Preprints
There are 6976 Preprints listed.
Paleobathymetric trends in Northern Hemisphere calcareous nannoplankton “boom-bust” successions following the Cretaceous/Paleogene (K/Pg) mass extinction
Published: 2025-10-12
Subjects: Earth Sciences, Physical Sciences and Mathematics
The Cretaceous/Paleogene (K/Pg) bolide impact ~66 Ma caused the near-demise of calcareous nannoplankton – key primary producers and major components of the biological pump that exports organic and inorganic carbon to the deep sea. Despite their ecological significance, resolving the exact impact of nannoplankton’s mass extinction on ecosystem structure and function is complicated by marked global [...]
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, ~1400–1850 CE) was characterized by colder winters and more frequent extreme weather events in the Northern Hemisphere. While changes in ocean circulation likely contributed to global cooling, the specific mechanisms remain poorly understood. Here, we investigate how ocean circulation changed before, during, and after the LIA using marine sediment cores from the [...]
Hydrologic Implications for Seasonally Draining Lakes in the Central Oregon Cascades
Published: 2025-09-12
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 [...]
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 [...]
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 [...]
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 [...]
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 [...]
Breaking the Cycle: Short Recurrence and Overshoot of an M9-class Kamchatka Earthquake
Published: 2025-09-18
Subjects: Physical Sciences and Mathematics
M9-class megathrust earthquakes in subduction zones are generally thought to release slip deficits on the plate interface accumulated over centuries. However, the 2025 Kamchatka earthquake (Mw 8.8--8.9) ruptured nearly the same area as the 1952 Mw 9.0 event, as shown by the aftershock distribution. This unusually short recurrence interval challenges conventional seismic-cycle models used for [...]
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 [...]
Efficient Self-Attention Based Joint Optimization for Lithology and Petrophysical Parameter Estimation in the Athabasca Oil Sands
Published: 2025-09-17
Subjects: Artificial Intelligence and Robotics, Earth Sciences, Geology, Geophysics and Seismology
Accurately identifying lithology and petrophysical parameters, such as porosity and water saturation, are essential in reservoir characterization. Manual interpretation of well-log data, the conventional approach, is not only labor-intensive but also susceptible to human errors. To address these challenges of lithology identification and petrophysical parameter estimation in the Athabasca Oil [...]
FLOCCULATION, GRAVITY FLOWS, AND TOTAL ORGANIC CARBON HOTSPOTS IN LAKE: INSIGHTS FROM FLUME EXPERIMENTS
Published: 2025-09-17
Subjects: Earth Sciences, Physical Sciences and Mathematics
Lakes serve as one of the significant sinks for organic carbon. For lake deposits, it is generally accepted that water depth is a primary control on the spatial distribution of total organic carbon (TOC) accumulation because the deeper part of a lake potentially has a higher organic population to be settled. However, lake TOC distribution is often spatially variable regardless of water depth, and [...]
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 [...]
Support for Forest Conservation Imperatives: A Robust Approach for Multi-dimensional, Spatially Explicit Resilience Assessment
Published: 2025-09-18
Subjects: Environmental Indicators and Impact Assessment, Forest Management, Natural Resources and Conservation, Terrestrial and Aquatic Ecology
Forest ecosystems are ecologically, socially, and culturally valuable, and are arguably considered essential to global sustainability. Climate change and altered disturbance regimes are threatening the future of forests around the globe. Many countries are coming together to support and implement conservation and monitoring initiatives to improve future prospects for the restoration and [...]
Dilution drives deep degassing of sulfur in hydrous magmas
Published: 2026-04-02
Subjects: Physical Sciences and Mathematics
Sulfur (S) is thought to degas deep from hydrous magmas (e.g., arc basalts), in contrast to water-poor magmas where S degasses at very shallow depths (e.g., Kīlauea, mid-ocean ridge basalts). Our modelling of degassing shows this occurs for magmas that are both reduced (i.e., S is present predominantly as H2S in the vapor and dissolved sulfide in the melt) and oxidised (i.e., SO2 in the vapor and [...]
Disturbance and incomplete recovery in the Cerrado-Amazon transition: Implications for conservation of a critical tropical ecotone
Published: 2025-10-20
Subjects: Geography, Remote Sensing, Social and Behavioral Sciences
The Cerrado-Amazon Transition (CAT) is the world's largest tropical forest–savanna ecotone and a key component of Brazil's “Arc of Deforestation”. It harbours high biodiversity but remains weakly protected and increasingly exposed to agricultural expansion, deforestation, and fire. Using Landsat time series (1986–2020), we developed a disturbance–recovery framework to track how repeated and [...]