Correlation between nitrate concentration in groundwater and parameters affecting aquifer intrinsic vulnerability

This paper is the result of a study which was carried out in order to verify if the traditional methods to evaluate the intrinsic vulnerability or vulnerability related parameters, are able to clarify the problem of nitrate pollution in groundwater. In particular, the aim was to evaluate limitations and problems connected to aquifer vulnerability methods applied to nitrate contamination prevision in groundwater. The investigation was carried out by comparing NO₃ ⁻ concentrations, measured in March and November 2004 in the shallow aquifer, and the vulnerability classes, obtained by using GOD and TOT methods. Moreover, it deals with a comparison between NO₃ ⁻ concentrations and single parameters (depth to water table, land use and nitrogen input). The study area is the plain sector of Piemonte (Northern Italy), where an unconfined aquifer nitrate contamination exists. In this area the anthropogenic presence is remarkable and the input of N-fertilizers and zootechnical effluents to the soil cause a growing amount of nitrates in groundwater. This approach, used in a large area (about 10,000 km²) and in several monitoring wells (about 500), allowed to compare the efficiency of different vulnerability methods and to verify the importance of every parameter on the nitrate concentrations in the aquifer. Furthermore it allowed to obtain interesting correlations in different hydrogeological situations. Correlations between depth to water table, land use and nitrogen input to the soil with nitrate concentrations in groundwater show unclear situations: in fact these comparisons describe the phenomenon trend and highlight the maximum nitrate concentrations for each circumstance but often show wide ranges of possible nitrate concentrations. The same situation could be observed by comparing vulnerability indexes and nitrate concentrations in groundwater. These results suggest that neither single parameters nor vulnerability methods (GOD and TOT) are able to describe individually the complex phenomena affecting nitrate concentrations in soil, subsoil and groundwater. In particular, the traditional methods for vulnerability analysis do not analyze physical processes in aquifers, such as denitrification and nitrate dilution. According to a recent study in the shallow unconfined aquifer of the Piemonte plain, dilution can be considered as the main cause for nitrate attenuation in groundwater.     

Upper cretaceous biostratigraphy of the south-central Pyrenees (Lleida,Spain)

Abstract

Biostratigraphical data using larger foraminifera and planktonic foraminifera permitted us to establish the correlation between shallow platform sediments rich in larger foraminifera (Montsec and Serres Marginals thrust sheets) and deeper ones containing planktonic foraminifera (Boixols thrust sheet).

Consequently, the Santa Fe limestones containing Ovalveolina-Praealveolinaassemblage represent the Cenomanian. Early Turonian ( ‘IT~ archaeocretacea and P. helvetica zones) exist in both, Montsec and Boixols thrust sheets and it is constituted by Pithonella limestones. Late Turonian (M. schneegansi zone) is only present in Boixols thrust sheet (Reguard Fm.), the Montsec thrust sheet having an erosive hiatus.

Late Coniacian-Early Santonian (D. Concavata zone) is represented in the Montsec thrust sheet (Cova Limestones) and in the eastern part of the Boixols thrust sheet (St. Corneli Fm.) by two differents facies giving two different microfaunal assemblages; the firts one, characterized by Ophtalmidiidae s.l indicate a restricted lagoonal environment while the second one, characterized by diverses species of complex agglutinated, Fabulariidae, Meandropsinidae and Rotaliidae, represents an open shallow platform. In the Boixols thrust sheet (Anseroles Fm.) dominate the planktonic foraminifera and small benthic.

In the late Santonian (D. asyrnetrica zone) the sea reached as far as Serres Marginales thrust sheet where sediments (Tragó de Noguera unit) are terrigenous and deposited in a very shallow platform. In the Montsec thrust sheet (Montsec marls) the larger foraminifera indicate a platform deeper than that of the Serres Marginals thrust sheet. In the Boixols thrust sheet the sediments are deposited in an outer platform (Herbasavina Fm.) or turbiditic basin (Mascarell Mb.).

During Campanian times the transgresion reaches the maximum. In the Serres Marginals sediments are deposited in a restricted shallow environment rich in Meandropsinidae (Serres Limestones). In the Montsec thrust sheet they are deposited in a platform with patch reefs and shoals (Terradets limestones) and in the Boixols one in an outer platform, talus and/or basin.

During Early Maastrichtian times (C. falsostuarti zone) terrigenous materials arrived in the basin, the rate of sedimentation increased outstripping the subsidence rate and the retreat of the sea to the north. Late Maastrichtian (C. gansseri zone) is only present in the Boixols thrust sheet.     

