Quote: Most of the Gulf isn't very condusive to tsunami impacts due to the shape of the coastline and duration of any tsunami fetch. Local NWS offices will warn for one, however, if the need arises -- the infrastructure is in place for that.
After the Indonesian Christmas quake, on one of the shows I watched about it, if I remember correctly, not all underwater quakes will cause tsunamis either. There's certain ones that will. I can't remember the differences though.