Preprints
Filtering by Subject: Physical Sciences and Mathematics
Antarctic elevation drives hemispheric asymmetry in polar lapse-rate climatology and feedback
Published: 2020-06-06
Subjects: Climate, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
The lapse-rate feedback is the dominant driver of stronger warming in the Arctic than the Antarctic in simulations with increased CO2. While Antarctic surface elevation has been implicated in promoting a weaker Antarctic lapse-rate feedback, the mechanisms in which elevation impacts the lapse-rate feedback are still unclear. Here we suggest that weaker Antarctic warming under CO2 forcing stems [...]
Carbon fractions in the world’s dead wood
Published: 2020-06-05
Subjects: Biogeochemistry, Earth Sciences, Environmental Sciences, Physical Sciences and Mathematics
Alarming increases in tree mortality due to environmental change suggest that contributions of dead wood to global carbon (C) cycles are rapidly increasing 1-3, with dead wood C flux estimates already approximating total annual anthropogenic C emissions 4. Quantifying C in dead wood critically depends on accurate estimates of dead wood C fractions (CFs) to convert dead woody biomass into C. Most [...]
Architecture and controls of thick, intensely bioturbated, storm-influenced shallow-marine successions: an example from the Jurassic Neuquén Basin (Argentina)
Published: 2020-06-05
Subjects: Earth Sciences, Geology, Paleontology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy, Tectonics and Structure
Thick (>100 m-thick), highly bioturbated storm-influenced shallow-marine deposits are not frequent in the stratigraphic record, but they tend to be unusually common in aggradational to retrogradational successions. Individual storm-event beds have typically low preservation in these successions, yet depositional settings are characterized on the basis of storms processes. We present a [...]
Mechanical Response of Shallow Crust to Groundwater Storage Variations: Inferences from Deformation and Seismic Observations in the Eastern Southern Alps, Italy
Published: 2020-06-05
Subjects: Earth Sciences, Geophysics and Seismology, Hydrology, Physical Sciences and Mathematics
Changes in continental water storage generate vertical surface deformation, induce crustal stress perturbations and modulate seismicity rates. However, the degree to which regional changes in terrestrial water content influence crustal stresses and the occurrence of earthquakes remains an open problem. We show how changes in groundwater storage, computed for a ~1000 km^2 basin, focus deformation [...]
A novel rules-based shoreface translation model for predicting future coastal change: ShoreTrans
Published: 2020-06-04
Subjects: Earth Sciences, Engineering, Geomorphology, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Other Engineering, Physical Sciences and Mathematics
Predicting change to global shorelines presents an increasing challenge as sea-level rise (SLR) accelerates. Many shoreline prediction models use variations of the ‘Bruun-rule’, failing to account for relevant processes and morphologic complexity. To address this, we introduce a simple rules-based model (ShoreTrans) designed for complex, real-world profiles that predicts change across a wide [...]
The New Era of Regional Coastal Bathymetry from Space: A Showcase for West Africa using Sentinel-2 Imagery
Published: 2020-06-04
Subjects: Environmental Monitoring, Environmental Sciences, Physical Sciences and Mathematics
Large-scale coastal bathymetry is an essential data product for use in coastal research and governance. Traditional methods of measuring bathymetry, using sonar deployed from ships, take an enormous amount of time to collect and process, and thus prevent the gathering of data at high spatial and temporal resolution at a regional scale. Space-borne missions, such as the European Space Agencys [...]
Eruptive dynamics in Plinian silicic eruptions
Published: 2020-06-04
Subjects: Earth Sciences, Physical Sciences and Mathematics, Volcanology
Plinian eruptions are characterized by high magma discharge rates and pyroclastic material containing extraordinary large numbers of bubbles. Upon ascent to the surface magma decompresses and volatiles become supersaturated, causing bubbles to nucleate with a rate dependent on the degree of supersaturation. Thus, the conventional view is that the number of bubbles nucleating within the erupting [...]
