Preprints
Filtering by Subject: Sedimentology
Spatially explicit spectral analysis of point clouds and geospatial data
Published: 2017-10-31
Subjects: Civil and Environmental Engineering, Civil Engineering, Computer Sciences, Earth Sciences, Engineering, Geomorphology, Geophysics and Seismology, Numerical Analysis and Scientific Computing, Physical Sciences and Mathematics, Sedimentology
The increasing use of spatially explicit analyses of high-resolution spatially distributed data (imagery and point clouds) for the purposes of characterising spatial heterogeneity in geophysical phenomena necessitates the development of custom analytical and computational tools. In recent years, such analyses have become the basis of, for example, automated texture characterisation and [...]
Shallow water benthic imaging and substrate characterization using recreational-grade sidescan-sonar
Published: 2017-10-31
Subjects: Civil and Environmental Engineering, Earth Sciences, Engineering, Geomorphology, Hydraulic Engineering, Physical Sciences and Mathematics, Sedimentology
In recent years, lightweight, inexpensive, vessel-mounted ‘recreational grade’ sonar systems have rapidly grown in popularity among aquatic scientists, for swath imaging of benthic substrates. To promote an ongoing ‘democratization’ of acoustical imaging of shallow water environments, methods to carry out geometric and radiometric correction and georectification of sonar echograms are presented, [...]
Preconditioning and triggering of offshore slope failures and turbidity currents revealed by most detailed monitoring yet at a fjord-head delta
Published: 2017-10-26
Subjects: Earth Sciences, Geology, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics, Sedimentology
Rivers and turbidity currents are the two most important sediment transport processes by volume on Earth. Various hypotheses have been proposed for triggering of turbidity currents offshore from river mouths, including direct plunging of river discharge, delta mouth bar flushing or slope failure caused by low tides and gas expansion, earthquakes and rapid sedimentation. During 2011, 106 turbidity [...]
Direct monitoring of active geohazards: emerging geophysical tools for deep-water assessments
Published: 2017-10-26
Subjects: Earth Sciences, Geology, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics, Sedimentology
Seafloor networks of cables, pipelines, and other infrastructure underpin our daily lives, providing communication links, information, and energy supplies. Despite their global importance, these networks are vulnerable to damage by a number of natural seafloor hazards, including landslides, turbidity currents, fluid flow, and scour. Conventional geophysical techniques, such as high-resolution [...]
Distal turbidites reveal a common distribution for large (>0.1 km3) submarine landslide recurrence
Published: 2017-10-26
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Probability, Sedimentology, Statistics and Probability
Submarine landslides can be far larger than those on land, and are one of the most important processes for moving sediment across our planet. Landslides that are fast enough to disintegrate can generate potentially very hazardous tsunamis, and produce long run-out turbidity currents that break strategically important cable networks. It is important to understand their frequency and triggers. We [...]
Turbulence, displacement, death and worms: a day in the life of a fluvial Carboniferous bivalve
Published: 2017-10-24
Subjects: Earth Sciences, Paleontology, Physical Sciences and Mathematics, Sedimentology
In the Pennsylvanian Rough Rock Flags and Rough Rock of northern England, trace fossils attributed to the non-marine bivalve Carbonicola are found. Carbonicola, recorded by Lockeia and associated trace fossils, lived a semi-infaunal lifestyle and thus were influenced by both the sediment in which they were hosted, and the currents which supplied their nutrients and oxygen. A number of [...]
Cenozoic contourites in the eastern Great Australian Bight, offshore southern Australia: implications for the onset of the Leeuwin Current
Published: 2017-10-24
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy, Volcanology
Thermohaline oceanic currents influence global heat transfer, controlling local and global variations in climate, biodiversity, and the terrestrial biosphere. Paleoceanographic studies typically use biostratigraphic and geochemical proxies to reconstruct the dynamics of these currents in Earth’s ancient oceans, although seismic reflection data have also been successfully employed, most commonly [...]
The stratigraphic record and processes of turbidity current transformation across deep-marine lobes
Published: 2017-10-24
Subjects: Earth Sciences, Physical Sciences and Mathematics, Sedimentology
Sedimentary facies in the distal parts of deep-marine lobes can diverge significantly from those predicted by classical turbidite models, and sedimentological processes in these environments are poorly understood. This gap may be bridged using outcrop studies and theoretical models. In the Skoorsteenberg Fm., a downstream transition from thickly-bedded turbidite sandstones to argillaceous, [...]
The Effect Of Clay Type On The Properties Of Cohesive Sediment Gravity Flows And Their Deposits
Published: 2017-10-23
Subjects: Earth Sciences, Physical Sciences and Mathematics, Sedimentology
The present knowledge of cohesive clay-laden sediment gravity flows (SGFs) and their deposits is limited, despite clay being one of the most abundant sediment types on earth and subaqueous SGFs transporting large volumes of sediment into the ocean. Lock-exchange experiments were conducted to contrast SGFs laden with noncohesive silica flour, weakly cohesive kaolinite, and strongly cohesive [...]