Holocene drainage systems of the English Fenland : roddons and their environmental significance

The roddons of the English Fenlands are fossilised silt and sand-filled tidal creek systems of mid- to late-Holocene age, incised into contemporaneous clay deposits. However, anthropogenic change (drainage and agriculture) has caused the former channels to become positive topographical features. Three stratigraphically discrete generations of roddon have been discriminated. They all show well-developed dendritic meander patterns, but there is little or no evidence of sand/silt infill during meandering; thus, unlike modern tidal creeks and rivers they typically lack laterally stacked point bar deposits, suggesting rapid infill. Major “trunk” roddons are rich in fine sands and there is little change in grain size from roddon mouth to the upper reaches, suggesting highly effective sand transport mechanisms and uniform conditions of deposition. Tributaries are silt-rich, while minor tributaries also have a significant clay component. During infill, active drainage networks appear to have been choked by sediment, converting mudflat/salt-marsh environments into widespread peat-forming freshwater reed swamps

The formation of cupper transition nano-layer in polytetrafluoroethylene surface by means of ion beam assisting deposition

The deposition of Cu on polytetrafluoroethylene surface assisted by the Ar ion beam with the temperature of 1 keV is investigated numerically. Ar ions provide the kinematic mixing of Cu atoms and atoms of substrate forming the connecting 10 nm layer of mixed material. This layer can ensure a good adhesion of Cu films deposited on polytetrafluoroethylene.Осаждение медного покрытия на поверхность политетрафторэтилена, стимулированное пучком ионов аргона с температурой 1 кэВ, изучалось методами численного моделирования. Ионы аргона обеспечивали смешивание атомов меди и поверхности, что позволило сформировать переходной слой шириной 10 нм. Такой слой может обеспечить хорошие адгезионные свойства металлической пленки, осажденной на поверхность политетрафторэтилена.Осадження мідного покриття на поверхню політетрафторетилену, стимульоване пучком іонів аргону з температурою 1 кеВ, вивчалось методами чисельного моделювання. Іони аргону забезпечували змішування атомів міді і поверхні, що дозволило сформувати перехідний шар шириною 10 нм. Такий шар може забезпечити гарні адгезійні властивості металевої плівки, обложеної на поверхню політетрафторетилену

Еволюція топоформанта -щина в слов’янських мовах та його рефлекси в реґіональній історичній ойконімії

У статті автор на широкому географічно-історичному тлі простежує еволюцію топоформанта -щина в слов'янській топонімії детально аналізує рефлекси цього суфікса в реґіональній історичній ойконімії на прикладі дев'яти назв (і 12-ти мікроойконімних варіантів) населених пунктів Галицької та Львівської земель Руського воєводства із подальшим встановленням їхньої етимологи.В статье автор на широком географическо-историческом фоне прослеживает эволюцию топонимического форманта -щина в славянской топонимии детально анализирует рефлексы этого суффикса в региональной исторической ойконимии на примере девяти названий (с 12-ю микроойконимными вариантами) населенных пунктов Галицкой и Львовской земель Русского воеводства с последующим установлением их этимологии.The author traces the evolution of topoformant -schyna on the basis of historical and geographical studies in Slavic Toponymy. Reflexes of the suffix are analyzed in regional historical oykonymy in 12 toponyms (and their 12 microokonymic variants) of villages and towns of Halych and Lviv Lands of Ruske Woyewodstwo. Their etymology is also analysed

