Preprints
There are 4725 Preprints listed.
Smooth crustal velocity models cause a depletion of high-frequency ground motions on soil in 2-D dynamic rupture simulations
Published: 2021-02-04
Subjects: Physical Sciences and Mathematics
A depletion of high-frequency ground motions on soil sites has been observed in recent large earthquakes and is often attributed to the nonlinear soil response. Here we show that the reduced amplitudes of high-frequency horizontal-to-vertical spectral ratios on soil can also be caused by a smooth crustal velocity model with low shear wave velocities underneath soil sites. We calculate near-fault [...]
Audible acoustics from low-magnitude fluid-induced earthquakes in Finland
Published: 2021-02-03
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Earthquakes are frequently accompanied by public reports of audible low-frequency noises. In 2018, public reports of booms or thunder-like noises were linked to induced earthquakes during a Engineered Geothermal System project in the Helsinki Metropolitan area. In response, two microphone arrays were deployed to record and study these acoustic signals while stimulation at the drill site [...]
Back to the fields: COVID-19 impact on agricultural activity detected with satellite data
Published: 2021-02-03
Subjects: Environmental Studies
In response to the 2020 COVID-19 pandemic, policymakers worldwide adopted unprecedented measures to limit disease spread, with major repercussions on labour markets and economic growth. Here we provide empirical evidence of their impact on agricultural activity due to sectoral labour reallocation. Analysing daily satellite data in a non-parametric machine learning statistical framework over [...]
Upper Mantle Radial Anisotropy Under the Indian Ocean from Higher Mode Surface Waves and a Hierarchical Transdismensional Approach
Published: 2021-02-03
Subjects: Earth Sciences, Geophysics and Seismology
We investigated the likelihood of radial anisotropy in the shallow and deep upper mantle, including the mantle transition zone (MTZ) under the Indian Ocean. Seismic anisotropy can be an indicator of mantle deformation through lattice preferred orientation of anisotropic crystals in the mantle. It has thus the potential to illuminate Earth's dynamic interior, but previous seismic tomography [...]
Waste Incinerators Undermine Clean Energy Goals
Published: 2021-02-03
Subjects: Climate, Oil, Gas, and Energy
A national clean energy standard, modeled upon existing state-level Renewable Portfolio Standards, has been proposed to decarbonize the U.S. electric grid. Most such state policies include municipal solid waste incineration as a form of “renewable” energy, despite incineration’s prominent role in perpetuating environmental injustice. This study finds that incinerators emit more greenhouse gas [...]
Distilling the Mechanism for the Madden-Julian Oscillation into a Simple Translating Structure
Published: 2021-02-02
Subjects: Physical Sciences and Mathematics
This paper presents a minimal model of the Madden--Julian Oscillation (MJO), isolating a robust mechanism that leads to the observed characteristic pattern and eastward propagation. A localized heat source due to condensation at the equator leads to a Gill-like pattern in the geopotential, which in turn induces moisture convergence and further condensation. Over a wide range of parameters [...]
Seasonal Arctic sea ice forecasting with probabilistic deep learning
Published: 2021-02-02
Subjects: Artificial Intelligence and Robotics, Earth Sciences, Statistics and Probability
Anthropogenic warming has led to an unprecedented year-round reduction in Arctic sea ice extent. This has far-reaching consequences for indigenous and local communities, polar ecosystems, and global climate, motivating the need for accurate seasonal sea ice forecasts. While physics-based dynamical models can successfully forecast sea ice concentration several weeks ahead, they struggle to [...]
Post-2018 caldera collapse re-inflation uniquely constrains Kīlauea's magmatic system
Published: 2021-02-02
Subjects: Physical Sciences and Mathematics
From August 2018 to May 2019, Kīlauea’s summit exhibited unique, simultaneous, inflation and deflation, apparent in both GPS time series and Small Baseline Subset (SBAS) derived cumulative InSAR displacement maps. This deformation pattern provides clear evidence that Halema`uma`u (HMM) and South Caldera (SC) are distinct reservoirs. Post-collapse inflation of the East Rift Zone (ERZ), as captured [...]
