Scientific Facets of the Search for Foreshocks

Tuesday, 16 December 2014: 8:00 AM
Warner Marzocchi, Istituto Nazionale di Geofisica e Vulcanologia, Roma, Italy
The role of Science as a distinctive enterprise of human activities has been often (harshly) debated by many scientists and philosophers. The largest scientific organization – the American Association for the Advancement of Science (AAAS) – has taken a clear position on this issue reporting “…the growing ability of scientists to make accurate predictions about natural phenomena provides convincing evidence that we are really gaining in our understanding of how the world works.” The term 'accurate' implicitly recalls the importance of model/hypothesis testing as further emphasized in the same AAAS document: “A hypothesis that cannot in principle be put to test of evidence may be interesting but it is not scientifically useful.” This talk explores these themes in a seismological context, in particular we review and discuss the earthquake predictability of foreshocks, defined in a generic sense as the seismic activity that precedes a large earthquake. Paraphrasing Donald Rumsfeld, we show what we know about foreshocks, what we know we don't know, and how to reveal possible unknown unknowns. We explore in detail an ideal (recursive) pathway to search for foreshocks that consists of: i) a collection of observations and the build of conceptual models, ii) the formulation of testable hypothesis, and iii) a prospective testing of the hypothesis with independent data. The vast literature on this issue shows that scientists are usually mostly concerned on the first of these points, but, as reminded by AAAS, all of them are necessary to make real scientific progresses on this field.