Preprints

There are 15 Preprints listed.

The Paradox of Increasing Initial Oil Production but Faster Decline Rates in Fracking the Bakken Shale: Implications for Long Term Productivity of Tight Oil Plays

Frank Male, Ian J Duncan

Published: 2020-10-21
Subjects: Oil, Gas, and Energy, Petroleum Engineering

In the US, tight oil is the largest source of liquid hydrocarbons and has driven the country to become the world’s largest oil producer. Eventually many countries will likely be producing very large quantiles of tight oil. However, how robust is tight oil production? The answer to this question will have an impact on the future geographic spread of oil production and will have geopolitical [...]

Dynamical analysis of a reduced model for the North Atlantic Oscillation

Courtney Quinn, Dylan Harries, Terence J. O'Kane

Published: 2020-10-21
Subjects: Applied Mathematics, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics

We apply a regularized vector autoregressive clustering technique to identify recurrent and persistent states of atmospheric circulation patterns in theNorthAtlantic sector (110W-0E, 20N-90N) associated with the Atlantic Ridge (AR) and the North Atlantic Oscillation (NAO). The technique additionally provides the temporal behavior in terms of a time-dependent switching between the respective [...]

Downhole distributed acoustic sensing reveals the wave field structure of the coastal microseisms

Stanislav Glubokovskikh, Roman Pevzner, Evgenii Sidenko, Konstantin Tertyshnikov, Boris Gurevich, Sergey Shatalin, Alexey Slunyaev, Efim Pelinovsky

Published: 2020-10-21
Subjects: Engineering, Physical Sciences and Mathematics

Ocean-generated seismic waves are omnipresent in passive seismic records around the world and present both a challenge for earthquakes observations and an input signal for interferometric methods for characterisation of the Earth's interior. Understanding of these waves requires the knowledge of the depth-dependence of the oceanic noise at the transition into continent. To this end, we examine 80 [...]

Leaf trait plasticity alters competitive ability and functioning of simulated tropical trees in response to elevated carbon dioxide

Marlies Kovenock, Charles D. Koven, Ryan G. Knox, Rosie A. Fisher, Abigail L. S. Swann

Published: 2020-10-21
Subjects: Biogeochemistry, Climate, Terrestrial and Aquatic Ecology

The response of tropical ecosystems to elevated carbon dioxide (CO$_2$) remains a critical uncertainty in projections of future climate. Here we investigate how leaf trait plasticity in response to elevated CO$_2$ alters projections of tropical forest competitive dynamics and functioning. We use vegetation demographic model simulations to quantify how plasticity in leaf mass per area and leaf [...]

High-Pressure Deformation of Iron–Nickel–Silicon Alloys and Implications for Earth’s Inner Core

Matthew C Brennan, Rebecca A Fischer, Samantha Couper, Lowell Miyagi, Daniele Antonangeli, Guillaume Morard

Published: 2020-10-21
Subjects: Earth Sciences, Geophysics and Seismology, Mineral Physics, Physical Sciences and Mathematics

Earth’s inner core exhibits strong seismic anisotropy, often attributed to the alignment of hexagonal close-packed iron (hcp-Fe) alloy crystallites with the Earth’s poles. How this alignment developed depends on material properties of the alloy and is important to our understanding of the core’s crystallization history and active geodynamical forcing. Previous studies suggested that hcp-Fe is [...]

The global melt inclusion C/Ba array: mantle variability, melting process, or degassing?

Simon Matthews, Oliver Shorttle, John Maclennan, John F Rudge

Published: 2020-10-21
Subjects: Earth Sciences, Geochemistry

The Earth’s mantle holds more carbon than its oceans, atmosphere and continents combined, yet the distribution of carbon within the mantle remains uncertain. Our best constraints on the distribution of carbon within the upper mantle are derived from the carbon-trace element systematics of ultra-depleted glasses and melt inclusions from mid-ocean ridge basalts. However, carbon-trace element [...]

Multi-layered salt-prone stratigraphy and its influence on rift-basin development; The Slyne and Erris basins, offshore NW Ireland

Conor O'Sullivan, Conrad Childs, Muhammad M. Saqab, John Walsh, Patrick Shannon

Published: 2020-10-21
Subjects: Tectonics and Structure

While salt-influenced rift basins have been identified across the European Atlantic margin, the Irish Atlantic margin remains the exception despite salt being proven in several boreholes. Using an extensive seismic database coupled with data from exploration wells and shallow boreholes, this study maps the distribution and composition of salt layers and investigates their role in the structural [...]

