Preprints
Filtering by Subject: Physical Sciences and Mathematics
Observational estimates of dynamic topography through space and time
Published: 2021-01-24
Subjects: Biogeochemistry, Cosmochemistry, Earth Sciences, Geochemistry, Geology, Geomorphology, Geophysics and Seismology, Paleobiology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy, Tectonics and Structure, Volcanology
Earth's mantle undergoes convection on million-year timescales as heat is transferred from depth to the surface. Whilst this flow has long been linked to the large-scale horizontal forces that drive plate tectonics and supercontinent cycles, geologists are increasingly recognising the signature of convection through transient vertical motions in the rock record, known as "dynamic topography". A [...]
Deciphering paleogeography from orogenic architecture: constructing orogens in a future supercontinent as thought experiment
Published: 2021-01-24
Subjects: Physical Sciences and Mathematics
Orogens that form at convergent plate boundaries typically consist of accreted rock units that form an incomplete archive of subducted oceanic and continental lithosphere, as well as of deformed crust of the former upper plate. Reading the construction of orogenic architecture forms the key to decipher the paleogeographic distribution of oceans and continents, as well as bathymetric and [...]
A review of last interglacial sea-level proxies in the eastern Mediterranean coastal region
Published: 2021-01-23
Subjects: Physical Sciences and Mathematics
Mediterranean ‘raised beaches’ were subject to Quaternary research since the early years of the 20th century. The uniqueness of a warm-loving molluscs fauna immigrating into the Mediterranean made the coastline a prime interest for studying Quaternary sea-level changes. Today, we have a detailed picture of this historically important coastline characterised by tectonically dormant coastal zone [...]
Developing luminescence analysis of Icelandic volcanic glass: a case study using the Þórsmörk Ignimbrite
Published: 2021-01-22
Subjects: Physical Sciences and Mathematics
Large volcanic eruptions from Iceland can produce significant volumes of glass-rich rhyolitic tephra, which are then deposited across NW Europe and the North Atlantic-Arctic region, forming time-parallel marker horizons useful to palaeoenvironmental studies. Here we investigate new ways of improving the tephrochronological record of Iceland using (thermo)luminescence analysis of rhyolitic [...]
Arctic soil patterns analogous to fluid instabilities
Published: 2021-01-22
Subjects: Physical Sciences and Mathematics
Slow-moving arctic soils commonly organize into striking large-scale spatial patterns called solifluction terraces and lobes. Though these features impact hillslope stability, carbon storage and release, and landscape response to climate change, no mechanistic explanation exists for their formation. Everyday fluids—such as paint dripping down walls—produce markedly similar fingering patterns [...]
High precision estimation of modeled aerosol direct radiative forcing
Published: 2021-01-22
Subjects: Physical Sciences and Mathematics
Aerosol radiative forcing can be difficult to quantify both accurately and precisely in global climate models. Long climate model integrations are often required and levels of statistical uncertainty can be substantial for some of the diagnostic methods and diagnosed forcings. Instantaneous estimates of sulfate aerosol direct radiative forcings in the present-day climate are compared to forcings [...]
An idealized 1.5-layer isentropic model with convection and precipitation for satellite data assimilation research. Part II: model derivation
Published: 2021-01-22
Subjects: Applied Mathematics, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
In this part II paper we present the analytical derivation of the isentropic 1.5-layer shallow water model described and used in part I of this study. The mathematical derivation presented here is based on a combined asymptotic and slaved Hamiltonian analysis. The scaling assumptions throughout the paper are supported by real observations based on radiosonde data. Eventually, a fully consistent [...]
An idealized 1.5-layer isentropic model with convection and precipitationfor satellite data assimilation research. Part I: model dynamics
Published: 2021-01-22
Subjects: Applied Mathematics, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
An isentropic 1.5-layer model based on modified shallow water equations is presented, including terms mimicking convection and precipitation. This model is an updated version of the isopycnal single-layer modified shallow water model presented in Kent et al. (2017). The clearer link between fluid temperature and model variables together with a double-layer structure make this revised, isentropic [...]
