Preprints
There are 5961 Preprints listed.
Bedform migration in a mixed sand and cohesive clay intertidal environment and implications for bed material transport predictions
Published: 2018-05-03
Subjects: Earth Sciences, Physical Sciences and Mathematics, Sedimentology
Many coastal and estuarine environments are dominated by mixtures of non-cohesive sand and cohesive mud. The migration rate of bedforms, such as ripples and dunes, in these environments is important in determining bed material transport rates to inform and assess numerical models of sediment transport and geomorphology. However, these models tend to ignore parameters describing the physical and [...]
Volcanic ash generation mechanisms: Fingerprints in phase distribution highlighted by QEMSCAN particle mineralogical analysis
Published: 2018-05-03
Subjects: Earth Sciences, Physical Sciences and Mathematics, Volcanology
Volcanic ash particle properties depend upon their genetic fragmentation processes. Here, we introduce QEMSCAN particle mineralogical analysis (PMA) to quantify the phase distribution in two ash samples collected during activity at Santiaguito, Guatemala and assess the fingerprint of fragmentation mechanisms. Volcanic ash from a Vulcanian explosion and from a pyroclastic density current resulting [...]
Rainfall-Runoff modelling using Long Short-Term Memory (LSTM) networks
Published: 2018-05-01
Subjects: Civil and Environmental Engineering, Earth Sciences, Engineering, Environmental Engineering, Hydrology, Physical Sciences and Mathematics
Rainfall-runoff modelling is one of the key challenges in the field of hydrology. Various approaches exist, ranging from physically based over conceptual to fully data driven models. In this paper, we propose a novel data driven approach, using the Long-Short-Term-Memory (LSTM) network, a special type of recurrent neural networks. The advantage of the LSTM is its ability to learn long-term [...]
Late Pliocene marine pCO2 reconstructions from the Subarctic Pacific Ocean
Published: 2018-04-30
Subjects: Earth Sciences, Geochemistry, Geology, Physical Sciences and Mathematics
The development of large ice-sheets across the Northern Hemisphere during the late Pliocene and the emergence of the glacial-interglacial cycles that punctuate the Quaternary mark a significant threshold in Earths climate history. Although a number of different mechanisms have been proposed to initiate this cooling and the onset of major Northern Hemisphere glaciation, reductions in atmospheric [...]
Structural Evolution of Salt-Influenced Fold-and-Thrust belts: A Synthesis and New Insights From Basins Containing Isolated Salt Diapirs
Published: 2018-04-30
Subjects: Earth Sciences, Physical Sciences and Mathematics, Tectonics and Structure
Lateral shortening is expressed in unique ways in salt basins, especially if pre-shortening diapirs are present. We present an overview and new 3-D conceptual models capturing the evolution of shortening structures formed in salt provinces dominated by precursor isolated diapirs (termed isolated-diapir provinces). In such provinces, isolated diapirs form only a minor volumetric component of a [...]
Variability of Net Radiation on Snow-Covered Forest Floor for a Range of Vegetation Densities along a Latitudinal Transect
Published: 2018-04-30
Subjects: Environmental Sciences, Natural Resources Management and Policy, Physical Sciences and Mathematics
Net radiation reaching the forest floor is influenced by vegetation density. Previous studies have confirmed that in mid-latitude conifer forests in Greenville, ME (45.5°N), net radiation decreases and then subsequently increases with increasing vegetation density, for clear sky conditions. This leads to existence of a net radiation minimum at an intermediate vegetation density. With increasing [...]
Rivers, reefs, and deltas; Geomorphological evolution of the Jurassic of the Farsund Basin, offshore southern Norway
Published: 2018-04-26
Subjects: Earth Sciences, Geology, Geomorphology, Physical Sciences and Mathematics, Tectonics and Structure
In many petroleum-bearing, data-poor ‘frontier’ basins, source, reservoir, and seal distribution is poorly constrained, making it difficult to identify petroleum systems and play models. However, 3D seismic reflection data provide an opportunity to directly map the three-dimensional distribution of key petroleum system elements, thereby supplementing typically sparse, one-dimensional sedimentary [...]
