Conclusions
Google Earth has been used to map active normal fault scarps that offset 12-18 ka landforms in the Apennines, Italy. This map provides precise locations for structures responsible for tectonic strain release and earthquake rupture. Spatial variation in fault slip occurs at a scale of tens of kilometres, whilst fault scarps have offsets of <30-40 metres and a geomorphic expression that can only be visualised on topographic images with spatial resolution at the metre-scale. Thus, until now, debate has surrounded the exact positions of scarps due, in part, to problems of visualising both the detailed geomorphic features and their regional variation. Provision of complete SPOT image coverage and topography within Google Earth allows individual scarps visited during fieldwork to be visualised at a regional scale within an easily-accessible interface. The resultant fault map is an important step towards agreement on a final fault map, which is needed to facilitate comparison of multi-seismic-cycle strain-rates defined by slip across fault scarps and single-seismic-cycle strain rates from instrumental seismicity and geodesy. Such a comparison is needed to constrain the stress-loading and strain-release patterns that govern earthquake recurrence, through improved understanding of the mechanics of the seismic cycle.