Preprints
Filtering by Subject: Earth Sciences
Pervasive foreshock activity across southern California
Published: 2019-06-22
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Foreshocks have been documented as preceding less than half of all mainshock earthquakes. These observations are difficult to reconcile with laboratory earthquake experiments and theoretical models of earthquake nucleation, which both suggest that foreshock activity should be nearly ubiquitous. Here we use a state-of-the-art, high-resolution earthquake catalog to study foreshock sequences of [...]
Multiple episodes of sand injection leading to accumulation and leakage of hydrocarbons along the San Andreas/San Gregorio fault system, California.
Published: 2019-06-22
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Sedimentology, Tectonics and Structure
The presence of sand injections has proven to enhance the likelihood of hydrocarbon traps within siliciclastic successions. Through the development of large interconnected networks of sills and dykes, sand injection complexes provide a volume of porous and permeable rocks within the low permeability host units. Overall, the formation of sand injection complexes requires extensive fracturing and [...]
Are magnetic stripes on the Cuvier Abyssal Plain (offshore NW Australia) diagnostic of oceanic crust?
Published: 2019-06-22
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Other Earth Sciences, Physical Sciences and Mathematics, Tectonics and Structure
Magnetic stripes have long been used to define the presence and age of oceanic crust. However, continental crust heavily intruded by magma can record magnetic reversals akin to those observed in oceanic crust. We re-evaluate the nature of the Cuvier Abyssal Plain (CAP), offshore NW Australia, which hosts magnetic stripes and has previously been defined as oceanic crust. We use magnetic, 2D [...]
Mixing, stratification and plankton under lake-ice during winter in a large lake: implications for spring dissolved oxygen levels
Published: 2019-06-22
Subjects: Earth Sciences, Environmental Sciences, Hydrology, Physical Sciences and Mathematics
The mixing and stratification present under the ice during winter can have a profound influence on the following summertime hypolimnetic oxygen levels. During winter, plankton rely on updrafts caused by convection to remain in the photic zone in ice-covered lakes, thus there is a crucial link in winter between light levels, under-ice circulation and dissolved oxygen (DO) production. Detailed [...]
Large uncertainty in volcanic aerosol radiative forcing derived from ice cores
Published: 2019-06-21
Subjects: Atmospheric Sciences, Climate, Earth Sciences, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics, Volcanology
Reconstructions of volcanic aerosol radiative forcing are required to understand past climate variability. Currently, reconstructions of pre-20th century volcanic forcing are derived from sulfate concentrations measured in polar ice cores, predominantly using a relationship between average ice sheet sulfate deposition and stratospheric sulfate aerosol based on a single explosive eruption - the [...]
Data-driven prediction of a multi-scale Lorenz 96 chaotic system using deep learning methods: Reservoir computing, ANN, and RNN-LSTM
Published: 2019-06-20
Subjects: Applied Mathematics, Artificial Intelligence and Robotics, Atmospheric Sciences, Climate, Computer Sciences, Dynamic Systems, Earth Sciences, Fluid Dynamics, Non-linear Dynamics, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics, Physics
In this paper, the performance of three deep learning methods for predicting short-term evolution and for reproducing the long-term statistics of a multi-scale spatio-temporal Lorenz 96 system is examined. The methods are: echo state network (a type of reservoir computing, RC-ESN), deep feed-forward artificial neural network (ANN), and recurrent neural network with long short-term memory [...]
Guerrilla Badges for Reproducible Geospatial Data Science (AGILE 2019 Short Paper)
Published: 2019-06-19
Subjects: Computer Sciences, Earth Sciences, Physical Sciences and Mathematics
The building blocks of research are developing at an unprecedented pace. Data collection, analysis, interpretation, presentation, review, and publication take place completely on computers. The final product often is still a static document with only limited links to the underlying digital material, making transparency and reproducibility a challenge. In this work we apply the mechanism of badges [...]
Comments on the paper “Two independent real-time precursors of the 7.8 M earthquake in Ecuador based on radioactive and geodetic processes – Powerful tools for an early warning system” by Toulkeridis et al. (2019)
Published: 2019-06-19
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
In the paper entitled “Two independent real-time precursors of the 7.8 M earthquake in Ecuador based on radioactive and geodetic processes – Powerful tools for an early warning system”, Toulkeridis et al. (2019) claim that they found radiation and GPS signal anomalies before the April 16th 2016 Pedernales earthquake (Ecuador) and that their findings can be used to forecast earthquakes in the [...]
