Preprints
Filtering by Subject: Earth Sciences
PYRENAIC ROCK GLACIERS: AN AIRBORNE AND MULTITEMPORAL LiDAR MONITORING CASE STUDY IN THE BESIBERRI AREA
Published: 2019-10-24
Subjects: Earth Sciences, Environmental Sciences, Geology, Geomorphology, Glaciology, Physical Sciences and Mathematics
The monitoring of rock glaciers is a current subject of interest because of its application as permafrost indicator and its sensitivity to climatic changes (especially temperature and precipitation). Alpine rock glaciers in the Pyrenees have been described by various authors, but to study them regionally has been a challenge since most of these studies are based on ground-based techniques. Two [...]
Inheritance of penetrative basement anisotropies by extension-oblique faults: Insights from analogue experiments
Published: 2019-10-24
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Tectonics and Structure
During rifting, pre-existing penetrative basement fabrics can affect new faults in cover rocks by a mechanism that does not appear to involve reactivation. This subtle form of inheritance can significantly impact fault network architecture in rift basins above laterally variable basement domains with geomechanical anisotropies. Here we use multi-layer, brittle-ductile, crustal-scale analogue [...]
Intermittent fluid connectivity during two-phase flow in a heterogeneous carbonate rock
Published: 2019-10-24
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Subsurface fluid flow is ubiquitous in nature, and understanding the interaction of multiple fluids as they flow within a porous medium is central to many geological, environmental, and industrial processes. It is assumed that the flow pathways of each phase are invariant when modelling subsurface flow using Darcys law extended to multiphase flow; a condition that is assumed to be valid during [...]
Major-element composition of sediments in terms of weathering and provenance: Implications for crustal recycling
Published: 2019-10-24
Subjects: Earth Sciences, Geochemistry, Physical Sciences and Mathematics
The elemental composition of a sediment is set by the composition of its protolith and modified by weathering, sorting, and diagenesis. An important problem is deconvolving these contributions to a sediment’s composition to arrive at information about processes that operate on the Earth’s surface. We approach this problem by developing a predictive and invertible model of sedimentary [...]
Dynamic fault parameters preprint
Published: 2019-10-24
Subjects: Earth Sciences, Physical Sciences and Mathematics, Tectonics and Structure
The behavior of faults under dynamic loading reflects the response of the shape and composition of the fault to the applied mechanical loading and environmental conditions. The interaction between the fault properties and the loading system is controlled by multiple variables that may generate an inherently complex behavior. The usage of multi-parametric variables can illuminate the controlling [...]
Complex Rupture of an Immature Fault Zone: A Simultaneous Kinematic Model of the 2019 Ridgecrest, CA Earthquakes
Published: 2019-10-24
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
The July 4, 2019 Mw6.4 and subsequent July 6, 2019 Mw7.1 Ridgecrest Sequence earthquakes ruptured orthogonal fault planes in the Little Lake Fault Zone, a low slip rate (1 mm/yr) dextral fault zone in the area linking the Eastern California Shear Zone and Walker Lane. This region accommodates nearly one fourth of plate boundary motion and has been proposed to be an incipient transform fault [...]
Distributed normal faulting in the tip zone of the South Alkyonides Fault System, Gulf of Corinth, constrained using 36Cl exposure dating of Late-Quaternary wave-cut platforms.
Published: 2019-10-24
Subjects: Earth Sciences, Physical Sciences and Mathematics, Tectonics and Structure
In order to investigate the geometry, rates and kinematics of active faulting in the region close to the tip of a major crustal-scale normal fault in the Gulf of Corinth, Greece, we have mapped faults and dated their offsets using a combination of 234U/230Th coral dates and in situ 36Cl cosmogenic exposure ages for sediments and wave-cut platforms deformed by the faults. Our results show that [...]
Investigating potential icequakes at Llaima volcano, Chile
Published: 2019-10-24
Subjects: Earth Sciences, Glaciology, Physical Sciences and Mathematics, Volcanology
Glacially- and magmatically-derived seismic events have been noted to heavily overlap in characteristics, thus there exists the potential for false-alarms or missed warnings at ice-covered volcanoes. Here we present the first study to specifically target icequakes at an ice-covered volcano in Southern Chile. Two months of broadband seismic data collected at Llaima volcano in 2015 were analyzed in [...]
