Correction to: A novel methodological approach for land subsidence prediction through data assimilation techniques     

Gazzola  Laura  Ferronato  Massimiliano  Frigo  Matteo  Janna  Carlo  Teatini  Pietro  Zoccarato  Claudia  Antonelli  Massimo  Corradi  Anna  Dacome  Maria Carolina  Mantica  Stefano 《Computational Geosciences》2021,25(5):1751-1751

Computational Geosciences - A Correction to this paper has been published: https://doi.org/10.1007/s10596-021-10079-6  相似文献   

Continuous assessment of landslides by measuring their basal temperature     

Seguí  Carolina  Veveakis  Manolis 《Landslides》2021,18(12):3953-3961

Landslides - In this study, we suggest a temperature-based assessment and mitigation approach for deep-seated landslides that allows to forecast the behavior of the slide and assess its stability....  相似文献   

A large epeiric methanogenic Bambuí sea in the core of Gondwana supercontinent?     

Sergio Caetano-Filho  Pierre Sansjofre  Magali Ader  Gustavo M.Paula-Santos  Cristian Guacaneme  Marly Babinski  Carolina Bedoya-Rueda  Matheus Kuchenbecker  Humberto L.S.Reis  Ricardo I.F.Trindade 《地学前缘(英文版)》2021,12(1):203-218

Carbon isotope compositions of both sedimentary carbonate and organic matter can be used as key proxies of the global carbon cycle and of its evolution through time,as long as they are acquired from waters where the dissolved inorganic carbon(DIC)is in isotope equilibrium with the atmospheric CO2.However,in shallow water platforms and epeiric settings,the influence of local to regional parameters on carbon cycling may lead to DIG isotope variations unrelated to the global carbon cycle.This may be especially true for the terminal Neoproterozoic,when Gondwana assembly isolated waters masses from the global ocean,and extreme positive and negative carbon isotope excursions are recorded,potentially decoupled from global signals.To improve our understanding on the type of information recorded by these excursions,we investigate the pairedδ^13Ccarb andδ^13Corg evolution for an increasingly restricted late Ediacaran-Cambrian foreland system in the West Gondwana interior:the basal Bambui Group.This succession represents a 1~(st)-order sedimentary sequence and records two majorδ^13Ccarb excursions in its two lowermost lower-rank sequences.The basal cap carbonate interval at the base of the first sequence,deposited when the basin was connected to the ocean,hosts antithetical negative and positive excursions forδ^13Ccarb andδ^13Corg,respectively,resulting inΔ^13C values lower than 25‰.From the top of the basal sequence upwards,an extremely positiveδ^13Ccarb excursion is coupled toδ^13Corg,reaching values of+14‰and-14‰,respectively.This positive excursion represents a remarkable basin-wide carbon isotope feature of the Bambui Group that occurs with only minor changes inΔ^13C values,suggesting change in the DIC isotope composition.We argue that this regional isotopic excursion is related to a disconnection between the intrabasinal and the global carbon cycles.This extreme carbon isotope excursion may have been a product of a disequilibria between the basin DIC and atmospheric CO2 induced by an active methanogenesis,favored by the basin restriction.The drawdown of sulfate reservoir by microbial sulfate reduction in a poorly ventilated and dominantly anoxic basin would have triggered methanogenesis and ultimately methane escape to the atmosphere,resulting in a^13C-enriched DIC influenced by methanogenic CO2.Isolated basins in the interior of the Gondwana supercontinent may have represented a significant source of methane inputs to the atmosphere,potentially affecting both the global carbon cycle and the climate.  相似文献   

Quantifying the impact of chemicals on stable carbon and oxygen isotope values of raw pollen     

Carolina Müller  Julian Hennig  Frank Riedel  Gerhard Helle 《第四纪科学杂志》2021,36(3):441-449

