http://earthquake.usgs.gov/earthquakes/recenteqsus/Quakes/nm1182.php#summary

The upshot of this is that we don't know why the swarm began, how long it will last, when it will stop, if a larger quake will occur and/or what causes it!

I still think that it it my Great Great Great Grandpa Joseph and his son John arguing about States' Rights! Seriously, this part of Arkansas is mountainous, beautiful, and has a lot of extremely fast streams which appear to be down cutting pretty rapidly through some great limestones! Heavily vegetated, which makes field work unpleasant I would suspect. I've only visited there to see where my father's family lived in the 1830s and onward, but strange and gorgeous country! I cannot imagine what the people who live there think of these quakes! Had some strange experiences around there--