Spring thermal resources for grapevine in Kőszeg (Hungary) deduced from a very long pictorial time series (1740–2009)

Since 1740 until now, the Book of Vine Branches encompasses beautiful pictorial representations of shoots and sprouts, collected every year on April 24th in the vineyards of the Hungarian town of K?szeg. A long time series (1740–2009) of sprouts phenological development coded with the BBCH scale is obtained through paintings visual inspection. Consequently, a model relating sprouts development with thermal resources accumulation is developed on the base of Wien daily air temperature series for the 1857–2009 period. Thermal resources is obtained with the Normal Heat Hours approach, a response curve method that takes into account the nonlinear response of phenological development to temperature. The model, calibrated and validated on the 1930–2009 period, shows an overestimation of thermal resources when applied to the 1857–1929, due to the more advanced phenology of that phase. Since this advance can be ascribed to genetics and management instead of more favorable thermal conditions, model outputs previous to 1930 are decreased by a constant factor. Finally, the 1740–2009 time series of grapevine spring thermal resources is obtained applying the model to the complete phenological time series. The analysis of the series highlights a first phase (1740–1780) characterized by high and stable availability of thermal resources during the 1740–1780, a second phase (1781–1820) with the lowest level of resources, a phase of intermediate availability (1821–1929) and a final present phase (1930–2009) with renewed high availability. The adopted method overcomes the lack of correlation for the post 1960 period shown by previous works.     

A New TanSat XCO_2 Global Product towards Climate Studies

The 1st Chinese carbon dioxide(CO2)monitoring satellite mission,TanSat,was launched in 2016.The 1st TanSat global map of CO2 dry-air mixing ratio(XCO2)measurements over land was released as version 1 data product with an accuracy of 2.11 ppmv(parts per million by volume).In this paper,we introduce a new(version 2)TanSat global XCO2 product that is approached by the Institute of Atmospheric Physics Carbon dioxide retrieval Algorithm for Satellite remote sensing(IAPCAS),and the European Space Agency(ESA)Climate Change Initiative plus(CCI+)TanSat XCO2 product by University of Leicester Full Physics(UoL-FP)retrieval algorithm.The correction of the measurement spectrum improves the accuracy(?0.08 ppmv)and precision(1.47 ppmv)of the new retrieval,which provides opportunity for further application in global carbon flux studies in the future.Inter-comparison between the two retrievals indicates a good agreement,with a standard deviation of 1.28 ppmv and a bias of?0.35 ppmv.     

The end of the Messinian Salinity Crisis in the western Mediterranean: Insights from the carbonate platforms of south-eastern Spain

How the Messinian Salinity Crisis (MSC) ended is still a matter of intense debate. The Terminal Carbonate Complex (TCC) is a late Messinian carbonate platform system that recorded western Mediterranean hydrological changes from the final stages of evaporite deposition till the advent of Lago-Mare fresh- to brackish water conditions at the very end of Messinian times. A multidisciplinary study has been carried out in three localities in south-eastern Spain to reconstruct the history of TCC platforms and elucidate their significance in the MSC. Overall, this study provides evidence that the TCC formed following a regional 4th order water level rise and fall concomitant with an opening-restriction trend. It can be subdivided into four 5th order depositional sequences (DS1 to DS4) recording two phases: (1) from DS1 to DS3, a tide-dominated ooidic to oobioclastic system with stenohaline faunas developed as a result of a 70 m water level rise. During this period, the TCC developed in a shallow sea with close to normal marine salinity; (2) in depositional sequence 4, a microbialite-dominated platform system developed. This is indicative of a significant environmental change and is attributed to a 30 to 40 m water level fall in the basins under study. These restricted conditions were coeval with intense evaporite deformation and brine recycling. The syn-sedimentary deformation of evaporites had a major impact on platform architecture and carbonate production, affecting the Messinian series throughout south-eastern Spain at the end of the TCC history. At that time, the TCC developed in a lake with fluctuating, brackish- to hypersaline water. These findings suggest a temporary restoration of marine conditions in the western Mediterranean marginal basins due to Atlantic water influxes prompted by a global sea level rise around 5.6 Ma. Whether marine conditions extended to the entire western Mediterranean still needs to be investigated.     

Discrimination of agricultural crops in a tropical semi-arid region of Brazil based on L-band polarimetric airborne SAR data

Recent articles are indicating that polarimetric data provide significantly more information than conventional or multi-polarized images, particularly due to the additional phase information. The objective of this paper is to evaluate the multi-polarized and fully polarimetric L-band airborne SAR-R99B data, in terms of their capability to distinguish among different agricultural crops in the western part of Bahia State, Brazil. Emphasis was given to coffee, cotton and pasture crops which were at well developed growing stages. Discrimination among crops was carried out using graphical analysis of mean backscatter values. Crop classification was performed for single and multiple polarizations, and fully polarimetric images with a classifier that uses the contextual Iterated Conditional Modes–ICM algorithm. The investigation confirmed the potential of L-band multi-polarized and polarimetric airborne SAR-R99B data to distinguish and classify agricultural crops in the tropical condition of the test-site. In addition, it clearly indicated the gradual and considerable improvement that was achieved going from single to three polarizations and from multi-polarized to fully polarimetric images.     

