Preprints
Filtering by Subject: Physical Sciences and Mathematics
Comment on ‘Unintentional unfairness when applying new greenhouse gas emissions metrics at country level’
Published: 2019-12-13
Subjects: Environmental Sciences, Other Environmental Sciences, Physical Sciences and Mathematics
Here, we provide a comment in response to a recently published paper ‘Unintentional unfairness when applying new greenhouse gas emissions metrics at country level’ by Rogelj and Schleussner (2019). We note a number of errors in their critique of the use of GWP* to relate cumulative and short-lived climate pollutants, argue that their logic is flawed, their ethical considerations are narrow and [...]
Fluid surface coverage showing the controls of rock mineralogy on the wetting state
Published: 2019-12-13
Subjects: Chemical Engineering, Earth Sciences, Engineering, Petroleum Engineering, Physical Sciences and Mathematics
The wetting state is an important control on flow in subsurface multi fluid phase systems, e.g., carbon storage and oil production. Advances in X-ray imaging allow us to characterise the wetting state using imagery of fluid arrangement within the pores of rocks. We derived a model from equilibrium thermodynamics relating fluid coverage of rock surfaces to wettability and fluid saturation. The [...]
Characterisation and controls on mineral-sorbed organic matter from a variety of groundwater environments
Published: 2019-12-13
Subjects: Environmental Sciences, Other Environmental Sciences, Physical Sciences and Mathematics
Detailed investigations into natural groundwater organic matter (OM) as carbon sources or sinks in the natural carbon cycle are generally limited. Groundwater OM concentration and composition is altered by biodegradation and sorption to minerals. In the saturated zone of an aquifer, dissolved organic matter (DOM) may represent a significant fraction of the natural groundwater dissolved organic [...]
Policy Bridge: Air Quality Impacts from Oil and Natural Gas Development in Colorado
Published: 2019-12-13
Subjects: Environmental Education, Environmental Health and Protection, Environmental Monitoring, Environmental Sciences, Oil, Gas, and Energy, Physical Sciences and Mathematics
The rise of hydraulic fracturing techniques has fostered rapid growth of oil and natural gas extraction in areas across the United States. In the Denver-Julesburg Basin (DJB), which mostly overlaps with Weld County in the Northern Colorado Front Range (NCFR) north of the City of Denver Metropolitan Area (DMA), the well drilling has increasingly approached, and in many instances moved into urban [...]
Four-dimensional surface motions of the Slumgullion landslide and quantification of hydrometeorological forcing
Published: 2019-12-10
Subjects: Earth Sciences, Geomorphology, Geophysics and Seismology, Other Earth Sciences, Physical Sciences and Mathematics
Landslides modify the natural landscape and cause fatalities and property damage worldwide. Quantifying landslide dynamics is challenging due to the stochastic nature of the environment. With its large area of ~1 km2 and perennial motions at ~10-20 mm per day, the Slumgullion landslide in Colorado, USA, represents an ideal natural laboratory to better understand landslide behavior. Here, we use [...]
Future heat extremes likely to have been underestimated
Published: 2019-12-10
Subjects: Environmental Sciences, Other Environmental Sciences, Physical Sciences and Mathematics
In a warming world, temperature extremes are expected to show a distinguishable change over much of the globe1 and in many regions this change has already been detected in observations2,3. Although previous studies predict an increase in heat extreme events, the magnitude of the change varies greatly among different models even for the same mean warming4. This uncertainty has been linked to [...]
Open Access publishing practice in Geochemistry: current state and look to the future
Published: 2019-12-09
Subjects: Biogeochemistry, Earth Sciences, Geochemistry, Physical Sciences and Mathematics
Open Access (OA) describes the free, unrestricted access to and re-use of research articles. Recently, a new wave of interest, debate, and practice surrounding OA publishing has emerged. In this paper, we provide a simple overview of the trends in OA practice in the broad field of geochemistry. Characteristics of the approach such as whether or not an article processing charge (APC) exists, what [...]
