Preprints
There are 4720 Preprints listed.
Mg/Ca and Sr/Ca as Palaeothermometers: New data from Middle Jurassic Belemnites from Germany and Portugal.
Published: 2022-04-03
Subjects: Physical Sciences and Mathematics
In belemnite macrofossil calcite, Mg/Ca and Sr/Ca ratios have long been proposed as a palaeotemperature proxy. However, its use has proved controversial with different studies yielding contradictory results. Oxygen isotopes (
The effect of a weak asthenospheric layer on surface kinematics, subduction dynamics and slab morphology in the lower mantle
Published: 2022-04-02
Subjects: Earth Sciences, Physical Sciences and Mathematics
On Earth, the velocity at which subducting plates are consumed at their trenches (termed `subduction rate' herein) is typically 3 times higher than trench migration velocities. The subduction rate is also 5 times higher than estimated lower mantle slab sinking rates. Using simple kinematic analyses, we show that if this present-day ``kinematic state'' operated into the past, the subducting [...]
Data from the drain: a sensor framework that captures multiple drivers of chronic coastal floods
Published: 2022-04-02
Subjects: Earth Sciences, Environmental Monitoring, Environmental Sciences, Hydrology, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Tide gauge water levels are commonly used as a proxy for flood incidence on land. These proxies are useful for projecting how sea-level rise (SLR) will increase the frequency of coastal flooding. However, tide gauges do not account for land-based sources of coastal flooding and therefore flood thresholds and the proxies derived from them likely underestimate the current and future frequency of [...]
Weathering intensity and lithium isotopes: A reactive transport perspective
Published: 2022-04-02
Subjects: Earth Sciences, Physical Sciences and Mathematics
Lithium isotopes have emerged as a powerful tool to probe the response of global weathering to changes in climate. Due to the preferential incorporation of 6Li into clay minerals during chemical weathering, the isotope ratio δ7Li may be used to interrogate the balance of primary mineral dissolution and clay precipitation. This balance has been linked to relative rates of chemical and physical [...]
Straining to Learn Permeability
Published: 2022-04-02
Subjects: Engineering
Characterizing fluid flow in a porous material with permeability is fundamental to energy and hydrological applications, yet direct measurements of permeability are very difficult to conduct in situ. However, attending fluid flow through a material are various mechanical responses, e.g., strain fields, acoustic emission. These mechanical responses may hold important clues to the fluid flow in the [...]
A computational framework for time dependent deformation in viscoelastic magmatic systems
Published: 2022-04-01
Subjects: Applied Mathematics, Computer Sciences, Earth Sciences, Mathematics
Time-dependent ground deformation is a key observable in active magmatic systems, but is challenging to characterize. Here we present a numerical framework for modeling transient deformation and stress around a subsurface, spheroidal pressurized magma reservoir within a viscoelastic half-space with variable material coefficients, utilizing a high-order finite-element method and explicit [...]
Fencing farm dams to exclude livestock halves methane emissions and improves water quality.
Published: 2022-03-31
Subjects: Agricultural Science, Agriculture, Agronomy and Crop Sciences Life Sciences, Biochemistry, Biophysics, and Structural Biology, Earth Sciences, Environmental Sciences
Agricultural practices have created tens of millions of small artificial water bodies (“farm dams” or “agricultural ponds”) to provide water for domestic livestock worldwide. Among freshwater ecosystems, farm dams have some of the highest greenhouse gas (GHG) emissions per m2 due to fertilizer and manure run-off boosting methane production – an extremely potent GHG. However, management strategies [...]
Satellites detect a methane ultra-emission event from an offshore platform in the Gulf of Mexico
Published: 2022-03-31
Subjects: Environmental Sciences
Mitigation of methane emissions from fossil fuel extraction, processing and transport is one of the most effective ways to slow global warming. Satellite-based methods are being instrumental for the detection, characterization, and quantification of this type of emissions. However, despite the rapid development of satellite-based methane plume detection methods for terrestrial surfaces, there is [...]