Sea-level change in the Dutch Wadden Sea

Rising sea levels due to climate change can have severe consequences for coastal populations and ecosystems all around the world. Understanding and projecting sea-level rise is especially important for low-lying countries such as the Netherlands. It is of specific interest for vulnerable ecological and morphodynamic regions, such as the Wadden Sea UNESCO World Heritage region. Here we provide an overview of sea-level projections for the 21st century for the Wadden Sea region and a condensed review of the scientific data, understanding and uncertainties underpinning the projections. The sea-level projections are formulated in the framework of the geological history of the Wadden Sea region and are based on the regional sea-level projections published in the Fifth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC AR5). These IPCC AR5 projections are compared against updates derived from more recent literature and evaluated for the Wadden Sea region. The projections are further put into perspective by including interannual variability based on long-term tide-gauge records from observing stations at Den Helder and Delfzijl. We consider three climate scenarios, following the Representative Concentration Pathways (RCPs), as defined in IPCC AR5: the RCP2.6 scenario assumes that greenhouse gas (GHG) emissions decline after 2020; the RCP4.5 scenario assumes that GHG emissions peak at 2040 and decline thereafter; and the RCP8.5 scenario represents a continued rise of GHG emissions throughout the 21st century. For RCP8.5, we also evaluate several scenarios from recent literature where the mass loss in Antarctica accelerates at rates exceeding those presented in IPCC AR5. For the Dutch Wadden Sea, the IPCC AR5-based projected sea-level rise is 0.07±0.06m for the RCP4.5 scenario for the period 2018–30 (uncertainties representing 5–95%), with the RCP2.6 and RCP8.5 scenarios projecting 0.01m less and more, respectively. The projected rates of sea-level change in 2030 range between 2.6mma−1 for the 5th percentile of the RCP2.6 scenario to 9.1mma−1 for the 95th percentile of the RCP8.5 scenario. For the period 2018–50, the differences between the scenarios increase, with projected changes of 0.16±0.12m for RCP2.6, 0.19±0.11m for RCP4.5 and 0.23±0.12m for RCP8.5. The accompanying rates of change range between 2.3 and 12.4mma−1 in 2050. The differences between the scenarios amplify for the 2018–2100 period, with projected total changes of 0.41±0.25m for RCP2.6, 0.52±0.27m for RCP4.5 and 0.76±0.36m for RCP8.5. The projections for the RCP8.5 scenario are larger than the high-end projections presented in the 2008 Delta Commission Report (0.74m for 1990–2100) when the differences in time period are considered. The sea-level change rates range from 2.2 to 18.3mma−1 for the year 2100. We also assess the effect of accelerated ice mass loss on the sea-level projections under the RCP8.5 scenario, as recent literature suggests that there may be a larger contribution from Antarctica than presented in IPCC AR5 (potentially exceeding 1m in 2100). Changes in episodic extreme events, such as storm surges, and periodic (tidal) contributions on (sub-)daily timescales, have not been included in these sea-level projections. However, the potential impacts of these processes on sea-level change rates have been assessed in the report

Holocene water level movements in the lower Scheldt perimarine area

Gradient lines and local water level movements in the lower Scheldt river could be reconstructed on the basis of a number of newly collected radiocarbon datings. Due to the presence of a floodbasin effect in the lower Scheldt river region, local MHW level in the Belgian part of the river was situated below coastal MHW since about 4500 BP. This floodbasin effect controlled the rise of local MHW level up to 500 to 1000 AD. Since then, a marked decrease of the floodbasin effect caused a rapid rise of local MHW level and tidal amplitude along a large part of the lower Scheldt river on Belgian territory. The data also indicate that differential tectonic subsidence of the western and northern Netherlands with respect to the lower Scheldt area can not have been greater than about 1.6 cm/century over the last 5000 years

The late Holocene evolution of the Perimarine part of the river Scheldt

Following a brief overview of the Holocene evolution of the river Scheldt, the late Holocene evolution of the tidal part of the river is presented in detail. A number of different phases could be distinguished. At or near to the end of the accumulation of the clayey peat a new non- or microtidal river channel was incised. Due to lateral displacement of the river channel point bars were formed while at approximately the same time peat accumulation came to an end by the deposition of an upper clay layer. At about 900 to 1000 AD, tidal range increased considerably in the study area and the MHW level started to rise continuously up to the present day. At present, tidal range is of the order of 5 m. A number of palaeo-water level indicators have been critically examined, in order to obtain data on the evolution of local water level and its relation to sea level rise and to the morphological development of the Scheldt estuary. It is shown that local MHW level around 900 to 1000 AD was about 0.8 rn lower than contemporaneous MHW level at sea due to the presence of an important floodbasin effect in the Scheldt tidal river system. The increase of tidal range after this date has been caused by a decrease of the floodbasin effect, partly due to human intervention