Preprints
Filtering by Subject: Physical Sciences and Mathematics
The role of random vorticity stretching in tropical depression genesis
Published: 2021-03-23
Subjects: Physical Sciences and Mathematics
Tropical deep convection plays a key role at the tropical depression stage of tropical cyclogenesis by aggregating vorticity, but no existing theory can depict such a stochastic vorticity aggregation process. Vorticity probability distribution function (PDF) is proposed as a tool to predict the horizontal structure and wind speed of the tropical depression, a tropical cyclone in its early stage. [...]
Complex Network Theoretic Assessment of Precipitation Driven Meteorological Drought in India: Past and Future
Published: 2021-03-22
Subjects: Physical Sciences and Mathematics
Spatio-temporal analysis of droughts is of paramount importance especially for future climate scenarios. We use complex network theoretic measures to understand spatio-temporal properties of precipitation driven meteorological drought across India in past and future climate scenarios. We construct drought networks using Event synchronization (ES) for moderate and extreme drought conditions [...]
Carbon dioxide fluxes increase from day to night across European streams
Published: 2021-03-22
Subjects: Physical Sciences and Mathematics
Globally, inland waters emit over 2 Pg of carbon (C) per year as carbon dioxide (CO2), of which the majority originates from streams and rivers. Despite the global significance of fluvial CO2 emissions, little is known about their diel dynamics. We present the first large-scale assessment of day- and night-time CO2 fluxes at the water-air interface across European streams. Fluxes were directly [...]
Western Gondwana imaged by S receiver-functions (SRF): new results on Moho, MLD (mid-lithospheric discontinuity) and LAB (lithosphere-asthenosphere boundary)
Published: 2021-03-21
Subjects: Earth Sciences, Physical Sciences and Mathematics
We study the Moho, the mid-lithospheric discontinuity (MLD), and the lithosphere-asthenosphere boundary (LAB) from southern Africa to northern Arabia, from Archean cratons to active rifts, at 1° resolution using our comprehensive new database of shear-wave receiver functions (SRFs). The good agreement between the Moho depth obtained from our SRFs and published P-wave receiver function (PRF) [...]
Mechanical Stratigraphy Controls Normal Fault Growth and Dimensions, Outer Kwanza Basin, Offshore Angola
Published: 2021-03-19
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Tectonics and Structure
Mechanical stratigraphy controls the growth patterns and dimensions of relatively small normal faults, yet how its influences the development of much larger structures remains unclear. Here we use 3D seismic reflection data from the Outer Kwanza Basin, offshore Angola to constrain the geometry and kinematics of several normal faults formed in a deep-water clastic succession. The faults are up to [...]
Phosphorus mineral evolution and prebiotic chemistry: from minerals to microbes
Published: 2021-03-17
Subjects: Physical Sciences and Mathematics
Minerals are known to control the availability of non-volatile and bio-essential elements at Earth’s surface, e.g., phosphorus (P). Therefore, the role of minerals in prebiotic chemistry is a focal point of research into the origins of life. However, the mineralogical diversity of earliest Earth is not definitively known. This uncertainty is owed both to progressive change in the Earth system and [...]
Formation of continental microplates through rift linkage: Numerical modelling and its application to the Flemish Cap and Sao Paulo Plateau
Published: 2021-03-17
Subjects: Earth Sciences, Physical Sciences and Mathematics
Continental microplates are enigmatic plate boundary features, which can occur in extensional and compressional regimes. Here we focus on microplate formation and their temporal evolution in continental rift settings. To this aim, we employ the geodynamic finite element software ASPECT to conduct 3D lithospheric-scale numerical models from rift inception to continental breakup. We find that [...]
Reducing variability in OSL rock surface dating profiles.
