Geological Activity Explained 5 Why most tectonic fractures are short and only a few long скачать в хорошем качестве

Geological Activity Explained 5 Why most tectonic fractures are short and only a few long

This talk uses field examples of fracture systems in sedimentary rocks from the areas at and around Nash Point (on the north coast of the Bristol Channel, UK) and Kilve-Watchet (on the south coast of the Bristol Channel). In these areas there are fracture patterns of exceptional beauty and educational value. Using these field examples, I show that most tectonic fractures remain small because they become arrested at contacts between rock types with different mechanical properties or at existing fractures. Slip on a fracture during an earthquake is linearly related to the controlling dimension of the fracture. It follows that if the dimensions of the earthquake-producing fractures have power-law size distributions, then the earthquake slip and slip-surface distributions also have power-law distributions, and so will the earthquake magnitudes – as indeed they do.