oldest uranium-series ages show that the fan was deposited before 320 ka. These ages are consistent with a larger uranium-series dataset (n=39) from other glacial and glacio-fluvial formations surrounding Mount Orjen. Seismic profiling of the submerged portion of the fan in the Bay of Kotor shows well-preserved palaeochannels with inset terraces. The Lipci fan is unusual because even its distal segments are well preserved after exposure to multiple post-Marine Isotope Stage 12 regression–transgression cycles. This is probably due to the strong cementation of the fan sediments and its sheltered location in the Bay of Kotor.

It has long been hypothesised that beds of highly organic mud or sapropels seen in marine sediment cores retrieved from the floor of the eastern Mediterranean accumulated during times of high Nile fluvial discharge. Our recent fieldwork in the valleys of the Blue Nile, the White Nile and the main Nile has for the first time revealed a sequence of extreme flood episodes synchronous with sapropel units S5 (124 kyr), S4 (102 kyr), S3 (81 kyr), S2 (55 kyr) and S1 (13.5–6.5 kyr). There are more weakly defined links with Nile floods and sapropel units S9 (240 kyr), S8 (217 kyr), S7 (195 kyr), S6 (172 kyr), but the dating error terms are too large to allow us to be too definite. During times of extreme floods over the past 125 kyr, wide distributary channels of the Blue Nile flowed across the Gezira alluvial fan in central Sudan and transported a bed load of sand and gravel into the lower White Nile valley. The sands were reworked by wind to form source-bordering dunes, all of which contain heavy minerals of Ethiopian provenance. These source-bordering dunes were active at 115–105 kyr, 60 kyr and 12–7 kyr, all times of extreme Blue Nile floods. The flood and dune sediments were dated using a combination of optically stimulated luminescence (OSL) and radiocarbon analyses. The Quaternary record of Nile floods discussed here shows a precessional signal and reflects episodes of stronger summer monsoon and more northerly seasonal movement of the ITCZ, linked to times of higher insolation in northern tropical latitudes. Progressive aggradation of Holocene Nile channels in northern Sudan has had a profound influence upon human settlement in the last 8 kyr.

We have reconstructed long-term shifts in catchment sediment sources by analysing, for the first time, the strontium (Sr) and neodymium (Nd) isotope composition of dated floodplain deposits in the Desert Nile. The sediment load of the Nile has been dominated by material from the Ethiopian Highlands for much of the Holocene, but tributary wadis and aeolian sediments in Sudan and Egypt have also made major contributions to valley floor sedimentation. The importance of these sources has shifted dramatically in response to global climate changes. During the African Humid Period, before c. 4.5 ka, when stronger boreal summer insolation produced much higher rainfall across North Africa, the Nile floodplain in northern Sudan shows a tributary wadi input of 40–50%. Thousands of tributary wadis were active at this time along the full length of the Saharan Nile in Egypt and Sudan. As the climate became drier after 4.5 ka, the valley floor shows an abrupt fall in wadi inputs and a stronger Blue Nile/Atbara contribution. In the arid New Kingdom and later periods, in palaeochannel fills on the margins of the valley floor, aeolian sediments replace wadi inputs as the most important secondary contributor to floodplain sedimentation. Our sediment source data do not show a measurable contribution from the White Nile to the floodplain deposits of northern Sudan over the last 8500 years. This can be explained by the distinctive hydrology and sediment delivery dynamics of the upper Nile basin. High strontium isotope ratios observed in delta and offshore records – that were previously ascribed to a stronger White Nile input during the African Humid Period – may have to be at least partly reassessed. Our floodplain Sr records also have major implications for bioarchaeologists who carry out Sr isotope-based investigations of ancient human remains in the Nile Valley because the isotopic signature of Nile floodplain deposits has shifted significantly over time.

