Preprints
Filtering by Subject: Earth Sciences
Navigating groundwater model uncertainty analysis
Published: 2020-07-20
Subjects: Earth Sciences, Hydrology, Physical Sciences and Mathematics
The design of a groundwater model is based on the model objective, the management or research question that the model seeks to address. Designing the uncertainty analysis of a groundwater models likewise needs to consider the objective of the uncertainty analysis; how the uncertainty in model predictions will be used. In this paper a framework is presented to consider the various dimensions of [...]
Stress perturbations from hydrological and industrial loads and seismicity in the Salt Lake City region
Published: 2020-07-18
Subjects: Earth Sciences, Other Earth Sciences, Physical Sciences and Mathematics
The March 18, 2020 M5.7 Magna earthquake awakened people from decades of seismic quiescence in Salt Lake City, Utah. The event occurred just east of a mine tailings impoundment that receives ~60 million tons/yr of ore waste products since the early 1900s. Here we investigate elastic loading effects due to the anthropogenic mass transfer and various natural hydrological loads. We note a possible [...]
Sedimentary structures discriminations with hyperspectral imaging on sediment cores
Published: 2020-07-17
Subjects: Analytical Chemistry, Chemistry, Earth Sciences, Environmental Chemistry, Environmental Monitoring, Environmental Sciences, Multivariate Analysis, Optics, Physical Sciences and Mathematics, Physics, Sedimentology, Statistical Models, Statistics and Probability
Hyperspectral imaging (HSI) is a non-destructive high-resolution sensor, which is currently under significant development to analyze geological areas with remote devices or natural samples in a laboratory. In both cases, the hyperspectral image provides several sedimentary structures that need to be separated to temporally and spatially describe the sample. Sediment sequences are composed of [...]
dragon: A New Tool for Exploring Redox Evolution Preserved in the Mineral Record
Published: 2020-07-16
Subjects: Biogeochemistry, Earth Sciences, Physical Sciences and Mathematics
The flow of energy and elements between the geosphere and biosphere can be traced through changing redox chemistry of Earth’s surface. Deep-time trends in the mineral record, including mineral age and elemental composition, reveal a dynamic history of changing redox states and chemical speciation. We present a user-friendly exploratory network analysis platform called dragon (Deep-time Redox [...]
Whats down there? The structures, materials and environment of deep-seated tremor and slip
Published: 2020-07-16
Subjects: Earth Sciences, Geochemistry, Geology, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure
Episodic tremor and slow slip (ETS) events occur downdip of the seismogenic zone of numerous subduction megathrusts and plate boundary strike-slip faults. These events represent a fascinating and perplexing mode of fault failure that has greatly broadened our view of earthquake dynamics. In this contribution, we review constraints on the ETS deformation process from both geophysical observations [...]
Principles of Shortening in Salt Basins Containing Isolated Minibasins
Published: 2020-07-16
Subjects: Earth Sciences, Physical Sciences and Mathematics, Tectonics and Structure
Shortening styles in salt-influenced basins can vary markedly, with the volume and distribution of salt prior to shortening being a key control. Here we use a suite of physical models to examine styles of thin-skinned regional shortening in settings where the pre-shortening structure comprised minibasins surrounded by salt (‘isolated-minibasin’ provinces). Our models show that the high volume of [...]
Frequent Mass Movements from Glacial and Lahar Terraces, Controlled by Both Hillslope Characteristics and Fluvial Erosion, are an Important Sediment Source to Puget Sound Rivers
Published: 2020-07-16
Subjects: Earth Sciences, Geomorphology, Physical Sciences and Mathematics
Mass movements from glacial and lahar terraces in the middle and lower reaches of rivers draining the Washington Cascade Range to Puget Sound may represent a substantial portion of those rivers’ sediment supply and pose significant mass movement hazards. However, the quantitative importance of this sediment source is unknown, and the magnitudes, spatial distribution, styles, and controls of these [...]
Rapid heat discharge during deep-sea eruptions generates megaplumes and disperses tephra
Published: 2020-07-16
Subjects: Earth Sciences, Fluid Dynamics, Geology, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Other Physical Sciences and Mathematics, Physical Sciences and Mathematics, Physics, Volcanology
Deep-marine volcanism drives Earth’s most energetic transfers of heat and mass between the crust and the oceans. Seafloor magmatic activity has been correlated in time with the appearance of massive enigmatic plumes of hydrothermal fluid, known as megaplumes, yet little is known of the primary source and intensity of the hydrothermal energy release that occurs during [...]
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 [...]