Preprints
Filtering by Subject: Earth Sciences
Machine Learning Photogrammetric Analysis of Images Provides a Scalable Approach to Study Riverbed Grain Size Distributions
Published: 2023-09-01
Subjects: Earth Sciences, Geomorphology, Hydrology
The distribution of sediment grain size in streams and rivers is often quantified by the median grain size (d50), a key metric for understanding and predicting hydrologic and biogeochemical function of streams and rivers. Manual methods to measure d50 are time-consuming and ignore larger grains, while model-based methods to estimate d50 often over-generalize basin characteristics, and therefore [...]
Towards an astrochronological framework for the lower Paleoproterozoic Kuruman and Brockman Iron Formations
Published: 2023-09-01
Subjects: Earth Sciences, Physical Sciences and Mathematics, Stratigraphy
Recent evidence for astronomical-induced cycles in banded iron formations (BIFs) hints at the intriguing possibility of developing astrochronological, i.e. precise time-stratigraphic, frameworks for the earliest Proterozoic as also reconstructed for parts of the Mesozoic and Paleozoic. The ca 2.47-Ga Kuruman Iron Formation (Griqualand West Basin, South Africa) and Dales Gorge Member of the [...]
SeisMIC - an Open Source Python Toolset to Compute Velocity Changes from Ambient Seismic Noise
Published: 2023-09-01
Subjects: Computer Sciences, Earth Sciences, Environmental Monitoring, Environmental Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
We present SeisMIC, a fast, versatile, and adaptable open-source software to estimate seismic velocity changes from ambient seismic noise. SeisMIC includes a broad set of tools and functions to facilitate end-to-end processing of ambient noise data, from data retrieval and raw data analysis via spectrogram computation, over waveform coherence analysis, to post-processing of the final velocity [...]
Comprehensive review of geomechanics of underground hydrogen storage in depleted reservoirs and salt caverns
Published: 2023-08-31
Subjects: Applied Mechanics, Earth Sciences
Hydrogen is a promising energy carrier for a low-carbon future energy system, as it can be stored on a megaton scale (equivalent to TWh of energy) in subsurface reservoirs. However, safe and efficient underground hydrogen storage requires a thorough understanding of the geomechanics of the host rock under fluid pressure fluctuations. In this context, we summarize the current state of knowledge [...]
Yield strength determination based on dissipative energetic transition
Published: 2023-08-30
Subjects: Applied Mechanics, Civil Engineering, Earth Sciences
Mechanical yield strength is one of the most crucial mechanical properties to consider to remain operating in safe elastic regimes. Despite its importance, it remains ambiguous to measure as different disciplines acknowledge different definitions. Most common examples include the deviation from linear elasticity or the peak stress. This difference has significant consequences for the modelling of [...]
What can radar-based measures of subglacial hydrology tell us about basal shear stress? A case study at Thwaites Glacier, West Antarctica
Published: 2023-08-29
Subjects: Earth Sciences, Glaciology, Physical Sciences and Mathematics
Ice sheet models use observations to infer basal shear stress, but the variety of methods and datasets available has resulted in a wide range of estimates. Radar-based metrics such as reflectivity and specularity content have been used to characterize subglacial hydrologic conditions that are linked to spatial variations in basal shear stress. We explore whether radar metrics can be used to [...]
Lithium isotope constraints on the plumeworld hypothesis for the Marinoan Snowball Earth
Published: 2023-08-26
Subjects: Earth Sciences, Geochemistry, Physical Sciences and Mathematics
The Snowball Earth hypothesis predicts that continental chemical weathering was curtailed substantially during but rebounded strongly after the Marinoan ice age some 635 million years ago. Defrosting the planet would result in a plume of fresh glacial meltwater with a different chemical composition than underlying hypersaline seawater, generating an onshore-offshore geochemical gradient. Here we [...]
Why is it critical to revisit significance and consequences of salt precipitation during CO2 injection?
