NEIC has nothing.
Interesting link to underwater nuke explosions. http://www.cddc.vt.edu/host/atomic/nukeffct/enw77.htm
NEIC is 'edited'. I've seen events disappear form the display. Most notably some big explosions in Montana, that were speculated to be blasting for shelters for gov't officials. (Near the Cheney ranch).
NEIC routinely eliminates any non-natural seismic events from the site. Like a Stalin enemy, they are simply 'disappeared'...