Charles Explorer logo
🇬🇧

Analogue modelling in geosciences

Class at Faculty of Science |
MG420P16

Syllabus

1. Introduction: Modelling in natural sciences, numerical and analogue approach in geosciences (philosophy, history, recently studied problems)

2. A little bit about the theory: math/phys definition of the model, simplification of the problem (conservation laws, heat transfer, final definition of the model, definition and frame of model validity, boundary and initial conditions, scaling)

3. Let’s start: preparation and performing of models, evaluation and quantification of modelled features (velocimetry, photogrammetry, calculation of velocity fields and derived strain parameters, general deformation and flow of material)

4. Large-scale models: Models of mantle convection (Rayleigh and Nusselt number, thermal sources), convergent plate boundaries (subductions, collisions, folding, thrusting, brittle and ductile deformation in general, coupling of folds and faults, magmatism, evolution of Rayleigh-Taylor instability and inversion of the lower-middle crust), divergent boundaries (extension on mid-ocean ridges, magmatism, gravitationally driven orogenic collapse), strike-slip tectonics (simple shear deformation, horizontal movements, transform and transcurrent faults)

5. Mid-scale models: deformation of the crust during continental collision (role of décollement and detachment layers). Models of accretionary wedge based on granular materials and viscous detachment horizon. Models of orogeny with melting and folding of the lower crust.

6. Mid-small-scale models: Salt tectonics (diapirism, folding, sedimentation and erosion), magmatic intrusions (development of laccoliths, batholiths, dikes and sills, thermal models, mechanical models, combined models), models of volcanic bodies

7. Experiments in a low-pressure environment: sedimentary and cryogenic volcanism on surface of other terrestrial-type planetary bodies via Solar system

8. Summary and modelling perspectives The practical part will be held irregularly in blocks and covered by the Laboratory of Tectonic Modelling at the Institute of Geophysics ASCR (https://www.ig.cas.cz/en/observatories/tect-mod-lab/) and Laboratory of Experimental Tectonics (https://www.natur.cuni.cz/geology/paleontology/laboratories). Students will perform simple modelling and data can be used for their final mini-project. Absolvents will have extended knowledge in geodynamics as well as practical skills in analogue modelling including post processing based on image analysis methods.

Annotation

Analogue modelling (besides the numerical modelling) is a traditional way how to understand, quantify and predict the behaviour of complex geodynamical systems. Such systems are studied by wide spectra of geological and applied geophysical methods on local and large-scales (structural geology, petrology, geochronology, gravity and electromagnetic measurements etc.), however, usually we are limited by insufficient “hard" (field) data from inaccessible Earth parts. In contrast to the numerical approach, the analogue modelling is naturally 3D and uses real and conveniently scaled materials to represent the studied systems. The thermal and mechanical evolution of such materials is thus analogic to the “real” natural systems and both techniques are complementary to each other.

This course is primarily focused to the master students in geosciences. The core of the syllabus is to provide a guide through modelling philosophy and learn how to practically prepare, perform and quantify the models focused on lithosphere and mantle dynamics. It is also possible to slightly adapt the content according to needs of students.