Active normal fault evolution in Greece revealed by geomorphology and drainage patterns

Active normal fault systems in Greece are associated with characteristic geomorphology and drainage patterns that are recognizable in satellite images and digital topography. Some allowance must be made for the nature of the footwall rocks, which can exert an important influence on these patterns, and we examine the three main types in Greece: hard Mesozoic limestone, relatively soft schist, volcanic rocks or flysch, and very soft Neogene sediments. Drainage and geomorphology can be used to identify active faults that were previously unknown, but can also reveal information about Plio-Quaternary fault evolution and interaction that may be inaccessible by other means. We illustrate such processes with examples showing the migration of normal fault systems into their hanging wails, and the change in normal faulting activity from NW-SE faults to E-W faults, both of which are common in Greece.