Preprints
Filtering by Subject: Earth Sciences
Global inventories of inverted stream channels on Earth and Mars
Published: 2020-03-03
Subjects: Earth Sciences, Geology, Geomorphology, Physical Sciences and Mathematics
Data from orbiting and landed spacecraft have provided vast amounts of information regarding fluvial and fluvial-related landforms and sediments on Mars. One variant of these landforms are sinuous ridges that have been interpreted to be remnant evidence for ancient fluvial activity, observed at hundreds of martian locales. In order to further understanding of these martian landforms, this paper [...]
Stress drop variation of deep-focus earthquakes based on empirical Greens function
Published: 2020-03-03
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
We analyze source characteristics of global, deep-focus (> 350 km) earthquakes with moment magnitudes (Mw) larger than 6.0-8.2 using teleseismic P-wave and S-wave spectra and an empirical Greens functions approach. We estimate the corner frequency assuming Brunes source model and calculate stress drops assuming a circular crack model. Based on P-wave and S-wave spectra, the one-standard [...]
Dynamic fault interaction during a fluid-injection induced earthquake: The 2017 Mw 5.5 Pohang event
Published: 2020-03-03
Subjects: Earth Sciences, Geophysics and Seismology, Life Sciences, Physical Sciences and Mathematics
The November 15th, 2017 Mw 5.5 Pohang earthquake (South Korea) has been linked to hydraulic stimulation and fluid injections, making this the largest induced seismic event associated with an Enhanced Geothermal System (EGS). To understand its source dynamics and fault interactions, we conduct the first 3D high-resolution spontaneous dynamic rupture simulations of an induced earthquake. We account [...]
Mechanistic insights into sulfur rich oil formation, relevant to geological carbon storage routes. A study using (+) APPI FTICR-MS analysis
Published: 2020-03-03
Subjects: Earth Sciences, Geochemistry, Physical Sciences and Mathematics
Sulfur incorporation into sedimentary organic matter has a key role in carbon preservation in the geosphere. Such processes can inform strategies for human timescale carbon storage to mitigate climate change impacts and thus more detailed knowledge of sulfur incorporation into biomass species is needed. Until recently, detailed chemical characterization of sulfurized organic matter was only [...]
Effect of fault damage zones on long-term earthquake behavior on mature strike-slip faults
Published: 2020-03-03
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Mature strike-slip faults are usually surrounded by a narrow zone of damaged rocks characterized by low seismic wave velocities. Observations of earthquakes along such faults indicate that seismicity is highly concentrated within this fault damage zone. However, the long-term influence of the fault damage zone on complete earthquake cycles, i.e., years to centuries, is not well understood. We [...]
Slip on wavy frictional faults: is the 3rd dimension a sticking point?
Published: 2020-03-03
Subjects: Earth Sciences, Physical Sciences and Mathematics, Tectonics and Structure
The formulation for the 3D triangular displacement discontinuity boundary element method with frictional constraints is described in detail. Its accuracy in comparison to analytical solutions is then quantified. We show how this can be used to approximate stress intensity factors at the crack tips. Using this method, we go on to quantify how slip is reduced on fault surfaces with topography, [...]
Analytical prediction of seismicity rate due to tides and other oscillating stresses
Published: 2020-03-03
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics, Planetary Geophysics and Seismology, Planetary Sciences, Tectonics and Structure
Oscillatory stresses are ubiquitous on earth and other solid-surface bodies. Tides and seasonal signals perpetually stress faults in the crust. Relating seismicity to these stresses offers fundamental insight into earthquake triggering. We present a simple model that describes seismicity rate due to perpetual oscillatory stresses. The model applies to large amplitude, non-harmonic, and [...]
