Preprints
Filtering by Subject: Earth Sciences
Precursory slow slip and foreshocks on rough faults
Published: 2020-07-16
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Foreshocks are not uncommon prior to large earthquakes, but their physical mechanism controversial. Two interpretations have been put forward: 1. foreshocks are driven by aseismic nucleation; 2. foreshocks are cascades, with each event triggered by earlier ones. Here we study seismic cycles on faults with fractal roughness at wavelengths exceeding the nucleation length. We perform 2-D [...]
Bayesian inference for fault slip distributions based on ensemble modeling of the uncertainty of underground structure
Published: 2020-07-15
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
The prediction errors that originate from the uncertainty of underground structure is often a major contributor of the errors between the data and the model predictions in fault slip estimation using geodetic or seismic waveform data. However, most studies on slip inversions either neglect the model prediction errors or do not distinguish them from observation errors. Several methods that [...]
On the effect of grain fragmentation on frictional instabilities in faults with granular gouge
Published: 2020-07-15
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Physical Sciences and Mathematics
The evolution of frictional strength during stick-slip dynamics of a fault system is key to understanding the earthquake nucleation and rupture patterns. In mature faults, granular gouge is produced by wear, comminution or fragmentation during tectonic movements. In this work, we introduce a fragmentation model in the simulation of a sheared granular fault to explore the influence of grain [...]
“Enriching Lives within Sedimentary Geology”: Actionable Recommendations for Making SEPM a Diverse, Equitable and Inclusive Society for All Sedimentary Geologists
Published: 2020-07-15
Subjects: Earth Sciences, Education, Geology, Paleobiology, Paleontology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy
Innovative science benefits from diversity of thought and influence at all waypoints along the scientific journey, from early education to career-length contributions in research and mentorship. Scientific societies, like the Society for Sedimentary Geology (SEPM), steward their innovators and the direction of the science, thereby defining the societal impact and evolution of a discipline. They [...]
Fingerprinting fluid source in calcite veins: combining LA-ICP-MS U-Pb calcite dating with trace elements and clumped isotope palaeothermometry
Published: 2020-07-15
Subjects: Earth Sciences, Geochemistry, Geology, Physical Sciences and Mathematics
Application of geochemical proxies to vein minerals - particularly calcite - can fingerprint the source of fluids controlling various important geological processes from seismicity to geothermal systems. Determining fluid source, e.g. meteoric, marine, magmatic or metamorphic waters, can be challenging when using only trace elements and stable isotopes as different fluids can have overlapping [...]
Neoproterozoic Geochronology and Provenance of the Adelaide Superbasin
Published: 2020-07-15
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics
The Adelaide Superbasin (Adelaide Rift Complex, Stuart Shelf, Torrens Hinge Zone, Coombalarnie Platform, and Cambrian Stansbury and Arrowie Basins) is a vast sedimentary basin in southern Australia that initiated due to the break-up of central Rodinia and, evolved into the Australian passive margin on edge of the Pacific Basin. Rocks within it contain evidence for the evolving earth system [...]
Alkenone isotopes show evidence of active carbon concentrating mechanisms in coccolithophores as aqueous carbon dioxide concentrations fall below 7 µmolL-1
Published: 2020-07-15
Subjects: Biogeochemistry, Climate, Earth Sciences, Geochemistry, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Coccolithophores and other haptophyte algae acquire the carbon required for metabolic processes from the water in which they live. Whether carbon is actively moved across the cell membrane via a carbon concentrating mechanism, or passively through diffusion, is important for haptophyte biochemistry. The possible utilisation of carbon concentrating mechanisms also has the potential to overprint [...]
Age and geochemistry of the Boucaut Volcanics in the Neoproterozoic Adelaide Rift Complex, South Australia
Published: 2020-07-15
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics
The Adelaide Rift Complex in South Australia records the break-up of Rodinia at a time of great climatic and biological evolution. The Boucaut Volcanics within the Neoproterozoic Adelaide Rift Complex of the Adelaide Superbasin lie at the base of the Burra Group, marking the boundary between the Burra Group and underlying Callanna Group. Despite their significance as one of the few volcanic units [...]
