There are 2117 Preprints listed.

The distribution of hydrogen/water in Al and Ti-containing forsterite: A thermodynamic model

Joshua Martin Richard Muir, Michael Jollands, Feiwu Zhang, Andrew Walke

Published: 2021-04-15
Subjects: Physical Sciences and Mathematics

In forsterite the functional form of water is regard to be hydrogen. The distribution of this hydrogen across different sites in forsterite is important because it determines what rheological properties of forsterite are affected by water and how they are affected. In this study we use lattice dynamic Density Functional Theory (DFT) to build a thermodynamic model of hydrogen in forsterite that [...]

Unmixing river sediments for the elemental geochemistry of their source regions

Alex Lipp, Gareth Roberts, Alexander C Whittaker, Charles J. B. Gowing, Victoria Fernandes

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, as well as the locations of mineral deposits or contaminant sources. Previous work has shown that, by assuming conservative mixing, the geochemistry of [...]

A global hydrothermal reactor triggered prebiotic synthesis on Earth

Chiara Boschi, Andrea Dini, Gretchen L. Früh-Green, Luca Caricchi

Published: 2021-04-15
Subjects: Biogeochemistry, Earth Sciences, Geochemistry, Geology, Planetary Geology

Biosignatures in the rock record limit the time available for life to start on Earth to 600-800 million years1 (4.5-3.7 Ga; Hadean-Archean). Whether the conditions for the synthesis of complex organic molecules were unique to this time or remain present today is unclear, but understanding these conditions is essential for the search of life on other planets. The outer portion of the Hadean Earth [...]

Stress and Strain during Shock Metamorphism

Auriol S. P. Rae, Michael H. Poelchau, Thomas Kenkmann

Published: 2021-04-15
Subjects: Geology, Planetary Geology, Planetary Geophysics and Seismology, Tectonics and Structure

Shock metamorphism is the process by which rocks, and the minerals within them, transform during the passage of a shock wave. Shock effects, such as shatter cones, are critical for the identification of impact structures and have commonly been used to infer mechanical and structural information on the cratering process. To make these inferences, the mechanics of shock wave behavior must be [...]

Structure of the deep lithosphere between Pamir and Tarim

Wasja Bloch, Bernd Schurr, Xiaohui Yuan, Lothar Ratschbacher, Sanaa Reuter, Sofia‑Katerina Kufner, Qiang Xu, Junmeng Zhao

Published: 2021-04-14
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure

The Pamir protrudes ~300-km between the Tajik and Tarim lithosphere of central Asia. It overlies a Wadati-Benioff earthquake zone connected to a low velocity zone interpreted as crustal rocks. Together with the mantle lithosphere it constitutes the arc-shaped Asian slab. We use new seismic data to better constrain the lithospheric architecture of the Pamir where it abuts the Tarim block and test [...]

Microstructural differences between naturally-deposited and laboratory beach sands

Amy Ferrick, Vashan Wright, Michael Manga, Nicholas Sitar

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

Paul Omonge, Luke Olang, Mathew Herrnegger, Karsten Schulz

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 [...]

The morphology, evolution and seismic visibility of partial melt at the core-mantle boundary: Implications for ULVZs

Juliane Dannberg, Robert Myhill, Rene Gassmoeller, Sanne Cottaar

Published: 2021-04-14
Subjects: Geophysics and Seismology

Seismic observations indicate that the lowermost mantle above the core-mantle boundary is strongly heterogeneous. Body waves reveal a variety of ultra-low velocity zones (ULVZs), which extend not more than 100 km above the core-mantle boundary and have shear velocity reductions of up to 30%. While the nature and origin of these ULVZs remain uncertain, some have suggested they are evidence of [...]

Probing the DPRK nuclear test-site down to low seismic magnitude

Steven John Gibbons, Tormod Kværna, Sven Peter Näsholm, Svein Mykkeltveit

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 [...]

