Geophysical Research Articles

Reply to ‘how not to use U–Pb detrital zircon geochronology to infer regional tectonics: Comment on , Journal of African Earth Sciences, 104942’ by Rajesh et al

Reply to ‘how not to use U–Pb detrital zircon geochronology to infer regional tectonics: Comment on , Journal of African Earth Sciences, 104942’ by Rajesh et al

Research funding in different SCI disciplines: A comparison analysis based on Web of Science

Abstract To provide valuable insights for shaping future funding policies, in this study, we offer a comprehensive panorama of the research funding across 171 SCI disciplines in the decade 2011–2020, based on more than 13 million scientific literature records from the Web of Science. The relationship between funding and research impact is also explored. To this end, we employ two indicators: the universality and multiplicity of funding, to indicate the funding level and six indicators to gauge the impact advantages of funding. Our findings reveal an upward trend in both the universality (increasing from 66.30% to 74.26%) and multiplicity (increasing from 2.82 to 3.26) of funding over the decade concerned. The allocation of funding varies across disciplines, with life sciences and earth sciences receiving the highest percentage of funding (78.31%) and medicine having the highest multiplicity of funding (3.07). Engineering and computer science have seen relatively rapid growth in terms of universality and multiplicity of funding. Funded articles have a greater impact than unfunded ones. And this impact strengthens as the number of funding grants increases. Through regression analysis, the citation advantage of funding is also proven at the article level, although the usage advantage is not significant.

Increasing Academic Performance on Earth Science Among Grade 9 Learners through Developed Self-Learning Materials

Increasing Academic Performance on Earth Science Among Grade 9 Learners through Developed Self-Learning Materials

Evaluation of Geohazards Research in the World and Pacific Region: A Comparative Bibliometric Study

Geohazards are natural phenomena that endanger infrastructure, the environment, and human activity. Understanding and mitigating them is crucial for public safety, disaster preparedness, and sustainable land and resource management. This research objective is to analyze geohazard research trends globally and then compare them with countries around the Pacific Ring. Ninety-six geohazard publications were analyzed using bibliometric analysis and the VOSviewer application. The general trend of geohazard research increased slightly. It is critical in dealing with the expanding threats posed by geohazards, adapting to changing conditions, protecting vulnerable people, and leveraging technological improvements for more effective hazard management and disaster risk reduction. The Annual Offshore Technology Conference Proceedings and Engineering Geology are the most popular scholarly journals for authors to publish research on geohazard. The most popular topic area for geohazard papers is Earth and Planetary Sciences, followed by engineering, environmental science, and computer science. It is consistent with the growing use of technology in geohazard research. This study also includes an authorship profile. This research implies enhancing disaster risk reduction strategies and contributing to global efforts to address the challenges posed by geohazards.

Mapping paleoelevations along active continental margins with igneous geochemistry: A case study from South America

Mountains and mountain ranges, often situated at convergent plate margins, play a pivotal role in many fields of the Earth, climate, and biological sciences. Reconstructing past episodes of mountain building from the geological rock record is one of the main challenges for unravelling the ancient physical geography of Earth’s surface. Established methods for quantifying past elevations traditionally relied on sedimentary rocks, but in recent years, alternative approaches have emerged on the basis that geochemical signatures of magmatic rocks formed in convergent settings correlate with crustal thickness or elevation. Consequently, methods based on igneous samples have the potential to allow quantitative mapping of past topographic change for large spans of space and time where existing maps are largely based on a qualitative approach. Here, we investigate the application of paleoelevation estimates derived from geochemistry using the western margin of South America as a case study. We investigate their consistency with independent indicators of past elevations such as stratigraphy, stable isotopes, fossils etc. for Cenozoic samples along the Andean margin. For older times, we compare the estimated paleoelevations with more general aspects of the geological record, as well as paleoelevations from global paleogeography models widely used in climate modelling studies, to evaluate the extent to which these models are consistent with the igneous geochemical proxies. We find that estimates based on multiple geochemical proxies, and which account for variations in elevation as a function of MgO, are preferable to those based on individual proxies. The multi-mohometer estimates yield estimates of elevation that better match both present-day topography and Cenozoic paleoelevations, and retain more samples during the data filtering stage. In deeper time, we show that igneous geochemistry quantifies changes in elevation related to documented phases of crustal thickening and thinning, and is thus likely to allow improvements to existing maps of paleotopography.

