Challenges In Geosciences Research Articles

COVID-19 pandemic impacts on student learning in undergraduate mineralogy

Online and hybrid instruction as a response to the coronavirus (COVID-19) pandemic presented specific challenges in geosciences due to the role of laboratory and field activities. We carried out a research study on student learning in undergraduate mineralogy at a large public research university in the United States over a 4-year period including pre-pandemic in-person instruction and during pandemic online and hybrid instruction. A total of 94 students participated in course activities and mixed-method surveys. Survey results indicated that during the pandemic, students entered the course with lower sense of belonging relative to pre-pandemic students. Despite challenges related to instruction and student learning since 2020, the pandemic did not necessarily produce worse learning outcomes for mineralogy students as measured by course assessments. Structured course delivery and opportunities for interaction can offset challenges resulting from global emergencies.

Synthetic Aperture Radar for Geosciences

AbstractSynthetic Aperture Radar (SAR) has emerged as a pivotal technology in geosciences, offering unparalleled insights into Earth's surface. Indeed, its ability to provide high‐resolution, all‐weather, and day‐night imaging has revolutionized our understanding of various geophysical processes. Recent advancements in SAR technology, that is, developing new satellite missions, enhancing signal processing techniques, and integrating machine learning algorithms, have significantly broadened the scope and depth of geosciences. Therefore, it is essential to summarize SAR's comprehensive applications for geosciences, especially emphasizing recent advancements in SAR technologies and applications. Moreover, current SAR‐related review papers have primarily focused on SAR technology or SAR imaging and data processing techniques. Hence, a review that integrates SAR technology with geophysical features is needed to highlight the significance of SAR in addressing challenges in geosciences, as well as to explore SAR's potential in solving complex geoscience problems. Spurred by these requirements, this review comprehensively and in‐depth reviews SAR applications for geosciences, broadly including various aspects in air‐sea dynamics, oceanography, geography, disaster and hazard monitoring, climate change, and geosciences data fusion. For each applied field, the scientific advancements produced because of SAR are demonstrated by combining the SAR techniques with characteristics of geophysical phenomena and processes. Further outlooks are also explored, such as integrating SAR data with other geophysical data and conducting interdisciplinary research to offer comprehensive insights into geosciences. With the support of deep learning, this synergy will enhance the capability to model, simulate, and forecast geophysical phenomena with greater accuracy and reliability.

Interpreting Mineral Deposit Genesis Classification with Decision Maps: A Case Study Using Pyrite Trace Elements

Abstract Machine learning improves geochemistry discriminant diagrams in classifying mineral deposit genetic types. However, the increasingly recognized ‘black box’ property of machine learning has been hampering the transparency of complex data analysis, leading to the challenge in deep geochemical interpretation. To address the issue, we revisited pyrite trace elements and propose to use ‘Decision Map’, a cutting-edge visualization technique for machine learning. This technique reveals mineral deposit classifications by visualizing the ‘decision boundaries’ of high-dimensional data, a concept crucial for model interpretation, active learning, and domain adaptation. In the context of geochemical data classification, it enables geologists to understand the relationship between geo-data and decision boundaries, assess prediction certainty, and observe the data distribution trends. This bridges the gap between the insightful properties of traditional discriminant diagrams and the high-dimensional efficiency of modern machine learning. Using pyrite trace element data, we construct a decision map for mineral deposit type classification, which maintains the accuracy of machine learning while adding valuable visualization insight. Additionally, we demonstrate two applications of decision maps. First, we show how decision maps can help resolve the genetic type dispute of a deposit whose data was not used in training the models. Second, we demonstrate how the decision maps can help understand the model, which further helps find indicator elements of pyrite. The recommended indicator elements by decision maps are consistent with geologists’ knowledge. This study confirms the decision map’s effectiveness in interpreting mineral genetic type classification problems. In geochemistry classification, it marks a shift from conventional machine learning to a visually insightful approach, thereby enhancing the geological understanding derived from the model. Furthermore, our work implies that decision maps could be applicable to diverse classification challenges in geosciences.