Why do we have so many different hydrological models? A review based on the case of Switzerland
Published: 2021-02-02
Subjects: Hydrology, Water Resource Management
Hydrology plays a central role in applied and fundamental environmental sciences, but it is well known to suffer from an overwhelming diversity of models, particularly to simulate streamflow. We discuss here in detail how such diversity did arise based on the example of Switzerland. The case study's relevance stems from the fact that Switzerland, despite of being a small country, shows a variety [...]
Classification, segmentation and correlation of zoned minerals
Published: 2021-02-01
Subjects: Earth Sciences, Environmental Sciences, Geochemistry, Geology, Numerical Analysis and Scientific Computing, Statistics and Probability, Volcanology
Minerals exhibit zoning patterns that can be related to changes in the environment in which they grew. Using statistical methods that have been designed to segment optical images, we have developed a procedure to segment zonation within minerals and correlate these zones between multiple crystals using elemental maps. This allows us to quantify the complexity and variability of chemical zoning [...]
Ordination analysis in sedimentology, geochemistry and paleoenvironment - background, current trends and recommendations
Published: 2021-02-01
Subjects: Biogeochemistry, Earth Sciences, Environmental Indicators and Impact Assessment, Environmental Monitoring, Geochemistry, Geology, Geomorphology, Geophysics and Seismology, Glaciology, Multivariate Analysis, Oil, Gas, and Energy, Other Earth Sciences, Paleobiology, Paleontology, Sedimentology
Ordination is the name given to a group of methods used to analyze multiple variables without preceding hypotheses. Over the last few decades the use of these methods in Earth science in general, and notably in analyses of sedimentary sources, has dramatically increased. However, with limited resources oriented towards Earth scientists on the topic, the application of ordination analysis is at [...]
Quantitative chemical mapping of plagioclase as a tool for the interpretation of volcanic stratigraphy: an example from Saint Kitts, Lesser Antilles
Published: 2021-02-01
Subjects: Earth Sciences, Geochemistry, Geology, Stratigraphy, Volcanology
Establishing a quantitative link between magmatic processes occurring at depth and volcanic eruption dynamics is essential to forecast the future behaviour of volcanoes, and to correctly interpret monitoring signals at active centres. Chemical zoning in minerals, which captures successive events or states within a magmatic system, can be exploited for such a purpose. However, to develop a [...]
Dynamical attribution of North Atlantic interdecadal predictability to oceanic and atmospheric turbulence under realistic and optimal stochastic forcing
Published: 2021-02-01
Subjects: Climate, Environmental Sciences, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Unpredictable variations in the ocean originate from both external atmospheric forcing and chaotic processes internal to the ocean itself, and are a crucial sink of predictability on interdecadal timescales. In a global ocean model, we present i.) an optimisation framework to compute the most efficient noise patterns to generate uncertainty and ii.) a uniquely inexpensive, dynamical method for [...]
Temperature and water depth effects on brGDGT distributions in sub-alpine lakes of mid-latitude North America
Published: 2021-01-31
Subjects: Earth Sciences, Environmental Sciences, Physical Sciences and Mathematics
Branched glycerol dialkyl glycerol tetraethers (brGDGTs) in lake sediments are increasingly being used to reconstruct past temperatures. However, recent studies suggest that brGDGT distributions and concentrations vary with lake size and environmental conditions such as seasonality and its effects on water column temperature and chemistry. To test their use as a paleothermometer in high-altitude [...]
Observations of nonlinear momentum fluxes over the inner continental shelf
Published: 2021-01-31
Subjects: Oceanography and Atmospheric Sciences and Meteorology
Nonlinear momentum fluxes over the inner continental shelf are examined using moored observations from multiple years at two different locations in the Middle Atlantic Bight. Inner shelf dynamics are often described in terms of a linear alongshore momentum balance, dominated by frictional stresses generated at the surface and bottom. In this study, observations over the North Carolina inner shelf [...]