Swiss Seismological Service (SED)
I joined the Swiss Seismological Service in 2014 as a researcher in statistical seismology, seismicity analysis as well as seismic hazard and risk assessment. One of my main research interests is the spatio-temporal variation of the earthquake size distribution (the so-called b-value of the Gutenberg and Richter relationship) and its use in hazard and risk assessment. I am for example developing and testing statistical models of earthquakes targeted towards improving the medium term and short-term predictability. In the case of L’Aquila event in 2009 (Gulia et al., 2016, GRL, https://doi.org/10.1002/2015GL066686), I translated these forecasts into probabilistic seismic hazard and seismic risk.
In a recent study, I investigated in a highly systematic way, the spatio-temporal evolution of the earthquake size distribution and rupture potential throughout a seismic sequence, applying a stacking approach to several well-recored worldwide sequences (Gulia et al., 2018, GRL, https://doi.org/10.1029/2018GL080619; https://eos.org/research-spotlights/how-do-main-shocks-affect-subsequent-earthquakes). My research shows how, immediately after a main shock, the b-value increases by 20%–30% and remains elevated for at least the following 5 years, reducing the chance of the occurrence of a larger earthquake in the immediate vicinity of the fault. I also proposed an empirical relationship to be used to forecast aftershock hazard in a more realistic way. We are now investigating the use of these results for distinguishing between foreshocks and aftershocks in real-time.
Historical seismology is also part of my research interest: I contributed to the assessment of parameters (location, orientation, magnitude) of the seismogenic source by macroseismic intensities (Vannucci et al., 2019, Tectonophysics, https://doi.org/10.1016/j.tecto.2018.11.002) and to the updating and Earthquake Catalogue for the Italian territory, CPTI04 (Stucchi et al., 2007, http://esse1.mi.ingv.it/data/D18.pdf).
I investigated the systematic dependence of the b-value on the style-of-faulting in Italy (Gulia and Wiemer, 2010, GRL, https://doi.org/10.1029/2010GL043066) and explored new options for the Italian reference seismic hazard model, MPS04 (Gulia and Meletti, 2008, http://www3.inogs.it/bgta/provapage.php?id_articolo=418; Meletti et al., 2006, http://esse1.mi.ingv.it/data/D5.pdf).
I also worked on the data quality control as well as on quarry blast identification and removal from seismic catalogs (Gulia, 2010, Nat. Hazards, https://link.springer.com/article/10.1007/s11069-009-9426-8; Gulia et al., 2012, CORSSA, https://doi.org/doi:10.5078/corssa-93722864).
I am a member of the Community Online Resource for Statistical Seismicity Analysis (CORSSA).