Preprints
Filtering by Subject: Earth Sciences
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 [...]
Benthic biofilm potential for organic carbon accumulation in salt marsh sediments
Published: 2021-04-02
Subjects: Biogeochemistry, Earth Sciences, Geomorphology
Coastal salt marshes are productive environments with high potential for carbon accumulation and storage. Even though organic carbon in salt marsh sediment is typically attributed to plant biomass, it can also be produced by benthic photosynthetic biofilms. These biofilms, generally composed of diatoms and their secretions, are known for their high primary productivity and contribution to the [...]
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 [...]
Globally resolved surface temperatures since the Last Glacial Maximum
Published: 2021-03-31
Subjects: Climate, Earth Sciences, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Climate changes across the last 24,000 years provide key insights into Earth system responses to external forcing. Climate model simulations and proxy data have independently allowed for study of this crucial interval; however, they have at times yielded disparate conclusions. Here, we leverage both types of information using paleoclimate data assimilation to produce the first observationally [...]
Crustal-scale listric geometry of the San Andreas Fault driven by lower crustal flow
Published: 2021-03-31
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Physical Sciences and Mathematics
The San Andreas Fault (SAF) is one of the dominant components of the transform boundary between the Pacific and the North American Plate. Although the fault is verti-cal-to sub-vertical at shallow (<10 km) depth, it variably dips at angles of ca. 40-70º to the southwest near the western Transverse Range and to the northeast in its southern seg-ment at depths of ca. 10-20 km, and thus can be [...]
Towards a morphology diagram for terrestrial carbonates: evaluating the impact of carbonate supersaturation and alginic acid in calcite precipitate morphology
Published: 2021-03-30
Subjects: Earth Sciences, Environmental Sciences, Physical Sciences and Mathematics
Ancient and recent terrestrial carbonate-precipitating systems are characterised by a heterogeneous array of deposits volumetrically dominated by calcite. In these environments, calcite precipitates display an extraordinary morphological diversity, from single crystal rhombohedral prisms, to blocky crystalline encrustations, or spherulitic to dendritic aggregates. Despite many decades of thorough [...]