Pre-breakup extension in the northern North Sea defined by complex strain partitioning and heterogeneous extension rates
Published: 2019-10-24
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Tectonics and Structure
The early stages of continental rifting are accommodated by the growth of upper-crustal normal fault systems that are distributed relatively evenly across the rift width. Numerous fault systems define fault arrays, the kinematics of which are poorly understood due to a lack of regional studies drawing on high-quality subsurface data. Here we investigate the long-term (~150 Myr) growth of a [...]
Rotation, narrowing, and preferential reactivation of brittle structures during oblique rifting
Published: 2019-10-24
Subjects: Earth Sciences, Physical Sciences and Mathematics, Tectonics and Structure
Occurrence of multiple faults populations with contrasting orientations in oblique continental rifts and passive margins has long sparked debate about relative timing of deformation events and tectonic interpretations. Here, we use high-resolution three-dimensional thermo-mechanical numerical modeling to characterize the evolution of the structural style associated with varying geometries of [...]
Linking the evolution of terrestrial interiors and an early outgassed atmosphere to astrophysical observations
Published: 2019-10-16
Subjects: Astrophysics and Astronomy, Earth Sciences, Geophysics and Seismology, Other Astrophysics and Astronomy, Physical Sciences and Mathematics, Planetary Geophysics and Seismology, Planetary Sciences
A terrestrial planet is molten during formation and may remain molten due to intense insolation or tidal forces. Observations favour the detection and characterisation of hot planets, potentially with large outgassed atmospheres. We aim to determine the radius of hot Earth-like planets with large outgassing atmospheres. Our goal is to explore the differences between molten and solid silicate [...]
Rock strength and structural controls on fluvial erodibility: implications for drainage divide mobility in a collisional mountain belt
Published: 2019-10-13
Subjects: Earth Sciences, Geomorphology, Physical Sciences and Mathematics, Tectonics and Structure
Numerical model simulations and experiments have suggested that when migration of the main drainage divide occurs in a mountain belt, it can lead to the rearrangement of river catchments, rejuvenation of topography, and changes in erosion rates and sediment flux. We assess the progressive mobility of the drainage divide in three lithologically and structurally distinct groups of bedrock in the [...]
Plate tectonics drive deep biosphere microbial community structure
Published: 2019-10-13
Subjects: Earth Sciences, Environmental Microbiology and Microbial Ecology Life Sciences, Life Sciences, Microbiology, Other Earth Sciences, Physical Sciences and Mathematics
The deep subsurface is one of Earth’s largest biomes. Here, microorganisms modify volatiles moving between the deep and surface Earth. However, it is unknown whether large-scale tectonic processes affect the distribution of microorganisms across this subterranean landscape. We sampled subsurface microbial ecosystems in deeply-sourced springs across the Costa Rican convergent margin. Noble gases, [...]
“Conjugate margins” – An oversimplification of the complex southern North Atlantic rift and spreading system?
Published: 2019-10-13
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Tectonics and Structure
The prevalence of conjugate margin terminology and studies in the scientific literature is testimony to the contribution that this concept and approach has made to the study of passive margins, and more broadly extensional tectonics. However, when applied to the complex rift, transform and spreading system of the southern North Atlantic (i.e. the passive margins of Newfoundland, Labrador, [...]
River inflow dominates methane emissions in an Arctic coastal system
Published: 2019-10-13
Subjects: Biogeochemistry, Earth Sciences, Environmental Monitoring, Environmental Sciences, Fresh Water Studies, Geochemistry, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Measurements of greenhouse gases in Arctic waters are strongly biased toward low-ice summer conditions, with few observations during periods of seasonal ice retreat. We present a year-round time series of dissolved methane (CH4) and nitrous oxide (N2O), along with targeted observations during ice melt of CH4 and carbon dioxide (CO2) in a river and estuary adjacent to Cambridge Bay, Nunavut, [...]