Preprints
Filtering by Subject: Earth Sciences
Rapid quench piston cylinder apparatus: an improved design for the recovery of volatile-rich geological glasses from experiments at 0.5 - 2.5 GPa
Published: 2022-10-08
Subjects: Earth Sciences
The accurate and precise determination of the compositions of silicate glasses formed from melts containing the volatile components H2O and CO2 recovered from high-pressure, high-temperature experiments is essential to our understanding of geodynamic processes taking place within the planet. Silicate melts are often difficult to analyse chemically because the formation of quench crystals and [...]
Coupled otolith and foraminifera oxygen and carbon stable isotopes evidence paleoceanographic changes and fish metabolic responses
Published: 2022-10-07
Subjects: Earth Sciences
Capturing the mechanisms leading to the local extirpation of a species in deep-time is a challenge. Combining stable oxygen and carbon isotopic analyses on benthic and planktonic foraminifera and the otoliths of pelagic and benthic fish species, we reveal here the paleoceanographic regime shifts changes that took place in the Eastern Mediterranean from 7.2 to 6.5 Ma, in the precursor phase to the [...]
Bayesian inference on the initiation phase of the 2014 Iquique, Chile, earthquake
Published: 2022-10-03
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
We investigate the initiation phase of the 2014 Mw8.1 Iquique earthquake in northern Chile. In particular, we focus on the month preceding the mainshock, a time period known to exhibit an intensification of the seismic and aseismic activity in the region. The goal is to estimate the time-evolution and partitioning of seismic and aseismic slip during the preparatory phase of the mainshock. To do [...]
Loop Current attenuation after the Mid-Pleistocene Transition contributes to Northern hemisphere cooling
Published: 2022-10-02
Subjects: Earth Sciences, Environmental Sciences, Oceanography and Atmospheric Sciences and Meteorology
The beginning of the Mid-Pleistocene Transition (MPT) ~920 ka BP marked the expansion of northern hemisphere ice shields and caused a significant climate change in NW Europe. The MPT ended with the establishment of the 100 kyr ice age cyclicity at ~640 ka BP, due to orbital eccentricity changes. Previous studies explained the northern hemisphere cooling by cooling of sea-surface temperatures, [...]
Geochemical mapping by unmixing alluvial sediments: An example from northern Australia
Published: 2022-10-02
Subjects: Earth Sciences, Environmental Monitoring, Environmental Sciences, Geochemistry, Geomorphology, Natural Resource Economics, Sedimentology, Soil Science, Water Resource Management
Alluvial sediments have long been used in geochemical surveys as their compositions are assumed to be representative of areas upstream. Overbank and floodplain sediments, in particular, are increasingly used for regional to continental-scale geochemical mapping. However, during downstream transport, sediments from heterogeneous source regions are carried away from their source regions and mixed. [...]
Global groundwater warming
Published: 2022-10-01
Subjects: Earth Sciences, Physical Sciences and Mathematics
Aquifers contain the largest store of unfrozen freshwater, making groundwater critical for life on Earth. Groundwater temperatures infl uence stream thermal regimes, groundwater-dependent ecosystems, aquatic biogeochemical processes, water quality, and the geothermal potential. Yet little is known about how groundwater responds to surface warming across spatial and temporal scales. We simulate [...]
Impact of stress regime change on the permeability of a naturally fractured carbonate buildup (Latemar, The Dolomites, Northern Italy)
Published: 2022-09-30
Subjects: Earth Sciences
Changing stress regimes control fracture network geometry and influence porosity and permeability in carbonate reservoirs. Using outcrop data analysis and a displacement-based linear elastic finite element method, we investigate the impact of stress-regime change on fracture network permeability. The model is based on fracture networks, specifically fracture sub-structures. The Latemar, [...]
Comparative study of alteration sequences in pegmatitic aluminium phosphates
Published: 2022-09-29
Subjects: Earth Sciences, Geochemistry, Geology, Mineral Physics, Other Earth Sciences
Aluminium phosphates are mineral phases commonly occurring in rare-element pegmatites that record initial magmatic crystallization, metasomatic and hydrothermal replacements and precipitation and low-temperature alteration. Here we perform a comparative mineralogical study between several localities to assess similarities and variations in these parageneses and establish a general alteration [...]
