Preprints
Filtering by Subject: Earth Sciences
Reactivation Potential of Intraplate Faults in the Western Quebec Seismic Zone, Eastern Canada
Published: 2021-04-19
Subjects: Earth Sciences, Physical Sciences and Mathematics
The intraplate western Quebec seismic Zone (WQSZ) in eastern Canada experiences moderate seismicity that mainly results from reactivation of inherited structures under the present-day, NE-striking regional stress field and, possibly to a minor extent, through stress perturbations in response to glacio-isostatic adjustments. This work comprises the first numerical stress simulation-based study [...]
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 [...]
A global hydrothermal reactor triggered prebiotic synthesis on Earth
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 [...]
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 [...]
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 [...]
A simplified palaeoceanography archiving system (PARIS) and GUI for storage and visualisation of marine sediment core proxy data vs age and depth.
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
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 [...]
The state of pore fluid pressure and 3D megathrust earthquake dynamics
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 [...]
Impact of trench retreat rate on initiating focused back-arc extension within a mobile overriding plate
Published: 2021-04-09
Subjects: Earth Sciences
Rapid trench retreat, or slab roll-back, is often observed in subduction zones where active and focused back-arc extension develops. However, the correlation between trench retreat rate and back-arc extension has not been rigorously tested. Here we study the correlation by investigating a series of 2-D thermo-mechanical and internally driven numerical models with a mobile overriding plate in [...]
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 [...]
Seasonal changes of iceberg distribution and surface area in the Amundsen Sea Embayment
Published: 2021-04-06
Subjects: Earth Sciences, Oceanography and Atmospheric Sciences and Meteorology
Icebergs have a significant influence on local and potentially global climate by altering ocean and sea ice environments. An object-based method for automatic iceberg detection has been applied to 2442 SAR images acquired during all seasons between 2006-2012 in the Amundsen Sea Embayment (ASE), Antarctica. During this period a total count of icebergs and their surface area were calculated in [...]
Seismic Characterization and Depositional Significance of the Nahr Menashe deposits: Implications for the terminal phases of the Messinian Salinity Crisis in the Northeast Levant Basin, Offshore Lebanon.
Published: 2021-04-02
Subjects: Earth Sciences
Over the last decade, there has been a resurgence of interest in the climatic and tectonic mechanisms that drove the Messinian salinity crisis (MSC) and the associated deposition of thick evaporites. The MSC represents an unprecedented palaeoceanographic change that led to a very short (c. 660 kyr) ecological and environmental crisis. However, across the Levantine offshore basin, the [...]