Preprints
Filtering by Subject: Physical Sciences and Mathematics
A 400 Myr subduction memory in the mid-ocean ridge source
Published: 2026-10-21
Subjects: Physical Sciences and Mathematics
The upper mantle sampled by mid-ocean ridges carries the volatile imprint of past subduction, but the global distribution of hydration through time and how long that imprint survives mixing and melt extraction are poorly known. We investigate the history of mantle hydration by calculating where and when hydration occurred using a plate reconstruction model of subducted water over the past 410 [...]
A retrodictive theory of the origin of the Moon: a secondary circumterrestrial disk redistributed by the retrograde flyby of a rocky planet
Published: 2026-10-21
Subjects: Astrophysics and Astronomy, Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics, Planetary Geochemistry, Planetary Geology, Planetary Sciences, The Sun and the Solar System
The Moon is a datum, and the question is retrodictive: which physical pathways lead to it without a giant impact? The pathway examined starts from a young, hot proto-Earth, soft but never liquid, flattened and inflated by a 6 h rotation, surrounded by a disk of material that has not yet formed a satellite. A second rocky planet, planet B, passes close to the Earth against its rotation, without [...]
Comment on Golkar and de Oliveira (2026): Missing eddy covariance observations undermine reported OpenET biases
Published: 2026-10-21
Subjects: Physical Sciences and Mathematics
In a recent study published in Agricultural and Forest Meteorology, Golkar and de Oliveira (2026) reported systematic overestimation of evapotranspiration (ET) by OpenET across US climate zones and substantial improvements through machine learning bias correction. Here, we identify substantial inconsistencies in their eddy covariance (EC) reference data that challenge these conclusions. We first [...]
MCR-GeoChem: Aharmonized, quality-flagged open compilation of whole-rock and mineral geochemistry for the 1.1 Ga Midcontinent Rift in Michigan, Minnesota, and Wisconsin
Published: 2026-10-21
Subjects: Earth Sciences, Education, Environmental Sciences, Geochemistry, Geology, Higher Education, Physical Sciences and Mathematics
Nickel, copper, cobalt, and the platinum-group metals are all on the final 2025 U.S. List of Critical Minerals, and the 1.1-billion-year-old Midcontinent Rift around Lake Superior hosts some of the largest domestic resources of them. The rock chemistry needed to study these systems is public but fragmented: it is spread across the U.S. Geological Survey (USGS) National Geochemical Database, [...]
Stabilizing seismic source inversion by accounting for P-wave picking uncertainty: A waveform-shift covariance approach
Published: 2026-10-21
Subjects: Earth Sciences, Physical Sciences and Mathematics
In seismic source inversion using teleseismic P waves, P-wave arrival times are picked from observed waveforms and used to adjust their timing relative to the predicted arrivals. However, uncertainty in the picked arrival times remains after this correction. Picking errors shift the entire waveform and produce temporally correlated waveform errors. If these errors are not properly accounted for, [...]
Grounding-Line Retreat and Sea-Level Feedback in Pine Island Glacier: A Century-Scale Perspective
Published: 2026-10-21
Subjects: Earth Sciences, Glaciology, Physical Sciences and Mathematics
A vital component of the global climate system is the Antarctic Ice Sheet (AIS). West AIS’s major outlet is Pine Island Glacier (PIG), which has been rapidly thinned as well as accelerated recently. As per numerous studies, PIG is undergoing irreversible retreat and acceleration. Yet, there is a lack of studies on the coupled feedback mechanism between the ice sheets and Sea Level (SL) in the [...]
A static arrest criterion classifies some fault-spanning ruptures as arrested
Published: 2026-10-21
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
A static arrest length and a fully dynamic rupture are compared, one rupture at a time, for 60 antiplane and 60 in-plane cases on one 120 km fault with linear slip weakening and one correlation length of the initial stress. The standard deviations were fixed before those ruptures were drawn. The comparison tests the rule, used to build earthquake populations, that a rupture stops where its static [...]