Tsunami Early Warning from Global Navigation Satellite System Data using Convolutional Neural Networks
Published: 2022-09-29
Subjects: Earth Sciences, Geophysics and Seismology, Hydrology, Oceanography
We investigate the potential of using Global Navigation Satellite System (GNSS) observations to directly forecast full tsunami waveforms in real time. We train convolutional neural networks (CNNs) to use less than 9 minutes of GNSS data to forecast the full tsunami waveforms over 6 hours at select locations, and obtain accurate forecasts on a test dataset. Our training and test data consists of [...]
All aboard! Earth system investigations with the CH2O-CHOO TRAIN v1.0
Published: 2022-09-24
Subjects: Climate, Earth Sciences, Geochemistry, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Models of the carbon cycle and climate on geologic (>10^4 year) timescales have improved tremendously in the last 50 years due to parallel advances in our understanding of the Earth system and the increase in computing power to simulate its key processes. Despite these advances, balancing the Earth System's vast complexity with a model's computational expense is a primary challenge in model [...]
CloudSEN12 - a global dataset for semantic understanding of cloud and cloud shadow in Sentinel-2
Published: 2022-09-24
Subjects: Computer Sciences, Earth Sciences, Physical Sciences and Mathematics
Accurately characterizing clouds and their shadows is a long-standing problem in the Earth Observation community. Recent works showcase the necessity to improve cloud detection methods for imagery acquired by the Sentinel-2 satellites. However, the lack of consensus and transparency in existing reference datasets hampers the benchmarking of current cloud detection methods. Exploiting the [...]
Marine Radiocarbon Calibration in Polar Regions: A Simple Approximate Approach using Marine20
Published: 2022-09-23
Subjects: Earth Sciences, Environmental Sciences, Mathematics, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics, Statistics and Probability
The Marine20 radiocarbon (14C) age calibration curve, and all earlier marine radiocarbon calibration curves from the IntCal group, must be used extremely cautiously for the calibration of marine 14C samples from polar regions (outside ~ 40ºS – 40ºN) during glacial periods. Calibrating polar 14C marine samples from glacial periods against any Marine calibration curve (Marine20 or any earlier [...]
Characterisation of phosphate mineralogy in Montebras-en-Soumans Pegmatite, Massif Central, France
Published: 2022-09-22
Subjects: Earth Sciences, Geochemistry, Geology, Mineral Physics
Montebras-en-Soumans pegmatitic cupola hosts large pods of phosphate composed of primary amblygonite-montebrasite. These aluminium phosphate masses are considerably altered by post-magmatic processes producing a number of secondary metasomatic hydrothermal phosphates (lacroixite, wardite, morinite, viitaniemiite, apatite, triplite, eosphorite) and low-temperature phosphates (apatite, crandallite, [...]
Ocean heat uptake efficiency increase since 1970
Published: 2022-09-22
Subjects: Earth Sciences, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
The ocean stores the bulk of anthropogenic heat in the Earth system. The ocean heat uptake efficiency (OHUE) -- the flux of heat into the ocean per degree of global warming -- is therefore a key factor in how much warming will occur in the coming decades. In climate models, OHUE is well-characterised, tending to decrease on centennial timescales; in contrast, OHUE is not well-constrained from [...]
python-ags4: A Python library to read, write, and validate AGS4 geodata files
Published: 2022-09-21
Subjects: Civil and Environmental Engineering, Earth Sciences, Engineering, Environmental Engineering, Geochemistry, Geology, Geophysics and Seismology, Geotechnical Engineering
Data gathered from geotechnical, geoenvironmental, and geophysical investigations can be broadly described as "geodata". The AGS4 data format is one of the most widely used data transmittal formats for geodata and is used across the world. It is a plain text format consisting of multiple tables of comma-separated values, tied together with a robust data schema and a comprehensive suite of [...]