© 2015 Elsevier Ltd. In the Nile catchment, a growing number of site- and reach-based studies employ radiocarbon and, more recently, OSL dating to reconstruct Holocene river histories, but there has been no attempt to critically evaluate and synthesise these data at the catchment scale. We present the first meta-analysis of published and publically available radiocarbon and OSL dated Holocene fluvial units in the Nile catchment, including the delta region, and relate this to changing climate and river dynamics. Dated fluvial units are separated both geographically (into the Nile Delta and White, Blue, and Desert Nile sub-regions) and into depositional environment (floodplain and palaeochannel fills). Cumulative probability density frequency (CPDF) plots of floodplain and palaeochannel units show a striking inverse relationship during the Holocene, reflecting abrupt (

Microplastic contamination of the oceans is one of the world’s most pressing environmental concerns. The terrestrial component of the global microplastic budget is not well understood because sources, stores and fluxes are poorly quantified. We report catchment-wide patterns of microplastic contamination, classified by type, size and density, in channel bed sediments at 40 sites across urban, suburban and rural river catchments in northwest England. Microplastic contamination was pervasive on all river channel beds. We found multiple urban contamination hotspots with a maximum microplastic concentration of approximately 517,000 particles m−2. After a period of severe flooding in winter 2015/16, all sites were resampled. Microplastic concentrations had fallen at 28 sites and 18 saw a decrease of one order of magnitude. The flooding exported approximately 70% of the microplastic load stored on these river beds (equivalent to 0.85 ± 0.27 tonnes or 43 ± 14 billion particles) and eradicated microbead contamination at 7 sites. We conclude that microplastic contamination is efficiently flushed from river catchments during flooding.

International audience; The relatively warm climate conditions prevailing today in the Mediterranean region limit cold geomorphological processes only to the highest mountain environments. However, climate variability during the Late Pleistocene and Holocene has led to significant spatio-temporal variations of the glacial and periglacial domain in these mountains, including permafrost conditions.Here, we examine the distribution and evolution of permafrost in the Mediterranean region considering five time periods: Last Glaciation, deglaciation, Holocene, Little Ice Age (LIA) and present-day. The distribution of inactive permafrost-derived features as well as sedimentary records indicates that the elevation limit of permafrost during the Last Glaciation was between 1000 m and even 2000 m lower than present. Permafrost was also widespread in non-glaciated slopes above the snowline forming rock glaciers and block streams, as well as meter-sized stone circles in relatively flat summit areas. As in most of the Northern Hemisphere, the onset of deglaciation in the Mediterranean region started around 19-20 ka. The ice-free terrain left by retreating glaciers was subject to paraglacial activity and intense periglacial processes under permafrost conditions. Many rock glaciers, protalus lobes and block streams formed in these recently deglaciated environments, though most of them became gradually inactive as temperatures kept rising, especially those at lower altitudes. Following the Younger Dryas glacial advance, the Early Holocene saw the last massive deglaciation in Mediterranean mountains accompanied by a progressive shift of permafrost conditions to higher elevations. It is unlikely that air temperatures recorded in Mediterranean mountains during the Holocene favoured the existence of widespread permafrost regimes, with the only exception of the highest massifs exceeding 2500-3000 m. LIA colder climate promoted a minor glacial advance and the spatial expansion of permafrost, with the development of new protalus lobes and rock glaciers in the highest massifs. Finally, post-LIA warming has led to glacial retreat/disappearance, enhanced paraglacial activity, shift of periglacial processes to higher elevations, degradation of alpine permafrost along with geoecological changes.

Microplastic contamination of the aquatic environment is a global issue. Microplastics can be ingested by organisms leading to negative physiological impacts. The ingestion of microplastics by freshwater invertebrates has not been reported outside the laboratory. Here we demonstrate the ingestion of microplastic particles by Tubifex tubifex from bottom sediments in a major urban waterbody fed by the River Irwell, Manchester, UK. The host sediments had microplastic concentrations ranging from 56 to 2543 particles kg-1. 87% of the Tubifex-ingested microplastic particles were microfibres (55 - 4100 µm in length), whilst the remaining 13% were microplastic fragments (50 - 4500 µm in length). FT-IR analysis revealed ingestion of a range of polymer types, including polyethylene terephthalate (polyester) and acrylic fibres. Whilst microbeads were present in the host sediment matrix, they were not detected in Tubifex worm tissue. The mean concentration of ingested microplastics was 129 ± 65.4 particles g-1 tissue. We also show that Tubifex worms retain microplastics longer than other components of the ingested sediment matrix. Microplastic ingestion by Tubifex worms poses a significant risk for trophic transfer and biomagnification of microplastics up the aquatic food chain.

This commentary uses Google Books N-grams to briefly explore the changing use of the word geomorphology in books published in British English and American English. Both show a decline in the use of the term geomorphology in recent years. A singular feature of the British data is a very sharp rise and fall in the use of term geomorphology in books published since 1980. The steep falling limb (post 1993) of this curve is of particular concern and several possible explanations are put forward including, since 1986, the influence exerted by Research Assessment Exercises on publication practice in UK universities. The N-gram trends pose important questions for all geomorphologists and we should monitor them to gain a better understanding of where we need to be most visible to ensure the long-term health of our discipline. Copyright © 2014 John Wiley & Sons, Ltd.

