Preprints
There are 6583 Preprints listed.
Evidence for seawater Mg/Ca and dietary control on Mg incorporation in oyster shells
Published: 2025-09-17
Subjects: Geochemistry
The Mg/Ca ratio in bivalve shells has been investigated as a promising proxy for temperature reconstruction of the seawater. However, important discrepancies exist among the Mg/Ca-temperature calibrations reported for bivalves in the literature. These discrepancies currently limit the use of Mg/Ca for paleoclimate reconstructions based on bivalves and suggest that factors beyond temperature [...]
The Shapes and Sizes of Macroplastics and Other Litter in Rivers
Published: 2025-09-17
Subjects: Engineering, Life Sciences, Physical Sciences and Mathematics
Limited data exists on physical and geometric properties of river litter. To resolve this, we reveal the physical-structural relationships of river litter, using two of the most comprehensive datasets generated to date. First, we dissect the properties of river litter using a detailed dataset of over 14,052 riverbank items, for which their dimensions (longest L₁, intermediate L₂, shortest L₃) and [...]
Adverse Climate: Addressing Inclusion and Diversity Issues in the IPCC's Sixth Assessment and beyond
Published: 2025-09-17
Subjects: Social and Behavioral Sciences
In this essay, we reflect on what it means for the scientific community to collaborate effectively in global scientific assessments, drawing on our experience within the Intergovernmental Panel on Climate Change (IPCC) and with relevance beyond the IPCC to many other scientific collaborations. We amplify IPCC author voices through lived-experience narratives that reveal how systemic barriers [...]
Evaluating the potential of SMART subsea cable pressure sensors to constrain Subpolar North Atlantic circulation variability through Observing System Simulation Experiments
Published: 2025-09-17
Subjects: Oceanography and Atmospheric Sciences and Meteorology
Bolstering global ocean observing infrastructure is critical for understanding, quantifying, and predicting Earth’s climate variability and change. While new observing technologies are in development, their deployment and calibration often span years before becoming fully operational. This study evaluates one such system: SMART (Science Monitoring And Reliable Telecommunications) Subsea Cables, [...]
Coastal groundwater level trends reveal global susceptibility to seawater intrusion
Published: 2025-09-17
Subjects: Earth Sciences, Hydrology, Physical Sciences and Mathematics
Coastal groundwater is a vital freshwater source threatened by overabstraction and sea-level rise, yet global patterns of declining groundwater levels (GWLs) and susceptibility to seawater intrusion (SWI) remain poorly constrained. Here, we present the first global assessment based on in-situ observations from ~480,000 coastal monitoring locations. From 1990 to 2024, 21% of grid-cell aggregates [...]
A Hybrid Iron/Green-Rust-Urea Model for Prebiotic Chemistry: A Synthesis of Testable Pathways for Planetary Astrobiology
Published: 2025-09-17
Subjects: Earth Sciences, Geochemistry, Planetary Geochemistry, Planetary Geology, Planetary Hydrology, Planetary Sciences
We propose a quantitative, testable framework for abiogenesis that links submarine alkaline vents, which supply H₂, ΔpH, and Fe/Fe–S catalysis, to subaerial hot-spring fields that provide wet–dry concentration and UV-driven photoredox chemistry. To bridge dilution between environments, we specify mobile “holding pens” (green-rust/iron flocs, silica mats, pumice rafts, and sea-surface [...]
Exomorphic Catalysis: A Discipline Dedicated to Energetic Disequilibria and the Activation of Life-Potential in Non-Terrestrial Environments
Published: 2025-09-17
Subjects: Physical Sciences and Mathematics, Planetary Sciences
This white paper introduces exomorphic catalysis as a proposed discipline distinct from astrobiology and planetary engineering. Exomorphic catalysis investigates catalytic processes and energy disequilibria in planetary systems without assuming biology as the outcome, focusing instead on the conditions that enable or amplify self-sustaining chemical activation. The framework rests on three [...]