A regional assessment of methane emissions from natural gas production in the Transylvanian Basin, Romania
Published: 2026-10-21
Subjects: Physical Sciences and Mathematics
Romania hosts one of the largest and oldest natural gas production sectors in Europe, yet direct measurements of methane emissions from its principal gas-producing region, the Transylvanian Basin, remain limited. Here, we present the first basin-scale, measurement-based assessment of methane emissions from natural gas production facilities in the Transylvanian Basin based on 160 methane emission [...]
Fitful but sustained rupture of the 2026 Mw 7.6 Venezuela earthquake
Published: 2026-10-20
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
The devastating 2026 Venezuela earthquake was cataloged as a doublet of \Mw~7.2 and 7.5 events. Combining NISAR and ALOS-2 Synthetic Aperture Radar data, teleseismic source imaging, and ensemble Kalman inversion of multiple moment tensors and dynamic rupture simulations, we show that the 2026 Venezuela earthquake was instead a single \Mw~7.6 event with variable rupture speed and seismic moment [...]
Ecosystem community structure shapes carbon dynamics in the ocean
Published: 2026-10-19
Subjects: Climate, Marine Biology, Oceanography, Physical Sciences and Mathematics
Understanding how marine ecosystems influence air–sea CO2 flux under climate change remains a major uncertainty in ocean carbon-cycle projections. Progress is hampered by insufficient representation of ecosystem complexity in climate models and insufficient observations for developing and calibrating complex marine ecosystem models. We present a novel three-branch ensemble of the PlankTOM12 [...]
The Ill-Posed Question of Global Mean Temperature
Published: 2026-10-19
Subjects: Earth Sciences, Other Earth Sciences, Physical Sciences and Mathematics
The question "Does a global temperature exist?" was answered in the negative by C. Essex, R. McKitrick, and B. Andresen (EMA), who showed that different choices of mean yield different signs of the global temperature trend. We take EMA’s result as our point of departure and argue that its root cause is more fundamental than the particular data set or averaging formula employed: the very notion of [...]
Synergistic Use of Multitemporal SAR and Optical Data with Random Forest Approach for Rice Mapping in Bangladesh
Published: 2026-10-18
Subjects: Physical Sciences and Mathematics
Accurate in-season crop mapping is vital for national food security, yet traditional ground-based estimation methods in Bangladesh often lack precision. This study develops a robust machine-learning framework to map Boro rice in the Manikganj district by integrating Sentinel-1 Synthetic Aperture Radar (SAR) and Sentinel-2 optical imagery. To overcome the challenge of seasonal cloud cover, [...]
Long-term increases in station-derived drought near Apalachicola National Forest, Florida
Published: 2026-10-16
Subjects: Physical Sciences and Mathematics
Long local weather records can reveal changes in drought exposure, but a drought index calculated at one station must be distinguished from soil-water measurements across a forest. We updated daily temperature and precipitation observations at Tallahassee airport and recomputed the Keetch-Byram Drought Index (KBDI) with explicit quality control, rainfall interception, and missing-data rules. [...]
Paragliders as probes of the Alpine boundary layer: sink polars from 86 000 flight logs and the flow field of a valley
Published: 2026-10-15
Subjects: Atmospheric Sciences, Fluid Dynamics, Meteorology, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics, Physics
Paraglider flight logs are a dense, free and continuous record of the air over mountains: every thermal day, hundreds of pilots fly for hours along the slopes and across the valleys and record their vertical speed once per second. The obstacle is that a vario measures the air plus the sink of the glider, and the sink polars of paragliders are unknown. We obtain them from the logs themselves. [...]
Linking Hemispheric Warming Asymmetry to Anthropogenic Waste Heat
Published: 2026-10-15
Subjects: Earth Sciences, Environmental Sciences, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics, Physics
This paper proposes a potential link between the observed hemispheric warming asymmetry and the distribution of population and per capita energy consumption. Nearly 87% of the world’s population resides in the northern hemisphere, where per capita energy consumption has also been substantially higher than in the southern hemisphere. Consequently, anthropogenic waste heat discharged into the [...]