Preprints
There are 6390 Preprints listed.
The chitin raft hypothesis for the colonization of the open ocean by cyanobacteria
Published: 2025-01-08
Subjects: Life Sciences
It is often assumed planktonic cyanobacteria existed in Precambrian oceans, but that their productivity was constrained. However, available evidence suggests picocyanobacteria only colonized the open ocean near the Neoproterozoic-Phanerozoic boundary, close to the start of a period of sustained atmospheric oxygenation. If earlier open oceans were devoid of planktonic cyanobacteria, we lack [...]
Hydrogenotrophic metabolisms in the subsurface and their implications for underground hydrogen storage and natural hydrogen prospecting
Published: 2025-01-08
Subjects: Biogeochemistry, Earth Sciences, Environmental Microbiology and Microbial Ecology Life Sciences, Oil, Gas, and Energy
Hydrogen is a fundamental electron donor in diverse microbial metabolisms and it is considered the energetic currency exchanged within microbial communities in anaerobic environments. Hydrogen is also the major actor in the transition to alternative low-carbon energy sources, primarily due to its dual role as energy source and energy carrier and to the production of water as a byproduct of its [...]
Diverging trends in nitrate and phosphorus loads and yields across Illinois watersheds, 1997–2022
Published: 2025-01-08
Subjects: Environmental Health and Protection, Environmental Monitoring, Natural Resources and Conservation, Water Resource Management
Illinois is a major contributor of nutrients to the northern Gulf of Mexico. As such, the State of Illinois initiated efforts to curb nutrient runoff over the last several decades. To evaluate progress towards these reductions, water-quality data were used to estimate incremental loads and yields of nitrate plus nitrite (NO3) and total phosphorus (TP) from 1997–2022 for 49 Illinois watersheds, [...]
Submarine fans in the Kribi-Campo sub-basin, offshore Cameroon: Geomorphology and stratigraphic evolution during the Late Cretaceous
Published: 2025-01-08
Subjects: Education
GODEEEP-hydro: Historical and projected power system ready hydropower data for the United States
Published: 2025-01-08
Subjects: Hydrology, Power and Energy
Hydropower is a critical electricity resource in the United States which, in addition to low-cost electricity generation, provides valuable ancillary grid services, and supports the integration of nondispatchable weather-dependent resources (e.g., wind and solar). Despite its value to the grid, there are very few comprehensive datasets available from which to study both historical and future [...]
Seasonal compound renewable energy droughts in the Unites States
Published: 2025-01-07
Subjects: Hydrology, Oil, Gas, and Energy, Power and Energy
Variable renewable energy (VRE) droughts are periods of low renewable electricity production due to natural variability in the weather and climate. These compound renewable energy droughts occur when two or more (typically wind and solar) generation sources are in low availability conditions at the same time. Compound wind and solar droughts are most commonly studied at the hourly and daily [...]
Rethinking the Anatomy and Architecture of the Neoproterozoic Gneiss Domes in the Nubian Shield: Are they Extensional Metamorphic Core Complexes?
Published: 2025-01-06
Subjects: Physical Sciences and Mathematics
The Nubian Shield features amphibolite-grade, gneiss-cored domes surrounded by greenschist-grade island arc and ophiolitic assemblages. These structures exhibit anomalous intense ductile deformation and higher metamorphism than the surrounding rock units; yet, their nature, geometry, and origin remain controversial. The present study integrates field data, remote sensing, and detailed structural [...]
Grain size evolution in mantle convection models promotes continuous rather than episodic tectonics
Published: 2025-01-06
Subjects: Earth Sciences, Physical Sciences and Mathematics, Planetary Sciences
A long-persistent caveat of geodynamic models with Earth-like tectonic behavior is the need of an ‘ad hoc’ yield stress lower than any laboratory-inferred rock strength. Grain size reduction due to dynamic recrystallization provides local weak zones in the lithosphere thereby promoting lithospheric breakdown and continuous mobile-lid tectonics. Grain growth should instead (re-)strengthen the [...]
