Preprints
There are 5726 Preprints listed.
Leaf trait plasticity alters competitive ability and functioning of simulated tropical trees in response to elevated carbon dioxide
Published: 2020-10-21
Subjects: Biogeochemistry, Climate, Terrestrial and Aquatic Ecology
The response of tropical ecosystems to elevated carbon dioxide (CO$_2$) remains a critical uncertainty in projections of future climate. Here we investigate how leaf trait plasticity in response to elevated CO$_2$ alters projections of tropical forest competitive dynamics and functioning. We use vegetation demographic model simulations to quantify how plasticity in leaf mass per area and leaf [...]
High-Pressure Deformation of Iron–Nickel–Silicon Alloys and Implications for Earth’s Inner Core
Published: 2020-10-21
Subjects: Earth Sciences, Geophysics and Seismology, Mineral Physics, Physical Sciences and Mathematics
Earth’s inner core exhibits strong seismic anisotropy, often attributed to the alignment of hexagonal close-packed iron (hcp-Fe) alloy crystallites with the Earth’s poles. How this alignment developed depends on material properties of the alloy and is important to our understanding of the core’s crystallization history and active geodynamical forcing. Previous studies suggested that hcp-Fe is [...]
The global melt inclusion C/Ba array: mantle variability, melting process, or degassing?
Published: 2020-10-21
Subjects: Earth Sciences, Geochemistry
The Earth’s mantle holds more carbon than its oceans, atmosphere and continents combined, yet the distribution of carbon within the mantle remains uncertain. Our best constraints on the distribution of carbon within the upper mantle are derived from the carbon-trace element systematics of ultra-depleted glasses and melt inclusions from mid-ocean ridge basalts. However, carbon-trace element [...]
Multi-layered salt-prone stratigraphy and its influence on rift-basin development; The Slyne and Erris basins, offshore NW Ireland
Published: 2020-10-21
Subjects: Tectonics and Structure
While salt-influenced rift basins have been identified across the European Atlantic margin, the Irish Atlantic margin remains the exception despite salt being proven in several boreholes. Using an extensive seismic database coupled with data from exploration wells and shallow boreholes, this study maps the distribution and composition of salt layers and investigates their role in the structural [...]
Dynamics of core-mantle separation: influence of viscosity contrast and metal/silicate partition coefficients on the chemical equilibrium
Published: 2020-10-21
Subjects: Earth Sciences, Geochemistry, Geophysics and Seismology, Physical Sciences and Mathematics
The composition of the Earth's core and mantle is set by the chemical equilibrium between metals and silicates during core/mantle segregation. The metallic core separated from the mantle by gravitational descent in the form of diapirs in a magma ocean, and therefore the dynamics of the diapir's downward movement has an influence on the chemical equilibrium. In this study, we characterize the [...]
Amphibole Control on Copper Systematics in Arcs: Insights from the Analysis of Global Datasets
Published: 2020-10-21
Subjects: Earth Sciences, Geochemistry, Geology, Volcanology
Copper, sourced from porphyry deposits formed in arc settings, is a critical resource, and is primarily sourced from magmas. However, the processes that shape the copper contents of arc magmas are up for debate. Existing models place emphasis on different petrological agents that explain large-scale trends in copper systematics. Previous studies have noted the 'Cu paradox,' where the magmas with [...]
3-D seismic interpretation with deep learning: a brief introduction
Published: 2020-10-21
Subjects: Physical Sciences and Mathematics
Understanding the internal structure of our planet is a fundamental goal of the Earth Sciences. As direct observations are restricted to surface outcrops and borehole cores, we rely on geophysical data to study the Earth’s interior. Especially, seismic reflection data showing acoustic images of the subsurface, provide us with critical insights into sedimentary, tectonic and magmatic systems. The [...]
Weak influence of paleoenvironmental conditions on the subsurface biosphere of Lake Ohrid in the last 515 ka
Published: 2020-10-21
Subjects: Life Sciences
Lacustrine sediments are widely used to investigate the impact of climatic change on biogeochemical cycling. In these sediments, subsurface microbial communities are major actors of this cycling but can also affect the sedimentary record and overprint the original paleoenvironmental signal. We therefore investigated the subsurface microbial communities of the oldest lake in Europe, Lake Ohrid [...]