Tracking CO2 plumes in clay-rich rock by distributed fiber optic strain sensing (DFOSS): a laboratory demonstration
Published: 2018-04-26
Subjects: Earth Sciences, Environmental Monitoring, Environmental Sciences, Fluid Dynamics, Geology, Geophysics and Seismology, Hydrology, Mineral Physics, Oil, Gas, and Energy, Optics, Physical Sciences and Mathematics, Physics
Monitoring the migration of pore pressure, deformation, and saturation plumes with effective tools is important for the storage and utilization of fluids in underground reservoirs, such as geological stores of carbon dioxide (CO2) and natural gas. Such tools would also verify the security of the fluid contained reservoir–caprock system. Utilizing the swelling strain attributed to pressure [...]
Strain budget of the Ecuador-Colombia subduction zone: a stochastic view
Published: 2018-04-24
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
The 2016 Pedernales earthquake (Mw=7.8) ruptured a portion of the Colombia-Ecuador subduction interface where several large historical earthquakes have been documented since the great 1906 earthquake (M=8.6). Considering all significant ruptures that occurred in the region, it has been suggested that the cumulative moment generated co-seismically along this part of the subduction over the last [...]
Plants and Drought in a Changing Climate
Published: 2018-04-23
Subjects: Earth Sciences, Ecology and Evolutionary Biology, Life Sciences, Other Earth Sciences, Other Ecology and Evolutionary Biology, Physical Sciences and Mathematics
Purpose of review: Climate is changing in response to rising concentrations of atmospheric CO2 and it is commonly asserted that this will cause droughts to become more frequent and severe. However, different metrics of drought give diverging estimates of future impacts. I present a summary of the significant yet underappreciated influence that plant stomatal and growth responses to CO2 have on [...]
Controls on early‐rift geometry: new perspectives from the Bilila‐Mtakataka fault, Malawi
Published: 2018-04-23
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Tectonics and Structure
This study investigates the controls to fault and rift geometry for a young rift system. Our case study is a large fault in southern Malawi. The geometry of the fault at the surface, the scarp, and structures within the rocks the fault cuts through, are measured. We also calculate the scarp height. The orientation and height of the fault scarp implies that local stresses influence its geometry, [...]
Bimodal or quadrimodal? Statistical tests for the shape of fault patterns
Published: 2018-04-23
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Tectonics and Structure
Natural fault patterns, formed in response to a single tectonic event, often display significant variation in their orientation distribution. The cause of this variation is the subject of some debate: it could be ‘noise’ on underlying conjugate (or bimodal) fault patterns or it could be intrinsic ‘signal’ from an underlying polymodal (e.g. quadrimodal) pattern. In this contribution, we present [...]
Strain analysis of a seismically-imaged mass-transport complex, offshore Uruguay
Published: 2018-04-23
Subjects: Earth Sciences, Engineering, Geology, Life Sciences, Physical Sciences and Mathematics
Strain style, magnitude, and distribution within mass-transport complexes (MTCs) is important for understanding the process evolution of submarine mass flows and for estimating their runout distances. Structural restoration and quantification of strain in gravitationally-driven passive margins have been shown to approximately balance between updip extensional and downdip compressional domains; [...]
Marine and freshwater micropearls: Biomineralization producing strontium-rich amorphous calcium carbonate inclusions is widespread in the genus Tetraselmis (Chlorophyta)
Published: 2018-04-21
Subjects: Life Sciences, Other Life Sciences
The genus Tetraselmis (Chlorophyta) includes more than 30 species of unicellular micro-algae that have been widely studied since the description of the first species in 1878. Tetraselmis cordiformis (presumably the only freshwater species of the genus) was discovered recently to form intracellular mineral inclusions, called micropearls, which had been previously overlooked. These non-skeletal [...]
Sedimentary Architecture of an Ancient Linear Megadune (Barremian, Neuquén Basin): Insights into the Long-Term Development and Evolution of Aeolian Linear Bedforms
Published: 2018-04-20
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Sedimentology
Linear aeolian bedforms are the most abundant bedform type in modern Earth sand seas and are very common in our Solar System. Despite their abundance, the long-term development of these bedforms and its impact upon the resulting sedimentary architecture in the geological record is still poorly understood. The aims of this paper are to study the exposed record of an ancient linear megadune in [...]