  Research on the earthquake occurrences using a statistical methodology based
on point processes has mainly focused on the data featuring earthquake catalogs
which ignores the effect of environmental variables. In this paper, we
introduce inhomogeneous versions of the Cox process models which are able to
quantify the effect of geological factors such as subduction zone, fault, and
volcano on the major earthquake distribution in Sulawesi and Maluku, Indonesia.
In particular, we compare Thomas, Cauchy, variance-Gamma, and log-Gaussian Cox
models and consider parametric intensity and pair correlation functions to
enhance model interpretability. We perform model selection using the Akaike
information criterion (AIC) and envelopes test. We conclude that the nearest
distances to the subduction zone and volcano give a significant impact on the
risk of earthquake occurrence in Sulawesi and Maluku. Furthermore, the Cauchy
and variance-Gamma cluster models fit well the major earthquake distribution in
Sulawesi and Maluku.