This paper explores the modification of limestone bedrock and fine-grained sediment within the Pleistocene glacial and proglacial environments of the Orjen massif in western Montenegro. We have characterised the fine-grained components of till and outwash using lithological and particle size data. Two main types of fine-grained outwash sediment have been recognised and each is associated with a distinctive meltwater route. Fine-grained sediments deposited downstream of bedrock gorges (type 1 meltwater route) typically display a bimodal particle size distribution, where the carbonate silt fraction (10-60μm) has been depleted and non-carbonate silts become dominant. This probably reflects both physical sorting and corrosion of the fine-grained limestone sediment within the proglacial fluvial environment. The 10-60μm component matches the particle size characteristics of typical loess. Fine-grained outwash deposits from directly in front of the former ice margin (type 2 meltwater route) show unimodal particle size distributions which more closely resemble the grain size characteristics of the glacial till, but they also show evidence of silt depletion. We argue that the fine-grained sediment exported from glaciated limestone catchments during the cold stages of the Pleistocene formed an important source of the carbonate-rich loess in this region. © 2014 Swedish Society for Anthropology and Geography.

Large-scale coupling between headwater catchments and downstream depocentres is a critical influence on long-term fluvial system behaviour and on the creation of the fluvial sedimentary record. However, it is often difficult to examine this control over multiple Quaternary glacial cycles and it has not been fully explored in karst basins. By investigating the Pleistocene glacial and fluvial records on and around Mount Orjen (1894m) in Montenegro, we show how the changing connectivity between glaciated mountain headwater source zones and downstream alluvial basins is a key feature of long-term karst system behaviour - especially in relation to the creation and preservation of the surface sedimentary record. Middle and Late Pleistocene glacial deposits are well preserved on Mount Orjen. Uranium-series dating of 27 carbonate cements in fluvial sediments shows that many alluvial depocentres were completely filled with coarse glacial outwash before 350. ka during the largest recorded glaciation. This major glaciation is correlated with the Skamnellian Stage in Greece and Marine Isotope Stage 12 (MIS 12, c 480-420. ka). This was a period of profound landscape change in many glaciated catchments on the Balkan Peninsula. Later glaciations were much less extensive and sediment supply to fluvial systems was much diminished. The extreme base level falls of the Late Miocene produced the world's deepest karst networks around the Mediterranean. After MIS 12, the subterranean karst of Mount Orjen formed the dominant pathway for meltwater and sediment transfer so that the depositional basins below 1000m became disconnected (uncoupled) from the glaciated headwaters. There is little evidence of post-MIS 12 aggradation or incision in these basins. This absence of later Pleistocene and Holocene fluvial activity means these basins contain some of the thickest and best-preserved outwash deposits in the Mediterranean. © 2014 Elsevier Ltd.

The mountains of the Mediterranean world are now largely ice free, but many were repeatedly glaciated during the Quaternary ice age. This created spectacular glaciated landscapes with a rich array of glacial deposits and landforms. The glacial and glacio-fluvial records are often very well preserved and our understanding of the timing of Quaternary glaciation has very recently been transformed through the application of dating methods utilizing uranium-series and cosmogenic isotopes. Glacial records from the Mediterranean now boast some of the most robust chronologies for mountain glaciation anywhere in the world – they represent a unique archive of Quaternary environmental change of global significance. The southerly latitude and relatively small size of Mediterranean glaciers rendered them especially sensitive to Pleistocene and Holocene climate changes. This volume brings together the leading researchers and the latest research on Mediterranean glaciation. Several papers also explore glacier behaviour in the Holocene – including those glaciers of southernmost Europe at risk of disappearing this century.

