Preprints
There are 6976 Preprints listed.
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 [...]
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 [...]
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 [...]
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 [...]
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 [...]
Mercury stable isotopes constrain atmospheric sources to the Ocean
Published: 2020-08-29
Subjects: Earth Sciences, Environmental Sciences, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Human exposure to toxic mercury (Hg) is dominated by the consumption of seafood1,2. Earth system models suggest that Hg in marine ecosystems is supplied by atmospheric wet and dry Hg(II) deposition, with a 3 times smaller contribution from gaseous Hg(0) uptake3,4. Observations of marine Hg(II) deposition and Hg(0) gas exchange are sparse however5, leaving the suggested importance of Hg(II) [...]
Modelling an energetic tidal strait: investigating implications of common numerical configuration choices
Published: 2020-07-16
Subjects: Applied Mathematics, Civil and Environmental Engineering, Civil Engineering, Engineering, Numerical Analysis and Computation, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Characterising tidal hydrodynamics in the vicinity of submerged features can be demanding given the hostility of the marine environment. Logistical challenges in the measurement of such flows has promoted research on wake studies through physical and numerical modelling. In this study, site measurements and modelled data are combined to provide an insight into the regional hydrodynamics within a [...]
“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 [...]
TRAINING A PHYSICS-GUIDED CONVOLUTIONAL NEURAL NETWORK FOR SEISMIC INVERSION
Published: 2020-07-13
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 [...]
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 [...]
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 [...]
What Controls Salt‐Detached Contraction in the Translational Domain of the Outer Kwanza Basin, Offshore Angola?
Published: 2020-07-13
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 [...]
Fracture mechanics of rate-and-state faults and fluid injection induced slip
Published: 2020-07-08
Subjects: Earth Sciences, Engineering, Environmental Sciences, Geophysics and Seismology, Oil, Gas, and Energy, Physical Sciences and Mathematics, Physics
Propagation of a slip transient on a fault with rate-and-state dependent friction resembles a fracture which near tip region is characterized by large departure of the slip velocity and fault strength from the steady-state sliding. We develop a near tip solution to describe this unsteady dynamics, and obtain the fracture energy Gc, dissipated in overcoming strength-excursion away from [...]
How Extreme Weather Events Are Attributed to Anthropogenic Global Warming
Published: 2020-07-20
Subjects: Environmental Indicators and Impact Assessment, Environmental Sciences, Physical Sciences and Mathematics
Many politicians and media personalities continue to cast doubt on the idea that anthropogenic global warming (AGW) – the primary driver of current global climate change – could possibly be behind the growing frequency and severity of extreme weather events – the droughts, heatwaves, flooding, etc. that are every year breaking 100 year or greater historical records. This takes the form not just [...]
Tracking and measuring of clay shrinking and swelling using spaceborne remote sensing
Published: 2020-07-13
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 [...]