Early Ipswichian (last interglacial) sea level rise in the channel region: Stone Point Site of Special Scientific Interest,Hampshire, England

Constraining the speed of sea level rise at the start of an interglacial is important to understanding the size of the ‘window of opportunity’ available for hominin migration. This is particularly important during the last interglacial when there is no evidence for significant hominin occupation anywhere in Britain. There are very few finer grained fossiliferous sequences in the Channel region that can be used to constrain sea level rise and they are preserved only to the north of the Channel, in England. Of these, the sequence at Stone Point SSSI is by far the most complete. Data from this sequence has been previously reported, and discussed at a Quaternary Research Association Field Meeting, where a number of further questions were raised that necessitated further data generation. In this paper, we report new data from this sequence – thin section analysis, isotopic determinations on ostracod shells, new Optical Stimulated Luminescence ages and Amino Acid Recem analyses. These show early sea level rise in this sequence, starting during the pre-temperate vegetation zone IpI, but no early warming. The implications of this almost certainly last interglacial sequence for the human colonisation of Britain and our understanding of the stratigraphic relationship of interglacial estuarine deposits with their related fluvial terrace sequences is explored.     

Guidelines on the use of inverse velocity method as a tool for setting alarm thresholds and forecasting landslides and structure collapses

Predicting the time of failure is a topic of major concern in the field of geological risk management. Several approaches, based on the analysis of displacement monitoring data, have been proposed in recent years to deal with the issue. Among these, the inverse velocity method surely demonstrated its effectiveness in anticipating the time of collapse of rock slopes displaying accelerating trends of deformation rate. However, inferring suitable linear trend lines and deducing reliable failure predictions from inverse velocity plots are processes that may be hampered by the noise present in the measurements; data smoothing is therefore a very important phase of inverse velocity analyses. In this study, different filters are tested on velocity time series from four case studies of geomechanical failure in order to improve, in retrospect, the reliability of failure predictions: Specifically, three major landslides and the collapse of an historical city wall in Italy have been examined. The effects of noise on the interpretation of inverse velocity graphs are also assessed. General guidelines to conveniently perform data smoothing, in relation to the specific characteristics of the acceleration phase, are deduced. Finally, with the aim of improving the practical use of the method and supporting the definition of emergency response plans, some standard procedures to automatically setup failure alarm levels are proposed. The thresholds which separate the alarm levels would be established without needing a long period of neither reference historical data nor calibration on past failure events.     

The Calatabiano landslide (southern Italy): preliminary GB-InSAR monitoring data and remote 3D mapping

On 24 October 2015, following a period of heavy rainfall, a landslide occurred in the Calatabiano Municipality (Sicily Island, Southern Italy), causing the rupture of a water pipeline supplying water to the city of Messina. Following this event, approximately 250,000 inhabitants of the city suffered critical water shortages for several days. Consequently, on 6 November 2015, a state of emergency was declared (O.C.D.P. 295/2015) by the National Italian Department of Civil Protection (DPC). During the emergency management phase, a provisional by-pass, consisting of three 350-m long pipes passing through the landslide area, was constructed to restore water to the city. Furthermore, on 11 November 2015, a landslide remote-sensing monitoring system was installed with the following purposes: (i) analyse the landslide geomorphological and kinematic features in order to assess the residual landslide risk and (ii) support the early warning procedures needed to ensure the safety of the personnel involved in the by-pass construction and the landslide stabilization works. The monitoring system was based on the combined use of Ground-Based Interferometric Synthetic Aperture Radar (GB-InSAR) and terrestrial laser scanning (TLS). In this work, the preliminary results of the monitoring activities and a remote 3D map of the landslide area are presented.     

Moisture budget variations in the Yangtze River Basin, China, and possible associations with large-scale circulation

We analyzed seasonal and annual variations of the whole layer atmospheric moisture budget and precipitation during 1961–2005 and their associations with large-scale circulation in the Yangtze River basin, China. The results indicated increasing moisture budget in summer and winter, but decreasing moisture budget in spring and autumn. Positive correlations between moisture budget and precipitation illustrate tremendous impacts the moisture budget has on the precipitation changes across the Yangtze River basin. In terms of seasonal variations, significant correlations were observed between precipitation and moisture budget in spring and autumn in the upper Yangtze River basin. Besides, we also analyzed changes of geopotential height. The positive trends of the geopotential height (850 hPa) were observed in the East Asia and the negative trends in the middle and west Pacific Ocean, indicating increasing geopotential height from south to north in east Asia which largely limited the moisture propagation to north China. While decreasing meridional geopotential height from west to east along the Yangtze River basin caused more moisture propagation from the west to the east parts of the study region, which may benefit more precipitation in the middle and lower Yangtze River basin.     

