Spatio-temporal characteristics of geological phenomena: Linking patterns to processes

To predict and identify governing geological processes and their occurrence in space and time one needs to understand at what spatio-temporal scales they are active. The same goes for the design of experiments or numerical simulations and their up-scaling. If one chooses the wrong time window for an experiment, nothing may happen during that time.

Geological patterns in space and time are dependent on a number of processes that scale differently depending on whether or not they are linear or non-linear and on the involved constants (rate constants, diffusion constants). This is important for example for THMC processes in general, but also for the behavior of faults from the micro to macro scale or melt related processes in the Earth's lithosphere. Often the slowest process is dominating the time scale of pattern evolution, therefore cross-over points in space and time are of special interest, where the dominance of one process over another switches. Such cross-overs are critical points where the behavior of the system changes, especially when two processes are competing during pattern formation.

Here we explore five important processes namely elastic wave propagation, fluid or melt pressure diffusion, temperature diffusion, matter diffusion and reactions. For example, if a reactive fluid enters a fault, in a second the fluid pressure equilibrates on a m-scale, the temperature on a mm-scale and matter on the micro-meter scale. We will discuss examples of scaling relations with implications on how we can utilize such scaling phenomena for process understanding.