Clearly defined distal tephras are rare in rockshelter sediment records. Crvena Stijena, a Palaeolithic site in Montenegro, contains one of the longest (> 20 m) rockshelter sediment records in Europe with deposits ranging in age from Middle Pleistocene to mid-Holocene. A distinctive tephra is clearly exposed within the well stratified record approximately 6.5 m below the present land surface. We present geochemical data to confirm that this tephra is a distal equivalent of the Campanian Ignimbrite deposits and a product of the largest Late Pleistocene eruption in Europe. Originating in the Campanian volcanic province of southwest Italy, this tephra has been independently dated to 39.3 ka. It is a highly significant chronostratigraphic marker for southern Europe. Macrostratigraphic and microstratigraphic observations, allied with detailed particle size data, show that the tephra layer is in a primary depositional context and was transported into the rockshelter by aeolian processes. This site is unique because the tephra forms an abrupt boundary between the Middle and Upper Palaeolithic records. Before they can be used as chronostratigraphic markers in rockshelter and cave-mouth environments, it is essential to establish the stratigraphic integrity of distal tephras and the mechanisms and pathways involved in their transport and deposition.

Ice caps once covered large areas of Mount Orjen (1894 m), on the Adriatic coast of Montenegro/Bosnia Herzegovina/Croatia. The largest ice cap covered an area of c. 165 km2 and reached a maximum ice thickness of c. 450 m, in some areas reaching down to 500 m above modern sea level. U-series dating of secondary carbonates within moraines indicates that the most extensive glaciation occurred during the Middle Pleistocene, correlating with a major phase of glaciation in Greece to the south during MIS 12 (c. 480-430 ka). Later, less extensive, glaciations are also recorded in the cirques and valleys and correlate with glaciations during MIS 6 (190-130 ka) and MIS 5d-2 (110-11.7 ka). Each phase of glaciation would have required large amounts of snow accumulation. Under modern precipitation values, which at c. 5000 mm are some of the highest in Europe, mean annual temperatures would need to be only c. 5-6 °C lower in order to form similar sized glaciers today. A mean annual temperature depression of 12-13 °C would still require >1000 mm of snow accumulation (water equivalent) to balance ablation, suggesting sustained moisture supply during Pleistocene cold stages. Such sustained precipitation supply during Pleistocene cold stages is likely to have been facilitated by major temperature contrasts between the European landmass and the Mediterranean Sea, which are likely to have sustained lee-side vortices to the south of the Alps, in the Gulf of Genoa and Adriatic Sea, forming weak moisture-bearing depressions which tracked across the eastern Adriatic coastal mountains. Large ice caps on the Dinaric Alps would have blocked the inland penetration of these depressions, resulting in much drier conditions in the Balkan interior, creating favourable conditions for the deposition of thick accumulations of loess. The last glaciers on Orjen formed during the Younger Dryas (12.9-11.7 ka) and confirm the influence of North Atlantic Ocean circulation on Pleistocene climate change in this part of the Mediterranean. © 2010 Elsevier Ltd.

Our results show that the late Pleistocene Nile in northern Sudan was shifting position and actively aggrading at 145 ± 20 kyr, 83 ± 24 kyr, 32 ± 8 kyr and 20.7 ± 0.2 kyr and indicate, for the first time, a phase of high-energy flow in the White Nile at 27.8 ± 3.2 kyr, with still high but somewhat reduced flow in that river at 13.3 kyr, 10 kyr and 4.8-4.0 kyr. Beach ridges associated with a 386 m strandline of the White Nile have OSL ages of 27.5 ± 2.7 kyr and 14.5 ± 1.6 kyr. The Holocene terraces and former channels of the main Nile have ages of 11 kyr, 6.5-5.0 kyr and 4.8-4.0 kyr, after which there was a general decline in flood discharge. The now arid main Nile valley in northern Sudan was significantly wetter during the early to middle Holocene, with a lake up to 450 km2 in area, fed by an overflow channel from the early Holocene Nile between 9.5 kyr and 7.5 kyr. Previously stable late Pleistocene dunes were reactivated at intervals during the Holocene, with five samples from the White Nile valley indicating brief phases of Holocene dune activity at 9.9 ± 2.0 kyr, 9.0 ± 2.8 kyr, 6.6 ± 0.9 kyr, 4.8 ± 0.9 kyr and 2.9 ± 0.5 kyr, the earliest of which occurred within periods of generally wetter climate and higher Nile flow. The youngest freshwater shells on the Khor Abu Habl alluvial fan west of the White Nile correspond to a time of regionally wetter climate between 1.7 and 1.0 kyr. Our results suggest that millennial scale climatic instability may have been characteristic of Holocene climates in this region. © 2010 Elsevier Ltd. All rights reserved.