Duplex architecture and late‐orogenic backthrusting in Foredeep Units of the Northern Apennines (Italy)

The Northern Apennines of Italy is a fold and thrust belt that resulted from the NE‐ward progressive overthrusting of a Mesoalpine stacking (the ocean‐derived Ligurian Units) onto the detached sedimentary cover of the Adria plate continental margin (Foredeep Units). The Futa Pass area represents a key sector for the reconstruction of the deformation history of two Foredeep Units (Acquerino and Carigiola Units). The tectonic evolution of this sector is characterized by the superposition of three main deformation stages, with a constant NNE–SSW compression direction. The oldest structure is represented by the NNE‐verging Acquerino Unit duplex structure, the roof thrust of which is represented by the Ligurian stacking basal thrust. The interpretation of this structure as a large‐scale duplex is supported by the presence in the outer sectors of the Northern Apennines belt of Ligurian Units directly overthrust on younger Foredeep Units. In the second deformation stage the NNE‐verging Tavaiano Thrust developed. This regionally significant tectonic surface juxtaposes the Acquerino Unit (already developed as a duplex) and the overlying Ligurian Units, onto the Carigiola Unit. During this stage the fault pattern of the Carigiola Unit was also developed, characterized by two conjugate fault systems, coherent with a NNE–SSW maximum compression direction. During the last deformation stage, a backthrusting with a top‐to‐the SSW sense of movement (the Marcoiano Backthrust) brings the Carigiola Unit and its tectonic cover over the Acquerino and Ligurian Units, with the development of a large footwall syncline. The deformation history presented here differs from previous studies, and so provides a contribution to the debate on Northern Apennines tectonic evolution. Copyright © 2008 John Wiley & Sons, Ltd.     

A multi-method approach for the identification and quantification of water balance components of two lentic small water bodies

The protection of the globally widespread lentic small water bodies (LSWB) must be based on detailed knowledge about their hydrological connectivity and water balance. The study aimed to identify and quantify water balance components as well as surface-groundwater interaction of two LSWB in a characteristic lowland region with a combination of different methods. This includes the collection of hydrological data and the use of bromide and water stable isotopes (δ²H and δ¹⁸O) as tracers. With their help, mixing models were established, and daily water balances were assessed. The results show a strong bidirectional interaction of both LSWB systems with shallow groundwater. Bromide and stable isotope tracers allowed for the identification of the most relevant in- and outflow sources and pathways. Thereby, isotope data revealed isotopic enrichment typical for open-water bodies and only minor precipitation inputs mainly relevant at the end of the dry season. Water balance calculations suggested accentuated seasonal dynamics that were strongly influenced by shallow groundwater, which represented large inputs into both LSWB. By that, different phases could be identified, with high inflow rates in winter and spring and decreasing fluxes in summer. In one LSWB, a drainage system was found to have a major impact next to the shallow groundwater interaction. The findings of this research provide detailed insights into the influence and importance of shallow groundwater for LSWB in lowland regions. This impacts the diffuse input of agricultural pollutants into these ecologically important landscape features.     

An operational model to estimate hourly and daily crop evapotranspiration in hilly terrain: validation on wheat and oat crops

In this paper, we present an operational model to estimate the actual evapotranspiration (ET) of crops cultivated on hilly terrains. This new model has the following three characteristics: (1) ET modelling is based on a Penman?CMonteith (PM) type equation (Monteith 1965) where canopy resistance is simulated by following an approach already illustrated by Katerji and Perrier (Agronomie 3(6):513?C521, 1983); (2) the estimation of ET, by means of the PM equation, is made by using meteorological variables simulated on sloped sites as input; (3) these variables are simulated by using simple relationships linking the variables measured at a reference site on plane to the topographic characteristics of the site (slope, orientation, altitude as difference between reference, and sloped sites). This approach presents two advantages if compared with previously proposed models: Not only computation steps are greatly simplified but also error sources due to the simulation of climatic variables in sloped sites and the ET estimation are well distinguished. This model was validated at hourly and daily scales at four sites cultivated with wheat and oats offering a wide range of slope and orientation values: a reference site on plane, site 1 (9° sloping, NW orientation, 7 m from the reference site in plane), site 2 (6°, SE, 12 m) and site 3 (1°, SE, 18 m). At hourly scale, the new model performed well at all sites studied. The observed slope of the linear relationships between estimated and measured ET values ranged between 0.93 and 1.03, with coefficients of determination, r ², between 0.80 and 0.98. At daily scale, the slopes of the linear relationships between measured and estimated ET for the sites on plane and the sloped sites were practically the same (0.98?±?0.01); however, the coefficient of determination r ² observed in the site on plane was clearly greater (0.98) than that observed in the sloped sites (0.83). The presented analysis does not show any significant systematic effect of topography (slope and orientation of the plots) on the good performance of the proposed model for the ET estimation. Furthermore, we observed that coefficients of determination tend to decrease with the increase in the slope of the site, which translates into increased inaccuracy of the climatic variables simulation, in particular the net radiation, as the slope of the site increases. The proposed model allows to verify the different steps for calculating the fluxes, to identify the eventual sources of error and to make the needed corrections. For this reasons, the proposed model seems to be particularly ??operational??, i.e. a useful tool for estimating fluxes on hilly terrains.     