Investigating critical metals Ge and Ga in complex sulphide mineral assemblages using LIBS mapping

Elemental imaging using Laser-Induced Breakdown Spectroscopy (LIBS) mapping is increasingly applied to a wide range of materials. In geomaterials, phase identification and characterization (mineralogy) are crucial for solving a variety of problems in earth sciences and mining industry.Here we applied LIBS mapping to ore samples from the world-class Kipushi deposit, Democratic Republic of Congo, because these ores are known for their great mineral complexity and economic value, especially for their high potential in critical metals such as Ge and Ga.The mineralogy of the samples was reconstructed by combining two approaches: 1) element colocalization in LIBS maps that were selected based on the knowledge of occurring mineral species at the site and 2) correlation maps obtained by applying the Interesting Features Finder (IFF) algorithm. Reconstructed minerals include chalcopyrite, bornite, chalcocite, sphalerite, galena, pyrite, tennantite-(Zn), renierite, tungstenite, betekhtinite, carrollite, gallite, and a series of non-sulphide gangue minerals (quartz, carbonate and clay minerals). SEM-EDS was used to confirm the LIBS-derived mineralogy, especially for sub-pixel inclusions.Among other results, Ge and Ga are hosted as major elements in renierite and gallite, respectively, and also as trace-elements in chalcopyrite, bornite and tungstenite (for Ge), and chalcopyrite, bornite, sphalerite and renierite (for Ga). Particular attention was paid to iron interfering with gallium at 417.20 nm, for which simple background-corrected peak intensities were compared to a more advanced chemometric method (MCR-ALS). All the results were obtained with minimal time and efforts and, while only qualitative in nature, they already provide essential information about ore texture, mineralogical composition and trace-element distribution across the ore.

Cracking the code: An evidence-based approach to teaching Python in an undergraduate earth science setting

Scientific programming has become increasingly essential for manipulating, visualizing, and interpreting the large volumes of data acquired in earth science research. Yet few discipline-specific instructional approaches have been documented and assessed for their effectiveness in equipping geoscience undergraduate students with coding skills. Here we report on an evidence-based redesign of an introductory Python programming course, taught fully remotely in 2020 in the School of Oceanography at the University of Washington. Key components included a flipped structure, activities infused with active learning, an individualized final research project, and a focus on creating an accessible learning environment. Cloud-based notebooks were used to teach fundamental Python syntax as well as functions from packages widely used in climate-related disciplines. By analyzing quantitative and qualitative data from surveys, online learning platforms, student work, assessments, and a focus group, we conclude that the instructional design facilitated learning and supported self-guided scientific inquiry. Students with less or no prior exposure to coding achieved similar success as peers with more experience, an outcome likely mediated by higher engagement with course resources. We believe that the constructivist approach to teaching introductory programming and data literacy that we present could be broadly applicable across the earth sciences and in other scientific domains.

Geoeducation strategies in the Amazon, Napo Sumaco Aspiring UNESCO Global Geopark

The UNESCO Global Geoparks are grounded in three core principles: education, geoconservation, and geotourism. Since 2015, the Napo Sumaco Aspiring UNESCO Global Geopark (NSAUGG) in the Ecuadorian Amazon has concentrated its efforts on enhancing local capabilities through Earth Sciences education, underscoring the safeguarding of natural and cultural heritage and environmental stewardship. A comprehensive educational dissemination model was implemented, incorporating both indoor and outdoor activities, geoscience education training, geodiversity knowledge enhancement, and the creation of content and workshops that integrate classroom and field-based learning and evaluation. The concepts of geodiversity and geoparks were disseminated to adults and youth, primarily members of the native peoples' communities, particularly those employed at the community tourism centers and the geopark guides designated as “Yuyaiwa Pushak Runakuna.” A total of 60 individuals from the NSAUGG populations between Tena and Archidona cantons participated in the educational activities, which involved 19 geoeducators. These initiatives facilitated an appreciation of the geopark's diverse heritages, including its geological, biological, and cultural assets. The geoeducation efforts fostered geotourism, with the Yuyaiwa Pushak Runakuna acquiring greater value through their assimilation of geological and speleological knowledge. This is evident in their use of geological vocabulary and understanding of geological processes and materials in guiding activities for both national and foreign tourists. The most significant achievement is the establishment of “Geoeducation for Sustainability” actions, which promotes collective life through knowledge dialogues based on Minka (voluntary community work) and Turkana (reciprocity and barter). These actions encouraged a deeper connection to the geopark's heritage and strengthened community cohesion.

