Preprints
Filtering by Subject: Earth Sciences
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 [...]
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 [...]
Why is it critical to revisit significance and consequences of salt precipitation during CO2 injection?
Published: 2023-08-24
Subjects: Earth Sciences, Environmental Sciences, Geochemistry
Among the candidates for CO2 sequestration, deep saline aquifers are considered the best option because of their storage capacity and proximity to emission sources. Injection of large volumes (million tons scale) of supercritical CO2 into the geological formations causes evaporation of formation water near wellbores and precipitation of salt crystals inside the porous medium. CO2-induced salt [...]
Determining the Pressure – Temperature – Composition (P-T-X) conditions of magma storage
Published: 2023-08-23
Subjects: Earth Sciences, Physical Sciences and Mathematics, Volcanology
Determining the pressures and temperatures at which melts are stored in the crust and upper mantle, and the major element composition, redox state and volatile contents of these melts, is vital to constrain the structure and dynamics of magmatic plumbing systems. In turn, constraining these parameters helps understand the geochemical and structural evolution of the Earth’s lithosphere, and [...]
Impact of rift history on the structural style of intracontinental rift-inversion orogens
Published: 2023-08-23
Subjects: Earth Sciences, Tectonics and Structure
Although many collisional orogens form after subduction of oceanic lithosphere between two continents, some orogens result from strain localization within a continent via inversion of structures inherited from continental rifting. Intracontinental rift-inversion orogens exhibit a range of structural styles, but the underlying causes of such variability have not been extensively explored. Here, we [...]
GossenAIA2015-RapaNuislides
Published: 2023-08-21
Subjects: Earth Sciences, Environmental Sciences, Physical Sciences and Mathematics
A slide presentation from AIA 116th Annual Conference, New Orleans, Jan 8-11 2015. The 149 slides in pdf format are from the original Keynote presentation: Deforestation, Drought and Humans: The Collapse Theory is Dead-New Evidence of Sustainability and Survival.
Understanding Drought Awareness from Web Data
Published: 2023-08-17
Subjects: Computer Sciences, Earth Sciences, Mathematics, Oceanography and Atmospheric Sciences and Meteorology, Statistics and Probability
We used computer vision (U-Net) model to leverage Standardized Precipitation Evapotranspiration Index (SPEI), Google Trends Search Interest (SI), and Twitter data to understand patterns with which people in Continental United States (CONUS) indicate awareness of and interest in droughts. We found significant statistical relationships between the occurrence of meteorological droughts (MD), as [...]
Beyond microbial carbon use efficiency
Published: 2023-08-16
Subjects: Biogeochemistry, Earth Sciences, Environmental Microbiology and Microbial Ecology Life Sciences, Life Sciences, Physical Sciences and Mathematics, Soil Science
Microbial carbon use efficiency (CUE) is defined as the proportion of microbial biomass growth C versus substrate C uptake, and thus provides a useful measure of microbially driven accumulation and loss of soil organic carbon (SOC) 1. In a recent study published in Nature 2, the authors use a data-driven machine learning approach to conclude that CUE promotes global SOC storage based on a [...]
imc-precip-iso: Open monthly stable isotope data of precipitation over the Indonesian Maritime Continent
Published: 2023-08-12
Subjects: Climate, Earth Sciences, Environmental Sciences, Fresh Water Studies, Hydrology, Physical Sciences and Mathematics, Water Resource Management
Stable isotopes, $\delta^2$H, $\delta^{18}$O, and d-excess, are valuable tools as natural tracers of diffusion processes and phase changes in the global hydroclimatological cycle. The Indonesian Maritime Continent (IMC) is an archipelago area surrounded by very warm waters which induce convective activities as the primary heat source driving global atmospheric circulation. Given the central role [...]
CEDAR-GPP: spatiotemporally upscaled estimates of gross primary productivity incorporating CO2 fertilization
Published: 2023-08-09
Subjects: Earth Sciences, Physical Sciences and Mathematics
Gross primary productivity (GPP) is the largest carbon flux in the Earth system, playing a crucial role in removing atmospheric carbon dioxide and providing the sugars and starches needed for ecosystem metabolism. Despite the importance of GPP, however, existing estimates present significant uncertainties and discrepancies. A key issue is the underrepresentation of the CO2 fertilization effect, a [...]
Eocene (50-55 Ma) greenhouse climate recorded in nonmarine rocks of San Diego, CA, USA
Published: 2023-08-08
Subjects: Chemistry, Climate, Earth Sciences, Geochemistry, Geology, Physical Sciences and Mathematics, Soil Science, Stratigraphy
Nonmarine rocks in sea cliffs of southern California store a detailed record of weathering under tropical conditions millions of years ago, where today the climate is much drier and cooler. This work examines early Eocene (~50-55 million-year-old) deeply weathered paleosols (ancient, buried soils) exposed in marine terraces of northern San Diego County, California, and uses their geochemistry and [...]
Exclusive Seismoacoustic Detection and Characterization of an Unseen and Unheard Fireball Over the North Atlantic
Published: 2023-08-08
Subjects: Astrophysics and Astronomy, Earth Sciences, Physical Sciences and Mathematics
Small meteoroids that enter Earth's atmosphere often go unnoticed because their detection and characterization rely on human observations, introducing observational biases in space and time. Acoustic shockwaves from meteoroid ablation convert to infrasound and seismic energy, enabling fireball detection using seismoacoustic methods. We analyzed an unreported fireball in 2022 near the Azores, [...]
MEIC-global-CO2: a new global CO2 emission inventory with highly-resolved source category and sub-country information
Published: 2023-08-03
Subjects: Earth Sciences, Environmental Sciences, Physical Sciences and Mathematics
CO2 emission inventory provides fundamental data for climate research and emission mitigation. Currently, most global CO2 emission inventories were developed with energy statistics from International Energy Agency (IEA) and were available at country level with limited source categories. Here, as the first step toward a high-resolution and dynamic updated global CO2 emission database, we developed [...]
Tephra dispersal and composition reveal the explosive onset of a large basaltic fissure eruption: Timanfaya, Lanzarote, 1730–1736 CE
Published: 2023-08-03
Subjects: Earth Sciences, Geochemistry, Geology, Physical Sciences and Mathematics, Stratigraphy, Volcanology
Basaltic fissure eruptions are chiefly characterized by sizable emissions of lava flows and volcanic gases, posing significant hazards. However, such eruptions may be punctuated by explosive episodes, which are comparatively poorly understood but may have important volcanic hazard and environmental implications. The 1730–1736 CE Timanfaya eruption on Lanzarote, Canary Islands, is a large basaltic [...]
Timing and Evolution of Structures within the Southeastern Greater Caucasus and Kura Fold-Thrust Belt from Multiproxy Sediment Provenance Records
Published: 2023-08-03
Subjects: Earth Sciences, Stratigraphy, Tectonics and Structure
The Greater Caucasus (GC) mountains are the locus of post-Pliocene shortening within the north central Arabia-Eurasia collision. Although recent low-temperature thermochronology constrains the timing of orogen formation, the evolution of major structures remains enigmatic - particularly regarding the internal kinematics within this young orogen and the associated Kura Fold-Thrust Belt (KFTB), [...]