δB, Sr, Mg and B in a modern Porites coral: the relationship between calcification site pH and skeletal chemistry

Sr/Ca, B/Ca, Mg/Ca and δ¹¹B were determined at high spatial resolution across ∼1 year of a modern Hawaiian Porites lobata coral by secondary ion mass spectrometry (SIMS). We observe significant variations in B/Ca, Mg/Ca, Sr/Ca and δ¹¹B over short skeletal distances (nominally equivalent to periods of <20 days). This heterogeneity probably reflects variations in the composition of the extracellular calcifying fluid (ECF) from which the skeleton precipitates. Calcification site pH (total scale) was estimated from skeletal δ¹¹B and ranged from 8.3 to 8.8 (± ∼0.1) with a mean of ∼8.6. Sr/Ca and B/Ca heterogeneity is not simply correlated with calcification site pH, as might be expected if Ca-ATPase activity increases the pH and decreases the Sr/Ca and B(OH)₄⁻/CO₃²⁻ ratios of the ECF. We produced a simple model of the ECF composition and the skeleton deposited from it, over a range of calcium transport and carbonate scenarios, which can account for these observed geochemical variations. The relationship between the pH and Sr/Ca of the ECF is dependent on the concentration of DIC at the calcification site. At higher DIC concentrations the ECF has a high capacity to buffer the [H⁺] changes induced by Ca-ATPase pumping. Conversely, at low DIC concentrations, this buffering capacity is reduced and ECF pH changes more rapidly in response to Ca-ATPase pumping. The absence of a simple correlation between ECF pH and skeletal Sr/Ca implies that calcification occurred under a range of DIC concentrations, reflecting variations in the respiration and photosynthesis of the coral and symbiotic zooxanthellate in the overlying coral tissues. Our observations have important implications for the use of coral skeletons as indicators of palaeo-ocean pH.     

Flamingos,salt lakes and volcanoes: hunting for evidence of past climate change on the high Altiplano of Bolivia

Hidden within the vast Bolivian Altiplano are archives of past climate change in the form of remarkable carbonate rocks surrounding lakes long since disappeared. Beyond the Salar de Uyuni, the largest salt flat in the world, lies a relatively untouched realm of volcanoes and salt lakes. Ancient shorelines from intervals in the Altiplano history, when large lakes were more abundant, may hold important information about a time when the climate in this region was punctuated by much wetter phases before present day aridity took a hold. Previous studies in this region have reconstructed robust chronological timelines for such events and highlight two large lake phases over the last 18 thousand years (the Tauca and Coipasa lake phases); however higher resolution climate data are scarce. Current studies on climate proxies from smaller lakes in southern Bolivia may shed light on some of these higher resolution climate events including El Niño–Southern Oscillation (ENSO) events. Laminated tufa found around the palaeoshorelines of the West Lípez Lakes is one such proxy, and can be analysed to investigate the potential roles of annual versus shorter‐term climatic variation in the evolving Altiplano climate at the time.     

Yearly evolution of Euro-Atlantic weather regimes and of their sub-seasonal predictability

It is often assumed that weather regimes adequately characterize atmospheric circulation variability. However, regime classifications spanning many months and with a low number of regimes may not satisfy this assumption. The first aim of this study is to test such hypothesis for the Euro-Atlantic region. The second one is to extend the assessment of sub-seasonal forecast skill in predicting the frequencies of occurrence of the regimes beyond the winter season. Two regime classifications of four regimes each were obtained from sea level pressure anomalies clustered from October to March and from April to September respectively. Their spatial patterns were compared with those representing the annual cycle. Results highlight that the two regime classifications are able to reproduce most part of the patterns of the annual cycle, except during the transition weeks between the two periods, when patterns of the annual cycle resembling Atlantic Low regime are not also observed in any of the two classifications. Forecast skill of Atlantic Low was found to be similar to that of NAO+, the regime replacing Atlantic Low in the two classifications. Thus, although clustering yearly circulation data in two periods of 6 months each introduces a few deviations from the annual cycle of the regime patterns, it does not negatively affect sub-seasonal forecast skill. Beyond the winter season and the first ten forecast days, sub-seasonal forecasts of ECMWF are still able to achieve weekly frequency correlations of r = 0.5 for some regimes and start dates, including summer ones. ECMWF forecasts beat climatological forecasts in case of long-lasting regime events, and when measured by the fair continuous ranked probability skill score, but not when measured by the Brier skill score. Thus, more efforts have to be done yet in order to achieve minimum skill necessary to develop forecast products based on weather regimes outside winter season.