Hasil untuk "Geology"

J. Zalasiewicz, Colin N. Waters, C. Summerhayes et al.

What is the reach of geology, today? The word evokes strata, minerals and fossils. But how about metro systems, farmyard animals, factory smoke, ballpoint pens, tree‐rings and the fluff that comes off our clothes? These kinds of objects are just part of the evidence that is now being assembled to build a picture of the Anthropocene—the idea that human activities are now sufficiently powerful and pervasive to build the geology of the present—and to influence the course of the geology of our planet's future, too.

R. Steiger, E. Jäger

Stuart Chapin, P. Matson, Harold A. Mooney et al.

G. Eglinton

S. M. Naqvi, J. Rogers

Micaela Fuel Pozo, Andrea Guatumillo Saltos, Yeseña Tipan Llumiquinga et al.

This study presents the development of Geolog-IA, a novel conversational system based on artificial intelligence that responds naturally to questions about geology theses from the Central University of Ecuador. Our proposal uses the Llama 3.1 and Gemini 2.5 language models, which are complemented by a Retrieval Augmented Generation (RAG) architecture and an SQLite database. This strategy allows us to overcome problems such as hallucinations and outdated knowledge. The evaluation of Geolog-IA's performance with the BLEU metric reaches an average of 0.87, indicating high consistency and accuracy in the responses generated. The system offers an intuitive, web-based interface that facilitates interaction and information retrieval for directors, teachers, students, and administrative staff at the institution. This tool can be a key support in education, training, and research and establishes a basis for future applications in other disciplines.

Michał Fajt, Grzegorz Machowski, Bartosz Puzio et al.

Abstract Low-field NMR (LF-NMR) is a widely applied technique for evaluating pore size distribution (PSD) in porous materials. Conventional approaches typically assume surface-controlled spin-spin relaxation and negligible diffusion contributions under the fast-diffusion regime, which introduces systematic errors when applied to nano- and microporous systems. In this work, we present the Effective Diffusion Cubic (EDC) model, a new framework for LF-NMR-based PSD estimation in tight rocks. The EDC method incorporates pore-size dependence of both the effective diffusion coefficient and the induced internal magnetic field gradient. Crucially, the effective diffusion coefficient, D(d), is parameterized by a logistic function that faithfully approximates the Padé form, enabling a precise quantification of diffusion-related effects on T2 relaxation. Applied to nine siliciclastic core samples, the EDC approach produced PSDs corrected for diffusion-induced distortions and in closer agreement with independent reference data compared to conventional models. These results demonstrate that the EDC methodology provides a physically consistent and more accurate means of quantifying pore systems, thereby enhancing NMR-based petrophysical characterization of tight rock formations.

Chunde Piao, Yanzhu Yin, Zhihao He et al.

Abstract Coal mining induces changes in the nature of rock and soil bodies, as well as hydrogeological conditions, which can easily trigger the occurrence of geological disasters such as water inrush, movement of the coal seam roof and floor, and rock burst. Transparency in coal mine geological conditions provides technical support for intelligent coal mining and geological disaster prevention. In this sense, it is of great significance to address the requirements for informatizing coal mine geological conditions, dynamically adjust sensing parameters, and accurately identify disaster characteristics so as to prevent and control coal mine geological disasters. This paper examines the various action fields associated with geological disasters in mining faces and scrutinizes the types and sensing parameters of geological disasters resulting from coal seam mining. On this basis, it summarizes a distributed fiber‐optic sensing technology framework for transparent geology in coal mines. Combined with the multi‐field monitoring characteristics of the strain field, the temperature field, and the vibration field of distributed optical fiber sensing technology, parameters such as the strain increment ratio, the aquifer temperature gradient, and the acoustic wave amplitude are extracted as eigenvalues for identifying rock breaking, aquifer water level, and water cut range, and a multi‐field sensing method is established for identifying the characteristics of mining‐induced rock mass disasters. The development direction of transparent geology based on optical fiber sensing technology is proposed in terms of the aspects of sensing optical fiber structure for large deformation monitoring, identification accuracy of optical fiber acoustic signals, multi‐parameter monitoring, and early warning methods.

