Preprints
Filtering by Subject: Earth Sciences
Questioning Dark Oxygen Production in the Deep-sea Ferromanganese Nodule Field
Published: 2024-10-04
Subjects: Earth Sciences, Geochemistry, Geology, Oceanography
Previous studies have concluded that the natural process where oxygen is consumed as decomposition of organic matter that supplied from shallow waters occurs on the deep-sea floor. Sweetman et al.1 presented the surprising observation that deep-sea ferromanganese nodules generate oxygen, which they labelled as dark oxygen production. The authors claimed that oxygen was generated through the [...]
Contrasting Land‑Uses Affect Chemical Composition of Organic Matter in Tropical Soils: A Case Study via Os Staining and FTIR
Published: 2024-10-03
Subjects: Earth Sciences, Environmental Sciences, Soil Science
Particulate organic matter (POM) is a significant component of soil organic carbon (SOC), particularly in tropical soils, where it often serves as a primary precursor for the formation of mineral-associated organic matter (MAOM). This study investigates the impact of contrasting land-use practices on composition of POM in tropical soils. Using dual-energy X-ray microtomography approach with [...]
Imaging a buried terrane with district-scale ambient noise tomography and gravity modelling: insights for scale-reduction in mineral exploration
Published: 2024-10-02
Subjects: Earth Sciences, Physical Sciences and Mathematics
Mineral exploration proceeds by a process of scale-reduction. Decisions need to be made at all stages as the physical search space becomes progressively reduced from regional through to district, camp and tenement/deposit scale. While there are many regional scale datasets available to explorers through public geoscience agencies, one of the most difficult steps to make is from the regional-scale [...]
Rapid transformation of biogenic silica to authigenic clay during reverse weathering
Published: 2024-10-01
Subjects: Earth Sciences, Geochemistry
Formation of authigenic clay minerals during early diagenesis of marine sediments, termed “reverse weathering” (RW), is an important process for regulating ocean pH and atmospheric CO2 over geologic time scales. It is also considered a“missing sink” of the modern marine Si cycle. Although the importance of RW has been increasingly recognized, the rate and mechanisms of this process remain [...]
Unveiling Year-Round Cropland Cover by Soil-Specific Spectral Unmixing of Landsat and Sentinel-2 Time Series
Published: 2024-09-27
Subjects: Agriculture, Earth Sciences, Environmental Indicators and Impact Assessment, Environmental Monitoring
Croplands are essential for food security but also impact the environment, biodiversity, and climate. Understanding, monitoring, modeling, and managing these impacts require accurate, comprehensive information on cropland vegetation cover.This study aimed to continuously monitor the state and vegetative processes of cropland, focusing on the assessment of bare soil and its cover with [...]
Improved Precision and Reference Materials for Stable Carbon Isotope Analysis in Basaltic Glasses using Secondary Ion Mass Spectrometry
Published: 2024-09-27
Subjects: Earth Sciences, Geochemistry, Volcanology
We introduce three new reference materials and a new high-precision set-up for stable carbon isotope analysis in basaltic glasses using large-geometry secondary ion mass spectrometry (SIMS) instrument. The new hydrous basaltic reference materials, characterised for carbon concentration and isotope composition by step-heating gas extraction and manometry followed by isotope ratio mass [...]
Assessing the timing of deep ocean oxygenation from uranium elemental and isotopic compositions of ophiolites
Published: 2024-09-26
Subjects: Earth Sciences, Geochemistry, Geology
The concentration of dissolved oxygen in the deep oceans has varied over Earth History, with the timing of the transition from anoxic to oxic deep oceans debated. Under modern-day, oxic, deep ocean conditions, alteration of the upper sections of mafic oceanic crust with U-rich seawater leads to U enrichment, low Th/U ratios, and heterogeneous 238U/235U ratios relative to fresh mid-ocean ridge [...]
Groundwater use to reduce natural hazard susceptibilities and inequities in the metacrisis
Published: 2024-09-26
Subjects: Earth Sciences, Environmental Sciences, Hydrology, Physical Sciences and Mathematics
Long-term thinking is broadly advocated for groundwater - the largest available freshwater resource that is essential for drinking water, irrigation and ecosystems around the world. Long-term thinking is crucial to support sustainability of this slowly renewed resource, but here we propose another crucial, novel and emerging approach for groundwater: short-term use over days and months during or [...]
