Understanding and modelling brittle deformation in the earth: insight from a novel experimental approach

Abstract

Current experimental approaches on faults provide a significant contribution to our understanding of brittle deformation in the crust. However, they rarely present a multiscale view of fault initiation, propagation and growth or the complex geometry of natural faults combined with other geological features such as folds and flow structures. We suggest new types of experiments that are inspired by the observations of natural phenomena on the water surface of a lake. In order to create similar structure to the nature, we have investigated different possibilities, hence designed and run the first series of novel experiments in a large water tank setup at the hydrodynamics laboratory of the University of Oslo. The water tank is equipped with cameras to dynamically image the experimental process. Using capillary waves and added impurity (pollen) to the water surface in a controlled laboratory set-up, our experiments created structures similar to faults, folds, and flow structures observed in nature. We suggest that these experiments can be utilised to not only study the fault growth process but also to answer some fundamental questions with regard to material properties such as friction and the stress configuration needed to create brittle and ductile deformation in the Earth.