Preprints
There are 7090 Preprints listed.
Coupled climate and subarctic Pacific nutrient upwelling over the last 850,000 years
Published: 2019-09-06
Subjects: Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
High latitude deep water upwelling has the potential to control global climate over glacial timescales through the biological pump and ocean-atmosphere CO2 exchange. However, there is currently a lack of continuous long nutrient upwelling records with which to assess this mechanism. Here we present geochemical proxy records for nutrient upwelling and glacial North Pacific Intermediate Water [...]
Bayesian calibration of the Mg/Ca paleothermometer in planktic foraminifera
Published: 2019-08-06
Subjects: Climate, Earth Sciences, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
The Mg/Ca ratio of planktic foraminifera is a widely-used proxy for sea-surface temperature, but is also sensitive to other environmental factors. Previous work has relied on correcting Mg/Ca for non-thermal influences. Here, we develop a set of Bayesian models for Mg/Ca in four major planktic groups -- Globigerinoides ruber (including both pink and white chromotypes), Trilobatus sacculifer, [...]
Interannual, probabilistic prediction of water resources over Europe following the heatwave and drought 2018
Published: 2019-08-01
Subjects: Earth Sciences, Hydrology, Meteorology, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
The year 2018 was one of the hottest and driest years in Europe having a large impact on agriculture, ecosystems and society. The associated drought in central and northern Europe underpins the need for water resources predictions at the seasonal to interannual time scale. In this study, we propose a probabilistic, terrestrial prediction system including water resources utilizing the Terrestrial [...]
Introduction of covariance components in slip inversion of geodetic data following a non-uniform spatial distribution and application to slip deficit rate estimation in the Nankai Trough subduction zone
Published: 2019-08-02
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
When spatial distribution of observation stations has bias in geodetic slip inversion, modeling errors in the inversion scheme may result in significant unnatural short-wave components in estimated slip distribution, which overfit to data. Combined use of both land and seafloor geodetic data in slip inversion often leads to such situations. To avoid overfitting, I proposed a method to [...]
Energetics of interfacial interactions of hydrocarbon fluids with kerogen and calcite using molecular modeling
Published: 2019-07-31
Subjects: Earth Sciences, Geochemistry, Physical Sciences and Mathematics
Understanding the fluid-rock interactions is essential to characterize the behavior of petroleum fluids in reservoir formations. Such knowledge is difficult to obtain due to the heterogeneous nature of hydrocarbon systems. This study investigated the interactions of light oil molecules with kerogen and calcite using molecular dynamics simulations. Specifically, octane and octanthiol were used as [...]
Fracture and Weakening of Jammed Subduction Shear Zones, Leading to the Generation of Slow Slip Events
Published: 2019-07-31
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Geodetic data have revealed that parts of subduction interfaces creep steadily or transiently. Transient slow slip events (SSEs) are typically interpreted as aseismic frictional sliding. However, SSEs may also occur via mixed visco‐brittle deformation, as observed in shear zones containing mixtures (mélange) of strong fractured clasts embedded in a weak visco‐brittle matrix. We test the [...]
The Byers Basin: Jurassic-Cretaceous tectonic and depositional evolution of the forearc deposits of the South Shetland Islands and its implications for the northern Antarctic Peninsula
Published: 2019-07-31
Subjects: Earth Sciences, Geochemistry, Geology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy, Tectonics and Structure
This paper addresses the Jurassic–Cretaceous stratigraphic evolution of fore-arc deposits exposed along the west coast of the northern Antarctic Peninsula. In the South Shetland Islands, Upper Jurassic deep-marine sediments are uncomformably overlain by a Lower Cretaceous volcaniclastic sequence that crops out on Livingston, Snow and Low islands. U-Pb zircon ages are presented for the upper [...]
Majority of potable water microplastics are smaller than the 20 µm EU methodology limit for consumable water quality
Published: 2024-06-08
Subjects: Medicine and Health Sciences, Physical Sciences and Mathematics
Microplastic (MP) content in nutrition including potable water is unregulated, although MP concentrations in bottled water can diverge by several orders of magnitude. The EU Directive 2020/2184 on consumable water quality recently proposed methodological approaches to the detection of MPs in potable water in the size range of 20-5000 µm. However, small MPs in the 1-20 µm range are far more likely [...]
