Probabilistic space- and time-interaction modeling of main-shock earthquake rupture occurrence

This paper presents a probabilistic formulation for modeling earthquake rupture processes of mainshocks. A correlated multivariate Bernoulli distribution is used to model rupture occurrence. The model captures time interaction through the use of Brownian passage-time (BPT) distributions to assess rupture interarrival in multiple sections of the fault, and it also considers spatial interaction through the use of spatial correlograms. The correlograms represents the effect of rupture nucleation and propagation. This model is proposed as an attractive alternative to existing probabilistic models because it (1) incorporates time and space interactions of mainshocks, (2) preserves the marginal distributions of interarrival times after including spatial rupture interactions (i.e., model consistency), and (3) has an implicit physical interpretation aligned with recent rupture behavior observations. The proposed model is applied to assess the occurrence of large interface earthquakes in the subduction zone along the Coast of Lima, Peru. The model matches both the annual magnitude exceedance rates and the average seismic moment release in the tectonic region. Time-dependent seismic hazard in the region is also calculated, and the results demonstrate that by accounting for recent earthquake occurrences, the inclusion of time-dependent effects can reduce the 30-year seismic hazard by a factor of four.