Inverse analysis to reconstruct hydraulic conditions of non-steady turbidity currents: Application to an ancient turbidite of the Kiyosumi Formation of the Awa Group, Boso Peninsula, central Japan
Published: 2020-10-21
Subjects: Earth Sciences, Physical Sciences and Mathematics, Sedimentology
This study proposes a new method of inverse analysis from ancient turbidites to the non-steady turbidity currents with consideration of multiple grain-size classes. The forward model employed in this study is based on the shallow water equation, and the initial condition of flows are assumed to be the lock-exchange type condition. To obtain a solution of the inverse problem, this study employed [...]
Grain Size and Beach Face Slope on Paraglacial Beaches of New England, USA
Published: 2020-10-21
Subjects: Earth Sciences, Environmental Sciences, Oceanography and Atmospheric Sciences and Meteorology
Approximately 100 paired summer and winter transects of beach face slope and intertidal grain size were examined from 18 separate beaches in southern New England that span meso- and micro- tidal regimes. Paraglacial materials provide the principal local sediment source to beaches in this region and grain-size distribution of beaches corresponds to adjacent surficial geology. Stratified glacial [...]
A machine learning approach for prioritizing groundwater testing for per-and polyfluoroalkyl substances (PFAS)
Published: 2020-10-19
Subjects: Environmental Engineering, Environmental Health and Protection, Environmental Monitoring, Geochemistry, Hydrology, Risk Analysis, Water Resource Management
Regulatory agencies are beginning to recognize and regulate per-and polyfluoroalkyl substances (PFAS) as concerning environmental contaminants. In groundwater management, testing and mitigation strategies are desirable, but can be time and cost-intensive processes. As a result, only a fraction of all groundwater wells has been tested for PFAS levels, resulting in potentially extended drinking [...]
Uncertainties in Projected Rainfall over Brazil: The Role of Climate Model, Bias Correction and Emission Scenario
Published: 2020-09-01
Subjects: Earth Sciences, Hydrology, Physical Sciences and Mathematics
The aim of this study is to answer four main questions: How well the Eta regional climate model simulates past precipitation over Brazil? What is the impact of bias correction on the reduction of model’s biases? What is the contribution of climate models, bias correction and emission scenarios to the total uncertainty of projected precipitation? And finally, what is the projected change in [...]
A continental-scale assessment of density, size, distribution, and historical trends of Australian farm dams
Published: 2020-09-01
Subjects: Environmental Monitoring, Environmental Sciences, Natural Resources and Conservation, Natural Resources Management and Policy, Physical Sciences and Mathematics, Water Resource Management
Australia is the second driest continent on Earth and freshwater is, therefore, a critical policy concern. Farm dams are ubiquitous and drive AU$17.7 billion of agricultural value, yet there has never been a formal census of Australian dams. In this study, we present a continental-scale assessment on density, distribution, and historical trends of farm dams in each State and Territory of [...]
What does the NDVI really tell us about crops? Insight from proximal spectral field sensors
Published: 2020-09-01
Subjects: Environmental Monitoring, Environmental Sciences, Other Physical Sciences and Mathematics, Physical Sciences and Mathematics
The use of remote sensing in agriculture is expanding due to innovation in sensors and platforms. Drones, high resolution instruments on CubeSats, and robot mounted proximal phenotyping sensors all feature in this drive. Common threads include a focus on high spatial and spectral resolution coupled with the use of machine learning methods for relating observations to crop parameters. As the [...]
Structure and age relationship of joint sets on the Lilstock Benches, UK, based on mapping a full resolution UAV-based image
Published: 2020-08-31
Subjects: Environmental Sciences, Other Environmental Sciences, Physical Sciences and Mathematics
Outcrop studies of fracture networks are important to understand such networks in the subsurface, but complete maps of all fractures in large outcrops are rare due to limitations of outcrop and image resolution. We present the first full-resolution UAV-based, Gigapixel dataset and DEM of the wave-cut Lilstock Benches in the southern Bristol Channel basin, a classic outcrop of layer-bound fracture [...]