Preprints
There are 5726 Preprints listed.
On the overlooked impact of river dams on beach erosion worldwide
Published: 2021-08-04
Subjects: Engineering
The current retreat of the world's coastline has a profound impact on human activities and ecosystems. The scientific community has primarily focused on the potential impact of sea level rise. At the global scale, the contribution of river sand loads to coastal erosion has been overlooked. Here we present the first global sand pathway model from land to sea. Our model reveals that sand tends to [...]
Geochemical constraints on the structure of the Earth’s deep mantle and the origin of the LLSVPs
Published: 2021-08-03
Subjects: Physical Sciences and Mathematics
Geophysical analysis of the Earth’s lower mantle has revealed the presence of two superstructures characterized by low shear wave velocities on the core-mantle boundary. These Large Low Shear Velocity Provinces (LLSVPs) play a crucial role in the dynamics of the lower mantle and act as the source region for deep-seated mantle plumes. However, their origin, and the characteristics of the [...]
Calibration, inversion and sensitivity analysis for hydro-morphodynamic models
Published: 2021-08-03
Subjects: Applied Mathematics, Fluid Dynamics, Geomorphology, Numerical Analysis and Computation, Partial Differential Equations, Programming Languages and Compilers
The development of reliable, sophisticated hydro-morphodynamic models is essential for protecting the coastal environment against hazards such as flooding and erosion. There exists a high degree of uncertainty associated with the application of these models, in part due to incomplete knowledge of various physical, empirical and numerical closure related parameters in both the hydrodynamic and [...]
Drivers of phytoplankton responses to summer storms in a stratified lake: a modelling study
Published: 2021-08-03
Subjects: Hydrology, Other Environmental Sciences, Terrestrial and Aquatic Ecology
Extreme wind events affect lake phytoplankton amongst others by deepening the mixed layer and increasing internal nutrient loading. Both increases and decreases of phytoplankton biomass after storms have been observed, but the precise mechanisms driving these responses remain poorly understood or quantified. In this study, we coupled a one-dimensional physical model to a biogeochemical model to [...]
The role of surface processes in basin inversion and breakup unconformity
Published: 2021-08-03
Subjects: Earth Sciences, Geology, Stratigraphy, Tectonics and Structure
At divergent plate boundaries, extensional tectonics lead to subsidence, continental rifting and the formation of continental margins. Yet, within this extensional context, transient compressional structures (stress inversion) and phases of uplift (depth inversion) are frequently recorded with no corresponding change in plate motion. Changes in gravitational potential energy during the rifting [...]
Making Drone Data FAIR Through a Community-Developed Information Framework
Published: 2021-08-02
Subjects: Computer and Systems Architecture, Library and Information Science
Small Uncrewed Aircraft Systems (sUAS) are an increasingly common tool for data collection in many scientific fields. However, there are few standards or best practices guiding the collection, sharing, or publication of data collected with these tools. This makes collaboration, data quality control, and reproducibility challenging. To that end, we have used iterative rounds of data modeling and [...]
Cryoturbation leads to iron-organic carbon associations along a permafrost soil chronosequence in northern Alaska
Published: 2021-08-02
Subjects: Physical Sciences and Mathematics
In permafrost soils, substantial amounts of organic carbon (OC) are potentially protected from microbial degradation and transformation into greenhouse gases by association with reactive iron (Fe) minerals. As permafrost environments respond to climate change, increased drainage of thaw lakes in permafrost regions is predicted. Soils will subsequently develop on these drained thaw lakes, but the [...]
Competition between 3D structural inheritance and kinematics during rifting: insights from analogue models
Published: 2021-08-01
Subjects: Physical Sciences and Mathematics
The competition between the impact of inherited weaknesses and plate kinematics determines the location and style of deformation during rifting, yet the relative impacts of these “internal” and “external” factors remain poorly understood, especially in 3D. In this study we used brittle-viscous analogue models to assess how multiphase rifting, i.e., changes in plate divergence rate or direction, [...]
Salt welding during canopy advance and shortening in the Green Canyon Area, northern Gulf of Mexico
Published: 2021-07-30
Subjects: Earth Sciences, Geology, Other Earth Sciences, Tectonics and Structure
Welds form due to tectonically-induced thinning and/or dissolution of salt, with their composition and completeness thought to at least partly reflect their structural position within the salt-tectonic system. Despite their importance as seals or migration pathways for accumulations of hydrocarbons and CO2, we have relatively few published examples of drilled subsurface welds; such examples would [...]
Microbial iron(III) reduction during palsa collapse promotes greenhouse gas emissions before complete permafrost thaw
Published: 2021-07-30
Subjects: Physical Sciences and Mathematics
Reactive iron (Fe) minerals can preserve organic carbon (OC) in soils overlying intact permafrost. With permafrost thaw, reductive dissolution of iron minerals releases Fe and OC into the porewater, potentially increasing the bioavailability of OC for microbial decomposition. However, the stability of this so-called rusty carbon sink, the microbial community driving mineral dissolution, the [...]
A theory of spontaneous tropical cyclogenesis from quasi-random convection
Published: 2021-07-30
Subjects: Physical Sciences and Mathematics
How the cumulus clouds organize into a tropical cyclone remains poorly understood. The difficulty lies in that the deep convection is noisy at the kilometer scale, but follows the physical feedbacks at the mesoscale. We build a barotropic numerical model to understand the interaction of the stochastic and deterministic processes in the genesis of a tropical depression. Deep convection is [...]
Imprint of the Pacific Walker Circulation in global precipitation δ18O
Published: 2021-07-30
Subjects: Climate, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
*This article is now published, and freely available from Journal of Climate at https://doi.org/10.1175/JCLI-D-21-0190.1* Characterising variability in the global water cycle is fundamental to predicting impacts of future climate change; understanding the role of the Pacific Walker circulation (PWC) in the regional expression of global water cycle changes is critical to understanding this [...]
The world’s second-largest, recorded landslide event: lessons learnt from the landslides triggered during and after the 2018 Mw 7.5 Papua New Guinea earthquake
Published: 2021-07-30
Subjects: Geology, Geomorphology, Geophysics and Seismology, Hydrology, Other Earth Sciences
Widespread landslide events provide rare but valuable opportunities to investigate the spatial and size distributions of landslides in relation to seismic, climatic, geological and morphological factors. This study presents a unique event inventory for the co-seismic landslides induced by the February 25, 2018 Mw 7.5 Papua New Guinea earthquake as well as its post-seismic counterparts including [...]
Characterizing and Correcting Phase Biases in Short-Term, Multilooked Interferograms
Published: 2021-07-30
Subjects: Earth Sciences, Geology
Interferometric Synthetic Aperture Radar (InSAR) is widely used to measure deformation of the Earth’s surface over large areas and long time periods. A common strategy to overcome coherence loss in long-term interferograms is to use multiple multilooked shorter interferograms, which can cover the same time period but maintain coherence. However, it has recently been shown that using this strategy [...]
Combining shallow-water and analytical wake models for tidal array micro-siting
Published: 2021-07-30
Subjects: Civil and Environmental Engineering, Civil Engineering, Engineering, Hydraulic Engineering, Oceanography
For tidal-stream energy to become a competitive renewable energy source, clustering multiple turbines into arrays is paramount. As a result, array optimisation is critical for achieving maximum power performance and reducing cost of energy. However, ascertaining an optimal array layout is a highly complex problem, subject to specific site hydrodynamics and multiple inter-disciplinary [...]