Preprints
Filtering by Subject: Physical Sciences and Mathematics
Generation of Earth’s Early Continents From a Relatively Cool Archean Mantle
Published: 2021-06-17
Subjects: Physical Sciences and Mathematics
Several lines of evidence suggest that the Archean (4.0–2.5 Ga) mantle was hotter than today’s potential temperature (TP ) of 1350 ýC. However, the magnitude of such di erence is poorly constrained, with TP estimation spanning from 1500 ýC to 1600 ýC during the Meso-Archean (3.2-2.8 Ga). Such di erences have major implications for the interpreted mechanisms of continental crust generation on [...]
An Outsized Role for the Labrador Sea in the Multidecadal Variability of the Atlantic Overturning Circulation
Published: 2021-06-15
Subjects: Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Climate models are essential tools for investigating intrinsic North Atlantic variability related to variations in the Atlantic meridional overturning circulation (AMOC), but recent observations have called into question the fidelity of models that emphasize the importance of Labrador Sea processes. A multi-century pre-industrial climate simulation that resolves ocean mesoscale eddies has a [...]
Remote bed-level change and overwash observation with low-cost ultrasonic distance sensors
Published: 2021-06-12
Subjects: Earth Sciences, Geomorphology, Physical Sciences and Mathematics
Few datasets exist of high-frequency, in situ measurements of storm overwash, an essential mechanism for the subaerial maintenance of barrier islands and spits. Here we describe a new sensor platform for measuring bed-level change and estimating overwash inundation depths. Our MeOw (Measuring Overwash) stations consist of two ultrasonic distance sensors, a microprocessor board, and a camera and [...]
Ubiquity of human-induced changes in climate variability
Published: 2021-06-12
Subjects: Atmospheric Sciences, Biogeochemistry, Climate, Earth Sciences, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
While climate change mitigation targets necessarily concern maximum mean state changes, understanding impacts and developing adaptation strategies will be largely contingent on how climate variability responds to increasing anthropogenic perturbations. Here we present a new 100-member large ensemble of climate change projections conducted with the Community Earth System Model version 2 to examine [...]
The relative importance of wind-driven and chimney effect cave ventilation: Observations in Postojna Cave (Slovenia)
Published: 2021-06-11
Subjects: Physical Sciences and Mathematics
Density-driven chimney effect airflow is the most common form of cave ventilation, allowing gas exchange between the outside and the karst subsurface. However, cave ventilation can also be driven by other mechanisms, namely winds. We discuss the mechanism and dynamics of wind-driven ventilation using observations in Postojna Cave, Slovenia. We show how seasonal airflow patterns driven by the [...]
Flexural strike-slip basins
Published: 2021-06-10
Subjects: Physical Sciences and Mathematics
Strike-slip faults are classically associated with pull-apart basins where continental crust is thinned between two laterally offset fault segments. Here we propose a subsidence mechanism to explain the formation of a new type of basin where no substantial segment offset or syn-strike-slip thinning is observed. Such “flexural strike-slip basins” form due to a sediment load creating accommodation [...]
The hazards of unconfined pyroclastic density currents: a new synthesis and classification according to their deposits, dynamics, and thermal and impact characteristics
Published: 2021-06-08
Subjects: Earth Sciences, Physical Sciences and Mathematics, Volcanology
Pyroclastic density currents (PDCs) that escape their confining channels are among the most dangerous of volcanic hazards. These unconfined PDCs are capable of inundating inhabited areas that may be unprepared for these hazards, resulting in significant loss of life and damage to infrastructure. Despite their ability to cause serious impacts, unconfined PDCs have previously only been described [...]
