Preprints
Filtering by Subject: Physical Sciences and Mathematics
Preliminary assessment of shipping noise monitoring using Distributed Acoustic Sensing on an optical fiber telecom cable
Published: 2021-01-30
Subjects: Physical Sciences and Mathematics
Distributed acoustic sensing (DAS) is a recent instrumental approach allowing to turn fiber-optic cables into dense arrays of acoustic sensors. This technology is attractive in marine environments where instrumentation is difficult to implement. A promising application is the monitoring of environmental and anthropic noise, leveraging existing telecommunication cables on the seafloor. We assess [...]
Was the January 26th, 1700 Cascadia earthquake part of an event sequence?
Published: 2021-01-30
Subjects: Physical Sciences and Mathematics
Coastal subsidence, dating of soil samples and tree rings, and sedimentological evidence of a tsunami point to coseismic activity on a sizable portion of the Cascadia subduction zone circa 1700. Documents from Japan reveal that on January 26th of that year there were tsunami impacts across distant locations in the country and past modeling shows that a large Cascadia earthquake is the most likely [...]
Upper Mississippi River Flow and Sediment Characteristics and Their Effect on a Harbor Siltation Case
Published: 2021-01-28
Subjects: Civil and Environmental Engineering, Civil Engineering, Earth Sciences, Engineering, Geomorphology, Hydraulic Engineering, Physical Sciences and Mathematics, Sedimentology
Upper Mississippi River flow and sediment characteristics downstream of St. Louis are presented in this study. Available and measured data were used to assess a harbor siltation case and dredging needs. Such data are also useful to researchers and engineers conducting work in the Mississippi River and large rivers in general. Flows were characterized in terms of the mean annual hydrograph, flow [...]
Goal-Oriented Error Estimation and Mesh Adaptation for Tracer Transport Modelling
Published: 2021-01-28
Subjects: Physical Sciences and Mathematics
This paper applies metric-based mesh adaptation methods to advection-dominated tracer transport modelling problems in two and three dimensions, using the finite element package Firedrake. In particular, the mesh adaptation methods considered are built upon goal-oriented estimates for the error incurred in evaluating a diagnostic quantity of interest (QoI). In the motivating example of modelling [...]
Tectonic evolution of an Early Cryogenian late-magmatic basin in central Madagascar
Published: 2021-01-28
Subjects: Earth Sciences, Physical Sciences and Mathematics
Central and southern Madagascar comprise a number of distinctive Archaean crustal blocks (the Antongil-Masora and Antananarivo domains) overlain by Proterozoic supracrustal sequences, preserved in the East African Orogen. Here, we present U–Pb and Lu–Hf isotopic data for two supracrustal units from detrital and metamorphic zircon grains. The lower sequence is comprised of quartzite and [...]
Back-propagating rupture evolution within a curved slab during the 2019 Mw 8.0 Peru intraslab earthquake
Published: 2021-01-28
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
The 26 May 2019 Mw 8.0 Peru intraslab earthquake ruptured the subducting Nazca plate where the dip angle of the slab increases sharply and the strike angle rotates clockwise from the epicentre to north. To obtain a detailed seismic source model of the 2019 Peru earthquake, including not only the rupture evolution but also the spatiotemporal distribution of focal mechanisms, we performed [...]
The active and passive roles of the ocean in generating basin-scale heat content variability
Published: 2021-01-28
Subjects: Climate, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
The role of ocean circulation in transforming surface forcing into interannual-to-multidecadal oceanic variability is an area of ongoing debate. Here, a novel method, establishing exact causal links, is used to quantitatively determine the role of ocean active and passive processes in transforming stochastic surface forcing into heat content variability. To this end, we use a global ocean model [...]
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: 2021-01-22
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 [...]