Marked upwelling and SST drop after the arrival of cyclone Dorian to the Atlantic Canadian coast
Published: 2019-12-09
Subjects: Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
In intertidal environments, temperature fluctuations at hourly temporal scales are ecologically relevant because of the physiological stress that organisms must endure as a result. Tides constitute the main source of such changes, as low tides periodically expose intertidal habitats to aerial conditions, which can exhibit unusually high and low temperatures in summer and winter, respectively. The [...]
U-Th dating of lake sediments: Lessons from the 700 kyr sediment record of Lake Junín, Peru
Published: 2019-12-09
Subjects: Earth Sciences, Geochemistry, Geology, Other Earth Sciences, Physical Sciences and Mathematics, Sedimentology
*----- NOTE: This is a peer reviewed preprint of a paper accepted in Quaternary Science Reviews as of June 8, 2020 -----* Deep sediment cores from long-lived lake basins are fundamental records of paleoenvironmental history, but the power of these reconstructions has often been limited by poor age control. Uranium-thorium (U-Th) dating has the potential to fill a gap in current geochronological [...]
Ferruginous oceans during OAE1a and collapse of the marine sulfate pool
Published: 2019-12-06
Subjects: Earth Sciences, Geochemistry, Physical Sciences and Mathematics
Seawater sulfate is one of the largest oxidant pools at Earth’s surface today and its concentration in the oceans is generally assumed to have varied between 5 and 28 mM since the early Phanerozoic Eon. Intermittent and potentially global Oceanic Anoxic Events (OAEs) are accompanied by changes in seawater sulfate concentrations and signal perturbations in the Earth system associated with major [...]
The interplay between clay fabric and mechanical response of deep-seated landslides
Published: 2019-12-05
Subjects: Civil and Environmental Engineering, Earth Sciences, Engineering, Geology, Geotechnical Engineering, Physical Sciences and Mathematics
Deep-seated landslides are amongst the most devastating natural hazards on earth, typically involving a rigid rock mass sliding over a weak, clayey shear-band. The mechanical response of this shear-band to the loading of the overburden is therefore critical for the stability of a landslide. We hereby show that this mechanical response is strongly linked to the mineralogy and microstructure of the [...]
Notes on the creation and manipulation of solid solution models
Published: 2019-12-05
Subjects: Chemistry, Earth Sciences, Materials Chemistry, Mineral Physics, Physical Sciences and Mathematics
A large class of solid solution models are built on the premise that exchange of chemical species takes place on a finite number of unique sites, and that the thermodynamic properties of the solution are a function of the proportions of species occupying each of the sites. The site-occupancy spaces spanned by such models are geometrically equivalent to convex polytopes, n-dimensional [...]
Stronger Atlantic hurricanes: Validating Elsner et al. (2008)
Published: 2019-12-04
Subjects: Climate, Earth Sciences, Environmental Sciences, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Using satellite derived wind speed estimates from tropical cyclones over the 25-year period 1981--2006, Elsner et al. (2008) showed the strongest tropical cyclones getting stronger. They related the increasing intensity to rising ocean temperatures consistent with theory. Oceans continued to warm since that paper was published so the intensity of the strongest cyclones should have continued [...]
Estimation of surface and deep flows from sparse SSH observations of geostrophic ocean turbulence using Deep Learning
Published: 2019-12-04
Subjects: Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Satellite altimeters provide global observations of sea surface height (SSH) and present a unique dataset for advancing our theoretical understanding of upper ocean dynamics and monitoring its variability. Considering that mesoscale SSH patterns of 50--300 km in size can evolve on timescales comparable to or shorter than satellite return periods, it is challenging to accurately reconstruct the [...]
A machine learning approach to tungsten prospectivity modelling using knowledge-driven feature extraction and model confidence
Published: 2019-12-04
Subjects: Earth Sciences, Geology, Other Earth Sciences, Physical Sciences and Mathematics
Novel mineral prospectivity modelling presented here applies knowledge-driven feature extraction to a data-driven machine learning approach for tungsten mineralisation. The method emphasises the importance of appropriate model evaluation and develops a new Confidence Metric to generate spatially refined and robust exploration targets. The data-driven Random Forest™ algorithm is employed to model [...]