Atmospheric thermal convection and strong chaotic fluctuations of global temperature on Earth and on Mars
Published: 2020-06-04
Subjects: Atmospheric Sciences, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
It is shown that the atmospheric thermal (buoyancy driven) convection plays the main role in generation of the strong chaotic fluctuations of the global temperature through the Kolmogorov-Bolgiano-Obukhov mechanism (in the frames of the distributed chaos approach). It is valid for the planets with substantial atmosphere such as the Earth and Mars. Direct numerical simulations, the Berkeley Earth [...]
Laboratory experiments and grain based discrete element numerical simulations investigating the thermo-mechanical behaviour of sandstone
Published: 2020-05-29
Subjects: Civil and Environmental Engineering, Earth Sciences, Engineering, Geotechnical Engineering, Physical Sciences and Mathematics
Thermo-mechanical loading can occur in numerous engineering geological environments, from both natural and anthropogenic sources. Different minerals and micro-defects in rock cause heterogeneity at a grain scale, affecting the mechanical and thermal properties of the material. Changes in strength and stiffness can occur from exposure to elevated temperatures, with the accumulation of localised [...]
Normal fault kinematics and the role of lateral tip retreat: An example from offshore NW Australia
Published: 2020-05-29
Subjects: Earth Sciences, Physical Sciences and Mathematics, Tectonics and Structure
Understanding how normal faults grow is key to determining the tectono-stratigraphic evolution of rifts, and the distribution and size of potentially hazardous earthquakes. According to recent studies, normal faults tend to grow in two temporally distinct stages: a lengthening stage, followed by a throw/displacement accumulation stage. However, this model is still debated and not widely supported [...]
Breakup Without Borders: How Continents Speed Up and Slow Down During Rifting
Published: 2020-05-29
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure
Relative plate motions during continental rifting result from the interplay of local with far-field forces. Here, we study the dynamics of rifting and breakup using large-scale numerical simulations of mantle convection with self-consistent evolution of plate boundaries. We show that continental separation follows a characteristic evolution with four distinctive phases: (1) An initial slow [...]
Evaluating single and multi-date Landsat classifications of land-cover in a seasonally dry tropical forest
Published: 2020-05-28
Subjects: Civil and Environmental Engineering, Earth Sciences, Engineering, Environmental Engineering, Environmental Monitoring, Environmental Sciences, Natural Resources and Conservation, Natural Resources Management and Policy, Other Civil and Environmental Engineering, Other Environmental Sciences, Physical Sciences and Mathematics
Accurate information on the land cover is crucial for efficient monitoring and development of environmental studies in the Brazilian Caatinga forest. It is the largest tropical seasonal forest in South America, presenting high biodiversity and is under intense anthropogenic disturbance. Caatingas land cover is heterogeneous, and rainfall is its primary phenological regulator, presenting mainly [...]
Where does subduction initiate and cease? A global scale perspective
Published: 2020-05-28
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure
The thermo-mechanical evolution of the Earths mantle is largely controlled by the dynamics of subduction zones, which connect the surface tectonic plates with the interior. However, little is known about the systematics of where subduction initiates and ceases within the framework of global plate motions and evolving continental configurations. Here, we investigate where new subduction zones [...]
Observation-based Simulations of Humidity and Temperature Using Quantile Regression
Published: 2020-05-28
Subjects: Atmospheric Sciences, Climate, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics, Statistics and Probability
The human impacts of changes in heat events depend on changes in the joint behavior of temperature and humidity. Little is currently known about these complex joint changes, either in observations or projections from general circulation models (GCMs). Further, GCMs do not fully reproduce the observed joint distribution, implying a need for simulation methods that combine information from GCMs [...]
A framework to quantify the human footprint in Africa using supply and demand of net primary production
Published: 2020-05-28
Subjects: Environmental Indicators and Impact Assessment, Environmental Sciences, Geography, Nature and Society Relations, Physical and Environmental Geography, Physical Sciences and Mathematics, Remote Sensing, Social and Behavioral Sciences, Spatial Science, Sustainability
The human-environment connection in the mostly rural drylands of Africa forms a complex, interlinked system that provides ecosystem services. This system is susceptible to climatic variability that impacts the supply of its products, and high population growth, which impacts the demand for these products. When plants remove carbon dioxide from the atmosphere through the process of photosynthesis, [...]