Rotational Flow Dominates Abrupt Seasonal Change in Zonally Asymmetric Tropical Meridional Circulation
Published: 2025-01-06
Subjects: Physical Sciences and Mathematics
By defining a pseudo meridional overturning streamfunction (Ψpseudo) at any zonal sector and defining a new vector-type, dual-component index (Abrupt Seasonal Change Index, ASCI), we diagnose zonally asymmetric abrupt seasonal change (ASC) of tropical meridional circulation. Ψpseudo converges to traditional, meridional overturning streamfunction (Ψm) after being averaged over a zonal circle [...]
2027: Waking the AKU-- A Cosmic Hyperobject View of the Ancient Giant Palm Forest on Rapa Nui
Published: 2025-01-06
Subjects: Astrophysics and Astronomy, Earth Sciences, Ecology and Evolutionary Biology, Environmental Sciences, Forest Sciences, Other Astrophysics and Astronomy, Other Environmental Sciences, Other Plant Sciences, Physical Sciences and Mathematics, Planetary Sciences, Plant Sciences, The Sun and the Solar System
Can a repeating climate event be termed as a cosmic hyperobject? Even if it is dynamically changing within hundreds of thousands of years? At the center of this paper is the science: observable data, 15,000 years of climate change on Rapa Nui. Reaching into the past however we begin with a much broader mathematical view from the eyes of Milankovitch theories of the cosmos that stretches a million [...]
Water Storage in Hydrous Minerals in the Shallow Martian Mantle
Published: 2025-01-06
Subjects: Earth Sciences, Geochemistry, Geology, Planetary Geochemistry
In this paper we investigate the possibility of storing water in the shallow martian mantle under water-saturated fluid absent conditions for different bulk silicate mars (BSM) compositions. We performed phase equilibria experiments on two BSM compositions with comparable Mg number for pressure between 2 and 4 GPa, temperatures between 950 to 1150°C, and for a water content of 0.3 % wt. The [...]
Evaluation of the InSightSeers and DART Boarders mission observer programmes
Published: 2025-01-04
Subjects: Education, Higher Education, Physical Sciences and Mathematics, Planetary Sciences
Encouraging diversity in planetary science requires making a particular effort to bring a broader range of people onto the mission teams that are the backbone of the field. Observer programmes, which offer early-career researchers the chance to embed within a mission team during a science meeting, are one way of doing this. Here we present a quantitative analysis of the effectiveness of two [...]
Techno-economic analysis of natural and stimulated geological hydrogen
Published: 2025-01-03
Subjects: Earth Sciences
Geological hydrogen has emerged as a low-cost and low-carbon primary source of energy. This study provides a comprehensive techno-economic analysis of natural geological hydrogen (GH) and stimulated geological hydrogen (SGH) production, reaffirming its potential as a low-cost energy source. For the United States, we estimate production costs at $0.54/kg for GH and $0.92/kg for SGH, demonstrating [...]
Is the Suez Rift in its post-rift phase?
Published: 2025-01-03
Subjects: Earth Sciences, Geology, Geomorphology, Physical Sciences and Mathematics, Tectonics and Structure
Failed rifts are widely assumed to enter post-rift quiescence after termination of intracontinental rifting, but a comprehensive understanding of their regional morphotectonics is lacking. Our quantitative, rift-scale geomorphic analyses in the Suez Rift, an archetypal failed rift in Egypt, reveals widespread rifting after presumed rift “failure”. Stacked topographic swaths document normal fault [...]
A Proposal to Create a Single Global Cap-and-Trade Scheme to Ensure a Ceiling on Gross CO2 Emissions below a Pre-set Allowable Carbon Budget
Published: 2025-01-03
Subjects: Environmental Studies
It is time for faithful and trustworthy world leaders to lead in establishing a “Global Cap-and-Trade regulatory framework” to change our course promptly. This framework aims to establish an institutional mechanism that ensures steadily decreasing global emission limits. The Scheme regulates upstream entities that import or produce fossil fuels, with the initiation of countries that share the [...]