Preprints
Filtering by Subject: Geomorphology
Grand Challenges (and Great Opportunities) in Sedimentology, Stratigraphy, and Diagenesis Research
Published: 2018-09-23
Subjects: Biogeochemistry, Earth Sciences, Geomorphology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy
Technological advances make these exciting times for geoscientists studying Earth surface processes, their depositional products, and interactions with the biosphere, hydrosphere, atmosphere, and lithosphere; from monitoring contemporary sediment transport processes to interpretation of sedimentary archives that record ancient environmental changes. We set out three research challenges: 1) [...]
Wood Jam Dynamics Database and Assessment Model (WooDDAM): A Framework to Measure and Understand Wood Jam Characteristics and Dynamics
Published: 2018-09-20
Subjects: Earth Sciences, Geomorphology, Physical Sciences and Mathematics
Wood jams in rivers and on floodplains play an essential role in shaping valley bottoms, and their dynamics regulate the ecology and morphology of river systems. We present the Wood Jam Dynamics Database and Assessment Model (WooDDAM) to improve understanding and management of natural and anthropogenic wood jams in rivers. WooDDAM is comprised of a field data collection protocol, an open database [...]
Effects of estuarine mudflat formation on tidal prism and large-scale morphology in experiments
Published: 2018-08-31
Subjects: Earth Sciences, Geomorphology, Physical Sciences and Mathematics
Human interference in estuaries has led to increasing problems of mud, such as hyper‐turbidity with adverse ecological effects and siltation of navigation channels and harbours. To deal with this mud sustainably, it is important to understand its long‐term effects on the morphology and dynamics of estuaries. The aim of this study is to understand how mud affects the morphological evolution of [...]
A Review of Machine Learning Applications to Coastal Sediment Transport and Morphodynamics
Published: 2018-08-23
Subjects: Earth Sciences, Geomorphology, Physical Sciences and Mathematics
A range of computer science methods termed machine learning (ML) enables the extraction of insight and quantitative relationships from multidimensional datasets. Here, we review the use of ML on supervised regression tasks in studies of coastal morphodynamics and sediment transport. We examine aspects of ‘what’ and ‘why’, such as ‘what’ science problems ML tools have been used to address, ‘what’ [...]
DEM-based Geomorphological Mapping and Landforms Characterization of a Tropical Karst Environment in Southeastern Brazil
Published: 2018-08-23
Subjects: Earth Sciences, Geomorphology, Physical Sciences and Mathematics
This work presents a 1:10,000 geomorphological mapping of an area in southeastern Brazil, based on morphometric analysis of Digital Elevation Models (DEMs), while classical methods focus on photo interpretation. Data derived from the DEM include elevation, slope gradient, slope aspect, vertical and horizontal curvatures, amplitude, elongation and wavelength of landforms. These parameters were [...]
A calibration workflow for coastal dune models
Published: 2018-08-21
Subjects: Earth Sciences, Geomorphology, Physical Sciences and Mathematics
Numerical models of coastal dune growth encode feedbacks and nonlinearities between sediment transport and plant growth. The range of processes and tunable parameters involved make model calibration an important step when using models for prediction. In this paper we outline a method to calibrate models of coastal dune formation and describe the process from end to end. The first step is [...]
Quantification of the Bed-scale Architecture of Submarine Depositional Environments and Application to Lobe Deposits of the Point Loma Formation, California
Published: 2018-08-12
Subjects: Earth Sciences, Geology, Geomorphology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy
As of August 2018, this work is in review in "The Depositional Record", a journal from the IAS (International Association of Sedimentologists) Submarine-fan deposits form the largest sediment accumulations on Earth and host significant reservoirs for hydrocarbons. While many studies of ancient fan deposits qualitatively [...]
New evidence for a major late Quaternary submarine landslide on the external western levee of Laurentian Fan
Published: 2018-08-07
Subjects: Earth Sciences, Geology, Geomorphology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy
The Laurentian Fan is one of the largest submarine fans on the western margin of the North Atlantic. Recently acquired high-resolution multibeam bathymetric data (60 m horizontal resolution) reveal a major mass transport deposit (MTD) on the Western Levee of Western Valley (WLWV), covering >14 000 km2 in water depths from 3900 m to >5000 m. Typical submarine landslide features are observed [...]
