Preprints
Filtering by Subject: Physical Sciences and Mathematics
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, [...]
Seismic Activities in Ghana: A Systematic Review
Published: 2023-08-08
Subjects: Education, Physical Sciences and Mathematics
Seismic activities pose significant challenges to societies globally. Therefore, it is crucial to understand their occurrence, patterns, and impacts. By studying seismic activities, including earthquakes, researchers can investigate their occurrence, distribution, and characteristics which can provide effective management and risk reduction strategies. The southern part of Ghana is prone to [...]
New Ediacaran biota from the oldest Nama Group, Namibia (Tsaus Mountains), and re-definition of the Nama Assemblage
Published: 2023-08-07
Subjects: Life Sciences, Physical Sciences and Mathematics
The Nama Group, Namibia (≥550.5 to <538 million years ago, Ma) preserves one of the most diverse metazoan fossil records of the terminal Ediacaran Period. We report numerous features that may be biological in origin from the shallow marine, siliciclastic, lowermost Mara Member (older than ca. 550.5 Ma) from the Tsaus Mountains. These include forms that potentially represent body fossils, [...]
Implementation and Evaluation of the Automated Model Reduction (AMORE) Version 1.1 Isoprene Oxidation Mechanism in GEOS-Chem
Published: 2023-08-04
Subjects: Engineering, Physical Sciences and Mathematics
Detailed chemical mechanisms are computationally challenging to include in large-scale chemical transport models such as GEOS-Chem. Employing a graph theory-based automated model reduction (AMORE) algorithm, we developed a new reduced (12 species and 23 reactions) gas-phase isoprene oxidation mechanism. We performed GEOS-Chem simulations for a full year (June 2018 – May 2019) with the default [...]
Fluid-rock interactions, hydrothermal processes, and accommodation of slip in shallow parts of the San Andreas and San Gabriel Faults, southern California
Published: 2023-08-03
Subjects: Physical Sciences and Mathematics
We examine fault-related rocks from the upper parts of the active San Andreas and ancient San Gabriel Faults, southern California, to determine the nature and origin of micro-scale composition and geochemistry of fault-related rocks. These data constrain the nature and extent of fluid-rock interactions and processes by which slip is accommodated on shallow portions of these faults. The steeply [...]
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 [...]
Estimating Reservoir Sedimentation Using Deep Learning
Published: 2023-08-03
Subjects: Engineering, Physical Sciences and Mathematics
Several reservoirs across the US are filling with sediment, which jeopardizes their functionality and increases maintenance costs. The US Army Corps of Engineers (USACE) developed the Reservoir Sedimentation Information (RSI) system to assess reservoir aggradation and track dam operation suitability for water-resource management and dam safety. The RSI dataset contains historical [...]
The ostracod clumped-isotope thermometer: A novel tool to reconstruct quantitative continental climate changes.
Published: 2023-08-02
Subjects: Life Sciences, Physical Sciences and Mathematics
This study presents the ostracod clumped-isotope (∆47) thermometer, a new tool that provides quantitative temperature and hydrological reconstruction from lacustrine systems, which are among the best archives to reconstruct continental paleotemperature variations. The relationship between ∆47 and the temperature at which ostracod shell crystallized, is determined by measuring ∆47 on different [...]
Pressurizing magma within heterogeneous crust: a case study at the Socorro Magma Body, New Mexico, USA
Published: 2023-08-02
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Surface deformation plays a key role in illuminating magma transport at active volcanoes, however, unambiguous separation of deep and shallow transport remains elusive. The Socorro Magma Body (SMB) lacks an upper crustal magma transport system, allowing us to link geodetic measurements with predictions of numerical models investigating rheologic heterogeneities and magma-mush interaction in the [...]
Application of the authigenic 10Be/9Be dating to constrain the age of a long-lived lake and its regression in an isolated intermontane basin: The case of Late Miocene Lake Turiec, Western Carpathians
Published: 2023-07-31
Subjects: Earth Sciences, Geochemistry, Physical Sciences and Mathematics, Sedimentology, Stratigraphy
The depositional record of intermontane basins provides a valuable archive of the temporal evolution of orogenic belts; their common isolated nature may, however, hinder the efficient usage of standard approaches to constrain the age of a basin fill. In this paper the authigenic 10Be/9Be dating method is employed and tested to construct an age model of the existence and regression of Lake Turiec, [...]
The paleoecology of Rano Kao and the Environmental dynamics on Rapa Nui -the last 15,000 years
Published: 2023-07-30
Subjects: Physical Sciences and Mathematics
Summary Recent Research at Ava Ranga Uka includes the coring of four water sites along an 8km long collapsed lava tube to find out if significant carbon and nitrogen relationships to drought and rainfall fluctuations could be found on the terrestrial landscape. In 2005 we conducted the first paleoecological studies using oxygen isotopes were conducted in Rano Kao and the core KAO3 produced [...]
Unsupervised clustering identifies thermohaline staircases in the Canada Basin of the Arctic Ocean
Published: 2023-07-28
Subjects: Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Thermohaline staircases are a widespread stratification feature that impact the vertical transport of heat and nutrients and are consistently observed throughout the Canada Basin of the Arctic Ocean. Observations of staircases from the same time period and geographic region form clusters in temperature-salinity ($T$--$S$) space. Here, for the first time, we use an automated clustering algorithm [...]
How big is a boulder? Evaluating fixed and process-based definitions for boulders
Published: 2023-07-28
Subjects: Life Sciences, Physical Sciences and Mathematics
Boulders are globally widespread and influence landscape processes across hillslopes, coasts, rivers and extra-terrestrial settings. Boulders are described as particles, sufficiently large, that the movement of an individual grain promotes substantial geomorphic change. Moving beyond this conceptual definition, however, requires a somewhat arbitrary decision of how to define a minimum boulder [...]