2. Scientific approach: monitoring, imaging, reconstruction, process modelling

To trace, quantify and forecast the evolution of topography in response to Solid-Earth processes and movements of surface waters, it is essential that researchers proficient in a wide range of sub-disciplines interact and collaborate. TOPO-EUROPE researchers will endeavour to convolve the results of geomorphologic, geological, geophysical, geodetic, remote sensing and geotechnologic investigations. Such an integrated, multidisciplinary approach has yet to be implemented on a truly European scale. A consortium of national research centres, geoscience institutes of universities and national geoscience surveys, each with proven strengths and capabilities in distinct scientific fields, will come together to develop research strategies that aim at an improved understanding of Europe's dynamic topography and enhanced forecasting capabilities. Twin goals are (i) to simulate the recent past by "inverting" geological data and (ii) to forecast the future by connecting the past, present and future evolution of the system as a whole. TOPO-EUROPE is linked via its members to a series of programs that focus on specific aspects of European topographic evolution (Fig. 4). Certain research activities are directed by regional groups, addressing sensitive areas such as densely populated river basins, lowlands, low lying flood- and/or tsunami-prone coastal areas, subsiding deltas and earthquake-prone areas.

The main progress in quantitative prediction is expected at the interface of modelling and observation where scientific hypotheses are confronted with the observed reality. In its most advanced version, the integrated sequence "observation, modelling, process quantification, optimization and prediction" is repeatedly carried out, both in time and space. Such an iterative approach is vital for the development and verification of fundamentally new concepts.

The TOPO-EUROPE research approach centres on the following four interrelated components:

• Component 1 ‘Monitoring the Earth system’
• Component 2 ‘Imaging and high-performance computing of the deep Earth and lithosphere’
• Component 3 ‘Dynamic topography reconstruction’
• Component 4 ‘Process modelling and validation’

These four components are inherent to the very nature of the Earth sciences, placed in the context of recent advances and challenges in science and technology. The relationship between the present and the past has - in a qualitative way - always been at the heart of Earth sciences. Owing to recent developments in observational, analytical and computational capabilities, this fundamental relationship can now be addressed in a quantitative manner. Within individual TOPO-EUROPE groups, this has already resulted in a number of pioneering contributions to the integration of observational and modelling studies.

In the TOPO-EUROPE network, the full coupling between processes in the mantle and lithosphere with those active at or near the Earth's surface will be further pursued, particularly in sedimentary basins, at continental margins and in tectonically active intraplate areas. Understanding these processes and their coupling is of fundamental importance in the exploration for and the management of Earth resources and the risk reduction of geological hazards, like landslides and earthquakes. By striving for a close cooperation with the industry, TOPO-EUROPE will be able to contribute to a closer interaction between fundamental and applied geosciences. Research objectives and potential frontier science opportunities of the four components are presented below.