Preprints
Filtering by Subject: Earth Sciences
Deformation mechanisms and characteristics of the meta-BIFs from an early Proterozoic shear system of the Southern Granulite Terrane (SGT), India
Published: 2022-01-27
Subjects: Earth Sciences
We studied three samples of Banded Iron Formation (BIF) rocks from Southern Granulite Terrane (SGT) of India, which was metamorphosed at high-pressure granulite facies and exhumed from 40-50 km depth. We examined the microstructure, texture, and deformation mechanisms of the primary minerals (quartz, magnetite, and hematite). Microstructures, variations in size and shape of quartz grains suggest [...]
Tectonics dominates over climatic and oceanographic factors in controlling the physiography of the Americas shelf-break at a continental scale
Published: 2022-01-25
Subjects: Earth Sciences, Physical Sciences and Mathematics
The continental shelf-break defines the boundary between shallow- and deep-ocean environments, and is modified by subaerial and submarine processes through geological time. The physiography of the shelf-break therefore records the cumulative influence of these processes, and dictates where, and how efficiently, particulates and pollutants are transported into the deep-ocean. Despite its [...]
Explaining Variance of Pleistocene Climate Sensitivity: Path, Epochal and CO2 dependence
Published: 2022-01-25
Subjects: Earth Sciences, Environmental Sciences, Other Earth Sciences, Physical Sciences and Mathematics
Improved high-resolution paleo records of atmospheric carbon dioxide (CO2) concentrations and reconstructions of Earth’s surface temperature are available. We analyze one authoritative Pleistocene data set to explore how the climate sensitivity parameter S varies under different system states, using linear regression of mean annual surface temperature changes against CO2 forcing changes. On the [...]
Deep submarine infiltration of altered geothermal groundwater on the south Chilean Margin
Published: 2022-01-25
Subjects: Earth Sciences, Geochemistry, Geology, Hydrology, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Other Earth Sciences, Physical Sciences and Mathematics
Submarine groundwater discharge is increasingly recognized as an important component of the oceanic geochemical budget, but knowledge of the distribution of this phenomenon is limited. To date, reports of meteoric inputs to marine sediments are typically limited to shallow shelf and coastal environments, whereas contributions of freshwater along deeper sections of tectonically active margins like [...]
Traversing the academic ladder as an early career researcher in earth and environmental sciences
Published: 2022-01-21
Subjects: Earth Sciences, Environmental Sciences
There is growing concern in Higher Education around job security, work-life balance and inequalities, and early career academics must make difficult trade-offs and life choices. Ample literature confirms that women navigating academia face additional challenges. Few studies have sought to connect contractual circumstances, employment priorities and their impacts on the life choices of individual [...]
Deep-water cycling and the Magmatic History of the Earth
Published: 2022-01-20
Subjects: Earth Sciences, Planetary Sciences
Earth is a magmatically active planet. Magmatism connects Earth's interior to its atmosphere, hydrosphere, and biosphere through cycling of volatiles, greenhouse gasses, and nutrients. Earth's magmatic history is intertwined with its thermal and tectonic evolution. How magmatism has evolved and been maintained in the face of planetary cooling remains an open question. We address this question [...]
Frequency-Difference Backprojection of Earthquakes
Published: 2022-01-20
Subjects: Earth Sciences
Back-projection has proven useful in imaging large earthquake rupture processes. The method is generally robust and does not require many assumptions about the fault geometry or the Earth velocity model. It can be applied in both the time and frequency domain. However, back-projection images are often obtained from records filtered in a narrow frequency range, limiting our ability to uncover the [...]
Subsurface Flow Batteries: Concept, Benefits and Hurdles
Published: 2022-01-19
Subjects: Earth Sciences
Storage of flow-battery electrolytes in aquifers is a novel concept for storing electrical energy in the subsurface. Flow-batteries operate by electrochemical transformations of electrolytes, rather than of electrodes, and their energy capacity can therefore be increased indefinitely by using larger electrolyte tanks. Saline aquifers may be the cheapest way to provide large-scale storage for this [...]
