Explosion or eruption (8)
I believe the answer is:
outburst
I believe this clue is a double definition.
'explosion' is the first definition.
(I have seen 'Explosion of emotion' mean 'outburst' so perhaps 'explosion' could also mean 'outburst')
'eruption' is the second definition.
(I've seen this before)
(Other definitions for outburst that I've seen before include "Angry words" , "Eruption of violent emotions" , "Effusion of violent emotion" , "Sudden disturbance" , "Unrestrained expression of strong emotion" .)