Basic Properties of Calcocambisol from a Location on North Dalmatian Plain

Calcocambisol is the most dominant soil type developed on Dinaric karst. It is formed by pedogenic processes acting on carbonate rocks, which include weathering, accumulation of insoluble residue, organic matter, and allogenic material and braunification. Further development of Calcocambisol includes leaching of clay from upper soil horizons and secondary accumulation in lower horizons. Calcocambisols are exclusively developed on carbonate rocks characterised by diverse relief forms resulting in variable soil depth over short distances and consequently different phases of soil development. Thus, the goal of this study was to analyse morphological, physical, and chemical properties of Calcocambisols in different stages of development from a location within the Krka National Park. Results of soil analysis showed similarities in morphological properties, soil field and air capacity, density and SOC content. On the other hand, differences in properties included different carbonate content and pH values of topsoil and difference in particle size distribution. These differences can be attributed to irregular rocky surface which plays important role in allogenic particles distribution and water percolation. Increased leaching of clay particles to deeper horizons results in diversification of Bt (argic) horizon, indicating more advanced stage of soil development towards Luvisol formation

The effect of visitors in a touristic cave and the resulting constraints on natural thermal conditions for palaeoclimate studies (Eagle Cave, central Spain)

[EN]Temperature in Eagle Cave, central Spain, was measured over a year to determine the effect of tourists on the natural environment. The mean cave temperature was 15.6°C in 2009, with a seasonal amplitude of <0.4°C. Access of tourists to the cavern produces thermal anomalies of <0.15°C, which are recovered overnight in most cases. During days with high visitor numbers, cumulative thermal anomalies may persist from one day to the next, causing an increase of cave temperature for longer periods. However, this anthropogenic effect disappears soon after the number of tourists reduces, lasting less than a week in most cases. Cumulative thermal anomalies are <0.02°C during most of the year and <0.1°C in periods with large number of visitors. The anthropogenic effect on cave temperature is non-persistent and has a small magnitude in comparison with natural oscillations. Thus, long-term absolute temperatures obtained from Eagle Cave are not affected by visitors. The input of thermal energy caused by tourists is absorbed as latent heat by the cave (causing evaporation), which prevents the increase of baseline temperatures in the environment. A condensation process occurs over cave walls and speleothems. This is the result of cooling the atmosphere during the thermal equilibration with cave walls once visitors leave. Although condensation is found in Eagle Cave, the magnitude of the process is not enough to cause any significant condensation corrosion that could damage speleothems as a result of the tourist visits. The cave is in thermal equilibrium with surface temperatures, and calibration studies will produce suitable results for palaeoclimate studies despite being a tourist cavern

Condensation corrosion alters the oxygen and carbon isotope ratios of speleothem and limestone surfaces

Condensation corrosion is a natural process which enhances the chemical weathering of limestone cave chambers and speleothems. We evaluated the use of carbonate tablets for detecting condensation corrosion in Glowworm Cave, New Zealand, using local limestone and speleothem as experimental substrates (herein tablets). Evidence for condensation corrosion was assessed via three methods: gravimetric (mass wasting), microscopic (surface pitting, recrystallization) and isotopic (δ¹³C and δ¹⁸O changes). Our results show little evidence of tablet mass loss throughout a 6-month deployment period. However, SEM imaging and isotope analysis (δ¹³C and δ¹⁸O) of the upper ∼50 μm layer of the tablets, suggest that condensation corrosion operates in the cave, especially in sectors affected by large diurnal microclimate variations. Most notably, condensation water altered the tablet surface δ¹³C and δ¹⁸O values. Small, positive shifts in surface δ¹³C and δ¹⁸O values are considered to reflect pure dissolution (where dissolution favours the removal of lighter isotopologues). In contrast, tablets that exhibited large positive shifts in δ¹³C in tandem with large negative shifts in δ¹⁸O values, are interpreted as showing calcite recrystallization and the inheritance of higher DIC δ¹³C values (¹³C fractionation by CO₂ degassing), lighter water δ¹⁸O values and/or kinetic fractionation of δ¹⁸O. This study therefore demonstrates that stable isotopes could be applied to detect paleoclimatic episodes of condensation corrosion in speleothems

Forecasting Amazon Rain-Forest Deforestation Using a Hybrid Machine Learning Model

The present work aims to carry out an analysis of the Amazon rain-forest deforestation, which can be analyzed from actual data and predicted by means of artificial intelligence algorithms. A hybrid machine learning model was implemented, using a dataset consisting of 760 Brazilian Amazon municipalities, with static data, namely geographical, forest, and watershed, among others, together with a time series data of annual deforestation area for the last 20 years (1999–2019). The designed learning model combines dense neural networks for the static variables and a recurrent Long Short Term Memory neural network for the temporal data. Many iterations were performed on augmented data, testing different configurations of the regression model, for adjusting the model hyper-parameters, and generating a battery of tests to obtain the optimal model, achieving a R-squared score of 87.82%. The final regression model predicts the increase in annual deforestation area (square kilometers), for a decade, from 2020 to 2030, predicting that deforestation will reach 1 million square kilometers by 2030, accounting for around 15% compared with the present 1%, of the between 5.5 and 6.7 millions of square kilometers of the rain-forest. The obtained results will help to understand the impact of man’s footprint on the Amazon rain-forest.This research was funded by DGIV-UDLA grant number SIS.MGR.21.01 and by Spanish Ministry of Science grant number PID2020-114867RB-I00

Laminación anual en un espeleotema del Holoceno inferior (Cueva de Kaite, Complejo Kárstico de Ojo Guareña, Burgos). Implicaciones paleoclimáticas

Annual laminations have been recognized in a rapid-growing, early Holocene, calcite stalagmite from Kaite cave (Ojo Guareña Karst Complex, N Spain) using petrographic analysis and U/Th dating performed with inductively coupled plasma mass spectrometry (ICP-MS). Each lamination reflects the annual growth of the speleothem, and the vertical changes in thickness of successive laminae are interpreted as changes in paleoprecipitation over the cave

Evaluation of Paris MoU Maritime Inspections Using a STATIS Approach

Port state control inspections implemented under the Paris Memorandum of Understanding (MoU) have become known as one of the best instruments for maritime administrations in European Union (EU) Member States to ensure that the ships docked in their ports comply with all maritime safety requirements. This paper focuses on the analysis of all inspections made between 2013 and 2018 in the top ten EU ports incorporated in the Paris MoU (17,880 inspections). The methodology consists of a multivariate statistical information system (STATIS) analysis using the inspected ship's characteristics as explanatory variables. The variables used describe both the inspected ships (classification society, flag, age and gross tonnage) and the inspection (type of inspection and number of deficiencies), yielding a dataset with more than 600,000 elements in the data matrix. The most important results are that the classifications obtained match the performance lists published annually by the Paris MoU and the classification societies. Therefore, the approach is a potentially valid classification method and would then be useful to maritime authorities as an additional indicator of a ship's risk profile to decide inspection priorities and as a tool to measure the evolution in the risk profile of the flag over time.This research was funded by University of Cadiz