Dynamics of core-mantle separation: influence of viscosity contrast and metal/silicate partition coefficients on the chemical equilibrium

Vincent Clesi, Julien Monteux, Baraa Qaddah, Michael Le Bars, Jean-Baptiste Wacheul, Mohamed Ali Bouhifd

Published: 2020-10-21
Subjects: Earth Sciences, Geochemistry, Geophysics and Seismology, Physical Sciences and Mathematics

The composition of the Earth's core and mantle is set by the chemical equilibrium between metals and silicates during core/mantle segregation. The metallic core separated from the mantle by gravitational descent in the form of diapirs in a magma ocean, and therefore the dynamics of the diapir's downward movement has an influence on the chemical equilibrium. In this study, we characterize the [...]

Global Systematics of Copper in Arc Magmas: A Big Data Approach

Nicholas Dewitt Barber, Marie Edmonds, Frances Jenner, Andreas Audétat, Helen Williams

Published: 2020-10-21
Subjects: Earth Sciences, Geochemistry, Geology, Volcanology

Copper, sourced from porphyry deposits formed in arc settings, is an increasingly scarce yet critical resource. The processes that shape the copper contents of magmas remain poorly understood. One theory is that magmas must be copper-rich in order to form porphyry deposits. Mature arcs have up to now played an outsized role in shaping existing models of copper systematics in magmas. Here we take [...]

Deep learning of geological structures in seismic reflecion data

Thilo Wrona, Indranil Pan, Rebecca E. Bell, Robert Gawthorpe, Haakon Fossen, Sascha Brune

Published: 2020-10-21
Subjects: Physical Sciences and Mathematics

Understanding the internal structure of our planet is a fundamental goal of the Earth Sciences. As direct observations are restricted to surface outcrops and borehole cores, we rely on geophysical data to study the Earth’s interior. Especially, seismic reflection data showing acoustic images of the subsurface, provide us with critical insights into sedimentary, tectonic and magmatic systems. The [...]

Weak influence of paleoenvironmental conditions on the subsurface biosphere of Lake Ohrid in the last 515 ka

Camille Thomas, Alexander Francke, Hendrik Vogel, Bernd Wagner, Daniel Ariztegui

Published: 2020-10-21
Subjects: Life Sciences

Lacustrine sediments are widely used to investigate the impact of climatic change on biogeochemical cycling. In these sediments, subsurface microbial communities are major actors of this cycling but can also affect the sedimentary record and overprint the original paleoenvironmental signal. We therefore investigated the subsurface microbial communities of the oldest lake in Europe, Lake Ohrid [...]

Inverse analysis to reconstruct hydraulic conditions of non-steady turbidity currents: Application to an ancient turbidite of the Kiyosumi Formation of the Awa Group, Boso Peninsula, central Japan

Kento Nakao, Hajime Naruse, Shuichi Tokuhashi

Published: 2020-10-21
Subjects: Earth Sciences, Physical Sciences and Mathematics, Sedimentology

This study proposes a new method of inverse analysis from ancient turbidites to the non-steady turbidity currents with consideration of multiple grain-size classes. The forward model employed in this study is based on the shallow water equation, and the initial condition of flows are assumed to be the lock-exchange type condition. To obtain a solution of the inverse problem, this study employed [...]

Grain Size and Beach Face Slope on Paraglacial Beaches of New England, USA

Jonathan D. Woodruff, Nicholas Venti, Stephen Mabee, Alycia DiTroia, Douglas Beach

Published: 2020-10-21
Subjects: Earth Sciences, Environmental Sciences, Oceanography and Atmospheric Sciences and Meteorology

Approximately 100 paired summer and winter transects of beach face slope and intertidal grain size were examined from 18 separate beaches in southern New England that span meso- and micro- tidal regimes. Paraglacial materials provide the principal local sediment source to beaches in this region and grain-size distribution of beaches corresponds to adjacent surficial geology. Stratified glacial [...]

A machine learning approach for prioritizing groundwater testing for per-and polyfluoroalkyl substances (PFAS)

Sarabeth George, Atray Dixit

Published: 2020-10-19
Subjects: Environmental Engineering, Environmental Health and Protection, Environmental Monitoring, Geochemistry, Hydrology, Risk Analysis, Water Resource Management

Regulatory agencies are beginning to recognize per-and polyfluoroalkyl substances (PFAS) as concerning and bioaccumulative compounds of which the use and environmental burden must be reduced. In the specific context of groundwater management, testing and mitigation strategies are desirable but can be time and cost-intensive processes. As a result, only a fraction of all groundwater wells has had [...]

Uncertainties in Projected Rainfall over Brazil: The Role of Climate Model, Bias Correction and Emission Scenario

Carolina Natel de Moura, Jan Seibert, Miriam Rita Moro Mine

Published: 2020-09-01
Subjects: Earth Sciences, Hydrology, Physical Sciences and Mathematics

The aim of this study is to answer four main questions: How well the Eta regional climate model simulates past precipitation over Brazil? What is the impact of bias correction on the reduction of model’s biases? What is the contribution of climate models, bias correction and emission scenarios to the total uncertainty of projected precipitation? And finally, what is the projected change in [...]

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