The Composition of Earth's Lower Mantle

Determining the composition of Earth's lower mantle, which constitutes almost half of its total volume, has been a central goal in the Earth sciences for more than a century given the constraints it places on Earth's origin and evolution. However, whether the major element chemistry of the lower mantle, in the form of, e.g., Mg/Si ratio, is similar to or different from the upper mantle remains debated. Here we use a multidisciplinary approach to address the question of the composition of Earth's lower mantle and, in turn, that of bulk silicate Earth (crust and mantle) by considering the evidence provided by geochemistry, geophysics, mineral physics, and geodynamics. Geochemical and geodynamical evidence largely agrees, indicating a lower-mantle molar Mg/Si of ≥1.12 (≥1.15 for bulk silicate Earth), consistent with the rock record and accumulating evidence for whole-mantle stirring. However, mineral physics–informed profiles of seismic properties, based on a lower mantle made of bridgmanite and ferropericlase, point to Mg/Si ∼ 0.9–1.0 when compared with radial seismic reference models. This highlights the importance of considering the presence of additional minerals (e.g., calcium-perovskite and stishovite) and possibly suggests a lower mantle varying compositionally with depth. In closing, we discuss how we can improve our understanding of lower-mantle and bulk silicate Earth composition, including its impact on the light element budget of the core. ▪The chemical composition of Earth's lower mantle is indispensable for understanding its origin and evolution.▪Earth's lower-mantle composition is reviewed from an integrated mineral physics, geophysical, geochemical, and geodynamical perspective.▪A lower-mantle molar Mg/Si of ≥1.12 is favored but not unique.▪New experiments investigating compositional effects of bridgmanite and ferropericlase elasticity are needed to further our insight.

Analysis of reflection of wave propagation in magneto-thermoelastic nonlocal micropolar orthotropic medium at impedance boundary

PurposeThis study aims to examine the plane wave reflection problem in micropolar orthotropic magneto-thermoelastic half space, considering the influence of impedance as a boundary in a nonlocal elasticity.Design/methodology/approachThis study presents the novel formulation of governing partial differential equations for micropolar orthotropic medium with impact of nonlocal thermo-elasticity under magnetic field.FindingsThis study provides the numerical results validation for a particular numerical data and expression for the amplitude ratios of reflected waves and identifies the existence of four different waves, namely, quasi longitudinal displacement qCLD-wave, quasi thermal wave qCT-wave, quasi transverse displacement qCTD-wave and quasi-transverse micro-rotational qCTM-wave. The study derives the velocity equation giving the speed and phase velocity of these waves. The study also shows that the small-scale size effect gives significant impact on phase velocity.Research limitations/implicationsThe graphical analysis examines the variation of speeds and coefficients of attenuation of these waves due to frequency, magnetic field and nonlocal parameters. Also, significant conclusions on the variation of reflection coefficient against nonlocal parameter, frequency, impedance parameter and angle of incidence are provided graphically.Practical implicationsThe creation of more effective micropolar orthotropic anisotropic materials which are very useful in the daily life and their applications in earth science are greatly impacted by the findings of this study.Originality/valueThe authors of the submitted document initiated and produced it collectively, with equal contributions from all members.

Introducing the New Editor-in-Chief of the <em>ESS Open Archive</em>

Learn about the person taking the helm of the Earth and Space Science Open Archive and their vision for the coming years.

