Preprints
Filtering by Subject: Physical Sciences and Mathematics
Controls on the distribution of hydrous defects in forsterite from a thermodynamic model
Published: 2021-04-15
Subjects: Physical Sciences and Mathematics
The distribution of hydrogen across different crystallographic sites and point defects in forsterite is important because it determines how many properties, such as rheology, conductivity, diffusion and elemental partitioning are affected by water. In this study we use lattice dynamics and Density Functional Theory (DFT) to build a thermodynamic model of H-bearing defects that incorporates both [...]
Source region geochemistry from unmixing downstream sedimentary elemental compositions
Published: 2021-04-15
Subjects: Earth Sciences, Geochemistry, Physical Sciences and Mathematics
The geochemistry of river sediments is routinely used to obtain information about geologic and environmental processes occurring upstream. For example, downstream samples are used to constrain chemical weathering and physical erosion rates upstream, as well as the locations of mineral deposits or contaminant sources. Previous work has shown that, by assuming conservative mixing, the geochemistry [...]
Structure and Stress Field of the Lithosphere between Pamir and Tarim
Published: 2021-04-14
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure
The Pamir plateau protrudes ~300 km between the Tajik- and Tarim-basin lithosphere of Central Asia. Whether its salient location and shape are caused by forceful indentation of a promontory of Indian mantle lithosphere is debated. We present a new local-seismicity and focal-mechanism catalog, and a P-wave velocity model of the eastern part of the collision system. The data suggest a [...]
Microstructural differences between naturally-deposited and laboratory beach sands
Published: 2021-04-14
Subjects: Civil and Environmental Engineering, Civil Engineering, Earth Sciences, Engineering, Geophysics and Seismology, Geotechnical Engineering, Physical Sciences and Mathematics, Sedimentology
The orientation of and contacts between grains of sand reflect the processes that deposit the sands. Grain orientation and contact geometry also influence mechanical properties. Quantifying and understanding sand microstructure thus provide an opportunity to understand depositional processes better and connect microstructure and macroscopic properties. We compare naturally-deposited beach sands [...]
Evaluation of satellite precipitation products for water allocation studies in the Sio-Malaba-Malakisi River Basin of East Africa
Published: 2021-04-14
Subjects: Physical Sciences and Mathematics
Study region: Sio Malaba Malakisi river basin, East Africa. Study Focus: Poor rain-gauge density is a limitation to comprehensive hydrological studies in Sub-Saharan Africa. Consequently, Satellite precipitation products (SPPs) provide an alternative source of data for possible use in hydrological modelling. However, there is need to test their reliabilities across varied hydro-climatic and [...]
Probing the DPRK nuclear test-site down to low seismic magnitude
Published: 2021-04-14
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
On 3 September 2017, the Democratic People’s Republic of Korea (DPRK) carried out its sixth declared underground nuclear test (NK6) at the Punggye‐ri test site. With body‐wave magnitude 6.1, this explosion was significantly larger than any of the previous five explosions, and it has been followed by numerous smaller seismic events. The explosion generated seismic waves dominated by significantly [...]
Quantification of the hydrological control on speleothem oxygen isotopic variability
Published: 2021-04-10
Subjects: Physical Sciences and Mathematics
Speleothems have long been regarded as state-of-the-art materials for terrestrial paleoclimate reconstruction owing to their potential for precisely dated chronologies and preservation of detailed oxygen isotopic (d18O) records that are routinely interpreted as a proxy for hydroclimate. Yet replicated speleothem d18O records from the same cave do not always agree, posing a conundrum: if these [...]
The Sediment Budget Estimator (SBE): a process-model for the stochastic estimation of fluxes and budgets of sediment through submarine channel systems.
Published: 2021-04-09
Subjects: Physical Sciences and Mathematics
Turbidity currents transport vast amounts of sediment through submarine channels onto deep-marine basin floor fans. There is a lack of quantitative tools for the reconstruction of the sediment budget of these systems. The aim of this paper is to construct a simple and user-friendly model that can estimate turbidity-current structure and sediment budget based on observable submarine channel [...]
