Preprints
Filtering by Subject: Geomorphology
Global inventories of inverted stream channels on Earth and Mars
Published: 2020-03-03
Subjects: Earth Sciences, Geology, Geomorphology, Physical Sciences and Mathematics
Data from orbiting and landed spacecraft have provided vast amounts of information regarding fluvial and fluvial-related landforms and sediments on Mars. One variant of these landforms are sinuous ridges that have been interpreted to be remnant evidence for ancient fluvial activity, observed at hundreds of martian locales. In order to further understanding of these martian landforms, this paper [...]
Structural inheritance and border fault reactivation during active early-stage rifting along the Thyolo fault, Malawi
Published: 2020-02-26
Subjects: Earth Sciences, Geology, Geomorphology, Physical Sciences and Mathematics, Tectonics and Structure
We present new insights on the geometry, initiation and growth of the Thyolo fault, an 85 km long active border fault in the southern Malawi Rift, from high-resolution topography, field and microstructural observations. The Thyolo fault is located towards the edge of the Proterozoic Unango Terrane, and is the border fault of the Lower Shire Graben, which has experienced four phases of extension [...]
Evidence of recurrent mass movement in front of the maximum slip area of the 1960 Chile earthquake: Implications for risk assessment and paleoseismology
Published: 2020-02-20
Subjects: Earth Sciences, Geology, Geomorphology, Geophysics and Seismology, Physical Sciences and Mathematics
We present evidence that suggests a new risk scenario for the Valdivia basin in south Chile, located in the area of the magnitude 9.5 1960 earthquake. In 1960, three mass movements, triggered by the earthquake shaking, dammed the upper course of the San Pedro River and threatened Valdivia City until it was opened in a controlled manner by its inhabitants. Published historical accounts indicate [...]
Entangled external and internal controls on submarine fan evolution: an experimental perspective
Published: 2020-02-02
Subjects: Earth Sciences, Geology, Geomorphology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy
Submarine fans are formed by sediment-laden flows shed from continental margins into ocean basins. Their morphology represents the interplay of external controls such as tectonics, climate, and sea-level with internal processes including channel migration and lobe compensation. However, the nature of this interaction is poorly understood. We used physical modelling to represent the evolution of a [...]
Integrating suspended sediment flux in large alluvial river channels: Application of a synoptic Rouse-based model to the Irrawaddy and Salween rivers
Published: 2020-02-02
Subjects: Earth Sciences, Geochemistry, Geology, Geomorphology, Hydrology, Physical Sciences and Mathematics, Sedimentology
A large portion of freshwater and sediment is exported to the ocean by a small number of major rivers. Many of these mega-rivers are subject to substantial anthropogenic pressures, which are having a major impact on water and sediment delivery to deltaic ecosystems. Due to hydrodynamic sorting, sediment grain size and composition varies strongly with depth and across the channel in large rivers, [...]
Suspended-sediment induced stratification inferred from concentration and velocity profile measurements in the lower Yellow River, China
Published: 2020-01-27
Subjects: Earth Sciences, Geomorphology, Physical Sciences and Mathematics, Sedimentology
Despite a multitude of models predicting sediment transport dynamics in an open-channel flow, the interaction between fluid and sediment, so to produce self-organized vertical density stratification, has not been robustly investigated and as such is poorly understood. This two-phase phenomenon develops in channels that possess low channel-bed slope and high sediment concentration. As the Yellow [...]
Rainsplash Erosion for Natural Slopes and Rainfall Conditions
Published: 2020-01-24
Subjects: Earth Sciences, Environmental Sciences, Geomorphology, Physical Sciences and Mathematics
Rainsplash is significant for interrill erosion since it facilitates the movement of loosened soil frangments. Because it is a technically dicult process to measure, many studies focus on experimental simulation under controlled conditions both in field and laboratory. Raindrop erosion studies have produced models to predict the erosivity due to raindrop impact on varying ground surfaces, with a [...]
Hydro-morphodynamics 2D modelling using a discontinuous Galerkin discretisation
Published: 2020-01-09
Subjects: Applied Mathematics, Computer Sciences, Earth Sciences, Geomorphology, Numerical Analysis and Computation, Partial Differential Equations, Physical Sciences and Mathematics, Sedimentology
The development of morphodynamic models to simulate sediment transport accurately is a challenging process that is becoming ever more important because of our increasing exploitation of the coastal zone, as well as sea-level rise and the potential increase in strength and frequency of storms due to a changing climate. Morphodynamic models are highly complex given the non-linear and coupled nature [...]
