The most common and most likely answer to this crossword clue is the 13 letter word SEISMOGRAPHER
I've seen this crossword clue in The Sunday Telegraph
S
E
I
S
M
O
G
R
A
P
H
E
R
Buddy explains!
The straight part
We know that "Scientist whose work is on shaky ground?" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case scientist whose work is on shaky ground? = seismographer.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.