Preprints
Filtering by Subject: Physical Sciences and Mathematics
The paleoecology of Rano Kao and the Environmental dynamics on Rapa Nui -the last 15,000 years
Published: 2023-07-31
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 [...]
Python workflow for segmenting multiphase flow in porous rocks
Published: 2023-07-25
Subjects: Engineering, Physical Sciences and Mathematics
The need for accurate, consistent and fast image processing has become an important part of the investigation of multiphase flow through porous media. We describe an open-source image processing workflow written in python, using the sci-kit toolbox. We demonstrate the methodology to segment multiple fluids (gas and brine), and the rock grains for a Bentheimer sandstone. This workflow can be [...]
Coherent subsiding structures in large eddy simulations of atmospheric boundary layers
Published: 2023-07-22
Subjects: Atmospheric Sciences, Physical Sciences and Mathematics
Coherent structures are characterized in high-resolution simulations of three atmospheric boundary layers: dry convection, marine cumulus, and stratocumulus. Based on radioactive-decaying tracers emitted at different altitudes (surface, top of well-mixed layer, and cloud top), a object-oriented methodology allows individual characterization of coherent tridimensional plumes within the flow. [...]
Present and future limits to climate change adaptation
Published: 2023-07-21
Subjects: Environmental Sciences, Environmental Studies, Physical Sciences and Mathematics, Social and Behavioral Sciences
Sustainable economic development and resilience to climate change impacts require human adaptation to a warming climate. It is possible that rising costs of climate change will provide incentives to increase adaptation actions in the future. This Perspective argues, by contrast, that adaptation to the costs of global warming is likely to be ineffective. Empirical evidence suggests that current [...]
Effect of basal friction on granular column collapse
Published: 2023-07-19
Subjects: Physical Sciences and Mathematics
The collapse behaviour of granular materials is influenced by many factors, such as aspect ratio and inter-particle friction. However, the specific impact of basal to grain friction on column collapse remains poorly understood. In this study, we systematically analyse the effect of basal friction on gravity-driven granular column collapse using a validated smoothed particle hydrodynamics (SPH) [...]
An adjoint-based optimization method for jointly inverting heterogeneous material properties and fault slip from earthquake surface deformation data
Published: 2023-07-19
Subjects: Physical Sciences and Mathematics
Analysis of tectonic and earthquake-cycle associated deformation of the crust can provide valuable insights into the underlying deformation processes including fault slip. How those processes are expressed at the surface depends on the lateral and depth variations of rock properties. The effect of such variations is often tested by forward models based on a priori geological or geophysical [...]
Commercial-Scale Demonstration of a First-of-a-Kind Enhanced Geothermal System
Published: 2023-07-18
Subjects: Engineering, Physical Sciences and Mathematics
Fervo Energy has completed construction of a commercial enhanced geothermal system (EGS) project and has qualified full functionality of the system through production testing at commercially relevant operating conditions. The project site is located in a nearfield setting adjacent to an operating geothermal power station in north-central Nevada and is designed to deliver an uplift in [...]
Recent increase in a recurrent pan-Atlantic wave-pattern driving concurrent wintertime extremes
Published: 2023-07-13
Subjects: Physical Sciences and Mathematics
Wintertime extremes such as cold spells and heavy precipitation can have severe socioeconomic impacts, disrupting critical infrastructures and affecting human wellbeing. Here, we relate the occurrence of local and concurrent cold or wet wintertime extremes in North America and Europe to a recurrent, quasi-hemispheric wave-4 Rossby wave pattern. We identify this pattern as a fundamental mode of [...]
Discovery of a new 12-km impact crater candidate at As Sail Al Kabeer, Saudi Arabia
Published: 2023-07-11
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Planetary Geology, Planetary Sciences
The Arabian shield of Saudi Arabia likely has many impact craters due to the old age of its rocks, however many of them have not yet been discovered due to their resemblance to plutons. Using satellite imagery, a 12-km wide circular structure with a central peak was identified at As Sail Al Kabeer, 40 kilometers north of the city of Taif in western Saudi Arabia. Fieldwork has shown that this [...]
Satellite-derived shorelines for monitoring of sandy beaches: a benchmark study
Published: 2023-07-10
Subjects: Civil and Environmental Engineering, Earth Sciences, Engineering, Environmental Engineering, Geomorphology, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Other Earth Sciences, Physical Sciences and Mathematics
Satellite remote sensing is becoming a widely used monitoring technique in coastal sciences. Yet, no benchmarking studies exist that compare the performance of popular satellite-derived shoreline (SDS) mapping algorithms against standardized sets of inputs and validation data. Here we present a new benchmarking framework to evaluate the accuracy of shoreline change observations extracted from [...]
Transporting Heat Flux From the US and Europe to Antarctica Guided by Regional Seismic Structure
Published: 2023-07-08
Subjects: Earth Sciences, Geophysics and Seismology, Glaciology, Physical Sciences and Mathematics
Subglacial geothermal heat flux affects the dynamics of the Antarctic ice sheet but is poorly known. We estimate heat flux across West Antarctica and the interior of East Antarctica by transporting heat flux observations from the contiguous US and Europe, based on seismic structure with a lateral resolution of about \qty{100}{km}. We transport with three Machine Learning models across a hierarchy [...]
Sequence stratigraphy of the Eocene-Miocene Mrayt Group, North-Western Rif (Morocco)
Published: 2023-07-07
Subjects: Physical Sciences and Mathematics
Detailed sequence stratigraphy of the Eocene-Miocene Mrayt Group in North-Western Rif (Morocco), allow identifying the nature and the sources of the sediment supplies, the sedimentary facies and the depositional environments as well as the factors that controlled the sedimentation. This work made it also possible to identify 16 facies sequences that have never been described before. facies [...]
Improved representation of laminar and turbulent sheet flow in subglacial drainage models
Published: 2023-07-07
Subjects: Earth Sciences, Glaciology, Physical Sciences and Mathematics
Subglacial hydrology models struggle to reproduce seasonal drainage patterns that are consistent with observed subglacial water pressures and surface velocities. We modify the standard sheet-flow parameterization within a coupled sheet--channel subglacial drainage model to smoothly transition between laminar and turbulent flow based on the locally computed Reynolds number in a physically [...]