Thank, you, Chris, for the long, detailed explanation. I haven't read all the posts since I posted last night, so I hope I don't ask any redundant questions.

Vietnam is a beautiful country of tall mountain peaks, and fertile valleys. Does anyone know if there are any active faults in Vietnam, and if so, where they run? I agree with you that this quake should set off a global swarm, if you will.

Much thanks,

Cathryn