Published: 2021-03-17
Subjects: Physical Sciences and Mathematics
In recent years, rock surface dating has seen the emergence of a technique based on optically stimulated luminescence (OSL). This application translates the depth of OSL signal bleaching within a rock surface into an exposure age or erosion rate at 1-10000 a timescales. Considerable effort has been undertaken to improve our understanding of OSL rock surface dating, yet a large amount of [...]
Prototyping a collaborative data curation service for coastal science
Published: 2021-03-16
Subjects: Environmental Sciences, Geomorphology, Physical Sciences and Mathematics
The growing push for open data has resulted in an abundance of data for coastal researchers, which can lead to problems for individual researchers related to discoverability of relevant data. One solution is to explicitly develop services for coastal researchers to help curate data for discovery, hosting discussions around reuse, community building, and finding collaborators. To develop the idea [...]
Pre-salt rift morphology controls salt tectonics in the Campos Basin, offshore SE Brazil
Published: 2021-03-14
Subjects: Physical Sciences and Mathematics
Classic models of gravity-driven salt tectonics commonly depict kinematically-linked zones of overburden deformation, characterised by updip extension and downdip contraction, separated by a weakly deformed zone associated with downdip translation above a relatively smooth base-salt surface. We use 2D and 3D seismic reflection and borehole data from the south-central Campos Basin to show that [...]
High resolution, annual maps of field boundaries for smallholder-dominated croplands at national scales
Published: 2021-03-12
Subjects: Agriculture, Environmental Monitoring, Environmental Sciences, Geographic Information Sciences, Geography, Life Sciences, Natural Resources and Conservation, Physical and Environmental Geography, Physical Sciences and Mathematics, Remote Sensing, Spatial Science, Sustainability
Mapping the characteristics of Africa's smallholder-dominated croplands, including the sizes and numbers of fields, can provide critical insights into food security and a range of other socioeconomic and environmental concerns. However, accurately mapping these systems is difficult because there is 1) a spatial and temporal mismatch between satellite sensors and smallholder fields, and 2) a lack [...]
Magma pathways in sill-complexes
Published: 2021-03-09
Subjects: Physical Sciences and Mathematics
The Loch Scridain Sill-complex on the Isle of Mull affords an opportunity to examine how magma moves through and builds sill-complexes (Holness & Humphreys 2003). For example, field and petrological evidence indicates the Tràigh Bhàn na Sgùrra Sill is segmented and comprised several thick channels, separated by thin sill portions, that facilitated longer-lived magma flow (Holness & Humphreys [...]
Segment tip geometry of sheet intrusions, I: Theory and numerical models for the role of tip shape in controlling propagation pathways.
Published: 2021-03-09
Subjects: Physical Sciences and Mathematics
Inferences about sheet intrusion emplacement mechanisms have been built largely on field observations of intrusion tip zones: magmatic systems that did not grow beyond their observed state. Here we use finite element simulation of elliptical to superelliptical crack tips, representing observed natural sill segments, to show the effect of sill tip shape in controlling local stress concentrations, [...]
Decadal shoreline erosion and recovery of beaches in modified and natural estuaries
Published: 2021-03-08
Subjects: Geomorphology, Physical Sciences and Mathematics
Sandy beaches in estuaries and bays (BEBs) are common landforms on the coasts of many major cities. They exist under a wide range of settings and their morphology is controlled by their distance from the estuary/bay entrance, exposure to different types of waves (e.g., ocean swells vs locally generated wind waves), proximity to flood-tide delta/shoals, and anthropogenic interventions (e.g., [...]
Recrystallization of ice enhances the creep and vulnerability to fracture of ice shelves
Published: 2021-03-08
Subjects: Earth Sciences, Geophysics and Seismology, Glaciology, Physical Sciences and Mathematics
The initiation of fractures and fast flow in floating regions of Antarctica have the potential to destabilize large regions of the grounded ice sheet, leading to significant sea-level rise. While observations have shown rapid, localized deformation and damage in the margins of fast-flowing glaciers, there remain gaps in our understanding of how rapid deformation affects the viscosity and [...]