Development of tailored gravity model based on global gravitational and topographic models and terrestrial gravity data for geophysical exploration of southern benue trough in southeast Nigeria

A major challenge in geosciences is the acquisition of high-resolution geophysical data that could help to better understand the Earth's interior and processes. In this study, we develop a Tailored Gravity Model (TGM) to fit local terrestrial gravity data collected throughout the Southern Benue Trough (situated in southeast Nigeria) by using Global Gravitational Models (GGMs), terrestrial gravity data, and Digital Elevation Models (DEMs). Specifically, we develop the TGM by computing gravity values from the XGM2019e_2159 global gravitational model on the topographic surface generated by using the Multi-Error-Removed Improved-Terrain (MERIT) DEM topographic heights, and algebraically adding the residual gravity effects obtained from the SRTM2gravity global model of spherical gravimetric terrain correction, while removing a detected systematic bias. An independent statistical evaluation of the terrestrial and tailored gravity data shows that most of the differences between these two datasets are within ±10 mGal, while the RMS of differences improved from 16.7 to 6.4 mGal and a systematic bias was removed. We used the tailored gravity data to compile the Bouguer gravity map. The gravity map produced from a high-resolution absolute gravity data reveals the spatial gravity pattern that is likely associated with aquifers and magmatic structures within the Southern Benue Trough. In agreement with published studies, the Bouguer gravity map demonstrates the folding, faulting, and upwelling or uplifting of the crust. Our gravimetric interpretation suggests that the elongated gravity high along the flexurally inverted and circular Abakaliki Anticlinorium in the Bouguer gravity map could indicate a possible existence of a reservoir of mineral ore bodies or mineral-bearing rocks.

Low paleolatitude of the Carajás Basin at ∼2.75 Ga: Paleomagnetic evidence from basaltic flows in Amazonia

Establishing the positions of continents during the initial stages of Earth's evolution is one of the most important challenges in geosciences today. This challenge is mainly due to the severe limitations in obtaining geological and/or geophysical data from early Earth time, particularly robust paleomagnetic data. Here, we report the first paleomagnetic data from an Archean block in the Amazonian craton, the Carajás Province, for ∼2.76–2.74 billion years ago (Ga), when extensive dominantly mafic volcanism (Parauapebas Formation) covered an area of ∼18,000 km2. The paleomagnetic investigation was conducted on fresh drill cores drilled into the Carajás iron ore mine and cutting across the Parauapebas Formation. After rotating the drill core segments to geographic coordinates using the viscous magnetic component, two characteristic components, Carajás 1 and 2 (C1 and C2) were identified and further used to calculate paleomagnetic poles: C1 (∼2759 Ma; 40.5°E, −44.6°S, N = 5 A95 = 6.5°, K = 18.5) and C2 (∼2749 Ma; 342.4°E, −54.3°S, N = 28, A95 = 14.8°, K = 27.8). Pole C2 is based on a bigger number of sites, passes a reversal test and is considered robust. A baked contact test was attempted for this component, but it is not conclusive. Our results, integrated with geological evidence reveals that the Carajás block occupied low latitudes at the time, and could have been part of the Superia supercraton during the Neoarchean (∼2.75 Ga) at equatorial latitudes. Finally, a consistent succession of six magnetic reversal events was identified in the lava flow sequence from the Parauapebas Formation, pointing to an already dynamic geodynamo pre-2.7 Ga.

A geospatial hybrid cloud platform based on multi-sourced computing and model resources for geosciences

ABSTRACTCloud computing has been considered as the next-generation computing platform with the potential to address the data and computing challenges in geosciences. However, only a limited number of geoscientists have been adapting this platform for their scientific research mainly due to two barriers: 1) selecting an appropriate cloud platform for a specific application could be challenging, as various cloud services are available and 2) existing general cloud platforms are not designed to support geoscience applications, algorithms and models. To tackle such barriers, this research aims to design a hybrid cloud computing (HCC) platform that can utilize and integrate the computing resources across different organizations to build a unified geospatial cloud computing platform. This platform can manage different types of underlying cloud infrastructure (e.g., private or public clouds), and enables geoscientists to test and leverage the cloud capabilities through a web interface. Additionally, the platform also provides different geospatial cloud services, such as workflow as a service, on the top of common cloud services (e.g., infrastructure as a service) provided by general cloud platforms. Therefore, geoscientists can easily create a model workflow by recruiting the needed models for a geospatial application or task on the fly. A HCC prototype is developed and dust storm simulation is used to demonstrate the capability and feasibility of such platform in facilitating geosciences by leveraging across-organization computing and model resources.