Causal hybrid modeling with double machine learning—applications in carbon flux modeling

Hybrid modeling integrates machine learning with scientific knowledge to enhance interpretability, generalization, and adherence to natural laws. Nevertheless, equifinality and regularization biases pose challenges in hybrid modeling to achieve these purposes. This paper introduces a novel approach to estimating hybrid models via a causal inference framework, specifically employing double machine learning (DML) to estimate causal effects. We showcase its use for the Earth sciences on two problems related to carbon dioxide fluxes. In the Q 10 model, we demonstrate that DML-based hybrid modeling is superior in estimating causal parameters over end-to-end deep neural network approaches, proving efficiency, robustness to bias from regularization methods, and circumventing equifinality. Our approach, applied to carbon flux partitioning, exhibits flexibility in accommodating heterogeneous causal effects. The study emphasizes the necessity of explicitly defining causal graphs and relationships, advocating for this as a general best practice. We encourage the continued exploration of causality in hybrid models for more interpretable and trustworthy results in knowledge-guided machine learning.

Unveiling the geoheritage, cultural geomorphology and geotourism potential of Zanskar region, NW Himalaya, India

The Zanskar region, nestled in the heart of the Tethyan Himalaya, represents a significant geological and cultural repository that has remained relatively unexplored by the global tourism industry. This study investigates Zanskar's geoheritage and cultural geomorphology, highlighting its importance for geotourism and advocating for the implementation of sustainable development to preserve its fragile ecosystem. Flowing northward from the Higher Himalayas, the Zanskar River, one of the largest northeast-flowing tributary of the Upper Indus River Basin (UIRB), traverses the complex, strongly folded, and thrusted Zanskar Range via a steep, narrow 60-kilometer-long gorge. Zanskar has consistently garnered attention from geoscientists and tourists owing to its unique geographic location and remoteness. Many areas and routes in Zanskar are challenging to reach, but it stands out as a prime location where glaciers can be accessed by road, making it an ideal destination for studying geoscience. Geologically, the study area is part of the Zanskar Range, with its boundaries defined by the Ladakh Range to the northeast and the Great Himalayan Range to the southwest. The Indus Tsangpo Suture Zone, the Tethyan Sedimentary Sequence, and the Higher Himalayan Crystalline Sequence are exposed from north to south. Zanskar serves as a pristine field museum for studying young Himalayan orogenic tectonics, featuring prominent exposures such as the Zanskar Shear Zone (ZSZ)/South Tibetan Detachment System (STDS) and the structural outcrop of Zangla, showcasing a variety of folding types. These folds signify different phases of deformation resulting from the Indo-Eurasian collision. Moreover, it serves as a prime sequence of Quaternary Glacial Periods (QGP), providing an ideal natural laboratory and an open, practical classroom for geoscientists and Earth science students. We propose ten geoheritage sites in Zanskar, which encompass cultural, geomorphological, and geological attractions with potential for geotourism in this region.

Fostering the Development of Earth Data Science Skills in a Diverse Community of Online Learners: A Case Study of the Earth Data Science Corps

Today’s data-driven world requires earth and environmental scientists to have skills at the intersection of domain and data science. These skills are imperative to harness information contained in a growing volume of complex data to solve the world’s most pressing environmental challenges. Despite the importance of these skills, Earth and Environmental Data Science (EDS) training is not equally accessible, contributing to a lack of diversity in the field. This creates a critical need for EDS training opportunities designed specifically for underrepresented groups. In response, we developed the Earth Data Science Corps (EDSC) which couples a paid internship for undergraduate students with faculty training to build capacity to teach and learn EDS using Python at smaller Minority Serving Institutions. EDSC faculty participants are further empowered to teach these skills at their home institutions which scales the program beyond the training lead by our team. Using a Rasch modeling approach, we found that participating in the EDSC program had a significant impact on undergraduate learners’ comfort and confidence with technical and nontechnical data science skills, as well as their science identity and sense of belonging in science, two critical aspects of recruiting and retaining members of underrepresented groups in STEM. Supplementary materials for this article are available online.