Impact of nested moisture cycles on coastal chalk cliff failure revealed by multi seasonal seismic and topographic surveys
Published: 2020-01-09
Subjects: Earth Sciences, Geomorphology, Physical Sciences and Mathematics
Cliff failure is a fundamental process shaping many coastlines worldwide. Improved insight into direct links between cliff failure and forcing mechanisms requires precise information on the timing of individual failures, which is difficult to obtain with conventional observation methods for longer stretches of coastline. Here we use seismic records and auxiliary data spanning 25 months to [...]
Landscape variables in the Indian (Peninsular) catchments: insights into hydro-geomorphic evolution
Published: 2020-01-02
Subjects: Earth Sciences, Geomorphology, Physical Sciences and Mathematics
The river systems in peninsular India are remained unexplored in terms of hydro-geomorphic evolution, though a few works are carried out in order to understand the tectonic and structural evolution with paleoclimate. Morphometric analysis at catchment scale delivers insights into the dynamics, erosion capacity, probability of flood occurrence, lithological and structural control, and genetic [...]
Active deformation and Plio-Pleistocene fluvial reorganization of the western Kura Fold-Thrust Belt, Georgia: implications for the evolution of the Greater Caucasus mountains and seismic hazard
Published: 2019-12-31
Subjects: Earth Sciences, Geology, Geomorphology, Physical Sciences and Mathematics, Tectonics and Structure
Since the Plio-Pleistocene, southward migration of shortening in the eastern part of the Greater Caucasus (GC) into the Kura foreland basin has progressively formed the Kura-Fold Thrust belt (KFTB) and Alazani piggyback basin, which separates the KFTB from the GC. Previous work argued for an eastward propagation of the KFTB, implying that the western portion in Georgia is the oldest, but this [...]
Four-dimensional surface motions of the Slumgullion landslide and quantification of hydrometeorological forcing
Published: 2019-12-09
Subjects: Earth Sciences, Geomorphology, Geophysics and Seismology, Other Earth Sciences, Physical Sciences and Mathematics
Landslides modify the natural landscape and cause fatalities and property damage worldwide. Quantifying landslide dynamics is challenging due to the stochastic nature of the environment. With its large area of ~1 km2 and perennial motions at ~10-20 mm per day, the Slumgullion landslide in Colorado, USA, represents an ideal natural laboratory to better understand landslide behavior. Here, we use [...]
Climate driven Holocene erosion in central Ukraine
Published: 2019-12-04
Subjects: Earth Sciences, Geomorphology, Physical Sciences and Mathematics
The younger Quaternary erosion history was reconstructed in a catchment close to the Chalcolithic giant settlement Maidanetske, central Ukraine based on dated sediment sequences. Four trenches and a long percussion drill-core were analyzed in a valley grading from a Loess covered plateau towards the Talianky River. The sediments were dated via a combination of radiocarbon dating, optical [...]
Dreibrodt et al.- Holocene erosion history in central Ukraine
Published: 2019-12-04
Subjects: Earth Sciences, Geomorphology, Physical Sciences and Mathematics
The younger Quaternary erosion history was reconstructed in a catchment close to the Chalcolithic giant settlement Maidanetske, central Ukraine based on dated sediment sequences. Four trenches and a long percussion drill-core were analyzed in a valley grading from a Loess covered plateau towards the Talianky River. The sediments were dated via a combination of radiocarbon dating, optical [...]
Optical wave gauging using deep neural networks
Published: 2019-12-04
Subjects: Civil and Environmental Engineering, Earth Sciences, Engineering, Geomorphology, Physical Sciences and Mathematics
We develop a remote wave gauging technique to estimate wave height and period from imagery of waves in the surf zone. In this proof-of-concept study, we apply the same framework to three datasets: the first, a set of close-range monochrome infrared (IR) images of individual nearshore waves at Duck, NC, USA; the second, a set of visible (i.e. RGB) band orthomosaics of a larger nearshore area near [...]