Phanerozoic sedimentary cover history of the Hudson Platform: a heuristic modeling perspective
Published: 2022-01-19
Subjects: Earth Sciences, Geochemistry, Geology, Geomorphology, Physical Sciences and Mathematics, Stratigraphy, Tectonics and Structure
Understanding the long-term erosion and burial history of cratons is challenging due to the incompleteness of the rock record. Low-temperature thermochronology is used to elucidate these surface histories by inverting thermochronological data for the time-temperature history and incorporating sparse constraints and other assumptions about the regional geologic evolution. However, imposing certain [...]
Fully distributed rainfall-runoff modeling using spatial-temporal graph neural network
Published: 2022-01-15
Subjects: Civil and Environmental Engineering, Earth Sciences, Engineering, Environmental Engineering, Hydrology
Recent studies using latest deep learning algorithms such as LSTM (Long Short-Term Memory) have shown great promise in time-series modeling. There are many studies focusing on the watershed-scale rainfall-runoff modeling or streamflow forecasting, often considering a single watershed with limited generalization capabilities. To improve the model performance, several studies explored an integrated [...]
How winds and river discharge affect circulation in a mesotidal estuary, San Francisco Bay, USA
Published: 2022-01-14
Subjects: Earth Sciences
Previous studies suggest importance of wind forcing on salt intrusion length and salt flux in river-dominated microtidal estuaries (with tidal range < 2 m). In this study, we investigate the role of wind forcing on salt intrusion in a mesotidal estuary, San Francisco Bay (SFB), with tidal ranges between 2 m and 4 m, through an open-source model of high transferability, the Semi-implicit [...]
Variations in Earth's 1D viscosity structure in different tectonic regimes
Published: 2022-01-14
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure
Past estimates of Earth’s mantle viscosity profile using the long-wavelength geoid suggest an increase in viscosity from the upper to lower mantle of roughly 2-3 orders of magnitude. We use a spatio-spectral localization technique with the geoid to estimate a series of locally constrained viscosity profiles covering two unique regions, the Pacific and Atlantic hemispheres. The Pacific region [...]
Explosive activity on Kīlauea’s Lower East Rift Zone fuelled by a volatile-rich, dacitic melt
Published: 2022-01-12
Subjects: Earth Sciences, Geochemistry, Physical Sciences and Mathematics, Volcanology
Magmas with matrix glass compositions ranging from basalt to dacite erupted from a series of 24 fissures in the first two weeks of the 2018 Lower East Rift Zone (LERZ) eruption of Kīlauea Volcano. Eruption styles ranged from low spattering and fountaining to strombolian activity. Major element trajectories in matrix glasses and melt inclusions hosted by olivine, pyroxene and plagioclase are [...]
Arc-parallel shears in collisional orogens: Global review and paleostress analyses from the NW Lesser Himalayan Sequence (Garhwal region, Uttarakhand, India)
Published: 2022-01-10
Subjects: Earth Sciences
Interest in hydrocarbon exploration from the the Lesser Himalayan Sequence (LHS) has recently been revived amongst petroleum geoscientists. Understanding the paleostress regime and the deformation processes are the two important steps to understand the structural geology of any (petroliferous) terrane. Arc-parallel shear is an integral deformation process in orogeny. The scale of the consequent [...]
Surface damage from perpendicular and oblique bullet impacts in stone
Published: 2022-01-09
Subjects: Earth Sciences
Controlled experiments were conducted to investigate the surface damage caused by perpendicular and oblique impacts of bullets into sandstone and limestone targets. Individual bullets fired in conditions simulating modern rifles at typical combat distances excavated craters with diameters from 22 to 74 mm and depths from 4 to 24 mm. Limestone target craters were up to twice as large and deep as [...]