Shark-fins: overturned patterns linked to shear instabilities at the flow-bed boundary. Examples from the deposits of the 2006 pyroclastic currents at Tungurahua volcano (Ecuador)
Published: 2018-08-06
Subjects: Earth Sciences, Geology, Geomorphology, Physical Sciences and Mathematics, Sedimentology, Volcanology
Enigmatic structures grouped under the term "shark-fins" are documented in laminated deposits of pyroclastic currents. They consist of an overturning of a few laminae on a decimeter scale, forming overbent "flames" or convolute laminae, which occur in successive, periodic patterns. More than 200 shark-fins were investigated and measured in cross-laminated deposits from the 2006 pyroclastic [...]
Pyroclastic dune bedforms: macroscale structures and lateral variations. Examples from the 2006 pyroclastic currents at Tungurahua (Ecuador)
Published: 2018-08-06
Subjects: Earth Sciences, Geology, Geomorphology, Physical Sciences and Mathematics, Sedimentology, Volcanology
Pyroclastic currents are catastrophic flows of gas and particles triggered by explosive volcanic eruptions. For much of their dynamics, they behave as particulate density currents and share similarities with turbidity currents. Pyroclastic currents occasionally deposit dune bedforms with peculiar lamination patterns, from what is thought to represent the dilute low concentration and [...]
Lithologic controls on the form of soil mantled hillslopes
Published: 2018-07-20
Subjects: Earth Sciences, Geology, Geomorphology, Physical Sciences and Mathematics
Slopes in steady-state soil-mantled landscapes tend to increase downslope in a way that balances local transport capacity with the sediment supplied from progressively larger source areas. Most formulations of sediment transport due to hillslope processes scale transport rate with local slope, which produces convex-up forms that are independent of the properties of the underlying lithologies. In [...]
Tectonic and oceanographic process interactions archived in the Late Cretaceous to Present deep-marine stratigraphy on the Exmouth Plateau, offshore NW Australia
Published: 2018-07-11
Subjects: Earth Sciences, Engineering, Geology, Geomorphology, Geophysics and Seismology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy, Tectonics and Structure
Deep-marine deposits provide a valuable archive of process interactions between sediment gravity flows, pelagic sedimentation, and thermo-haline bottom-currents. Stratigraphic successions can also record plate-scale tectonic processes (e.g. continental breakup and shortening) that impact long-term ocean circulation patterns, including changes in climate and biodiversity. One such setting is the [...]
Digital photogrammetry of historical aerial photographs using open-source software
Published: 2018-07-06
Subjects: Computer Sciences, Earth Sciences, Geomorphology, Physical Sciences and Mathematics, Programming Languages and Compilers, Software Engineering
Several collections of aerial photographs have been acquired in the Dominican Republic during the last 70 years. Although many of these sources are increasingly becoming available as scanned images, limited digital photogrammetric processing has been done, mainly because of the unaffordable prices of proprietary software licenses and the lack of clear workflows for processing historical photos. [...]
Delayed Recognition of Geomorphology Papers in The Geological Society of America Bulletin
Published: 2018-07-02
Subjects: Earth Sciences, Geomorphology, Physical Sciences and Mathematics
The Geological Society of America Bulletin was an early home for quantitative geomorphology research. Though geomorphology papers are not uniformly the highest cited papers in the Bulletin, many show ‘delayed recognition’ —they garner only few citations directly after publication, before suddenly being widely and numerously cited (sometimes decades after publication). I focus here on 1) [...]
Palaeolithic artefact deposits at Wadi Dabsa, Saudi Arabia; a multi-scalar geoarchaeological approach to building an interpretative framework
Published: 2018-06-21
Subjects: Earth Sciences, Geomorphology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy
Surface artefacts dominate the archaeological record of arid landscapes, particularly the Saharo-Arabian belt, a pivotal region in dispersals out of Africa. Discarded by hominins, these artefacts are key to understanding past landscape use and dispersals, yet behavioural interpretation of present-day artefact distributions cannot be carried out without understanding how geomorphological processes [...]