The modeling of earthquake risk for property insurance is an inexact science. This is because the inner workings of the triggers are so obscure from direct observation; events of interest are relatively infrequent; and the time period between events is so long. These difficulties lead directly to the kind of innovation and creativity necessary to build models that live up to George Box’s tenet that “all models are wrong, but some are useful.”
Our planet is not a solid piece of rock, but rather a boiling slush of magma, with slight movements across the surface hinting at the dynamic inner depths of the planet. Sometimes, the evidence of that inner activity is unleashed as a massive release of energy that rends and shakes the surface of the Earth — a.k.a, an earthquake.
Unlike most natural processes, geology happens over immensely long time frames. Earthquakes (and their Volcanic cousins) occur at intervals that are sometimes longer than the entirety of human history. Interestingly, earthquake records actually comprise some of the earliest historical records we possess.