The role of intracontinental deformation in supercontinent assembly: insights from the Ribeira Belt,Southeastern Brazil (Neoproterozoic West Gondwana)

In this study, we challenge the multiple collision model for the tectonic evolution of the Neoproterozoic Ribeira Belt in Southeastern Brazil. New U–Pb SHRIMP data reveal Palaeoproterozoic (2153 ± 15 Ma) and Cryogenian (783 ± 6 and 768 ± 8 Ma) granitic rocks in the Embu Domain, and detrital zircon data of metasedimentary units from the Embu and Costeiro domains suggest a coherent tectonic evolution for the whole Ribeira Belt. Rather than by multiple collisions, these data are best explained by a simpler tectonic model involving continent (craton)‐volcanic arc collisions in the Dom Feliciano and Brasilia belts that led to intracontinental crustal thickening of the adjacent thinned hinterland (Ribeira Belt) at ~640–610 Ma, followed by widespread post‐collisional magmatism and rift‐related sedimentation at ~600–540 Ma. We suggest that intracontinental orogeny is a relevant process during supercontinent assembly, as illustrated here by the evolution of significant parts of the Brasiliano orogen.     

Sr and Nd Characteristics of Brasiliano/Pan-African Granitoid Plutons of the Araçuaí Orogen, Southeastern Brazil: Tectonic Implications

Nd and Sr isotope data were obtained for three plutonic suites (595–505 Ma) and distinct young granitoid intrusions (503 Ma), from the southern part of the Neoproterozoic Araçuaí Orogen. The Sr and Nd isotopes (⁸⁷Sr/⁸⁶Sr, eNd) and TDM values from the plutons and distinct basement rocks are used to constrain the magma genesis of the granitoid plutons. These isotopic parameters, with e_Nd values ranging from −4 to −24 and T_DM ages from 1.3 to 2.8 Ga, for the granitoid suites, and −5 to −40 and 3.5 to 1.5 Ga, for the distinct Archean and Proterozoic basement complexes, suggest that the Jequitinhonha Complex metasediments are the main crustal source for most of these plutons, except for the youngest granitoid intrusions, which may have a protolith similar to the Mantiqueira and Guanhães complexes. Furthermore, the isotope data indicate a minor, but important, participation of Neoproterozoic oceanic lithosphere in the granite genesis, which corroborates with a confined orogenic model and a narrow oceanic consumption (B-subduction) for the Araçuaí Orogen.     

Late Neogene sequence stratigraphic evolution of the Foz do Amazonas Basin,Brazil

The margin of the Foz do Amazonas Basin saw a shift from predominantly carbonate to siliciclastic sedimentation in the early late Miocene. By this time, the Amazon shelf had also been incised by a canyon that allowed direct influx of sediment to the basin floor, thus confirming that the palaeo‐Amazon fan had already initiated by that time (9.5–8.3 Ma). Above this interval, during a prolonged lowstand, Messinian third‐order sequences are preserved only in the incised‐valley fills of the canyon with no equivalent strata on the shelf. Third‐ and fourth‐order sequences younger than Messinian are preserved on the shelf after sea‐level rise above the shelf by the early Pliocene. Sequences younger than 3.8 Ma often show fourth‐order cyclicity with an average duration of 400 ka (larger scale eccentricity cycles) often preserved in high‐sedimentation‐rate areas of river deltas. Mass wasting and transportation of slope sediments to the basin began to play an important role in sediment dispersal at least as far back as the mid‐Pliocene, after rapid progradation had produced steeper slopes more prone to failure.     

Seismological constraints on the 2018 Mt. Etna (Italy) flank eruption and implications for the flank dynamics of the volcano

3D earthquake locations, focal mechanisms and stress tensor distribution in a 16‐month interval covering the 2018 Mt. Etna flank eruption, enabled us to investigate the relationship between magma intrusion and structural response of the volcano and shed light on the dynamic processes affecting the instability of Mt. Etna. The magma intrusion likely caused tension in the flanks of the volcano, leading to significant ground deformation and redistribution of stress on the neighbouring faults at the edge of Mt. Etna's unstable sector, encouraging the ESE sliding of the eastern flank of the volcano. Accordingly, FPSs of the post‐eruptive events show strike slip faulting mechanisms, under a stress regime characterized by a maximum compressive σ₁, NE‐SW oriented. In this perspective, any flank eruption could temporarily enhance the sliding process of both the southern and eastern flanks of the volcano.