In this article, we show why the geological model of the 21 August 2017 earthquake proposed by Nappi et al. (2018) has less uncertainty than the source model proposed by De Novellis et al. (2018). As a matter of fact, the Nappi et al. (2018) model takes into account all geophysical and geological information collected soon after the earthquake. On the contrary, the model proposed by De Novellis et al. (2018) is based on a limited database, which does not include (1) the available geological and macroseismic information and (2) the extensive scientific literature concerning the correlation between seismic source and surface faulting, also in volcanic areas similar to Ischia.
Nevertheless, we are grateful for the comments from De Novellis et al. (2018) because they give us the opportunity to consider the epistemological landscape in which we should frame the research for the best source model of the 21 August 2017 Casamicciola earthquake.