Evidence confirms an anthropic origin of Amazonian Dark Earths
Published: 2021-01-22
Subjects: Biogeochemistry, Earth Sciences, Geochemistry, Geomorphology, Physical Sciences and Mathematics, Soil Science
First described over 120 years ago in Brazil, Amazonian Dark Earths (ADEs) are expanses of dark soil that are exceptionally fertile and contain large quantities of archaeological artefacts. The elevated fertility of the dark and often deep A horizon of ADEs is widely regarded as an outcome of pre-Columbian human influence. Controversially, in their recent paper Silva et al.2argue that the higher [...]
Data-Driven Inference of the Mechanics of Slip Along Glacier Beds Using Physics-Informed Neural Networks: Case study on Rutford Ice Stream, Antarctica
Published: 2021-01-19
Subjects: Physical Sciences and Mathematics
Reliable projections of sea-level rise depend on accurate representations of how fast-flowing glaciers slip along their beds. The mechanics of slip are often parameterized as a constitutive relation (or `sliding law') whose proper form remains uncertain. Here, we present a novel deep learning-based framework for learning the time evolution of drag at glacier beds from time-dependent ice velocity [...]
The building blocks of igneous sheet intrusions: insights from 3D seismic reflection data
Published: 2021-01-19
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Tectonics and Structure, Volcanology
The propagating margins of igneous sills (and other sheet intrusions) may divide into laterally and/or vertically separated sections, which later inflate and coalesce. These components elongate parallel to and thus record the magma flow direction, and can form either due to fracture segmentation (i.e., ‘segments’) or brittle and/or non-brittle deformation of the host rock (i.e., ‘magma fingers’). [...]
Earthquake rupture on multiple splay faults and its effect on tsunamis
Published: 2021-01-16
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Detailed imaging of accretionary wedges reveals splay fault networks that could pose a significant tsunami hazard. However, the dynamics of multiple splay fault activation during megathrust earthquakes and the consequent effects on tsunami generation are not well understood. We use a 2-D dynamic rupture model with complex topo-bathymetry and six curved splay fault geometries constrained from [...]
Measurement error analysis of surface-bonded distributed fiber-optic strain sensor subjected to linear gradient strain: Theory and experimental validation
Published: 2021-01-16
Subjects: Engineering, Physical Sciences and Mathematics
Strain transfer analysis is an important means of assessing the measurement accuracy of embedded or surface-bonded fiber-optic sensors; however, the effect of complex strain fields in substrates has not been well elucidated. Here, a theoretical model was proposed for the analysis of strain transfer mechanisms in surface-bonded distributed fiber-optic sensors due to linear strain gradients. [...]
Time to Depth Seismic Reprocessing of Vintage Data: a Case Study in the Otranto Channel (South Adriatic Sea)
Published: 2021-01-14
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Physical Sciences and Mathematics
In this chapter, we present a case study focused on the reprocessing of marine seismic line MS-29, acquired in 1971 in the Otranto Channel, in the South Adriatic Sea (Italy). This line crosses the channel between South Italy and Albania, a key location for understanding the geodynamics of the North Adria Plate. The work is divided into two steps. The first step consists of a modern broadband [...]
Proximal to distal grain-size distribution of basin-floor lobes: A study from the Battfjellet Formation, Central Tertiary Basin, Svalbard
Published: 2021-01-14
Subjects: Earth Sciences, Physical Sciences and Mathematics
The grain-size distribution of sediment particles is an important aspect of the architecture of submarine fans and lobes. It governs depositional sand quality and reflects distribution of particulate organic carbon and pollutants. Documenting the grain-size distribution of these deep-marine sedimentary bodies can also offer us an insight into the flows that deposited them. Submarine lobes are [...]