Preprints
Filtering by Subject: Earth Sciences
Sampling across large-scale geological gradients to study geosphere-biosphere interactions
Published: 2022-07-25
Subjects: Biogeochemistry, Earth Sciences, Environmental Sciences, Geochemistry, Life Sciences, Microbiology
Despite being one of the largest microbial ecosystems on Earth, with >1029 microbial cells, many basic open questions remain about how life exists and thrives in the deep subsurface biosphere, inside Earth’s crust. Much of this ambiguity is due to the fact that it is exceedingly difficult and (often prohibitively expensive) to directly sample the deep subsurface, requiring elaborate drilling [...]
Geochemical implication of Eu isotopic ratio in anorthosite: new evidence of Eu isotope fractionation during feldspar crystallization
Published: 2022-07-25
Subjects: Earth Sciences, Physical Sciences and Mathematics
Rare earth element geochemistry can provide critical information on the evolution of the crust-mantle system. Europium (Eu) exists in divalent and trivalent states, and Eu2+ can substitute for Ca2+ during plagioclase feldspar crystallization in reducing magmas. This leads to positive Eu anomaly in Ca-plagioclase-rich anorthosite derived from the mantle and negative Eu anomalies in fractionated [...]
Machine Learning for Elastic-Electrical Cross-Property Modelling Of Sandstones
Published: 2022-07-25
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Improving slope stability estimates by incorporating geophysical and remote sensing monitoring data into hydro-geomechanical modeling
Published: 2022-07-20
Subjects: Earth Sciences
Landslides are a major natural hazard, threatening communities and infrastructure worldwide. The mitigation of these hazards relies on the understanding of their causes and triggering processes, directly depending on soil properties, land use, and their variations over time. In this study, we propose a new approach combining geophysics and remote sensing with hydrological and geomechanical [...]
Understanding Slow-moving Landslide Triggering Processes Using Low-cost Passive Seismic and Inclinometer Monitoring
Published: 2022-07-20
Subjects: Earth Sciences
Landslides are a major natural hazard, threatening communities and infrastructures worldwide. Mitigation of these hazards relies on understanding their causes and triggering processes, which critically depend on subsurface characteristics and their variations over time. In this study, we present a novel approach combining passive seismic and low-cost inclinometer monitoring methods to improve the [...]
A Technical Overview of the North Carolina ECONet
Published: 2022-07-20
Subjects: Agricultural Science, Agriculture, Atmospheric Sciences, Climate, Earth Sciences, Environmental Education, Environmental Monitoring, Environmental Public Health, Environmental Sciences, Forest Management, Meteorology, Oceanography and Atmospheric Sciences and Meteorology, Plant Sciences
Regional weather networks–also referred to as mesonets–are imperative for filling in the spatial and temporal data gaps between nationally supported weather stations. The North Carolina Environment and Climate Observing Network (ECONet) fills this regional role; it is a mesoscale network of 44 (as of 2023) automated stations collecting 12 environmental variables every minute across North [...]
Mechanical Analysis of Fault Slip Rate Sites within the San Gorgonio Pass Region, Southern California USA
Published: 2022-07-16
Subjects: Earth Sciences, Tectonics and Structure
Crustal deformation models show incompatibility between inferred fault geometry and geologic slip rates where model and geologic slip rates disagree. We do not know if the impact of these incompatibilities is local to sites or has wider effect on the fault system deformation. Here, we investigate the roles of structural position of sites and uncertainty of slip rates using one suite of mechanical [...]
Large hot provinces at the base of the mantle stabilise the palaeomagnetic field
Published: 2022-07-15
Subjects: Earth Sciences, Other Earth Sciences
A crucial characteristic of Earth’s magnetic field, known since 1600, is that it approximates a dipole (bar magnet) aligned with the planetary rotation axis. Previous studies have disagreed over the extent to which this situation has persisted through geological time which is important for determining solar wind shielding and building palaeogeographic reconstructions. It has recently become [...]
Sinh-arcsinh-normal distributions to add uncertainty to neural network regression tasks: applications to tropical cyclone intensity forecasts
Published: 2022-07-15
Subjects: Artificial Intelligence and Robotics, Earth Sciences, Statistical Methodology
A simple method for adding uncertainty to neural network regression tasks in earth science via estimation of a general probability distribution is described. Specifically, we highlight the sinh-arcsinh-normal distributions as particularly well suited for neural network uncertainty estimation. The methodology supports estimation of heteroscedastic, asymmetric uncertainties by a simple modification [...]
Slab to back-arc to arc: fluid and melt pathways through the mantle wedge beneath the Lesser Antilles
Published: 2022-07-14
Subjects: Earth Sciences, Geochemistry, Geophysics and Seismology, Tectonics and Structure, Volcanology
Volatiles expelled from subducted plates melt the overlying warm mantle, feeding arc volcanism. However, debates continue over the factors controlling melt generation and transport and how these determine the placement of volcanoes. To broaden our synoptic view of these fundamental mantle wedge processes, we image seismic attenuation beneath the Lesser Antilles arc, an end-member system that [...]
Barren ground depressions, natural H2 and orogenic gold deposits: spatial link and geochemical model
Published: 2022-07-11
Subjects: Earth Sciences, Ecology and Evolutionary Biology, Geochemistry, Geology, Geomorphology, Soil Science
A review of the localities in continental rocks where H2-rich gases have been reported, showed that they are mainly located near gold deposits. Two types of geomorphological features known as markers of gas venting in sedimentary basins were also systematically observed near orogenic gold deposits on satellite images. They consist in both barren ground depressions and high densities of small (< [...]
Mantle flow pattern associated with the Patagonian slab window determined from azimuthal anisotropy
Published: 2022-07-08
Subjects: Earth Sciences, Physical Sciences and Mathematics
Geological processes in Southern Patagonia are affected by the Patagonian slab window, formed by the subduction of the Chile Ridge and subsequent northward migration of the Chile Triple Junction. Using shear wave splitting analysis, we observe strong splitting of up to 2.5 s with an E-W fast direction just south of the triple junction and the edge of the subducting Nazca slab. This region of [...]
Initiation of deposition in supercritical turbidity currents downstream of a slope break.
Published: 2022-07-07
Subjects: Earth Sciences
Turbidity currents flowing across the ocean floor encounter changes of the local bathymetry including abrupt reductions in slope gradient also known as slope breaks. Turbidity currents flowing across a slope break will change their flow dynamics and may start to deposit as a consequence. Previous experiments on turbidity currents crossing a slope break have indeed observed abrupt changes of flow [...]
Seismic interferometry in the presence of an isolated noise source
Published: 2022-07-03
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Seismic interferometry gives rise to a correlation wavefield that is closely related to the Green's function under the condition of uniformly distributed noise sources. In the presence of an additional isolated noise source, a second contribution to this wavefield is introduced that emerges from the isolated source location at negative lapse time. These two contributions interfere, which may bias [...]
The root to the Galápagos mantle plume on the core-mantle boundary
Published: 2022-07-01
Subjects: Earth Sciences, Physical Sciences and Mathematics
Ultra-low velocity zones (ULVZs) are thin anomalous patches on the boundary between the Earth's core and mantle, revealed by their effects on the seismic waves that propagate through them. Here we map a broad ULVZ near the Galápagos hotspot using shear-diffracted waves. Forward modelling assuming a cylindrical shape shows the patch is ~600 km wide, ~20 km high, and its shear velocities are ~25% [...]