Preprints
There are 5493 Preprints listed.
Centennial- and orbital-scale erosion beneath the Greenland Ice Sheet
Published: 2021-09-01
Subjects: Earth Sciences, Geochemistry, Geomorphology, Glaciology
Erosion beneath glaciers and ice sheets is a fundamental Earth-surface process dictating landscape development, which in turn influences ice-flow dynamics and the climate sensitivity of ice masses. The rate at which subglacial erosion takes place, however, is notoriously difficult to observe because it occurs beneath modern glaciers in a largely inaccessible environment. Here, we present 1) [...]
Oxidized Mantle Sources of HIMU and EM-type Ocean Island Basalts
Published: 2021-09-01
Subjects: Earth Sciences, Geochemistry, Geology
Oxygen fugacity (fO2) is a fundamental variable in igneous petrology with utility as a potential tracer of recycled surficial materials in the sources of mantle-derived lavas. It has been postulated that ocean island basalts (OIB) have elevated fO2 relative to mid-ocean ridge basalts (MORB) owing to more oxidized source regions. To clarify this issue, trace-element systematics of olivine grains [...]
An overview of multimethod imaging approaches in environmental geophysics
Published: 2021-08-30
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Quantitative characterization of subsurface properties is critical for many environmental applications and serves as the basis to simulate and better understand dynamic subsurface processes. Geophysical imaging methods allow to image subsurface property distributions and monitor their spatio-temporal changes in a minimally invasive manner. While it is widely agreed upon that models integrating [...]
Pedogenic processes and the drying of Mars
Published: 2021-08-30
Subjects: Physical Sciences and Mathematics
What exactly caused Mars to lose its liquid water billions of years ago remains as one of the most enduring questions in planetary science. New insights from Mars suggest that crustal hydration – the formation of hydrated minerals during aqueous alteration of the crust – contributed to the long-term drying of the planet. Here, we advance the hypothesis that hydration of the Martian crust could [...]
A high-resolution downscaled CMIP6 projections dataset of essential surface climate variables over the globe coherent with the ERA5-Land reanalysis for climate change impact assessments
Published: 2021-08-30
Subjects: Earth Sciences, Environmental Sciences, Oceanography and Atmospheric Sciences and Meteorology
A high-resolution climate projections dataset is obtained by statistically downscaling climate projections from the CMIP6 experiment using the ERA5-Land reanalysis from the Copernicus Climate Change Service. This global dataset has a spatial resolution of 0.1°x 0.1°, comprises 5 climate models and includes two surface daily variables at monthly resolution: air temperature and precipitation. Two [...]
Extreme smog challenge of India intensified by increasing lower tropospheric stability
Published: 2021-08-30
Subjects: Atmospheric Sciences, Climate
Air pollution in India severely impacts the air quality, public health and economy in one of the world’s most densely populated regions. Persistent agricultural fires during the late-autumn period and widespread winter-time pollution contribute to the extreme smog in south Asia, especially affecting the entire northern India. While the links between anthropogenic emissions, air quality and health [...]
Fault rock heterogeneity can produce fault weakness and reduce fault stability
Published: 2021-08-30
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Tectonics and Structure
Geological heterogeneity is abundant in crustal fault zones; however, its role in controlling the mechanical behaviour of faults is poorly constrained. Here, we present laboratory friction experiments on laterally heterogeneous faults, with patches of strong, rate-weakening quartz gouge and weak, rate-strengthening clay gouge. The experiments show that the heterogeneity leads to a significant [...]
Linking earthquake magnitude-frequency statistics and stress in visco-frictional fault zone models
Published: 2021-08-28
Subjects: Geophysics and Seismology
The ability to estimate the likelihood of given earthquake magnitudes is critical for seismic hazard assessment. Earthquake magnitude-recurrence statistics are empirically linked to stress, yet which fault-zone processes explain this link remains debated. We use numerical models to reproduce the interplay between viscous creep and frictional sliding of a fault-zone, for which inter-seismic [...]
No demonstrated link between sea-level and eruption history at Santorini
Published: 2021-08-24
Subjects: Physical Sciences and Mathematics
Previous studies have suggested a link between rates of sea-level variation and eruptions globally [McGuire et al., 1997], with Satow and coauthors [2021] presenting the first detailed comparison between sea-level change and eruptive history for a single island-volcano. They use robust, high-resolution ages for volcanic deposits at Santorini, combined with a 2D numerical model to correlate [...]
Parsimonious velocity inversion applied to the Los Angeles Basin, CA
Published: 2021-08-24
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
The proliferation of dense arrays promises to improve our ability to image geological structures at the scales necessary for accurate assessment of seismic hazard. However, combining the resulting local high-resolution tomography with existing regional models presents an ongoing challenge. We developed a framework based on the level-set method that infers where local data provide meaningful [...]
Spectral boundary integral method for simulating static and dynamic fields from a fault rupture in a poroelastodynamic solid
Published: 2021-08-24
Subjects: Applied Mechanics, Geophysics and Seismology, Partial Differential Equations, Tribology
The spectral boundary integral method is popular for simulating fault, fracture, and frictional processes at a planar interface. However, the method is less commonly used to simulate off-fault dynamic fields. Here we develop a spectral boundary integral method for poroelastodynamic solid. The method has two steps: first, a numerical approximation of a convolution kernel and second, an efficient [...]
Fire-Generated Tornadic Vortices
Published: 2021-08-23
Subjects: Atmospheric Sciences, Meteorology
Fire-generated tornadic vortices (FGTVs) linked to pyrocumulonimbi (pyroCb) are a potentially deadly, yet poorly understood and seldom observed wildfire hazard. In this study we use radar and satellite observations to examine three FGTV cases during high impact wildfires during the 2020 fire season in California, USA. We establish that these FGTVs each exhibit tornado-strength anticyclonic [...]
SUBSTRATE ENTRAINMENT, DEPOSITIONAL RELIEF, AND SEDIMENT CAPTURE: IMPACT OF A SUBMARINE LANDSLIDE ON FLOW PROCESS AND SEDIMENT SUPPLY
Published: 2021-08-23
Subjects: Physical Sciences and Mathematics
Submarine landslides can generate complicated patterns of seafloor relief that influence subsequent flow behaviour and sediment dispersal patterns. While the large-scale morphology of submarine landslide deposits, or mass transport deposits (MTDs), can be resolved in seismic data, the nature of their upper surface, and its impact on facies distributions and stratal architecture of overlying [...]
Comprehensive aerial survey quantifies high methane emissions from the New Mexico Permian Basin
Published: 2021-08-21
Subjects: Atmospheric Sciences, Engineering, Environmental Sciences, Oceanography and Atmospheric Sciences and Meteorology, Oil, Gas, and Energy, Physical Sciences and Mathematics
Limiting emissions of climate-warming methane from oil and gas (O&G) is a major opportunity for short-term climate benefits. We deploy a basin-wide airborne survey of the New Mexico Permian Basin, spanning 35,923 km^2, 26,292 active wells, and over 15,000 km of natural gas pipelines using an independently-validated hyperspectral methane point source detection and quantification system. The [...]
Surface and subsurface damage caused by bullet impacts into sandstone
Published: 2021-08-20
Subjects: Earth Sciences
The shift of armed conflicts to more urbanised environments has increased risk to cultural her-itage sites. Small arms impacts are ubiquitous in these circumstances, yet the effects and mecha-nisms of damage caused are not well known. A sandstone target was shot under controlled con-ditions to investigate surface and subsurface damage. A 3D model of the damaged block, created by structure from [...]