Seismic incident analysed for a sketch (10)
I believe the answer is:
aftershock
'seismic incident' is the definition.
'analysed for a sketch' is the wordplay.
'analysed' is an anagram indicator.
'for'+'a'+'sketch'='forasketch'
'forasketch' anagrammed gives 'AFTERSHOCK'.
(Other definitions for aftershock that I've seen before include "another shake" , "What might have cracked open house" , "no great shakes" , "that causes another little wobble" , "Tremor following earthquake" .)