Geometry and topology of estuary and braided river channel networks automatically extracted from topographic data
Published: 2019-06-19
Subjects: Computer Sciences, Earth Sciences, Geomorphology, Physical Sciences and Mathematics
Automatic and objective extraction of channel networks from topography in systems with multiple interconnected channels, like braided rivers and estuaries, remains a major challenge in hydrology and geomorphology. Representing channelized systems as networks provides a mathematical framework for analyzing transport and geomorphology. In this paper, we introduce a mathematically rigorous [...]
Optimizing Regional Climate Model Output for Hydro-Climate Applications in the Eastern Nile Basin
Published: 2019-06-19
Subjects: Civil and Environmental Engineering, Climate, Earth Sciences, Engineering, Hydrology, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
This study focuses on the Eastern Nile (EN) Basin, most of whose water flows into the High Aswan Dam (HAD), Egypt. It is, therefore, crucial to have an accurate hydrological assessment overtime to plan water resource management in the area. With complex topography, it is important to capture most of the physics captured with the least bias in meteorological information. Weather Research and [...]
Tracing the migration of mantle CO2 in gas fields and mineral water springs in south-east Australia using noble gas and stable isotopes
Published: 2019-06-19
Subjects: Earth Sciences, Geochemistry, Physical Sciences and Mathematics
Geochemical monitoring of CO2 storage requires understanding of both innate and introduced fluids in the crust as well as the subsurface processes that can change the geochemical fingerprint of CO2 during injection, storage and any subsequent migration. Here, we analyse a natural analogue of CO2 storage, migration and leakage to the atmosphere, using noble gas and stable isotopes to constrain the [...]
Active fault scarps in southern Malawi and their implications for the distribution of strain in incipient continental rifts
Published: 2019-06-19
Subjects: Earth Sciences, Geomorphology, Physical Sciences and Mathematics, Tectonics and Structure
The distribution of deformation during the early stages of continental rifting is an important constraint on our understanding of continental breakup. Incipient rifting in East Africa has been considered to be dominated by slip along rift border faults, with a subsequent transition to focussed extension on axial segments in thinned crust and/or with active magmatism. Here, we study [...]
Probing the chemical transformation of seawater-soluble crude oil components during microbial oxidation
Published: 2019-06-19
Subjects: Biogeochemistry, Chemistry, Earth Sciences, Environmental Chemistry, Environmental Sciences, Life Sciences, Microbiology, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Oil, Gas, and Energy, Physical Sciences and Mathematics
Studies assessing the environmental impacts of oil spills focus primarily on the non-water-soluble components, leaving the fate of the water-soluble fraction (WSF) largely unexplored. We employed untargeted chemical analysis along with biological information to probe the transformation of crude oil WSF in seawater, in the absence of light, in a laboratory experiment. Over a 14-day incubation, [...]
Stepwise chemical abrasion–isotope dilution–thermal ionization mass spectrometry with trace element analysis of microfractured Hadean zircon
Published: 2019-06-16
Subjects: Earth Sciences, Geochemistry, Geology, Physical Sciences and Mathematics
The Hadean Jack Hills zircons represent the oldest known terrestrial material, providing a unique and truly direct record of Hadean Earth history. This zircon population has been extensively studied via high spatial resolution, high throughput in situ isotopic and elemental analysis techniques such as secondary ionization mass spectrometry (SIMS), but not by comparatively destructive, [...]
Technical note: Limitations on the use of space borne differential SAR interferometry for systematic monitoring and failure forecast of alpine landslides
Published: 2019-06-16
Subjects: Civil and Environmental Engineering, Earth Sciences, Engineering, Environmental Engineering, Geology, Geotechnical Engineering, Physical Sciences and Mathematics
Recent advances on satellite geodesy have boosted our capabilities to map and monitor landslides globally with unprecedented resolutions. In this scenario, differential interferometry of space borne synthetic aperture radar imagery (DInSAR) plays a major role in identifying surface displacements associated to slope instabilities and in monitoring their spatial and temporal evolution. However, [...]