Preprints
Filtering by Subject: Earth Sciences
Technical note on the multi-GNSS, multi-frequency and near real-time ionospheric TEC monitoring system for South America
Published: 2019-02-21
Subjects: Atmospheric Sciences, Earth Sciences, Geophysics and Seismology, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Development of regional services able to provide ionospheric total electron content (TEC) maps with a high spatial resolution, and in near real-time, are of high importance for applications and the research community. We provide here the methodologies, and a preliminary assessment, of such a system. The system relies on the public Global Navigational Satellite Systems (GNSS) infrastructure in [...]
Long Range Correlation in Redox Potential Fluctuations Signals Energetic Efficiency of Bacterial Fe(II) Oxidation
Published: 2019-02-21
Subjects: Biogeochemistry, Earth Sciences, Environmental Sciences, Physical Sciences and Mathematics
Differentiating biotic and abiotic processes in nature remains a persistent challenge, specifically in evaluating microbial contributions to geochemical processes through time. Building on previous work reporting that biologically-influenced systems exhibit stronger long-range correlation than abiotic systems, this study evaluated the relationship between long-range correlation of redox [...]
Deep Learning Application for 4D Pressure Saturation Inversion Compared to Bayesian Inversion on North Sea Data
Published: 2019-02-21
Subjects: Applied Statistics, Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics, Statistics and Probability
In this work we present a deep neural network inversion on map-based 4D seismic data for pressure and saturation. We present a novel neural network architecture that trains on synthetic data and provides insights into observed field seismic. The network explicitly includes AVO gradient calculation within the network as physical knowledge to stabilize pressure and saturation changes separation. [...]
geomIO: an open-source MATLAB toolbox to create the initial configuration of 2D/3D thermo-mechanical simulations from 2D vector drawings
Published: 2019-02-21
Subjects: Earth Sciences, Physical Sciences and Mathematics
Creating the initial geometry and temperature configuration of 3D numerical simulations is a challenging task. Professional tools are expensive. They often have a steep learning curve and do mostly not interface with the numerical simulation software used by the geodynamics and tectonics academic community. There, we developed geomIO (geometry Input/Output), a MATLAB toolbox to create the initial [...]
Bayesian Dynamic Finite-Fault Inversion: 2. Application to the 2016 Mw6.2 Amatrice, Italy, Earthquake
Published: 2019-02-19
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
In 2016 Central Italy was struck by a sequence of three normal faulting earthquakes with moment magnitude (Mw) larger than 6. The Mw 6.2 Amatrice event (08/24) was the first one, causing building collapse and about 300 casualties. The event was recorded by a uniquely dense network of seismic stations. Here we perform its dynamic source inversion to infer the fault friction parameters and stress [...]
The influence of base-salt relief, rift topography and regional events on salt tectonics offshore Morocco
Published: 2019-02-19
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Tectonics and Structure
This study integrates borehole-calibrated 2D and 3D seismic interpretation with numerical models to provide a regional analysis of the complex salt tectonics offshore central Morocco. We investigate the mechanisms controlling along-margin structural variations, the effects of thick-skinned shortening and the sequential evolution of allochthonous sheets. Additionally, we analyse how base-salt [...]
Minibasin depocentre migration during diachronous salt welding, offshore Angola
Published: 2019-02-16
Subjects: Earth Sciences, Geology, Other Earth Sciences, Physical Sciences and Mathematics, Tectonics and Structure
Salt tectonics is an important part of the geological evolution of many continental margins, yet the four-dimensional evolution of the minibasins, the fundamental building block of these and many other salt basins, remains poorly understood. Using high-quality 3D seismic data from the Lower Congo Basin, offshore Angola we document the long-term (>70 Myr) dynamics of minibasin subsidence. We [...]
