Preprints
Filtering by Subject: Earth Sciences
Exploring the depositional, diagenetic and carbon-oxygen isotope record of an evolving Ordovician carbonate system, Tarim Basin, China
Published: 2022-04-20
Subjects: Earth Sciences, Physical Sciences and Mathematics
Bulk-rock based carbon-oxygen chemostratigraphy should be combined with a detailed understanding of depositional facies (mineralogy, porosity), its 2D-chronostratigraphic architecture, and diagenesis. The Ordovician of the western Tarim Basin recorded a peculiar litho-biostratigraphic succession. The Darriwilian Yijianfang Formation formed part of a carbonate ramp dominated by filter feeders. [...]
Turbulence structure and the development of secondary outer-bank flow cells at multiple discharges in a meander bend
Published: 2022-04-20
Subjects: Earth Sciences, Geomorphology
The erosion of the outer-banks of meander bends is mediated by the form roughness of the bank topography, which has been shown to affect near bank three-dimension flow structures and shear stresses. As the scales of bank roughness is known to vary vertically from bank toe to bank edge variations in flow discharge are likely to driver changes in near-bank flow velocities and turbulent structures [...]
Modeling the size of co-seismic landslides via data-driven models: the Kaikōura's example
Published: 2022-04-19
Subjects: Earth Sciences, Geomorphology
The last three decades have witnessed a substantial methodical development of data-driven models for landslide prediction. However, this improvement has been dedicated almost exclusively to models designed to recognize locations where landslides may likely occur in the future. This notion is referred to as landslide susceptibility. However, the susceptibility is just one, albeit fundamental, [...]
Production of diverse brGDGTs by Acidobacterium Solibacter usitatus in response to temperature, pH, and O2 provides a culturing perspective on brGDGT paleoproxies and biosynthesis
Published: 2022-04-15
Subjects: Earth Sciences
Expansion and intensification of the North American Monsoon during the Pliocene
Published: 2022-04-14
Subjects: Climate, Earth Sciences, Geochemistry, Oceanography and Atmospheric Sciences and Meteorology
Southwestern North America, like many subtropical regions, is predicted to become drier in response to anthropogenic warming. However, during the Pliocene, when carbon dioxide was above pre-industrial levels, multiple lines of evidence suggest that southwestern North America was much wetter. While existing explanations for a wet Pliocene invoke increases in winter rain, recent modeling studies [...]
Interactive Hydrological Modelling and Simulation on Client-Side Web Systems: An Educational Case Study
Published: 2022-04-13
Subjects: Civil and Environmental Engineering, Earth Sciences, Education, Engineering, Engineering Education, Environmental Education, Environmental Engineering, Hydraulic Engineering, Hydrology, Numerical Analysis and Scientific Computing, Other Civil and Environmental Engineering, Physical Sciences and Mathematics, Science and Mathematics Education, Water Resource Management
Computational hydrological models and simulations are fundamental pieces of the workflow of contemporary hydroscience research, education, and professional engineering activities. In support of hydrological modelling efforts, web-enabled tools for data processing, storage, computation, and visualization have proliferated. Most of these efforts rely on server resources for computation and data [...]
Plate Tectonics, Mixed Heating Convection and the Divergence of Mantle and Plume Temperatures
Published: 2022-04-13
Subjects: Earth Sciences, Physical Sciences and Mathematics
Petrological data indicate that upper mantle and mantle plume temperatures diverged 2.5 billion years ago. This has been interpreted as plate tectonics initiating at 2.5 Ga with Earth operating as a single plate planet before then. We take an Occam’s razor view that the continuous operation of plate tectonics can explain the divergence. We validate this hypothesis by comparing petrological data [...]
Observations and models of dynamic topography: Current status and future directions.
Published: 2022-04-10
Subjects: Earth Sciences
The slow creeping motion of Earth’s mantle drives transient changes in surface topography across a variety of spatial and temporal scales. Recent decades have seen substantial progress in understanding this so-called `dynamic topography’, with a growing number of studies highlighting its fundamental role in shaping the surface of our planet. In this review, we outline the current frontiers of [...]
