Preprints
There are 5432 Preprints listed.
An Ice-Free Arctic Ocean During the Last Interglacial: An unsupported statement
Published: 2023-09-01
Subjects: Physical Sciences and Mathematics
The Last Interglacial has attracted the attention of researchers as it was globally characterized by a climate optimum warmer than that of the preindustrial period. In particular, several attempts at reconstructing the Arctic Ocean sea-ice extent of this interval were made based on marine sedimentary archives, all failed to find clear evidence of sea-ice-free conditions. An article published [...]
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 [...]
Understanding Europe’s forest harvesting regimes
Published: 2023-08-31
Subjects: Environmental Sciences, Forest Management, Forest Sciences, Life Sciences, Natural Resources Management and Policy, Nature and Society Relations
The functioning and structure of most European forests are actively shaped by intensive human use. Harvesting of wood is one of the key processes of forest management, making it a crucial element to include in any large-scale analysis of forest ecosystems. Yet, our understanding of how forests are harvested across Europe is limited, as the true harvest regimes – a realisation of decisions made by [...]
The Whakamaru Magmatic System (Taupō Volcanic Zone, New Zealand), Part 2: Evidence from ignimbrite deposits for pre-eruptive distribution of melt-dominated magma and magma mushes
Published: 2023-08-31
Subjects: Physical Sciences and Mathematics
The complex volcanology and petrology of the Whakamaru volcanic deposits in Aotearoa New Zealand have thus far obscured the number of eruptive phases and the relative timing of these eruption(s). We investigate pumice clasts from multiple localities to elucidate the relative timing of the eruptions, with a focus on the pre-eruptive conditions of the melt-dominated magma bodies that fed the [...]
The Whakamaru Magmatic System (Taupō Volcanic Zone, New Zealand), Part 1: Evidence from tephra deposits for the eruption of multiple magma types through time
Published: 2023-08-31
Subjects: Physical Sciences and Mathematics
The Whakamaru group eruptions (349 ± 4 ka; Downs et al., 2014) are the largest known eruptions in the history of the young Taupō Volcanic Zone, Aotearoa New Zealand. The complex field relationships of the ignimbrites have thus far obscured the timing and history of their eruption(s). We present new evidence from fall deposits correlated with the Whakamaru eruptions to complement the ignimbrite [...]
Global trade and the resilience of food supply to extreme weather exposure
Published: 2023-08-31
Subjects: Agriculture, Physical and Environmental Geography, Sustainability
Climate change is increasing the risk of extreme weather events, potentially threatening crop yields and global food security. A key benefit of international trade is risk sharing, because global aggregate production is more stable than that of individual countries which may be adversely affected by extremes. However, countries vary in the degree to which they source commodities from trading [...]
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 [...]
Knowledge Graphs for Seismic Data and Metadata
Published: 2023-08-31
Subjects: Databases and Information Systems, Geophysics and Seismology
The increasing scale and diversity of seismic data, and the growing role of big data in seismology, has raised interest in methods to make data exploration more accessible. This paper presents the use of knowledge graphs (KGs) for representing seismic data and metadata to improve data exploration and analysis, focusing on usability, flexibility, and extensibility. Using constraints derived from [...]
Independent estimates of net carbon uptake in croplands: UAV-LiDAR and machine learning vs. eddy-covariance
Published: 2023-08-30
Subjects: Engineering, Life Sciences, Physical Sciences and Mathematics
Understanding sequestration of organic carbon (C) in agroecosystems is of primary importance for greenhouse gas (GHG) accounting in managed ecosystems, reducing the environmental footprint of land use, and inform crediting programs. However, a broader application of precise C accounting is currently constrained by a limited number of direct flux measurements. Aside well-studied ecosystems via [...]
Generation of LOMU type alkali basalts in East Asia by melting and melt metasomatism of the asthenospheric mantle by a Paleoproterozoic subducted slab component
Published: 2023-08-29
Subjects: Geochemistry, Geology, Volcanology
The origin of alkali basalts with distinctive time-integrated low U/Pb (low µ, LOMU) from East Asia is controversial due to the complex geochemical and tectonic signatures reported from this region. We report new data on the petrology and geochemistry of the Higashi-Matsuura and Kita-Matsuura alkali basalts from southwest Japan, which confirm the presence of a LOMU-type mantle component below the [...]
Yield strength determination based on dissipative energetic transition
Published: 2023-08-29
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 [...]
Changing Water Supplies and Solutions to the Water Crisis: An Earth Systems Analysis of the American Southwest
Published: 2023-08-27
Subjects: Water Resource Management
The pressing issue of water scarcity in the Southwestern United States has been a topic of increasing concern in recent years. To address this critical problem, this research-driven essay aims to conduct an in-depth earth systems analysis to evaluate the complexities and implications of water shortages in the region. The study centers on three main objectives: (1) identifying the underlying [...]
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 [...]