A simplified palaeoceanography archiving system (PARIS) and GUI for storage and visualisation of marine sediment core proxy data vs age and depth.

Bryan C. Lougheed, Claire Waelbroeck, Nicolas Smialkowski, Natalia Vazquez Riveiros, Stephen Obrochta

Published: 2021-04-14
Subjects: Climate, Earth Sciences, Oceanography

Scientific discovery can be aided when data is shared following the principles of findability, accessibility, interoperability, reusability (FAIR) data (Wilkinson et al., 2016). Recent discussions in the palaeoclimate literature have focussed on defining the ideal database format for storing data and associated metadata. Here, we highlight an often overlooked primary process in widespread [...]

Past fires and post-fire impacts reconstructed from a southwest Australian stalagmite

Liza McDonough, Pauline C Treble, Andy Baker, Andrea Borsato, Silvia Frisia, Gurinder Nagra, Katie Coleborn, Michael Gagan, Sirine C Fakra, David PATERSON

Published: 2021-04-14
Subjects: Earth Sciences, Environmental Sciences

Our current understanding of climate and its relationship to fires is generally confined to the recent past where instrumental records and satellite imagery are available. Speleothem records of past environmental change provide a unique opportunity to explore fire frequency and intensity in the past, and the antecedent climatic conditions leading to fire events. Here, we compare fire sensitive [...]

Upstream oil and gas production and ambient air pollution in California

David J.X. Gonzalez, Christina K. Francis, Gary M. Shaw, Mark R. Cullen, Michael Baiocchi, Marshall Burke

Published: 2021-04-14
Subjects: Environmental Health and Protection, Environmental Public Health, Oil, Gas, and Energy

Background. Prior studies have found that residential proximity to upstream oil and gas production is associated with increased risk of adverse health outcomes. Emissions of ambient air pollutants from oil and gas wells in the preproduction and production stages has been proposed as conferring risk of adverse health effects, but the extent of air pollutant emissions from wells is not clear. [...]

Towards an operational irrigation management system for Sweden with a water-food-energy nexus perspective

Pietro Elia Campana, Pablo Lastanao, Sebastian Zainali, Jie Zhang, Tomas Landelius, Forrest Melton

Published: 2021-04-14
Subjects: Agriculture, Environmental Engineering

The 2018 drought in Sweden has triggered questions about climate adaptation and mitigation measures, especially in the agricultural sector, which suffered the most. This study applies a water-food-energy nexus modelling framework to evaluate drought impacts on irrigation and agriculture in Sweden using 2018 and 2019 as case studies. A previous water-food-energy nexus model was updated to [...]

The state of pore fluid pressure and 3D megathrust earthquake dynamics

Elizabeth Madden, Thomas Ulrich, Alice-Agnes Gabriel

Published: 2021-04-14
Subjects: Earth Sciences

The importance of pore fluid pressure (Pf) for fault strength, stress state and slip behavior holds promise for explaining spatio-temporal subduction zone megathrust behavior, but the coseismic state of Pf and its distribution with depth are poorly constrained. Here, we analyze fault stress states and 3D rupture dynamics of six scenarios based on the 2004 Mw 9.1 Sumatra-Andaman earthquake. We [...]

Imaging the seismic velocity structure of the crust and upper mantle in the northern East African Rift using Rayleigh wave tomography

Emma Louise Chambers, Nicholas Harmon, Catherine Rychert, Ryan Gallacher, Derek Keir

Published: 2021-04-13
Subjects: Geophysics and Seismology

Within the northern East African Rift, multiple seismic models have been produced to understand the evolution of magmatism, however variations in method, resolution, and scale make direct comparisons challenging. The lack of instrumentation off rift further limits our understanding of the spatial extent of tectonic and magmatic processes, which is crucial to understanding magmatic continental [...]


You can search by:

  • Title
  • Keywords
  • Author Name
  • Author Affiliation