[Mike Darancette]

Is the Gulf region close to any historic subduction zone?

[fightinJAG]

I don't know. But it experienced a major (6.0) earthquake in this area in 2006.

Check out the location of the earthquake HERE.

Excerpt:

This is the largest of more than a dozen shocks that have been instrumentally recorded from the eastern Gulf of Mexico in the past three decades, and it is the most widely felt. The most recent significant earthquake in the region occurred on February 10th, 2006 and had a magnitude of 5.2. We have not associated this earthquake with a specific causative fault."

This is an unusual event because it is far removed from an active plate boundary.