Erosion, chemical weathering and sedimentation in mountain landscapes
Mountain environments host highly dynamical and widespread erosion, sedimentation, and weathering processes. These processes cover a wide range of temporal and spatial scales, from glacial & periglacial erosion, mechanical & chemical weathering, rock fall, debris flows, landslides, to river aggradation & incision. These processes react to a wide spectrum of external and internal forcings, including permafrost retreat, strong precipitation events, climate change, earthquakes or sudden internal failure. Measuring the dynamical interplay of erosion, sedimentation as well as quantifying their rates and fluxes is an important part of source to sink research but it is highly challenging and often limited by difficult terrain. Furthermore, these dynamical processes can threaten important mountain infrastructures and need to be understood and quantified for a better societal and engineering preparation to the natural hazards they pose.
We welcome contributions investigating:
- sediment mobilization and deposition
- links between erosion, weathering, and the carbon cycle
- concepts of dynamics and connectivity of sediments and solutes
- quantification of erosion, sedimentation, and weathering fluxes in space and time
- sediment travel times and transport processes
- interaction of stabilizing and destabilizing processes on the slopes
We invite presentations that focus on conceptual, methodological, or modelling approaches or a combination of those in mountain environments and particularly encourage early career scientists to apply for this session.
A wide variety of erosional processes and sediment transport processes act to shape landscapes and generate the sedimentary record. Often, the most sensitive records of sediment production, transport, and deposition are found within detrital archives, which include (but are not limited to) physical sedimentology and textural analyses, detrital thermochronometry, cosmogenic nuclides and other geochemical tools, and stratigraphic analyses.
This session examines how detrital records can be used to study erosion, sedimentation, and sediment provenance. We seek studies that use detrital tools to address open questions in geomorphology and sedimentology, such as: (i) signal propagation through landscapes; (ii) the climatic and tectonic controls on sediment production and transport; (iii) variability in the processes and rates of erosion; (iv) decoding basin deposits for information about past environments; and (v) thresholds governing surface processes. Contributions are welcome from field, experimental, and modelling studies across all temporal and spatial scales.
Connectivity in geomorphology (IAG-working group), hydrological and soil system sciences: concepts, methods and societal implications
In the past two decades, connectivity has emerged as a relevant conceptual framework for understanding the transfer of water and sediment through landscapes. In geomorphology, the concept has had particular success in the fields of fluvial geomorphology and soil erosion to better explain rates and patterns of hydro-geomorphic geomorphic change in catchment systems. Although much progress has been made in the understanding of the physical processes that control the flows of matter through the landscape, applying this understanding across a range of scales has long hampered progress.
This session invites contributions from all areas of geomorphology (incl. soil science and hydrology) illustrating or identifying the role of connectivity for geomorphology on a local, regional or global scale. Specific themes we would like to promote are:
- advancement of the theory of connectivity, including sound and unambiguous definitions of
connectivity and related parameters,
- methodology development for measuring connectivity in field and laboratory settings,
having a special focus on experiments for conceptualizing the different processes involved,
- the development and application of suitable models and indices of connectivity,
- determining how the concept can be used to enable sustainable land and water management
The session is organized by the IAG-working group “Connectivity in geomorphology” aiming to develop an international network of connectivity scientists, to share expertise and develop a consensus on the definition and scientific agenda regarding the emerging field of connectivity in geomorphology.
Tectonics, erosion, and climate in orogenic settings: evolution and interactions determined from sediment records
The interlinked influences of tectonics, erosion and climate govern the topographic and debatably also structural evolution of mountain belts. In turn, the evolution of any given mountain belt can influence the development of the regions’ climate, erosion and sedimentation patterns. Sedimentary records can preserve a rich archive of a region’s tectonics, erosion and/or climate history that can be interrogated through application of a number of approaches utilising, for example, sediment provenance, detrital thermochronology, determination of sedimentation rates and facies, and stable isotope studies. Suitable continental records may exist in foreland basins and retro-arc settings located proximal to the mountain sources, and scientific drilling has been important in recovering records from the modern oceans. Located potentially far from the mountains, many submarine fans may preserve more complete and readily dated sedimentary sections. Analysis and comparison of strata across different parts of a mountain belt can potentially allow a more detailed spatial and temporal understanding of climatic and tectonic evolution of a region as an orogen uplifts and subsequently collapses. Although the Asian Monsoon-Himalayan system is the classic example of tectonic-erosion-climate interactions, similar relationships have been invoked in South America, Papua New Guinea, Taiwan and the Pyrenees during the Cenozoic alone. We invite contributions that utilise sediment records to unravel the links and relationships between tectonics, erosion or climate change, in recent or ancient orogenic settings, using traditional and novel application of field, laboratory and/or modelling techniques.
