Blow up in central Perth (5)
I believe the answer is:
erupt
'blow' is the definition.
(I've seen this in another clue)
'up in central perth' is the wordplay.
'in' is an insertion indicator.
'central' says to take the centre.
The centre of 'perth' is 'ert'.
'up' placed inside 'ert' is 'ERUPT'.
(Other definitions for erupt that I've seen before include "spout" , "Break out like Etna" , "Blow up like volcano" , "Burst forth, like 25" , "Spurt lava" .)