FiSH; MATLAB tools to turn fault data into seismic-hazard models

Faults have been increasingly integrated into seismic-hazard assessments. We have developed a package of MATLAB (http://www.mathworks.com/products/matlab, last accessed January 2016) tools (called FiSH), designed to help seismic-hazard modelers analyze fault data. These tools enable the derivation of expected earthquake rates, given common fault data, and allow researchers to test the consistency between the magnitude-frequency distributions (MFDs) assigned to a fault and some available observations. The basic assumption of FiSH is that the geometric and kinematic features of a fault are the expression of its seismogenic potential. Three tools have been designed to integrate the variable levels of information available: (1) the first tool allows users to convert fault geometry and slip rates into a global budget of the seismic moment released in a given time frame, taking uncertainties into account; (2) the second tool computes the recurrence parameters and associated uncertainties from historical and/or paleoseismological data; and (3) the third tool outputs time-independent or time-dependent earthquake rates for different MFD models. We present a test case to illustrate the capabilities of FiSH, on the Paganica normal fault in central Italy that ruptured during the 2009 L'Aquila earthquake sequence (mainshock M (sub w) 6.3). The source codes are open, and we encourage users to handle the scripts, communicate with us regarding bugs, and/or suggest further improvements. Our intent is to distribute these tools in order to help researchers to pinpoint potential inconsistencies and obtain reliable fault-based seismic-hazard evaluations.