north korea threatened on sunday to conduct what it called " a new form of nuclear test " , raising the level of rhetoric after members of the united nations security council condemned the north 's korean central news agency ( kcna ) in pyongyang march 17 , 2014 .
we generally think of north korea as digging tunnels and then conducting a single test in each tunnel in 2006 , 2009 and 2013 .
after pyongyang fired two medium - range rodong ballistic missiles into the sea off the east coast of the korean peninsula on wednesday , the 15 - member security council on thursday condemned the launches violating u.n. resolutions .
north korea had finished preparations for another nuclear weapons explosion at its test site .
 
 
what if north korea ’s recent excavations are not for new tunnel entrances .
 
the pattern of excavation at punggye - ri , however , raises a disquieting possibility .