A Special Issue on Emerging Nanogeosciences Nanogeosciences: A Revolutionary Challenge in Geosciences

<i>A Special Issue on</i> Emerging Nanogeosciences Nanogeosciences: A Revolutionary Challenge in Geosciences

Evaluation of surface layer flux parameterizations using in-situ observations

Appropriate calculation of surface turbulent fluxes between the atmosphere and the underlying ocean/land surface is one of the major challenges in geosciences. In practice, the surface turbulent fluxes are estimated from the mean surface meteorological variables based on the bulk transfer model combined with the Monnin-Obukhov Similarity (MOS) theory. Few studies have been done to examine the extent to which such a flux parameterization can be applied to different weather and surface conditions. A novel validation method is developed in this study to evaluate the surface flux parameterization using in-situ observations collected at a station off the coast of Gulf of Mexico. The main findings are: (a) the theoretical prediction that uses MOS theory does not match well with those directly computed from the observations. (b) The largest spread in exchange coefficients is shown in strong stable conditions with calm winds. (c) Large turbulent eddies, which depend strongly on the mean flow pattern and surface conditions, tend to break the constant flux assumption in the surface layer.

An Out-of-core GPU Approach for Accelerating Geostatistical Interpolation

Geostatistical methods provide a powerful tool to understand the complexity of data arising from Earth sciences. Since the mid 70's, this numerical approach is widely used to understand the spatial variation of natural phenomena in various domains like Oil and Gas, Mining or Environmental Industries. Considering the huge amount of data available, standard implementations of these numerical methods are not efficient enough to tackle current challenges in geosciences. Moreover, most of the software packages available for geostatisticians are designed for a usage on a desktop computer due to the trial and error procedure used during the interpolation. The Geological Data Management (GDM) software package developed by the French geological survey (BRGM) is widely used to build reliable three-dimensional geological models that require a large amount of memory and computing resources. Considering the most time-consuming phase of kriging methodology, we introduce an efficient out-of-core algorithm that fully benefits from graphics cards acceleration on desktop computer. This way we are able to accelerate kriging on GPU with data 4 times bigger than a classical in-core GPU algorithm, with a limited loss of performances.

Synthetic near Σ5 (210)/[100] grain boundary in YAG fabricated by direct bonding: structure and stability

Several macroscopic physical and chemical properties, such as rheology, elasticity, or transport properties are governed by grain boundary processes. An improved understanding of the structure and evolution of grain boundaries has thus become a key challenge in geosciences and material sciences. Here, we report the structure of near Σ5 (210)/[100] grain boundaries in Y3Al5O12 (YAG), which were synthesised by the wafer direct bonding method. The produced grain boundaries were annealed at different temperatures, ranging from 673 to 1,873 K. The grain boundaries annealed at different temperatures are not distinguishable based on their flatness and apparent cohesiveness in high resolution TEM (HRTEM) micrographs, but show a considerable step in their mechanical stability at around 1,273 K, a temperature that corresponds to roughly half the melting temperature of YAG. This study further focuses on the effect of a slight misorientation of the two crystals on the grain boundary structure and we discuss if the boundary can reach a state of minimum energy configuration during annealing. Along the grain boundaries, we observed a long-range strain contrast with a periodicity of 40 nm, which has not been reported for high-angle grain boundaries so far. We conclude that this contrast is caused by faceting along the grain boundary plane, which is needed to achieve minimum energy configuration of the grain boundary plane.

