Whenever one earthquake pops up, and then another somewhere else in the world, there is always the popular question "Are they related?". Frankly, my dear, I don't give a damn, but some people do.
If earthquakes are controlled by fluids, which is my big thing, then it is possible that a distant earthquake can pressurize some situations. That's because you can have a huge amount of fluid, with a very narrow top. A tiny bit of compression can move a lot of fluid at the restriction.
There is also the fact that a totally random series of events can appear in clusters, simply because it would not be random if they took place at exactly even time intervals. So, are these random clusters, or mechanically linked? Who cares?