Purification protocols to extract pollen from lake sediments contain chemicals that alter the carbon and oxygen pollen-isotope values according to pollen characteristics and family affiliation. Modern (raw) pollen of broad-leaved (Alnus glutinosa, Betula pendula, Carpinus betulus, Corylus avellana, Fagus sylvatica and Quercus robur) and coniferous tree species (Picea abies and Pinus sylvestris) were treated with potassium hydroxide (KOH), hydrofluoric acid (HF), sodium hypochlorite (NaClO) and sulphuric acid (H₂SO₄) to test the impact on δ¹³C_pollen and δ¹⁸O_pollen and assess the applicability in purification protocols. Pollen of broad-leaved and coniferous trees reacted differently to chemical exposure, but response patterns are generally alike. Alterations of δ¹³C_pollen values vary between + 1.0‰ (B. pendula, NaClO-treatment) and −5.0‰ (P. sylvestris, H₂SO₄-treatment). The δ¹³C_pollen values of raw and chemically treated samples seem to be related after treatments with KOH, NaClO and HF, whereas the application of H₂SO₄ led to inconsistent changes among species. The impact of chemicals on δ¹⁸O_pollen are more diverse and offsets range between +1.1‰ (C. avellana, NaClO-treatment) and −17.9‰ (P. sylvestris, H₂SO₄-treatment). In general, the use of isotope-altering chemicals in purification protocols should be brought to a minimum, but the application of KOH and NaClO seems mostly unproblematic before δ¹³C_pollen and δ¹⁸O_pollen analysis.  相似文献   

Collins Glacier Retreat Process and Regional Climatic Variations,King George Island,Antarctica          下载免费PDF全文

Carolina Lorenz Simoes  Katia Kellem da Rosa  Fabiane Fernanda Czapela  Rosemary Vieira  Jefferson Cardia Simoes 《Geographical review》2015,105(4):462-471

This paper investigates the recent climatic variability and changes in snow line and ice front position in Collins Glacier, King George Island, South Shetland Islands, Antarctic Peninsula. This region has recorded one of the largest temperature increases in the past fifty years and has been demonstrated to be highly sensitive to climate changes. To monitor recent changes (1983–2006), we determined the fluctuations of the terminus and snow line of the glacier via remote sensing data and field observation in the summer of 2013. We conclude that the Collins Glacier has responded slowly to regional climate changes (decades or even centuries), as glacial responses to climatic events do not depend solely on one environmental variable. The glacier presented more retreat and elevation of the snow line in the north sector. The retreat data are correlated with the mean monthly temperature and annual number of days of melting‐degree variations.  相似文献   

Intraseasonal variability of the Atlantic Intertropical Convergence Zone during austral summer and winter     

Ana Carolina Nóbile Tomaziello  Leila M. V. Carvalho  Adilson W. Gandu 《Climate Dynamics》2016,47(5-6):1717-1733

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Sedimentary facies,fossil distribution and depositional setting of the late Ediacaran Tamengo Formation (Brazil)     

Kamilla Borges Amorim  Jhon Willy Lopes Afonso  Juliana de Moraes Leme  Cleber Quidute Clemente Diniz  Laura Carolina Montenegro Rivera  Juan Camilo Gómez-Gutiérrez  Paulo César Boggiani  Ricardo Ivan Ferreira Trindade 《Sedimentology》2020,67(7):3422-3450

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Experimental verification of effective anisotropic crack theories in variable crack aspect ratio medium          下载免费PDF全文

Jessica P. Henriques  Jose J. S. de Figueiredo  Leo K. Santos  Daniel L. Macedo  Icaro Coutinho  Carolina B. da Silva  Alberto L. Melo  Mykel Sousa  Felipe L. Azevedo 《Geophysical Prospecting》2018,66(1):141-156

