ľ¹Ï¸£ÀûÓ°ÊÓ

Earthquakes are among the deadliest and costliest natural disasters. Densely populated cities, for example San Francisco, Istanbul, and Tokyo, are in the immediate vicinity of active plate boundaries with the direct and indirect consequences of earthquakes and associated tsunamis affecting millions of people. The devastating impact of earthquakes on human lives is only one of many aspects that renders the investigation of the underlying physico-chemical processes operating during earthquakes an important scientific goal.

This PhD thesis shows that deformation of carbonate rocks during earthquakes in the presence of fluids leads to a variety of phase transformations and the reaction of the deformation products with fluids. The coupled mechanisms operating are crystal breakdown and dissolution into the fluids with subsequent reprecipitation of the same carbonate minerals. Formation of elemental, amorphous carbon suggests that hydrogen from electrolysis reduces CO₂ driven by tribolelectric charging. In addition, fluid-assisted grain growth and recrystallisation modifies the microstructural appearance and produces a nanogranular fabric without the need of high-stress grain fracturing.

The results raise the question whether seismic carbonate deformation can be described and modelled by solid-state deformation mechanisms. As a consequence, such thermochemical transformation mechanism may be more common than previously expected and need consideration when investigating and modelling seismic deformation.

The PhD thesis shows that thermochemical processes in earthquake geology are an important factor and part of the main processes and need further consideration.