&lt;i&gt;Preface&lt;/i&gt; 4th EGU Alexander von Humboldt Conference &quot;The Andes: Challenge for Geosciences&quot;

US Geological Survey, USAThis special volume of Advances in Geosciences is de-voted to some of the papers presented during the 4th EGUAlexander von Humboldt Conference on, “The Andes: Chal-lenge for Geosciences” held 24–28 November 2008 in San-tiago de Chile. We hope this volume will become a valuablereference for scientists engaged in understanding some of themany questions and challenges posed by the impressive An-des Cordillera.Co-organized by the European Geosciences Union (EGU)and the Universidad de Chile, the conference was attendedby more than 200 scientists from 28 countries worldwide.Topics covered during this 5-day-long interdisciplinarymeeting were:– Cryosphere and Hydrology– Climate, Climate Variability and Climate Change– Tectonics and Geodynamics– Climate-Tectonics-Surface Processes– Water Resources in Future Climate Scenarios– Impact of Subduction on Tectonics, Volcanism and At-mospheric Chemistry– Geo-Ecology and Sustainability– Risk in the GeosciencesThese topics were introduced by keynote and invitedspeakers, who, in concert with the highly interdisciplinaryaudience, set the scene for vivid discussions.The organizers of the 4th EGU Humboldt Conference,now in the role of Guest Editors of this special volume ofAdvances in Geosciences, like to use this opportunity forthanking the numerous sponsors and all those who helped inthe organization. We particularly like to thank the keynotespeakers most of whom have given valuable additionalhelp towards setting up the scientific program and in thereview process for this volume. Last but not least we thankall authors who provided their papers for this proceedingsvolume.P. Fabian, R. Garreau, C. Schneiderand R. TillingSpecial Volume EditorsPublished by Copernicus Publications on behalf of the European Geosciences Union.

A review of the GGP network and scientific challenges

The Global Geodynamics Project (GGP) started on July 1, 1997 and is now in its 11th year of operation. It has a relatively small number of stations (24), compared to seismic (GSN) or geodetic (GPS) networks, but it is the only database that is accumulating relative gravity measurements worldwide. As any scientific organization matures, there is a change in the culture of the project and the people involved. To remain viable, it is necessary not only to maintain the original goals, but also to incorporate new ideas and applications on the science involved. The main challenges within GGP are to ensure: (a) that the instruments are properly calibrated, (b) that data is being recorded with the highest accuracy, and with appropriate hydrological instrumentation, and (c) that the flow of data from all recording stations to the ICET database continues as agreed in within the GGP framework. These practical matters are the basis for providing high quality recordings that will extend the usefulness of the network into the future to meet new challenges in geosciences. Several new stations have been brought into operation in the past few years, but the data availability from some of these stations still leaves room for improvement. Nevertheless, the core group of stations established more than 10 years ago has been able to maintain the high standards of the original concept, and much research has been published using network data in areas as diverse as hydrology, polar motion, and Earth’s normal modes. GGP will also participate in some of the scientific tasks of the Global Geodetic Observing System program, at least initially by providing relative gravity measurements for collocation with other high precision geodetic measurements.

Strong Earthquakes: A Challenge for Geosciences and Civil Engineering--A New Collaborative Research Center in Germany

INTRODUCTION The Collaborative Research Center (CRC) 461 Strong Earthquakes: A Challenge for Geosciences and Civil Engineering has been funded by the Deutsche Forschungsgemeinschaft (German Research Foundation) and is supported by the State of Baden-Wurtemberg and the University of Karlsruhe. Collaborative Research Centers (SonderForschungsBereiche—SFB) aim at strategic research on issues that require intensive cooperation across various disciplines. CRCs form a framework for the development of these interactions and are expected to operate with a long-term (6 to 12 years) perspective. CRCs are peer-reviewed every three years. CRC 461 was established in July 1996 and aims at strategic research in the field of strong earthquakes with a regional focus on earthquakes and earthquake engineering in Romania. OBJECTIVES The focus of the research program is the strong earthquake activity in the Romanian Vrancea area (Figure 1). Over several centuries strong earthquakes in this area have caused a high toll of casualties and damage...