Comparative Analysis between Remote Sensing Burned Area Products in Brazil: A Case Study in an Environmentally Unstable Watershed

Forest fires can profoundly impact the hydrological response of river basins, modifying vegetation characteristics and soil infiltration. This results in a significant increase in surface flow and channel runoff. In response to these effects, many researchers from different areas of earth sciences are committed to determining emergency measures to rehabilitate river basins, intending to restore their functions and minimize damage to soil resources. This study aims to analyze the mapping detection capacity of burned areas in a river basin in Brazil based on images acquired by AMAZÔNIA-1/WFI and the AQ1KM product. The effectiveness of the AMAZÔNIA-1 satellite in this regard is evaluated, given the importance of the subject and the relatively recent introduction of the satellite. The AQ1KM data were used to analyze statistical trends and spatial patterns in the area burned from 2003 to 2023. The U-Net architecture was used for training and classification of the burned area in AMAZÔNIA-1 images. An increasing trend in burned area was observed through the Mann–Kendall test map and Sen’s slope, with the months of the second semester showing a greater occurrence of burned areas. The NIR band was found to be the most sensitive spectral resource for detecting burned areas. The AMAZÔNIA-1 satellite demonstrated superior performance in estimating thematic accuracy, with a correlation of above 0.7 achieved in regression analyses using a 10 km grid cell resolution. The findings of this study have significant implications for the application of Brazilian remote sensing products in ecology, water resources, and river basin management and monitoring applications.

An Assessment of Changes in the Thermal Environment during the COVID-19 Lockdown: Case Studies from the Greenland and Norwegian Seas

The COVID-19 lockdown had a significant impact on human activities, reducing anthropogenic heat and CO2 emissions. To effectively assess the impact of the lockdown on the thermal environment, we used the sliding paired t-test, which we improved from the traditional sliding t-test by introducing the paired t-test for sliding statistical tests, to test the abrupt change in the thermal environment. Furthermore, an additive decomposition model and wavelet analysis method were used to analyze the characteristics of trend and irregular change, coherence, and phase difference of the time series data with respect to the thermal environment. We chose the Greenland Sea and the Norwegian Sea, regions highly sensitive to changes in climate and ocean circulation, as case studies and used remote sensing data of the sea surface temperature (SST) and the atmospheric CO2 concentration data obtained from the Goddard Earth Sciences Data and Information Services Center from January 2015 to December 2021 for the analysis. The results show that although the annual spatial mean SST in 2020 is lower than the mean of all 7 years in most areas of the two seas, there is no evidence of a significant mutation in the decrease in the SST during the lockdown in 2020 compared with the temperatures before, according to the sliding paired t-test. The analysis of the irregular components of the monthly mean SST decomposed by an additive decomposition model also does not show the anomalously low SST during the lockdown in 2020. In addition, the lockdown had almost no impact on the increasing trend of CO2 concentration. The wavelet analysis also shows that there is no obvious anomaly in coherence or phase difference between the periodic variation of the SST and the CO2 concentrations in 2020 compared with other years. These results suggest that the direct effect of the COVID-19 lockdown on the thermal environment of the study area could be negligible.

A new approach to counting fossil and modern pollen grains: The orderly count

Palynology, the study of pollen and spores, plays a crucial role in various scientific disciplines, including earth sciences (paleovegetation and paleoclimatology), botany, allergy, archaeology, forensic sciencs and cosmetics. This study delves into the critical question in fossil pollen analysis studies: the minimum count of pollen grains required for accurate estimation of vegetation composition. Various statistical methods have been proposed over the years to address this question. Our research introduces an alternative technique, the orderly count, tailored to the nature of palynological analysis. We apply this method to diverse sediment catchments, including peat bogs, marine and lake sediments, from different geographical locations. Additionally, we revisit the reliability coefficients and propose adjustments for more accurate results. Our findings suggest that relying on statistical methods without considering the specific characteristics of palynological data may lead to low reliability. We advocate for the integration of dissimilarity criteria and the orderly count in sample size assessments for enhanced accuracy in palynological analyses. Our study emphasizes the importance of choosing appropriate methodologies aligned with the unique aspects of palynology to ensure robust and reliable results.