Alexandru Rusu, Octavian Groza, Nicolae Popa et al.

This study evaluates the impact of different territorial contexts on academic mobility within the framework of the Erasmus Programme, using data on Key Action 1 exchanges between 2015 and 2023. Using official EU datasets and a gravity model framework, the research investigates how economic performance, geographical distance, EU membership, AUF (Agence Universitaire de la Francophonie) regional affiliation, and state contiguity shape international academic flows. The research developed two gravity models: one aimed to measure the potential barriers to academic flows through a residuals analysis, and the second integrated territorial delineations as predictors. In both models, the core of the explanatory variable is formed by indicators describing the economic performance of states and the distance between countries. When applied, the models converge in emphasizing that the inclusion of states in different territorial configurations has a strong effect on the structuring of academic flows. This suggests that the Erasmus Programme exhibits trends of overconcentration of flows in a limited number of countries, questioning the need for a more polycentric strategy and a reshaping of the funding mechanisms. Even if the gravity models behave well, given the limited number of predictors, further studies may need to incorporate qualitative indicators for a more comprehensive evaluation of the interactions.

Zhao Li, Weiping Jiang, Tonie van Dam et al.

Nonlinear variations in the coordinate time series of global navigation satellite system (GNSS) reference stations are strongly correlated with surface displacements caused by environmental loading effects, including atmospheric, hydrological, and nontidal ocean loading. Continuous improvements in the accuracy of surface mass loading products, performance of Earth models, and precise data-processing technologies have significantly advanced research on the effects of environmental loading on nonlinear variations in GNSS coordinate time series. However, owing to theoretical limitations, the lack of high spatiotemporal resolution surface mass observations, and the coupling of GNSS technology-related systematic errors, environmental loading and nonlinear GNSS reference station displacements remain inconsistent. The applicability and capability of these loading products across different regions also require further evaluation. This paper outlines methods for modeling environmental loading, surface mass loading products, and service organizations. In addition, it summarizes recent advances in applying environmental loading to address nonlinear variations in global and regional GNSS coordinate time series. Moreover, the scientific questions of existing studies are summarized, and insights into future research directions are provided. The complex nonlinear motion of reference stations is a major factor limiting the accuracy of the current terrestrial reference frame. Further refining the environmental load modeling method, establishing a surface mass distribution model with high spatiotemporal resolution and reliability, exploring other environmental load factors such as ice sheet and artificial mass-change effects, and developing an optimal data-processing model and strategy for reprocessing global reference station data consistently could contribute to the development of a millimeter-level nonlinear motion model for GNSS reference stations with actual physical significance and provide theoretical support for establishing a terrestrial reference frame with 1 mm accuracy by 2050.

Atul C. Thakur, Richard C. Remsing

The surface of Saturn's moon Titan is coated with small molecule organic solids termed cryominerals. Cryominerals play an analogous role to minerals on Earth in Titan's surface geology and geochemistry. To develop a predictive understanding of Titan's surface geochemistry, we need to characterize the structure and dynamics of cryominerals at the molecular scale. We use ab initio molecular dynamics simulations to quantify the structure and dynamics of the acetonitrile:acetylene (1:2) co-crystal at Titan surface conditions. We suggest that acetonitrile:acetylene is in a plastic phase, in which acetonitrile molecules are dynamically disordered about the N-C-C axis on sub-picosecond timescales, and that this rotational, plastic disorder persists at least to temperatures of 30 K. We anticipate that many cryominerals may have plastic phases at or near Titan surface conditions, and understanding this disorder will be crucial to predicting chemistry on Titan's surface.

Lucas Valadares Vieira, Mara Abel, Fabricio Henrique Rodrigues et al.

