Work Plan

The interplay of tectonic-surface-climate processes is responsible for the growth and decay of mountain belts and basins, i.e. topography and mass (re)distribution from deeper parts of the crust to the surface and vice-versa, and at the earth surface. The coupled dynamic system encompasses pathways of material through movement, delivery, (re)distribution and accumulation, i.e. the source-sink relation. Climate and tectonics erode orogenic mountain ranges exhuming deeply buried rocks and erosion controls sediment production and transport at a variety of spatial and temporal scales.

Many conceptual models have been developed to link the observations in the field to the forces and processes affecting topography, morphology and structure at different geological sites. However the mechanisms and strengths of the coupling and feedbacks between tectonics and surface processes are still poorly understood because of the lack of insight into the causes of the variability in spatial and temporal patterns and rates.

Source-to-sink studies in continental margins have shown that the nature of sediment source, transfer and sink zones is determined by the geo-setting. Patterns and rates of sediment delivery through drainage nets are related to the tectonic, climatic and land use settings of the region. So the nature and rate of differing geomorphic processes that deliver sediments vary markedly in areas with tectonically stable and tectonically active settings. This in turn results in significant variability in sediment transfer relationships, with rapid transfer of materials in some landscapes, extensive residence times of storage units in others, and landscapes in which sediments transfer linkages may be spatially and temporally disconnected.

Many factors set the threshold for movement and they therefore control sediment production, storage and output. Threshold may shift with a change in climate and/or vegetation, or in response to the magnitude and frequency of geologic forcing factors such as earthquakes, neotectonics and storm events, or also isostatic response and adjustment to redistribution of mass. The temporal and spatial scales at which these processes operate, are different in orders of magnitude making it crucial for this program to link scales. In order to determine the role that events of a given magnitude play in the production and dispersal of sediments in large drainage basins, spatial and temporal variations in thresholds, process dominance, and inherited effects due to prior events will be assessed and constrained. To fully understand and appreciate the dynamic system and the controlling factors and forces it is crucial to study, quantify and model the complete system in relation to the controlling forces and factors.

In order to achieve our objectives the workpackages include:

Source region: Step-wise analysis of inherited structural patterns, (tectonic) geomorphology, mapping key geomorphic landforms and their hazard assessment, high resolution surface analysis and field geophysics (GPR, geoelectrics, seismics), structural patterns induced by differential uplift and their climatic, glaciation and (neo)tectonic control, (shallow) structures with human impact, quantification of the sedimentary budget and evolution of the drainage system.

Past sink analogues of currently active sinks: Dynamics of Quaternary systems in neotectonic active basins, sediment balance from the passive to active basins, deriving relative past to present-day precipitation systems using the relative abundance of faunal eco-physiologic groups

Carrier: the river network evolution: Recent evolution of the hydrographic network, catastrophic flooding and landsliding events, quantitative 3Dgeometry and Quaternary evolution of recent deltaic systems.

Active sink, the areas of active deposition: The history of active sink sedimentation versus source output / passive sink fill, the balance between the water level evolution in the Messinian - Holocene and the (neo)tectonic/climatic framework, high-end marine geophysics technologies in positioning seismically imaging the seafloor and sub-bottom horizons and enhanced coring technologies, offshore multi-channel reflection profiling, swath multibeam bathymetry and sonar data, deep tow side scan sonar and sub-bottom profiler surveys, regular gravity and box coring;

Regional Integration and modelling: Drainage network evolution in response to neotectonic and climatic events, space geodesy quantification of mechanisms of stress and strain transfer, Pliocene – Quaternary climate reconstruction and modelling, sedimentological mass-balance modelling, step-wise understanding of the transition from orogenic building and erosion to subsequent collapse and sediment accumulation, physical modelling of stress and strain transfer from active plate margins into continental interiors.