Volcanic and volcano-tectonic activity forecasting: a review on seismic approaches

Forecasting volcanic activity is a difficult problem that is being addressed worldwide from different perspectives. Significant advances have been made after the introduction of non-linear dynamical systems theory and the use of power-law distributions of different geophysical parameters in the Earth Sciences. In particular, frequency-magnitude power-law statistics evidences the scale-invariance and self-organization of seismicity, and brittle fracture models show that under certain conditions, a precursory causal evolution characterized by an accelerating strain rate culminates in a catastrophic failure of the system under stress. The precursory organization of the seismicity and the distinct characteristics of the seismic events have allowed the development of forecasting tools. In this work we present some examples of forecasting methods based on seismic observations at different volcanoes in the world, and how results and experiences has been used to improve both hardware and software tools developed for short-term forecasting of volcanic and seismo-volcanic activity.