South Atlantic Anomaly Influence on Jet‑Stream Dynamics and Surface Climate
Published: 2025-09-14
Subjects: Earth Sciences, Physics
This work proposes a novel causal framework for recent climate change, departing fundamentally from greenhouse-gas-centric models. The central hypothesis is that the primary driver of global warming and biospheric stress is the degradation of Earth’s magnetic shielding—most clearly manifested in the progressive enlargement of the South Atlantic Anomaly (SAA), expanding ~5% per two decades within [...]
Massive High-Fidelity Focal Mechanisms Reveal Detailed Structure of Re-Activated Faults During Hydraulic Fracturing in Western Canada
Published: 2025-09-14
Subjects: Geophysics and Seismology
Microseismic focal mechanism solutions (FMSs) are essential for understanding reservoir stress changes and rock fracturing during hydraulic fracturing. While machine learning has shown strong performance in seismic data processing tasks, including phase picking and magnitude estimation, as well as identifying P-wave first-motion polarity for moderate to large earthquakes to invert FMSs, its [...]
Hydrologic Implications for Seasonally Draining Lakes in the Central Oregon Cascades
Published: 2025-09-13
Subjects: Hydrology, Physical Sciences and Mathematics
The hydrogeology of volcanic terrain exhibits characteristics that reflect both a legacy of volcanic construction and transient evolution of bedrock hydraulic conductivity on million year timescales. Here, we study a drainage basin in the Central Oregon High Cascades in which Holocene lava flows dammed streams, creating seasonal lakes that fill with the spring snowmelt, and drain completely over [...]
Economic and Environmental Comparison of Open Field and Screenhouse Vegetable Farming in Nigeria
Published: 2025-09-12
Subjects: Agriculture
This study compares screenhouse, rainfed, and irrigated vegetable farming systems in Northwest Nigeria, focusing on their economic and environmental performance. Screenhouse farming demonstrates superior yield, cost-efficiency, and sustainability, producing up to 90% more saleable output than rainfed systems and using over 95% less water per kilogram of produce. Although initial investment is [...]
Stress interactions between earthquakes and volcanoes in South Iceland: Application to Eyjafjallajökull and Katla
Published: 2025-09-12
Subjects: Physical Sciences and Mathematics
South Iceland contains some of Iceland´s best-known volcanoes (Hekla, Katla, and Eyjafjallajökull) as well as one of its two main seismic zones, namely the South Iceland Seismic Zone (SISZ). The part of the SISZ that produces continuous microseismicity is a 70-km-long and 10-20-km wide zone, located between the active volcanic zones referred to as the West Volcanic Zone and East Volcanic Zones. [...]
Lorenz Energy Cycle Climatology for the Southwestern Atlantic Cyclones
Published: 2025-09-12
Subjects: Atmospheric Sciences, Meteorology
This study presents a climatological assessment of the Lorenz Energy Cycle (LEC) applied to South Atlantic cyclones, using a Semi-Lagrangian framework. Over 6,700 cyclones were identified from ERA5 reanalysis (1979–2020), and LEC components were computed and averaged across four objectively defined life cycle phases: incipient, intensification, mature, and decay. Results reveal a coherent energy [...]
Sudden freshening and cooling of western North Atlantic slope water at the onset of the Little Ice Age based on Magnesium-to-Calcium ratio and oxygen stable isotope record.
Published: 2025-09-12
Subjects: Earth Sciences, Physical Sciences and Mathematics
The Little Ice Age (LIA), a period from ~1400 CE to 1850 CE, was characterized by colder winters and more frequent extreme weather events, particularly in the Northern Hemisphere. While the exact causes of the LIA remain a topic of ongoing research, evidence suggests that changes in ocean circulation likely contributed to the observed global cooling, although the specific mechanisms and drivers [...]
Stream acidification and metal mobilization linked to permafrost degradation
Published: 2025-09-11
Subjects: Environmental Sciences
We document rapid, climate-driven intensification of sulfide-mineral oxidation in permafrost-underlain headwater catchments of the Yukon and Mackenzie river basins—the two largest (sub)Arctic rivers in North America. Over the past decade, acidic (pH ~3) seepages have appeared in these headwaters that mobilize metals at acutely toxic concentrations and degrade water quality and chemistry in [...]