Use of multi-spectral visible and near-infrared satellite data for timely estimates of the Earth's surface reflectance in cloudy conditions: Part 2 - image restoration with HICO satellite data in overcast conditions
Published: 2021-06-08
Subjects: Physical Sciences and Mathematics
Satellite-based visible and near-infrared imaging of the Earth's surface is generally not performed in moderate to highly cloudy conditions; images that look visibly cloud covered to the human eye are typically discarded. Here, we expand upon previous work that employed machine learning (ML) to estimate underlying land surface reflectances at red, green, and blue (RGB) wavelengths in cloud [...]
On the statistical learning analysis of rain gauge data over the Natuna Islands
Published: 2021-06-08
Subjects: Applied Statistics, Atmospheric Sciences, Longitudinal Data Analysis and Time Series, Meteorology, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics, Statistics and Probability
This article presents state-of-the-art statistical learning methods for analyzing rain gauge data over the Natuna Islands. By using shape preserving piecewise cubic interpolation, we managed to interpolate 671 null values from the daily precipitation data. Dominant periodicity analysis of daily precipitation signals using Lomb-Scargle Power Spectral Density shows annual, intraseasonal, and [...]
Use of multi-spectral visible and near-infrared satellite data for timely estimates of the Earth's surface reflectance in cloudy and aerosol loaded conditions: Part 1 - application to RGB image restoration over land with GOME-2
Published: 2021-06-07
Subjects: Physical Sciences and Mathematics
Space-based quantitative passive optical remote sensing of the Earth's surface typically involves the detection and elimination of cloud-contaminated pixels as an initial processing step. We explore a fundamentally different approach; we use machine learning with cloud contaminated satellite multi-spectral data to estimate underlying terrestrial surface reflectances at red, green, and blue (RGB) [...]
Equilibrated gas and carbonate standard-derived paired clumped isotope (Δ47 and Δ48) values on the absolute reference frame
Published: 2021-06-05
Subjects: Physical Sciences and Mathematics
Rationale: Carbonate clumped isotope geochemistry has primarily focused on mass spectrometric determination of m/z 47 CO2 for geothermometry, but theoretical calculations and recent experiments indicate paired analysis of the m/z 47 (13C18O16O) and m/z 48 (12C18O18O) isotopologues (referred to as Δ47 and Δ48) can be used to study non-equilibrium isotope fractionations and refine temperature [...]
Influence of fault zone maturity on fully dynamic earthquake cycles
Published: 2021-06-04
Subjects: Physical Sciences and Mathematics
We study the mechanical response of two-dimensional vertical strike-slip fault to coseismic damage evolution and interseismic healing of fault damage zones by simulating fully dynamic earthquake cycles. Our models show that fault damage zone structure evolution during the seismic cycle can have pronounced effects on the mechanical behavior of locked and creeping fault segments. Immature fault [...]
Multi-task deep learning of daily streamflow and water temperature
Published: 2021-06-03
Subjects: Hydrology, Physical Sciences and Mathematics
Deep learning models can accurately predict many hydrologic variables including streamflow and water temperature; however, these models have typically predicted hydrologic variables independently. This study explored the benefits of modeling two interdependent variables, daily average streamflow and daily average stream water temperature, together using multi-task deep learning. A multi-task [...]
The effect of temperature-dependent material properties on simple thermal models of subduction zones
Published: 2021-06-03
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
To a large extent, the thermal structure of a subduction zone determines where seismicity occurs through the transition from brittle to ductile deformation and the depth of dehydration reactions. Thermal models of subduction zones can help understand this seismicity by accurate modelling of the thermal structure of the subduction zone. Here, we assess a common simplification in thermal models of [...]
The erosive power of the Malvinas Current: Influence of bottom currents on morpho-sedimentary features along the northern Argentine margin (SW Atlantic Ocean)
Published: 2021-06-02
Subjects: Physical Sciences and Mathematics
Sediment deposits formed mainly under the influence of bottom currents (contourites) are widely used as high-resolution archives for reconstructing past ocean conditions. However, the driving processes of Contourite Depositional Systems (CDS) are not entirely understood. The aim of this study is to establish a clearer link between contourite features and the oceanographic processes that form [...]