Can someone who knows something about geology comment: is it normal for semi-large earthquakes to be correlated like this? When we went to Google News, the first thing we found were other earthquakes in Colorado and off Indonesia.
Anyways, Indonesia would be totally unrelated, it's part of the Ring of Fire, geological activity there is expected and their big one happened on Sunday. Stuff today is just aftershocks.
Colorado and Virginia might be correlated since it's uncommon (but not unexpected) for stuff east of the Rockies to rattle about but I'd lean towards it just being a coincidence since they're 12 hours (05:46:19 UTC and 17:51:03 UTC) and ~2650 km apart.
Generally any quake comes with a corresponding set of tremors based on the initial quake. These tend to be along the same or related fault lines. The Colorado quake could be related. Indonesia probably not as much.
It is near 0% likely that the Colorado earthquake and Virginia earthquake are related as VA and CO are on different faults. It's not 0% because, quite frankly, it's hard to model the earth.
This wikipedia article on plate tectonics explains how the Earth crust is composed of different sections all sliding past/under each other. http://en.wikipedia.org/wiki/Plate_tectonics Since the earthquakes occur at the friction points between the plates, this should help explain why Japan and California has a lot, and Virginia and Colorado not so much.
One of the major problems humans have with earthquakes is the assumption that we should/can predict them. As such, whenever there are earthquakes close in time to one another, the first assumption is that the first earthquake caused the second. Aftershocks are such an example where this assumption holds because the primary earthquake causes secondary earthquakes. However, in the general case, this assumption does not hold.
The gravity of this situation is clear in Italy where seismologists are on trial for manslaughter for not predicting the L’Aquila earthquake: http://www.nature.com/news/2011/110526/full/news.2011.325.ht...
The open letter in support of these seismologists is here (I'm #4580): http://www.mi.ingv.it/open_letter/
But think about it logically. Earthquake is a quick release of kinetic energy of a tectonic plate in one relatively small location. But the whole plate moves! So yes, earthquakes happening on the same plate's boundary can very well be correlated, IMHO (not pretending to be a geology expert or anything, but the topic is fascinating).
Virginia is not in any way connected to Pacific Ring of Fire though.