Integrated geotechnical, sedimentological and geophysical investigation of seafloor instabilities in the Gulf of Lions Western Mediterranean
Published: 2020-03-03
Subjects: Earth Sciences, Physical Sciences and Mathematics, Sedimentology
The Gulf of Lions presents recurring mass-transport deposits (MTDs) within the Plio-Quaternary sediments suggesting a long history of mass-movements. The two large, surficial MTDs are located on the eastern and western levee of the Rhone canyon over an area exceeding 6000 km2 and volumes exceeding 100 km3. Both MTDs were emplaced 21 ka ago (peak of the Last Glacial Maximum), suggesting a common [...]
Magma diversity reflects recharge regime and thermal structure of the crust
Published: 2020-03-03
Subjects: Earth Sciences, Geochemistry, Geology, Physical Sciences and Mathematics, Volcanology
The chemistry of magmas erupted by volcanoes is a message from deep within the Earth’s crust, which if decrypted, can provide essential information on magmatic processes occurring at inaccessible depths. While some volcanoes are prone to erupt magmas of a wide compositional variety, others sample rather monotonous chemistries through time. Whether such differences are a consequence of physical [...]
Constraining mechanisms of quartz precipitation during silicification and chemical sedimentation in the in the ~2.7 Ga Abitibi Greenstone Belt, Canada
Published: 2020-03-03
Subjects: Earth Sciences, Geochemistry, Physical Sciences and Mathematics
Silica-rich Precambrian rocks often preserve geochemical information and microfossil remnants from the early biosphere. Because these rocks are such critical geochemical and paleontological archives, we need robust tools to identify the chemical and physical conditions under which siliceous Precambrian rocks form, and determine how such information links to the specific depositional environment. [...]
Critical fluid injection volumes for uncontrolled fracture ascent
Published: 2020-03-02
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Hydro-fracturing is a routine industrial technique whose safety depends on fractures remaining confined within the target rock volume. Both observations and theoretical models show that, if the fluid volume is larger than a critical value, pockets of fluid can propagate large distances in the Earths crust in a self-sustained, uncontrolled manner. Existing models for such critical volumes are [...]
Pre-inversion normal fault geometry controls inversion style and magnitude, Farsund Basin, offshore southern Norway
Published: 2020-02-28
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Tectonics and Structure
Inversion may localise along pre-existing structures within the lithosphere, far from the plate boundaries along which the causal stress is greatest. Inversion style and magnitude is expressed in different ways, depending on the geometric and mechanical properties of the pre-existing structure. A three-dimensional approach is thus required to understand how inversion may be partitioned and [...]
Global groundwater sustainability
Published: 2020-02-28
Subjects: Earth Sciences, Hydrology, Physical Sciences and Mathematics
No abstract but introduction: Groundwater resources are the most reliable source of freshwater on the planet, so long as they are sustainably managed. While serious groundwater depletion and contamination are well documented in several regions around the world, other regions have the potential to leverage under-developed groundwater resources to fuel local human development. Here, I argue for the [...]
Mapping invasive Lupinus polyphyllus Lindl. in semi-natural grasslands using object-based analysis of UAV-borne images
Published: 2020-02-28
Subjects: Biodiversity, Earth Sciences, Environmental Sciences, Life Sciences, Physical Sciences and Mathematics, Plant Sciences
Knowledge on the spatio-temporal distribution of invasive plant species is vital to maintain biodiversity in grasslands which are threatened by the invasion of such plants and to evaluate the effect of control activities conducted. Manual digitising of aerial images with field verification is the standard method to create maps of the invasive Lupinus polyphyllus Lindl. (Lupine) in semi-natural [...]
Mapping surface displacement using a pair of interferograms: comparative study
Published: 2020-02-26
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure, Volcanology
Interferometric analysis of Synthetic Aperture Radar satellite images (InSAR) measures only one component of ground deformation, in the satellite line-of-sight direction. In order to fully resolve the three dimensional (3D) ground displacement field, InSAR images acquired with different imaging geometries are required. Despite the increase in the number of SAR missions, an area is most frequently [...]