Rivers of the Variscan Foreland: fluvial morphodynamics in the Pennant Formation of South Wales, UK
Published: 2022-04-07
Subjects: Earth Sciences, Sedimentology
The morphodynamics of ancient rivers can be reconstructed from fluvial stratigraphy using quantitative techniques to provide insights into the driving forces behind the sedimentary systems. This work explores how these drivers can be evaluated from Paleozoic stratigraphy. Field measurements are taken in fluvial sediments from the Westphalian (Bolsovian and Asturian; 315.2–308 Ma) Pennant [...]
Comment on “If not brittle: Ductile, Plastic, or Viscous? By Kelin Wang”
Published: 2022-04-07
Subjects: Earth Sciences, Materials Science and Engineering
In continuum mechanics, viscous materials are those that lack rigidity and elastic response under shear stress. We argue that using the term viscous to refer to the aseismic lithosphere is thus a misnomer, as it denies the propagation of S-waves through the lithosphere in total contradiction to decades of seismic surveys. Likewise, viscous materials lack yield stress, which is another feature [...]
Economic Analysis of CCUS: Accelerated Development for CO2 EOR and Storage in Residual Oil Zones Under the Context of 45Q Tax Credit
Published: 2022-04-07
Subjects: Earth Sciences, Petroleum Engineering
Residual oil zones (ROZ) undergoing CO2-EOR may benefit from specific strategies to maximize their value. We evaluated several strategies for producing from a Permian Basin, West Texas, USA field’s ROZ. This ROZ lies below the main pay zone (MPZ) of the field. Such brownfield ROZs occur in the Permian Basin and elsewhere. Since brownfield ROZs are hydraulically connected to the MPZs, development [...]
Strategies for and Barriers to Collaboratively Developing Anti-racist Policies and Resources as Described by Geoscientists of Color Participating in the Unlearning Racism in Geoscience (URGE) Program
Published: 2022-04-07
Subjects: Earth Sciences, Education
The Unlearning Racism in Geosciences (URGE) program guides groups of geoscientists as they draft, implement, and assess anti-racist policies and resources for their workplace. Some participating Geoscientists of Color (GoC) shared concerns about microaggression, tokenism, and power struggles within their groups. These reports led us to collect and analyze data that describe the experiences of GoC [...]
Feedbacks between internal and external Earth dynamics
Published: 2022-04-06
Subjects: Earth Sciences
Countless continuously interacting processes determine the functioning and evolution of the Earth. Even geodynamic and climate changes, which have been classically studied independently because they pertain to different Earth ‘spheres’, are linked by mutual cause-effect relationships that recent research has just started to recognize and quantify. Modeling, be it analogue or numerical, is a trump [...]
The deep Arctic Ocean and Fram Strait in CMIP6 models
Published: 2022-04-04
Subjects: Earth Sciences, Oceanography and Atmospheric Sciences and Meteorology
Arctic sea ice loss has become a symbol of ongoing climate change, yet climate models still struggle to reproduce it accurately, let alone predict it. A reason for this is the increasingly clear role of the ocean, especially that of the "Atlantic layer", on sea ice processes. We here quantify biases in that Atlantic layer and the Arctic Ocean deeper layers in 14 representative models that [...]
The effect of a weak asthenospheric layer on surface kinematics, subduction dynamics and slab morphology in the lower mantle
Published: 2022-04-02
Subjects: Earth Sciences, Physical Sciences and Mathematics
On Earth, the velocity at which subducting plates are consumed at their trenches (termed `subduction rate' herein) is typically 3 times higher than trench migration velocities. The subduction rate is also 5 times higher than estimated lower mantle slab sinking rates. Using simple kinematic analyses, we show that if this present-day ``kinematic state'' operated into the past, the subducting [...]