Al Hawi, a 4-km-wide impact structure in northern Saudi Arabia
Published: 2024-09-23
Subjects: Astrophysics and Astronomy, Earth Sciences, Geology, Geomorphology, Other Earth Sciences, Physical Sciences and Mathematics, Physics, Planetary Geology, Planetary Sciences, The Sun and the Solar System
The northern region of Saudi Arabia hosts several impact craters and structures. This paper describes the discovery of a 4-km-wide complex impact structure located in the paleozoic sedimentary rocks of northern Saudi Arabia 210 kilometers north east of the city of Tabuk. The impact structure is composed of a central peak displaying intense folding and shock metamorphism surrounded by an inner [...]
Challenges and Opportunities of Data Driven Advance Classification for Hard Rock TBM excavations
Published: 2024-09-21
Subjects: Applied Statistics, Civil and Environmental Engineering, Civil Engineering, Earth Sciences, Geology, Geotechnical Engineering
Excavation with tunnel Boring Machines (TBMs) is a widely used method of tunneling in all ground types including soil and rock today. The paper addresses the shift from traditional subjective methods to data-driven approaches for advance classification of TBMs in hard rock tunnel excavation. By leveraging continuous TBM operational data, these methodologies offer more objective, transparent, [...]
Gravity affects magma-induced crustal deformation: comparing laccoliths on the Moon, Mars, and Earth
Published: 2024-09-21
Subjects: Earth Sciences, Planetary Sciences
Dome-shaped, uplifted surface areas and associated fractures on Mars and the Moon are inferred to result from the shallow emplacement of magma intrusions. This inference originates from analog observations of Earth’s volcanic and igneous plumbing systems. Computational models help estimate those inferred magma bodies' geometry and emplacement depth. Such models have not yet simulated the dynamic [...]
B3AM: A beamforming toolbox for three-component ambient seismic noise analysis
Published: 2024-09-20
Subjects: Earth Sciences, Environmental Engineering, Environmental Sciences, Geotechnical Engineering
We introduce the code package B3AM for beamforming of three-component ambient noise array data, which is available for MATLAB and Python. We explain the theory behind three-component beamforming and polarisation analysis in particular, provide an overview of the workflow, and discuss the output using a worked example based on the MATLAB implementation. The strength of the presented code package [...]
Dynamics of the polycrisis: temporal trends, spatial distribution and interconnections of national shocks (1970-2019)
Published: 2024-09-20
Subjects: Earth Sciences, Social and Behavioral Sciences
Polycrisis has emerged as a new property of the Anthropocene, driven by the co-interaction of multiple shocks and stressors. Although sector-specific studies offer insights into the changing frequency and intensity of these disruptions, a holistic, cross-sectoral analysis remains absent, limiting a more integrated understanding of the phenomenon. To fill this gap, we have compiled a database that [...]
Contributions to the discussion of novel detection of dark oxygen production at the abyssal seafloor
Published: 2024-09-18
Subjects: Biogeochemistry, Earth Sciences
There is an overwhelming consensus between researchers based on a vast body of peer-reviewed literature that deep sea ecosystems constitute an oxygen sink. Specific studies on abyssal seafloor regions that contain polymetallic nodules have also confirmed this result. In contrast to this well-founded and longstanding paradigm, Sweetman et al. claim to provide evidence to support a hypothesis that [...]
Guidelines for Sensitivity Analyses in Process Simulations for Solid Earth Geosciences
Published: 2024-09-18
Subjects: Applied Mathematics, Earth Sciences, Education, Partial Differential Equations, Physical Sciences and Mathematics, Science and Mathematics Education, Tectonics and Structure
Numerical simulations are widely used as tools to understand processes or to make predictions about states and their evolution in time. However, in the process of a simulation setup, a multitude of choices and simplifications have to be made - beginning from the definition of the implemented physical laws, over model discretization and spatial parameterisation, to the definition of initial and [...]