Density and supercritical flow dynamics, bedform dynamics and associated deposits: current understanding of a complex interplay
Particle-laden density flows (e.g. pyroclastic flows, snow avalanches, rivers, turbidity currents) transport huge amounts of sediments across our planet and form some of the largest sediment accumulations on Earth. Interaction of density flows with erodible beds can create a wide range of bedforms and deposits whose morphology relates to the parent flow conditions (e.g. antidunes, chutes-and-pools, cyclic steps which are suggested to result from supercritical flows). However, we know little about the triad of flow dynamics, flow interaction with erodible beds and bedforms, and the resulting sedimentary products. How can we read resting sedimentary deposits and invert the parent dynamic flow conditions from them?
This session aims to bring together field researchers, experimentalists and numerical modellers with an expertise in sedimentology, fluid mechanics and related disciplines to further explore density and supercritical flow dynamics, bedform dynamics and the sedimentary structures they produce. The session welcomes studies across differing spatial and temporal scales, from large-scale organisation patterns down to the grain-scale, as well as the palaeo-dynamic and morphodynamic aspects of control and feedback between flow, sediment transport, bedform evolution and deposits.
Techniques for quantifying the sources and the dynamics of sediment in river catchments across a range of spatial and temporal scales
Obtaining quantitative information on the spatial pattern of soil redistribution during storms and on the spatial sources supplying sediment to rivers is required to improve our understanding of the processes controlling these transfers and to design effective control measures. It is also crucial to quantify the transfer or the residence times of material transiting rivers along the sediment cascade, and to reconstruct the potential changes in sources that may have occurred at various temporal scales. During the last few decades, several sediment tracing or fingerprinting techniques have contributed to provide this information, in association with other methods (including soil erosion modelling and sediment budgeting). However, their widespread application is limited by several challenges that the community should address as priorities.
We invite specific contributions to this session that address any aspects of the following:
• Developments of innovative field measurement and sediment sampling techniques;
• Soil and sediment tracing techniques for quantifying soil erosion and redistribution;
• Sediment source tracing or fingerprinting studies, using conventional (e.g. elemental/isotopic geochemistry, fallout radionuclides, organic matter) or alternative (e.g. colour, infrared, particle morphometry) approaches;
• Investigations of the current limitations associated with sediment tracing studies (e.g. tracer conservativeness, uncertainty analysis, particle size and organic matter corrections);
• Applications of radioisotope tracers to quantify sediment transit times over a broad range of timescales (from the flood to the century);
• The association of conventional techniques with remote sensing and emerging technologies (e.g. LiDAR);
• Integrated approaches to developing catchment sediment budgets: linking different measurement techniques and/or models to understand sediment delivery processes.
Investigation of sediment transport processes due to geophysical flows
Transport of sediments due to the action of geophysical flows occurs in fluvial, estuarine, aeolian and other natural or man-made environments on Earth and has been shown to play important formative roles in planets and satellites such as Mars, Titan, and Venus. Understanding the motion and the causes of motion of sediments is still one of the most fundamental problems in hydrological and geophysical sciences. Such processes can vary across a wide range of scales leading to sediment transport and scour which can directly impact both the form (geomorphology) and, on Earth, the function (ecology and biology) of natural surface water systems and the built infrastructure surrounding them. In particular, the feedback between flow and sediment transport is a key process in surface dynamics, finding a range of important applications, from hydraulic engineering and natural hazards protection to landscape evolution and river ecology.
We welcome specific topics of interest that include (but are not restricted to):
-particle-scale mechanics of particle entrainment and disentrainment
-upscaling and averaging techniques for stochastic processes related to granular processes
-interaction among grain sizes in poorly sorted mixtures, including particle segregation
-momentum/energy transfer between turbulent flows and particless
-derivation and solution of conservation equations
-reach scale sediment transport and geomorphic processes
-shallow water hydro-sediment-morphodynamic processes
-fluvial processes in response to reservoir operation schemes