Preprints
Filtering by Subject: Physical Sciences and Mathematics
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; [...]
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 [...]
Present-day stress orientations in the Great Sumatran Fault in North Sumatra
Published: 2018-04-20
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics
Trench-parallel strike slip faults develop at lithospheric scale during oblique high-angle subduction. A “sliver” plate forms due to slip partitioning between the subduction plane (margin-normal slip) and the strike slip fault (margin-parallel slip). This process ultimately controls the location of volcanoes and earthquakes. The Great Sumatran Fault (GSF) is a showcase of this tectonic [...]
The relationships between regional Quaternary uplift, deformation across active normal faults and historical seismicity in the upper plate of subduction zones: The Capo D’Orlando Fault, NE Sicily.
Published: 2018-04-20
Subjects: Earth Sciences, Geology, Geomorphology, Physical Sciences and Mathematics
In order to investigate deformation within the upper plate of the Calabrian subduction zone we have mapped and modelled a sequence of Late Quaternary palaeoshorelines tectonically‐deformed by the Capo D’Orlando normal fault, NE Sicily, which forms part of the actively deforming Calabrian Arc. In addition to the 1908 Messina Strait earthquake (Mw 7.1), this region has experienced damaging [...]
Spatial association between regionalizations using the information-theoretical V-measure
Published: 2018-04-19
Subjects: Categorical Data Analysis, Computer Sciences, Environmental Sciences, Geographic Information Sciences, Geography, Numerical Analysis and Scientific Computing, Physical Sciences and Mathematics, Social and Behavioral Sciences, Statistics and Probability, Theory and Algorithms
There is a keen interest in inferring spatial associations between different variables spanning the same study area. We present a method for quantitative assessment of such associations in the case where spatial variables are either in the form of regionalizations or in the form of thematic maps. The proposed index of spatial association – called the V-measure – is adapted from a measure [...]
Unsupervised clustering of Southern Ocean Argo float temperature profiles
Published: 2018-04-19
Subjects: Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
The Southern Ocean has complex spatial variability, characterized by sharp fronts, steeply tilted isopycnals, and deep seasonal mixed layers. Methods of defining Southern Ocean spatial structures traditionally rely on somewhat ad-hoc combinations of physical, chemical, and dynamic properties. As a step towards an alternative approach for describing spatial variability in temperature, here we [...]