Why is the Hurricane Season So Sharp?
Published: 2021-04-09
Subjects: Atmospheric Sciences, Climate, Meteorology, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Understanding tropical cyclone (TC) climatology is a problem of profound societal significance and deep scientific interest. The annual cycle is the biggest radiatively-forced signal in TC variability, presenting a key test of our understanding and modeling of TC activity. TCs over the North Atlantic (NA) basin, which are usually called hurricanes, have a sharp peak in the annual cycle, with more [...]
Paleoclimate Changes in the Pacific Northwest Over the Past 36,000 Years from Clumped Isotope Measurements and Isotope-Enabled Model Analysis
Published: 2021-04-07
Subjects: Climate, Geochemistry, Geology, Physical Sciences and Mathematics, Soil Science
Since the last glacial period, North America has experienced dramatic changes in regional climate, including the collapse of ice sheets and changes in effective precipitation. We use clumped isotopes and analysis of transient climate simulations to provide constraints on hydroclimate changes in the Pacific Northwest. The coldest soil temperatures (~10.5 ±1.°C to 14.9 ±1.2°C) occurred [...]
Orbital, the Box - An interactive educational tool for in-depth understanding of astronomical climate forcing.
Published: 2021-04-07
Subjects: Adult and Continuing Education, Astrophysics and Astronomy, Climate, Earth Sciences, Education, Educational Methods, Geology, Geophysics and Seismology, Higher Education, Instructional Media Design, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics, The Sun and the Solar System
“Orbital, the Box” provides an interactive tool with graphical user interface (GUI) for stimulating active, visual learning for understanding of astronomical climate forcing. This cross-platform tool can be run locally on a personal computer using a standard web browser environment with no need for plugins, thus maximising accessibility for students and teachers alike. The tool facilitates in the [...]
Near-real-time and state-level monitoring of U.S. CO2 emissions
Published: 2021-04-07
Subjects: Earth Sciences, Environmental Sciences, Physical Sciences and Mathematics
As the ambition and urgency of climate mitigation efforts across the U.S. increase, annual estimates of national CO2 emissions provide only vague and outdated information about changes and progress. Using near-real-time activity data compiled from numerous sources, here we present and analyze daily, state-level estimates of fossil fuel CO2 emissions from January 2019 through December 2020. Our [...]
The concavity of submarine canyon longitudinal profiles
Published: 2021-04-07
Subjects: Earth Sciences, Geology, Geomorphology, Physical Sciences and Mathematics, Sedimentology
Submarine canyons incise continental shelves and slopes, and are important conduits for the transport of sediment, nutrients, organic carbon and pollutants from continents to oceans. Submarine canyons bear morphological similarities to subaerial valleys, such as their longitudinal (long) profiles. Long profiles record the interaction between erosion and uplift, making their shape, or concavity, a [...]
Long-term hydrometeorological time-series analysis over the central highlands of West Papua
Published: 2021-04-06
Subjects: Physical Sciences and Mathematics
This article introduces an innovative data-driven approach to examining the long-term temporal rainfall patterns in the central highlands of West Papua, Indonesia. Through the utilization of wavelet transforms, we identified signs of a negative temporal correlation between the El Niño-Southern Oscillation (ENSO) and the 12-month Standardized Precipitation Index (SPI-12). Building upon this [...]
An overview of the evolving jurisdictional scope of the U.S. Clean Water Act for hydrologists
Published: 2021-04-02
Subjects: Earth Sciences, Environmental Sciences, Hydrology, Physical Sciences and Mathematics, Water Resource Management
The Clean Water Act (CWA) is the primary federal mechanism by which the physical, chemical, and biological integrity of streams, lakes, and wetlands are protected in the U.S. The CWA has evolved considerably since its initial passage in 1948, including explicit expansions and contractions of jurisdictional scope through a series of legislative actions, court decisions, and agency rules. Here, we [...]