Coupled, Physics-based Modeling Reveals Earthquake Displacements are Critical to the 2018 Palu, Sulawesi Tsunami
Published: 2019-02-16
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
The September 2018, Mw 7.5 Sulawesi earthquake occurring on the Palu-Koro strike-slip fault system was followed by an unexpected localized tsunami. We show that direct earthquake-induced uplift and subsidence could have sourced the observed tsunami within Palu Bay. To this end, we use a physics-based, coupled earthquake-tsunami modeling framework tightly constrained by observations. The model [...]
Modeling megathrust earthquakes across scales: one-way coupling from geodynamics and seismic cycles to dynamic rupture
Published: 2019-02-15
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Taking the full complexity of subduction zones into account is important for realistic modelling and hazard assessment of subduction zone seismicity and associated tsunamis. Studying seismicity requires numerical methods that span a large range of spatial and temporal scales. We present the first coupled framework that resolves subduction dynamics over millions of years and earthquake dynamics [...]
Reconstructing the Anak Krakatau flank collapse that caused the December 2018 Indonesian tsunami
Published: 2019-02-15
Subjects: Earth Sciences, Physical Sciences and Mathematics, Volcanology
Volcanogenic tsunamis are one of the deadliest volcanic phenomena. Understanding their triggering processes and mitigating their effect remains a major challenge. On 22 December 2018, flank failure of the Anak Krakatau volcano in Indonesia generated a tsunami which killed more than 400 people. This event was captured in unprecedented detail by high-resolution satellite imagery and eyewitness [...]
McHargue et al Architectural Diversity of Submarine Lobes
Published: 2019-02-14
Subjects: Earth Sciences, Geology, Geomorphology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy
The most popular model for submarine unconfined lobate deposits has the following attributes: (1) a single feeder channel that delivers sediment, (2) a set of distributary channels present only in the proximal part of the lobate body, and (3) unchannelized tabular deposits present in the middle and distal part of the lobate deposit. This model has become a standard to guide interpretation of [...]
The Stratigraphic Record of Minibasin Subsidence, Precaspian Basin, Kazakhstan
Published: 2019-02-14
Subjects: Earth Sciences, Geology, Other Earth Sciences, Physical Sciences and Mathematics, Stratigraphy, Tectonics and Structure
Minibasins are fundamental components of many salt-bearing sedimentary basins, where they may host large volumes of hydrocarbons. Although we understand the basic mechanics governing their subsidence, we know surprisingly little of how minibasins subside in three-dimensions over geological timescales, or what controls such variability. Such knowledge would improve our ability to constrain initial [...]
Current Problems of Water Supply and Usage in Central Asia, Tian Shan Basin
Published: 2019-02-13
Subjects: Earth Sciences, Ecology and Evolutionary Biology, Environmental Studies, Geography, Geology, Geomorphology, Glaciology, Hydrology, Life Sciences, Other Geography, Physical and Environmental Geography, Physical Sciences and Mathematics, Social and Behavioral Sciences, Spatial Science
The paper focuses on analysis of Central Asian hydro-energetic system and water usage in Tian Shan region. Tian Shan system is an important water resource in Central Asia: river waters are intensely taken for hydropower energy, urban systems, irrigation. But geopolitics in Tian Shan is difficult: it crosses five densely populated countries. The problem consists in water delivery between countries [...]
Structural architecture and composition of crystalline basement offshore west Norway
Published: 2019-02-13
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure
Numerous studies have investigated the geodynamic history and lithological composition of the Proterozoic basement, Caledonian nappes, and Devonian extensional basins and shear zones onshore west Norway. However, the offshore continuation of these structures, into the northern North Sea, where they are suspected to have influenced the structural evolution of the North Sea rift, is largely [...]
Bayesian Dynamic Finite-Fault Inversion: 1. Method and Synthetic Test
Published: 2019-02-12
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Dynamic earthquake source inversions aim to determine the spatial distribution of initial stress and friction parameters leading to dynamic rupture models that reproduce observed ground motion data. Such inversions are challenging, particularly due to their high computational burden, thus so far only few attempts have been made. Using a highly efficient rupture simulation code, we introduce a [...]