Preprints
There are 6976 Preprints listed.
Slip on wavy frictional faults: is the 3rd dimension a sticking point?
Published: 2020-03-03
Subjects: Earth Sciences, Physical Sciences and Mathematics, Tectonics and Structure
The formulation for the 3D triangular displacement discontinuity boundary element method with frictional constraints is described in detail. Its accuracy in comparison to analytical solutions is then quantified. We show how this can be used to approximate stress intensity factors at the crack tips. Using this method, we go on to quantify how slip is reduced on fault surfaces with topography, [...]
Critical fluid injection volumes for uncontrolled fracture ascent
Published: 2020-03-03
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Hydro-fracturing is a routine industrial technique whose safety depends on fractures remaining confined within the target rock volume. Both observations and theoretical models show that, if the fluid volume is larger than a critical value, pockets of fluid can propagate large distances in the Earths crust in a self-sustained, uncontrolled manner. Existing models for such critical volumes are [...]
Mechanistic insights into sulfur rich oil formation, relevant to geological carbon storage routes. A study using (+) APPI FTICR-MS analysis
Published: 2020-03-03
Subjects: Earth Sciences, Geochemistry, Physical Sciences and Mathematics
Sulfur incorporation into sedimentary organic matter has a key role in carbon preservation in the geosphere. Such processes can inform strategies for human timescale carbon storage to mitigate climate change impacts and thus more detailed knowledge of sulfur incorporation into biomass species is needed. Until recently, detailed chemical characterization of sulfurized organic matter was only [...]
Power law scaling model predicts N2O emissions along the Upper Mississippi River basin
Published: 2020-03-03
Subjects: Civil and Environmental Engineering, Engineering, Environmental Engineering
Nitrous oxide, N2O, is widely recognized as one of the most important greenhouse gases, and responsible for stratospheric ozone destruction. A significant fraction of N2O emissions to the atmosphere is from rivers. Reliable catchment-scale estimates of these emissions require both high-resolution field data and suitable models able to capture the main processes controlling nitrogen transformation [...]
Preliminary hand-held thermal imaging results of sequential monitoring of a simulated deceased individual on terrestrial ground
Published: 2020-02-26
Subjects: Other Physical Sciences and Mathematics, Physical Sciences and Mathematics
Thermal imaging is commonly used by forensic search investigators to locate missing persons, but there is little research on it’s actual effectiveness to detect individuals after death. This paper aims to answer fundamental questions on how long thermal imaging is effective to detect a body lying on the surface and when is the optimal time in a day to survey. A simulated murder victim, using a [...]
Urgent Tsunami Computing
Published: 2020-02-07
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Tsunamis pose a hazard that may strike a coastal population within a short amount of time. To effectively forecast and warn for tsunamis, extremely fast simulations are needed. However, until recently such urgent tsunami simulations have been infeasible in the context of early warning and even for high-resolution rapid post-event assessment. The implementation of efficient tsunami numerical codes [...]
Mapping surface displacement using a pair of interferograms: comparative study
Published: 2020-02-26
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure, Volcanology
Interferometric analysis of Synthetic Aperture Radar satellite images (InSAR) measures only one component of ground deformation, in the satellite line-of-sight direction. In order to fully resolve the three dimensional (3D) ground displacement field, InSAR images acquired with different imaging geometries are required. Despite the increase in the number of SAR missions, an area is most frequently [...]
Integrating UAV photogrammetry with terrestrial laser scanning to characterize managed forest stands
Published: 2020-03-04
Subjects: Forest Sciences, Geography, Life Sciences, Remote Sensing, Social and Behavioral Sciences
Terrestrial laser scanning (TLS) provides detailed three-dimensional representation of the surrounding forest structure. However, due to close-range hemispherical scanning geometry the ability of TLS technique to comprehensively characterize the upper parts of forest canopy is often limited. To overcome challenges in upper canopy characterization, TLS point cloud were complemented with a point [...]
Kinetics and Products of Chromium(VI) Reduction by Iron(II/III)-Bearing Clay Minerals
Published: 2020-02-25
Subjects: Earth Sciences, Environmental Sciences, Life Sciences, Physical Sciences and Mathematics
Hexavalent chromium is a water-soluble pollutant, the mobility of which can be controlled by reduction of Cr(VI) to less soluble, environmentally benign Cr(III). Iron(II/III)-bearing clay minerals are widespread potential reductants of Cr(VI), but the kinetics and pathways of Cr(VI) reduction by such clay minerals are poorly understood. We reacted aqueous Cr(VI) with two abiotically reduced clay [...]
Magma diversity reflects recharge regime and thermal structure of the crust
Published: 2020-03-03
Subjects: Earth Sciences, Geochemistry, Geology, Physical Sciences and Mathematics, Volcanology
The chemistry of magmas erupted by volcanoes is a message from deep within the Earth’s crust, which if decrypted, can provide essential information on magmatic processes occurring at inaccessible depths. While some volcanoes are prone to erupt magmas of a wide compositional variety, others sample rather monotonous chemistries through time. Whether such differences are a consequence of physical [...]
Earthquake cycle modeling of the Cascadia subduction zone
Published: 2019-04-05
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
The Cascadia subduction zone hosts great $\mathrm{M}_\mathrm{W} > 8.5$ earthquakes, but studying these events is hindered by our short observational record. Earthquake cycle simulation provides an alternative window into the behavior of the subduction zone. Here, we present simulations over 3,800 years, 14 ruptures and hundreds of slow slip events on a high-fidelity geometric representation of [...]
Structural inheritance and border fault reactivation during active early-stage rifting along the Thyolo fault, Malawi
Published: 2020-02-26
Subjects: Earth Sciences, Geology, Geomorphology, Physical Sciences and Mathematics, Tectonics and Structure
We present new insights on the geometry, initiation and growth of the Thyolo fault, an 85 km long active border fault in the southern Malawi Rift, from high-resolution topography, field and microstructural observations. The Thyolo fault is located towards the edge of the Proterozoic Unango Terrane, and is the border fault of the Lower Shire Graben, which has experienced four phases of extension [...]
Mapping invasive Lupinus polyphyllus Lindl. in semi-natural grasslands using object-based analysis of UAV-borne images
Published: 2020-02-28
Subjects: Biodiversity, Earth Sciences, Environmental Sciences, Life Sciences, Physical Sciences and Mathematics, Plant Sciences
Knowledge on the spatio-temporal distribution of invasive plant species is vital to maintain biodiversity in grasslands which are threatened by the invasion of such plants and to evaluate the effect of control activities conducted. Manual digitising of aerial images with field verification is the standard method to create maps of the invasive Lupinus polyphyllus Lindl. (Lupine) in semi-natural [...]
Global groundwater sustainability
Published: 2020-02-29
Subjects: Earth Sciences, Hydrology, Physical Sciences and Mathematics
No abstract but introduction: Groundwater resources are the most reliable source of freshwater on the planet, so long as they are sustainably managed. While serious groundwater depletion and contamination are well documented in several regions around the world, other regions have the potential to leverage under-developed groundwater resources to fuel local human development. Here, I argue for the [...]
Subducted oceanic crust as the origin of seismically slow lower-mantle structures
Published: 2020-02-21
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Mantle tomography reveals the existence of two large low shear velocity provinces (LLSVPs) at the base of the mantle. We examine here the hypothesis that they are piles of oceanic crust that have steadily accumulated and warmed over billions of years. We use existing global geodynamic models in which dense oceanic crust forms at divergent plate boundaries and subducts at convergent ones. The [...]