This paper presents an ontology of portions of matter with practical implications across scientific and industrial domains. The ontology is developed under the Unified Foundational Ontology (UFO), which uses the concept of quantity to represent topologically maximally self-connected portions of matter. The proposed ontology introduces the granuleOf parthood relation, holding between objects and portions of matter. It also discusses the constitution of quantities by collections of granules, the representation of sub-portions of matter, and the tracking of matter provenance between quantities using historical relations. Lastly, a case study is presented to demonstrate the use of the portion of matter ontology in the geology domain for an Oil & Gas industry application. In the case study, we model how to represent the historical relation between an original portion of rock and the sub-portions created during the industrial process. Lastly, future research directions are outlined, including investigating granularity levels and defining a taxonomy of events.

Atefe Darzi, Benedikt Halldorsson, Fabrice Cotton et al.

Seismic wave amplification due to localized site conditions is an important aspect of regional seismic hazard assessment. Without systematic studies of frequency-dependent site-effects during strong Icelandic earthquakes, various local site proxies of large-scale studies in other seismic regions have been used in Iceland. Recently, earthquake site-effects were rigorously quantified for 34 stations in Southwest Iceland for the first time and correlated to distinct Icelandic geological units of hard rock, rock, lava rock, and sedimentary soil. These units are prevalent throughout Iceland and herein we present 1) nationwide maps of proxies (slope, Vs30, geological units) that may contribute to a better estimation of site effects and associated, 2) frequency-dependent site-amplification maps of Iceland. The frequency-dependent site factors for each geological unit are presented at 1-30 Hz and PGA. Finally, we generate site amplification maps based on recent large-scale models developed in other seismic regions (ESRM20) and various site proxies they are based on (geology- and slope-based inferred Vs30, geomorphological sedimentary thickness). We compare site-proxy maps and amplification maps from both Icelandic and large-scale, non-Icelandic, models. Neither spatial patterns nor amplification levels in either proxy or amplification maps from large-scale non-Icelandic studies resemble those observed from local quantitative strong-motion research as presented in this study. We attribute the discrepancy primarily to the young geology of Iceland and its formation history. Additionally, we compare model performance across frequencies by assessing the bias of model predictions against empirical site amplifications in the South Iceland Seismic Zone, accounting for site-to-site variability of residuals indicating the superior performance of the local amplification model.

Mathis Caprais, Oriane Shviro, Ugo Pensec et al.

Modeling underground temperatures provides a practical application of the one-dimensional heat equation. In this work, the one-dimensional heat equation in surface soil is extended to include heat carried by the vertical flow of rainwater through the soil. Analytical solutions, with and without water flow, illustrate the influence of rainwater circulation on the sub-surface propagation of seasonal temperature variations, an important effect that is generally neglected in textbooks. The surface temperature variations are damped by the soil, and this effect was used by the Troglodytae in Egypt or the Petra in South Jordan to insulate against extreme temperatures. For a realistic case of horizontally layered geology, a finite difference Python code was developed for the same purpose. Subsurface temperatures were also measured over a full year at depths up to 1.8 m and used to estimate the thermal skin depth and thermal wavelength. This study provides students with a practical example of how a textbook physics problem can be modified to extract information of contemporary importance in geophysics and global warming.

Manuela Davanzo, Giosuè Cuccurullo, Elena Zwirner et al.

We report the first observation of the psammophyte plant species Pancratium maritimum L. (Amaryllidaceae) in the Friuli Venezia Giulia region, Italy. Four adult individuals were observed in spring 2023 on the residual dunes of Lignano Sabbiadoro municipality behind a beach resort. Although we lack genetic analysis to determine its provenance, considering the absence of locally cultivated individuals and the expansion of the species in the neighboring region of Veneto, with individuals located ca. 20 km from this reported observation, we believe that its arrival in Friuli Venezia Giulia should be considered a spontaneous spread of a new native species for the region. This finding indicates that the species now has a distribution extending along the entire Italian coastline.

Damaris Leiva-Tafur, Jesús Rascón, Fernando Corroto de la Fuente et al.