Palaeoflood research has developed rapidly since the 1970s as the value of assembling long flood histories has become more widely appreciated across the Earth and environmental sciences, and in river basin management and related policy formulation. Palaeoflood science links several disciplines and involves a wide range of field-based, theoretical, and modelling approaches. Increasingly, researchers are using palaeoflood data to explore linkages between various components of global change and the past dynamics of river systems. Pleistocene and Holocene flood records are now providing essential context for the short gauged records that are commonly used for flood hazard assessment and river basin management. Recent advances in palaeoflood science were presented at the 4th International Palaeoflood Workshop in Crete in June 2007. This paper reviews the background to this meeting, sets out the structure and key themes of this special issue, and outlines potential future research directions. © 2009 Elsevier B.V. All rights reserved.

Research published in the 1990s reshaped fundamental ideas about Quaternary geography and the tempo of global environmental change. Data from the Greenland ice cores and from North Atlantic marine sediments show that the last cold stage was punctuated by a remarkable series of abrupt and high-amplitude changes in climate and oceanographic conditions (Bond et al., 1993; Dansgaard et al., 1993). These dis-coveries are driving a new research agenda focused on the causal mechanisms and how ecosystems and geomorphological processes on the surrounding continents reacted to such rapid and repeated oscillations in Quaternary climate (Fuller et al., 1998; Allen et al., 1999; Walker and Lowe, 2007). Some researchers have returned to previously well-studied sites to scrutinise records at much higher resolution in order to examine the sensitivity and response of terrestrial environments during this period (e.g., Tzedakis et al., 2002). It is now clear that these fi ndings have major ramifi cations for all components of Physical Geography – for geomorphology, bioge-ography and climatology and how we conceptualise the interactions between them. These fi ndings have also led to new research questions and new approaches in the study of human-environment interactions during the Quaternary Period; especially the Palaeolithic archaeology of the last cold stage (Woodward and Goldberg, 2001; Gamble et al., 2004; Mellars, 2006; Tzedakis et al., 2007).Much earlier in the 20th century, in the absence of reliable stratigraphic frame-works for both the Quaternary and archaeological records, it proved diffi cult to tackle even very basic questions about the nature of the relationship between Qua-ternary environmental change and the human past. Peake (1922, p. 6), for example, outlined some of the central issues at this time

Pleistocene glacial activity transformed the runoff regimes and sediment loads of many river systems in the Mediterranean region. New data from northwest Greece show marked contrasts in ice volume and extent between cold stages of the Middle and Late Pleistocene. These altered the long-term meltwater routes and sediment supply conditions in glaciated river catchments. The Voidomatis River basin (384 km2) of northwest Greece now contains one of the best dated records of Middle and Late Pleistocene glacial and fluvial activity that is constrained by over 40 radiometric dates. This paper evaluates the glacial and fluvial geomorphological records to establish a series of correlations and to produce a fuller picture of Middle and Late Pleistocene landscape dynamics in a glaciated Mediterranean catchment. We propose a model of long-term river response to headwater glaciation for the Voidomatis River basin that may have some broader significance for mountain catchments in the Mediterranean and elsewhere. The transfer and storage of coarse-grained river sediment during the Late Pleistocene was strongly conditioned by the major Middle Pleistocene glaciations of MIS 12 and MIS 6. Glaciers were much smaller during the last cold stage (MIS 5d to 2), but meltwater floods still dominated suspended sediment fluxes throughout this period. Uniquely, the Voidomatis River basin contains fine-grained slackwater sediments that record the transition from glacial to interglacial conditions in the Mediterranean region at the end of the last cold stage. Sediment source data from the slackwater deposits record a relatively rapid reorganisation of the hydrology and sediment supply conditions in the catchment between about 20 and 17 ka. These deposits have allowed us to explore flood history and the dynamics of suspended sediment sources during this period for the first time. The use of quantitative sediment fingerprinting in palaeoflood studies has yielded a new understanding of long-term catchment dynamics that has not hitherto been attainable using conventional techniques. © 2008 Elsevier B.V. All rights reserved.