Physical modelling of cracked/fractured media using downscaled laboratory experiments has been used with great success as a useful alternative for understanding the effect of anisotropy in the hydrocarbon reservoir characterization and in the crustal and mantle seismology. The main goal of this work was to experimentally verify the predictions of effective elastic parameters in anisotropic cracked media by Hudson and Eshelby–Cheng's effective medium models. For this purpose, we carried out ultrasonic measurements on synthetic anisotropic samples with low crack densities and different aspect ratios. Twelve samples were prepared with two different crack densities, 5% and 8%. Three samples for each crack density presented cracks with only one crack aspect ratio, whereas other three samples for each crack density presented cracks with three different aspect ratios in their composition. It results in samples with aspect ratio values varying from 0.13 to 0.26. All the cracked samples were simulated by penny‐shaped rubber inclusions in a homogeneous isotropic matrix made with epoxy resin. Moreover, an isotropic sample for reference was constructed with epoxy resin only. Regarding velocity predictions performed by the theoretical models, Eshelby–Cheng shows a better fit when compared with the experimental results for samples with single and mix crack aspect ratio (for both crack densities). From velocity values, our comparisons were also performed in terms of the ε, γ, and δ parameters (Thomsen parameters). The results show that Eshelby–Cheng effective medium model fits better with the measurements of ε and γ parameters for crack samples with only one type of crack aspect ratio.  相似文献   

Diatom assemblages from surface sediments of the Río de la Plata estuary,Uruguay     

Laura Perez  Ernesto Brugnoli  Pablo Muniz  Inés Sunesen  Eugenia A. Sar  Carolina Crisci 《新西兰海洋与淡水研究杂志》2018,52(3):383-397

The Río de la Plata estuary (RdlP) exhibits environmental gradients associated with the freshwater input and oceanic water intrusion. The aim of this study was to assess diatom species distribution in surface sediment samples related to such environmental gradients. The internal section of RdlP was dominated by Aulacoseira spp., Eunotia spp., Staurosirella martyi, Actinocyclus normanii and Thalassiosira baltica, indicatives of low salinity levels and high trophic conditions, associated with the riverine and estuarine regimes. The external section was dominated by Coscinodiscus radiatus, Thalassiosira spp., Paralia sulcata, Cyclotella striata, among other marine taxa, indicatives of high salinity and low trophic conditions, associated with the influence of the Southwestern Atlantic Ocean. Furthermore, the intermediate section presents a mixture of both diatom groups representing mixing conditions. The observed diatom species groups capture fairly well the RdlP environmental variability and can be reliably used for paleoenvironmental studies in this and other similar estuarine systems.  相似文献   

Physical contact interactions with scleractinian corals in hard substrate communities          下载免费PDF全文

Ana Carolina Grillo  Roberta Martini Bonaldo  Bárbara Segal 《Marine Ecology》2018,39(1)

Shallow reefs are among the most diverse ecosystems, and their substrate is densely occupied by sessile organisms that frequently contact physically and interact mutually. Nevertheless, the relative importance of species abundance in shaping physical contacts in these ecosystems remains largely unknown. The aim of this study was to evaluate physical contact interactions, by using tools derived from the complex network theory, between hard corals and other benthic organisms in four areas along the Brazilian coast comprising coral reefs and rocky shores with different physical and biotic structures. It was also investigated whether interactions with corals occurred as expected by the abundance of the benthic organisms in each area, and whether corals belonging to families known as more aggressive interacted less with other organisms. In all areas, the abundance of both corals and contacting organisms directly influenced the abundance of interactions between benthic organisms, regardless of the physical or biological characteristics of the habitat and of the interacting organisms. In addition, coral species interacted more with the most abundant benthic group, the epilithic algal matrix, in all areas. Nevertheless, some evidence was found about biological mechanisms helping to explain the structure of the studied interactions, although to a lesser extent. The obtained networks presented high nestedness and connectance, but low modularity. These patterns indicate the low specificity of the studied interactions and reinforce the role of abundance as an important driver of contacts between sessile organisms in shallow hard bottom ecosystems.  相似文献