my understanding is that kamchatka is something like the mountains in bc, and no more populated. it's about as far from moscow as you can get in russia.
it's a great place for underground nuclear testing, like the kind that was recently attacked in iran.
there's been a lot of earthquakes in kamchatka this month. it's an observation, nothing more.
earthquakes do happen in clusters. that's true. aftershocks tend to follow big earthquakes, so you might keep an eye out for that.