Fine-grained sediment is perhaps the most widespread and pervasive contaminant in aquatic systems reflecting its role in influencing the quality of the water (e.g., turbidity, vector of chemicals and other pollutants) and its detrimental effect on infrastructure (e.g., dams, turbines) and aquatic habitats (e.g., salmonid spawning grounds) through sedimentation. Determining the sources of fine-grained sediment thus represents an important requirement for watershed and coastal management, as well as for understanding the evolution of landscapes and ocean basins. Sediment source fingerprinting utilizes the diagnostic physical, chemical and biological properties (i.e., tracers) of source materials to enable samples of collected sediment to be apportioned to these sources. This review examines the development of the technique within the earth and ocean sciences, focusing mainly on agricultural landscapes. However, the development of new tracers, such as compound-specific stable isotopes, has allowed the technique to be applied in a growing number of environmental settings including forested (including wildfire-impacted forests), urban and estuarine/coastal settings. This review also describes other applications of the fingerprinting approach such as geoarchaeological (e.g., archaeological site formation), forensic (e.g., identifying the sources of soil/sediment particles in criminal investigations) and human health (e.g., identifying the sources of airborne particulate matter, PM2.5) applications. Identifying commonalities in methods and approaches between environments and disciplines should foster collaboration and the exchange of ideas. Furthermore, refinement of the sediment source fingerprinting technique requires that several methodological issues be addressed. These methodological issues range from the initial sampling design to the interpretation of the final apportionment results. This review also identifies and assesses these methodological concerns., This review was initiated as part of a project on developing improved protocols for sediment fingerprinting in Canadian watersheds funded by the Natural Sciences and Engineering Research Council of Canada (STPGP 413426-2011). Additional ideas stem from several sessions on sediment source tracing and fingerprinting at the European Geosciences Union conferences, a Coordinated Research Project of the International Atomic Energy Agency, and from a workshop held at the Scripps Institute, University of California-San Diego, funded by the European Union.

Limestone and ophiolite rocks are common across the eastern Mediterranean and many of the highest mountains are formed in these rock types. In northwest Greece, Pleistocene glacial erosion was much more effective on limestone terrain where pronounced glacial incision and subglacial glacio-karst processes produced locally-complex topography. This enabled Pleistocene glaciers to form on a range of slope orientations in contrast to ophiolite terrains, where glaciers were strongly controlled by aspect. On limestone terrains, the largest ice masses formed on south-facing slopes, whereas in neighbouring higher mountains formed in ophiolite, glaciers were much more restricted and predominantly formed on north- and east-facing slopes. © 2006 Elsevier B.V. All rights reserved.

A major reduction in summer temperatures during a Middle Pleistocene glacial cycle caused the most extensive glaciation recorded in the Mediterranean region. Glaciers in the mountains of Greece formed during marine isotope stage (MIS) 12 (474 000-427 000 years BP) under climatic conditions characterised by mean summer temperatures at least 11 °C cooler than today and annual precipitation of ≤ 2300 mm at the equilibrium line altitude (1741 m a.s.l.). This represents the coldest mean summer temperatures recorded in Greece during at least the last 430 000 years. Later Pleistocene glaciations (MIS 6 and 5d-2) were characterised by warmer summer temperatures and higher annual precipitation. © 2006 Elsevier B.V. All rights reserved.

Most of the existing data on the effective particle size characteristics of fluvial suspended sediment derive from instantaneous sampling methods that may not be representative of the overall suspended sediment loads. This presents difficulties when there is a need to incorporate effective particle size data into numerical models of floodplain sedimentation and sediment-associated contaminant transfer. We have used a field-based water elutriation apparatus (WEA) to assemble a large (36 flood) database on the time-integrated nature of the effective and absolute particle size characteristics of suspended sediment in four subcatchments of the River Exe basin of southwest England. These catchments, encompass a wide range of terrains and fluvial environments that are broadly representative of much of the UK and temperate, low relief northwest Europe. The WEA provides important data on the physical characteristics of composite particles that are not attainable using other methods. This dataset has allowed, for the first time, detailed interbasin comparisons of the time-integrated particle size characteristics of suspended sediment and reliable estimates of the contribution of five effective size classes to the mean annual suspended sediment load of the study catchments. The suspended sediment load of each river is dominated by composite rather than primary particles, with, for example, almost 60% (by mass) of the sediment load of the River Exe at Thorverton transported as composite particles > 16 μm in size. All the effective size classes contain significant clay components. A key outcome of this study is the recognition that each catchment has a distinctive time-integrated effective particle size signature. In addition, the time-integrated effective particle size characteristics of the suspended loads in each of the catchments display much greater spatial variability than the equivalent absolute particle size distributions. This indicates that the processes producing composite particles vary significantly between these catchments, and this has important implications for our understanding of the dynamics of suspended sediment properties. Copyright © 2007 John Wiley & Sons, Ltd.