Displacement/length scaling relationships for normal faults; a review, critique, and revised compilation
Published: 2022-03-30
Subjects: Earth Sciences, Physical Sciences and Mathematics
The relationship between normal fault displacement (D) and length (L) varies due to numerous factors, including fault size, maturity, basin tectonic history, and host rock lithology. Understanding how fault D and L relate is useful, given related scaling laws are often used to help refine interpretations of often incomplete, subsurface datasets, which has implications for hydrocarbon and [...]
Spatial scale evaluation of forecast flood inundation maps
Published: 2022-03-30
Subjects: Hydrology, Physical Sciences and Mathematics
Flood inundation forecast maps provide an essential tool to disaster management teams for planning and preparation ahead of a flood event in order to mitigate the impacts of flooding on the community. Evaluating the accuracy of forecast flood maps is essential for model development and improving future flood predictions. Conventional, quantitative binary verification measures typically provide a [...]
Late Glacial and Holocene Palaeolake History of the Última Esperanza Region of Southern Patagonia
Published: 2022-03-29
Subjects: Earth Sciences, Geochemistry, Geology, Geomorphology, Glaciology, Hydrology, Paleobiology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy, Volcanology
We undertook multiproxy analyses on two sediment cores from Lago Pato, a small lake basin at 51°S topographically separated from Lago del Toro in Torres del Paine (TdP), to provide insights into glacier dynamics and lake level change in the TdP and Última Esperanza region over the last ~30,000 cal a BP (30 ka). Lago Pato is situated in a region overridden by the Southern Patagonian Icefield [...]
Coastal River Response to Transgression: A New Look at the Trinity Incised Valley Using Multi-Resolution Seismic Imaging
Published: 2022-03-29
Subjects: Earth Sciences, Geology, Geomorphology, Geophysics and Seismology, Sedimentology
Modern lowland river systems show transitions in flow characteristics near coastlines that lead to systematic changes in sediment deposition and stratigraphic architecture. Sensitivity of fluvial morphodynamics to base-level has important implications for the prediction and interpretation of fluvial stratigraphy, particularly in deposits formed during periods of relative sea-level rise such as [...]
Stratigraphic architecture of the world’s oldest shale gas play: The 1400-1200 Ma Velkerri and Kyalla formations in the Beetaloo Sub-Basin
Published: 2022-03-29
Subjects: Earth Sciences
The Mesoproterozoic Velkerri and Kyalla formations in the Beetaloo Sub-basin in northern Australia contain the world’s oldest shale plays. In unconventional exploration, the main challenge is the identification of sweet spots from which hydrocarbons can be produced economically. In fine-grained siliciclastic intervals, the distribution of these sweet spots is mainly controlled by the evolution of [...]
Decoupling between strain localisation and the microstructural record revealed by in-situ strain measurements in polycrystalline ice
Published: 2022-03-28
Subjects: Earth Sciences, Glaciology, Tectonics and Structure
We explore the links between strain localisation and microstructural evolution in ice Ih deformed by dislocation creep. Using digital image correlation (DIC), we monitored the evolution of the strain field in two coarse-grained columnar ice samples deformed by creep (uniaxial compression at constant load) at -7 °C and 0.5 MPa up to 9.5% bulk shortening. After a brief transient (<0.2% bulk [...]
A mid-20th century estimate of global vegetation carbon stocks based on inventory statistics
Published: 2022-03-28
Subjects: Environmental Studies, Forest Sciences, Geography
Biomass carbon stocks (BCS) play a vital role in the climate system, but benchmarked estimates prior to the late 20th century remain scarce. Here, by making use of an early global forest resource assessment and harmonizing information on land use and carbon densities, we establish a global BCS account for the year 1950. Our best-guess BCS estimate is 450.7 PgC (median of all modulations: 518.3 [...]