Published: 2023-08-24
Subjects: Earth Sciences, Environmental Sciences, Geochemistry
Among the candidates for CO2 sequestration, deep saline aquifers are considered the best option because of their storage capacity and proximity to emission sources. Injection of large volumes (million tons scale) of supercritical CO2 into the geological formations causes evaporation of formation water near wellbores and precipitation of salt crystals inside the porous medium. CO2-induced salt [...]
Determining the Pressure – Temperature – Composition (P-T-X) conditions of magma storage
Published: 2023-08-24
Subjects: Earth Sciences, Physical Sciences and Mathematics, Volcanology
Determining the pressures and temperatures at which melts are stored in the crust and upper mantle, and the major element composition, redox state and volatile contents of these melts, is vital to constrain the structure and dynamics of magmatic plumbing systems. In turn, constraining these parameters helps understand the geochemical and structural evolution of the Earth’s lithosphere, and [...]
Impact of rift history on the structural style of intracontinental rift-inversion orogens
Published: 2023-08-23
Subjects: Earth Sciences, Tectonics and Structure
Although many collisional orogens form after subduction of oceanic lithosphere between two continents, some orogens result from strain localization within a continent via inversion of structures inherited from continental rifting. Intracontinental rift-inversion orogens exhibit a range of structural styles, but the underlying causes of such variability have not been extensively explored. Here, we [...]
GossenAIA2015-RapaNuislides
Published: 2023-08-21
Subjects: Earth Sciences, Environmental Sciences, Physical Sciences and Mathematics
A slide presentation from AIA 116th Annual Conference, New Orleans, Jan 8-11 2015. The 149 slides in pdf format are from the original Keynote presentation: Deforestation, Drought and Humans: The Collapse Theory is Dead-New Evidence of Sustainability and Survival.
Understanding Drought Awareness from Web Data
Published: 2023-08-17
Subjects: Computer Sciences, Earth Sciences, Mathematics, Oceanography and Atmospheric Sciences and Meteorology, Statistics and Probability
We used computer vision (U-Net) model to leverage Standardized Precipitation Evapotranspiration Index (SPEI), Google Trends Search Interest (SI), and Twitter data to understand patterns with which people in Continental United States (CONUS) indicate awareness of and interest in droughts. We found significant statistical relationships between the occurrence of meteorological droughts (MD), as [...]
Beyond microbial carbon use efficiency
Published: 2023-08-16
Subjects: Biogeochemistry, Earth Sciences, Environmental Microbiology and Microbial Ecology Life Sciences, Life Sciences, Physical Sciences and Mathematics, Soil Science
Microbial carbon use efficiency (CUE) is defined as the proportion of microbial biomass growth C versus substrate C uptake, and thus provides a useful measure of microbially driven accumulation and loss of soil organic carbon (SOC) 1. In a recent study published in Nature 2, the authors use a data-driven machine learning approach to conclude that CUE promotes global SOC storage based on a [...]
imc-precip-iso: Open monthly stable isotope data of precipitation over the Indonesian Maritime Continent
Published: 2023-08-12
Subjects: Climate, Earth Sciences, Environmental Sciences, Fresh Water Studies, Hydrology, Physical Sciences and Mathematics, Water Resource Management
Stable isotopes, $\delta^2$H, $\delta^{18}$O, and d-excess, are valuable tools as natural tracers of diffusion processes and phase changes in the global hydroclimatological cycle. The Indonesian Maritime Continent (IMC) is an archipelago area surrounded by very warm waters which induce convective activities as the primary heat source driving global atmospheric circulation. Given the central role [...]
CEDAR-GPP: spatiotemporally upscaled estimates of gross primary productivity incorporating CO2 fertilization
Published: 2023-08-09
Subjects: Earth Sciences, Physical Sciences and Mathematics
Gross primary productivity (GPP) is the largest carbon flux in the Earth system, playing a crucial role in removing atmospheric carbon dioxide and providing the sugars and starches needed for ecosystem metabolism. Despite the importance of GPP, however, existing estimates present significant uncertainties and discrepancies. A key issue is the underrepresentation of the CO2 fertilization effect, a [...]