TRAINING A PHYSICS-GUIDED CONVOLUTIONAL NEURAL NETWORK FOR SEISMIC INVERSION
Published: 2020-07-12
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
The determination of subsurface elastic property models is crucial in quantitative seismic data processing and interpretation. This problem is commonly solved by deterministic physical methods, such as tomography or full waveform inversion (FWI). However, these methods are entirely local, and require accurate initial models. Deep learning represents a plausible class of methods for seismic [...]
Tracking and measuring of clay shrinking and swelling using spaceborne remote sensing
Published: 2020-07-12
Subjects: Earth Sciences, Geophysics and Seismology, Hydrology, Physical Sciences and Mathematics
New capabilities for measuring and monitoring are needed to improve the shrink/swell hazard. A new French experimental site at Chaingy (Centre-Val de Loire) has been instrumented using extensometers at the surface and soil moisture sensors in the clay layer. Here we show by direct comparison between remote and in situ data for a period longer than three years that the vertical ground [...]
What Controls Salt‐Detached Contraction in the Translational Domain of the Outer Kwanza Basin, Offshore Angola?
Published: 2020-07-12
Subjects: Earth Sciences, Engineering, Geology, Life Sciences, Physical Sciences and Mathematics, Tectonics and Structure
It is now well‐established that base‐salt relief drives complex deformation patterns in the mid‐slope domain of salt‐bearing passive margins, in a location classically thought to be dominated by simple horizontal translation. However, due to a lack of detailed studies drawing on high‐quality, 3D seismic reflection data, our understanding of how base‐salt relief controls four‐dimensional patterns [...]
Impact of Hydrostratigraphic Continuity in Heterogeneity on Brine-to-Freshwater Interface Dynamics; Implications from a 2-D Parametric Study in an Arid and Endorheic Basin
Published: 2020-07-10
Subjects: Earth Sciences, Hydrology, Physical Sciences and Mathematics
Despite the prevalence of density-driven flow systems in brine-rich aquifers of arid climates and coastal aquifers, the impact of realistic geologic conditions remains poorly constrained regarding interface geometry in arid regions and time-sensitive density-dependent dynamics in brine-bearing aquifers in general. Salar de Atacama provides an analog for exploring interface dynamics in arid [...]
Post-Processing a Conceptual Rainfall-Runoff Model with an LSTM
Published: 2020-07-10
Subjects: Earth Sciences, Environmental Sciences, Hydrology, Physical Sciences and Mathematics
Machine learning is becoming an increasingly important part of streamflow forecasting, but as these models to date lack a physical basis, there is a potential that they may produce values that are not realistic. We tested a simple post-processing strategy that uses the outputs from a calibrated conceptual model (the Sacramento Soil Moisture Accounting Model with Snow-17; SAC-SMA) as inputs into a [...]
Automatic atmospheric correction for shortwave hyperspectral remote sensing data using a time-dependent deep neural network
Published: 2020-07-10
Subjects: Earth Sciences, Other Earth Sciences, Physical Sciences and Mathematics
Atmospheric correction is an essential step in hyperspectral imaging and target detection from spectrometer remote sensing data. State-of-the-art atmospheric correction algorithms either require filed-measurements or prior knowledge of atmospheric characteristics to improve the predicted accuracy, which are computational expensive and unsuitable for real time application. In this paper, we [...]
Iron oxide reactivity controls organic matter mineralization in ferruginous sediments
Published: 2020-07-10
Subjects: Biogeochemistry, Earth Sciences, Life Sciences, Physical Sciences and Mathematics
Ferruginous sediments were widespread during the Archaean and Proterozoic Eons, but our knowledge about organic matter mineralization remains mostly conceptual, as analogous modern ferruginous sediments are largely unstudied. In sediments of ferruginous Lake Towuti, Indonesia, methanogenesis dominates organic matter mineralization despite abundant reactive ferric iron phases persisting throughout [...]