Joint sensing of bedload flux and water depth by seismic data inversion
Published: 2019-08-01
Subjects: Environmental Monitoring, Environmental Sciences, Other Environmental Sciences, Physical Sciences and Mathematics, Water Resource Management
Rivers are the fluvial conveyor belts routing sediment across the landscape. While there are proper techniques for continuous estimates of the flux of suspended solids, constraining bedload flux is much more challenging, typically involving extensive measurement infrastructure or labour-intensive manual measurements. Seismometers are potentially valuable alternatives to in-stream devices, [...]
The Gondwanan margin in West Antarctica: insights from Late Triassic magmatism of the Antarctic Peninsula
Published: 2019-07-31
Subjects: Earth Sciences, Geochemistry, Geology, Physical Sciences and Mathematics, Tectonics and Structure
Triassic orthogneisses of the Antarctic Peninsula provide evidence for the Palaeozoic and Mesozoic geological evolution of southern Gondwana within Pangaea. These rocks are sporadically exposed in southeastern Graham Land and northwestern Palmer Land, although reliable geochronological, geochemical and isotopic data are sparse. We combine new geochronological (LA-ICP-MS zircon U-Pb), geochemical, [...]
SediNet: A configurable deep learning model for mixed qualitative and quantitative optical granulometry
Published: 2019-07-31
Subjects: Civil and Environmental Engineering, Civil Engineering, Earth Sciences, Engineering, Geomorphology, Physical Sciences and Mathematics
I describe a configurable machine-learning framework to estimate a suite of continuous and categorical sedimentological properties from photographic imagery of sediment, and to exemplify how machine learning can be a powerful and flexible tool for automated quantitative and qualitative measurements from remotely sensed imagery. The model is tested on a large dataset consisting of 400 images and [...]
Detection and temperature estimation of gas flares with nocturnal Landsat OLI
Published: 2019-11-02
Subjects: Earth Sciences, Environmental Sciences, Oil, Gas, and Energy, Physical Sciences and Mathematics
Natural gas flaring is a worldwide polluting activity carried out during oil production. Satellite imagery has emerged as a low-cost, objective tool to measure and monitor gas flaring. Since 2012, hectometre-resolution infrared imagery from the Suomi NPP VIIRS sensor has been used to operationally monitor global gas flaring (Elvidge et al. 2016). Since 2013, nocturnal acquisitions of Landsat 8 [...]
Development of an Integrated Geological-Engineering Framework for Assessing the Heat Extraction Potential from the Geopressured Wilcox Reservoir on the Gulf Coast of Texas
Published: 2025-08-18
Subjects: Engineering
This study aims to establish a comprehensive framework for evaluating the geothermal potential of High-Pressure and High-Temperature (HPHT) aquifers or geopressured geothermal reservoirs in the Wilcox Formation on the onshore Gulf Coast of Texas, USA. The framework integrates geological and engineering approaches to determine the feasibility and viability of harnessing geothermal energy from [...]
Offsetting Carbon Capture and Storage costs with methane and geothermal energy production through reuse of a depleted hydrocarbon field coupled with a saline aquifer
Published: 2019-07-26
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics
Co-production of methane and geothermal energy from produced subsurface brines with onsite power generation and carbon capture has been proposed as a technically feasible means to reduce the costs of offshore carbon storage sites. In such a facility, methane is degassed from produced brine, this brine is then cooled allowing the extraction of heat and then CO2 is dissolved into it for reinjection [...]
Comment on Evaristo & McDonnell, Global analysis of streamflow response to forest management
Published: 2019-07-25
Subjects: Earth Sciences, Environmental Sciences, Forest Management, Forest Sciences, Hydrology, Life Sciences, Physical Sciences and Mathematics, Water Resource Management
Forests play a key role in the water cycle, so both planting and removing forests can affect streamflow. In a recent Nature article1, Evaristo and McDonnell used a gradient-boosted-tree model to conclude that streamflow response to forest removal is predominantly controlled by the potential water storage in the landscape, and that removing the worlds forests would contribute an additional 34,098 [...]