Prospects of a thousand-ion Sn2+ Coulomb-crystal clock with sub-10−19 inaccuracy

Optical atomic clocks are the most accurate and precise measurement devices of any kind, enabling advances in international timekeeping, Earth science, fundamental physics, and more. However, there is a fundamental tradeoff between accuracy and precision, where higher precision is achieved by using more atoms, but this comes at the cost of larger interactions between the atoms that limit the accuracy. Here, we propose a many-ion optical atomic clock based on three-dimensional Coulomb crystals of order one thousand Sn2+ ions confined in a linear RF Paul trap with the potential to overcome this limitation. Sn2+ has a unique combination of features that is not available in previously considered ions: a 1S0 ↔ 3P0 clock transition between two states with zero electronic and nuclear angular momentum (I = J = F = 0) making it immune to nonscalar perturbations, a negative differential polarizability making it possible to operate the trap in a manner such that the two dominant shifts for three-dimensional ion crystals cancel each other, and a laser-accessible transition suitable for direct laser cooling and state readout. We present calculations of the differential polarizability, other relevant atomic properties, and the motion of ions in large Coulomb crystals, in order to estimate the achievable accuracy and precision of Sn2+ Coulomb-crystal clocks.

First report of Sansabaina acicula, an organic-cemented siliceous agglutinated foraminifera from the Early Permian glaciomarine Pebbley Beach Formation, Southern Sydney Basin, southeastern Australia

A ca 6 cm-thick microfossil coquina bed dominated by plastically deformed and siliceous tubular test fragments is described for the first time from the Lower Permian (Artinskian) Pebbley Beach Formation of coastal and glacial marine origin in the southern Sydney Basin, southeastern Australia. The test fragments are mostly very large, straight, smooth, nearly cylindrical in shape, and the test walls are composed mainly of homogenous microcrystalline quartz grains. This homogeneous siliceous test-wall microstructure is interpreted to have resulted from diagenetic alteration of what might have been originally organic-cemented, flexible (not rigid) and siliceous agglutinated walls. As such, this microscopic tubular test is identified as Sansabaina acicula, an organic-cemented siliceous-agglutinated foraminifera originally described from the Kungurian Quinnanie Shale in the Carnarvon Basin of Western Australia. The discovery of Sansabaina acicula supports the previous interpretation of the studied strata being deposited in a stressed marine shelf environment. G. R. Shi [guang@uow.edu.au], Sangmin Lee* [lsam@uow.edu.au], Paul F. Carr [pcarr@uow.edu.au] and Brian G. Jones [briangj@uow.edu.au], School of Earth, Atmospheric and Life Sciences, University of Wollongong, Northfields Avenue, NSW 2522 Australia David W. Haig [david.haig@uwa.edu.au], Oceans Institute, The University of Western Australia, 35 Stirling Highway, Perth, WA 6009, Australia.

Colonial legacies and the British geological survey in cold war South Asia: 1960s–1980s

ABSTRACT This article explores change and continuity in the institutional objectives and actions of the British Geological Survey across independent South Asian countries, namely India, Pakistan, Afghanistan, Bangladesh, Nepal, Ceylon/Sri Lanka, and Burma/Myanmar. By focusing on this geographical space from the 1960s, the article tells a political tale of adjustment, in which the colonial background of the British presence in the region was overlain by the Cold War foreground of international competition. The Geological Survey had the required pedigree to prolong the British presence in important technical arenas of these emerging nation-states, albeit within the redefined parameters of development, overlapping interests, and competing benefits. The article sketches the Survey’s history of exchange and collaboration across South Asian countries (except Bhutan), as its projects adapted to national preferences and global pressures. It traces how and why its proposals prioritised certain interactions over others and tracks the ways-and-means through which it pursued geological and attendant commercial aims. The article also attempts to situate these interplays within regional and ideological frames, within which politically conscious technocrats sought capital and influence to reorient earth science objectives so that these could simultaneously accrue national products and generate neo-colonial prestige.