Cattle ranching is a fundamental economic activity in northern Peru, where proper management of water resources is crucial. This study, a pioneer in the region, evaluated water quality and its suitability for human consumption, vegetable irrigation, and livestock production. It is also the first study to document the presence of metals and metalloids in vulnerable areas because they are located at the headwaters of river watersheds. The spatiotemporal evaluation of physicochemical parameters, metals, and metalloids was performed in five micro-watersheds (Cabildo, Timbambo, Pomacochas, Atuen, and Ventilla) from water samples collected in the dry season (October 2017) and wet season (March 2018). The parameters were analyzed using microwave plasma atomic emission spectrometry. The results were contrasted with international and Peruvian quality standards related to dairy cow production. The highest values of pH, total dissolved solids, and electrical conductivity were reported during the dry season, and the highest turbidity during the wet season. Of the metals evaluated, arsenic (As) was omnipresent in all the micro-watersheds, followed by lead (Pb).In contrast to World Health Organization regulations, concentrations of As, cadmium (Cd), Pb, and iron represent a risk; according to Peruvian regulations, As and Pb exceed the concentrations established for use in animal drinking water and vegetable irrigation, and according to water guidelines for dairy cattle, concentrations of As, Pb, Cd, and Al exceed the permitted limits. The high concentrations of these metals in the study area are attributable to a synergy between natural factors, such as Andean geology and livestock activity. The data reported will allow for proper water resource management, pollution prevention, and the design and adoption of mitigation measures.

Shekhar Sharan Goyal, Raviraj Dave, Rohini Kumar et al.

Abstract Intensive agricultural practices have powered green revolutions, helping nations attain self-sufficiency. However, these fertilizer-intensive methods and exploitative trade systems have created unsustainable agricultural systems. To probe the environmental consequences on production hubs, we map the fate of Nitrogen and Phosphorus in India’s interstate staple crop trade over the recent decade. The nation’s food bowls, while meeting national food demand, are becoming pollution-rich, sustaining around 50% of the total surplus from trade transfer, accounting for 710 gigagrams of nitrogen per year and 200 gigagrams of phosphorus per year. In combination with water balance analysis, surplus nutrient conversion to a graywater footprint further highlights an aggravated situation in major producer regions facing long-term water deficits. Given India’s role in global food security, identifying the nation’s environmental vulnerability can help in designing appropriate policy interventions for sustainable development.

Filippo Bigi, Guillaume Fraux, Nicholas J. Browning et al.

Spherical harmonics provide a smooth, orthogonal, and symmetry-adapted basis to expand functions on a sphere, and they are used routinely in physical and theoretical chemistry as well as in different fields of science and technology, from geology and atmospheric sciences to signal processing and computer graphics. More recently, they have become a key component of rotationally equivariant models in geometric machine learning, including applications to atomic-scale modeling of molecules and materials. We present an elegant and efficient algorithm for the evaluation of the real-valued spherical harmonics. Our construction features many of the desirable properties of existing schemes and allows to compute Cartesian derivatives in a numerically stable and computationally efficient manner. To facilitate usage, we implement this algorithm in sphericart, a fast C++ library which also provides C bindings, a Python API, and a PyTorch implementation that includes a GPU kernel.

K. J. Luke, Abhinav Mishra, Vihaan Ghare et al.

Science-AI Symbiotic Group at Seven Square Academy, Naigaon was formed in 2023 with the purpose of bringing school students to the forefronts of science research by involving them in hands on research. In October 2023 a new project was started with the goal of studying the lunar surface by real-time observations and open source data. Twelve students/members from grades 8, 9, 10 participated in this research attempt wherein each student filled an observation metric by observing the Moon on various days with a Bresser Messier 150mm/1200mm reflector Newtonian telescope. After the observations were done, the members were assigned various zones on the lunar near side for analysis of geological features. Then a data analysis metric was filled by each of students with the help of Lunar Reconnaissance Orbiter Camera's/ LROC's quickmap open access data hosted by Arizona State University. In this short paper a brief overview of this project is given. One example each of observation metric and data analysis metric is presented. This kind of project has high impact for school science education with minimal costs. This project can also serve as an interesting science outreach program for organisations looking forward to popularise planetary sciences research at school level.