Stride around island, climbing frozen mass (6)

I believe the answer is:
icecap
'frozen mass' is the definition.
The definition and answer can be both natural objects as well as being singular nouns.
Maybe there's a link between them I don't understand?
'stride around island climbing' is the wordplay.
'stride' becomes 'pace' (synonyms).
'around' becomes 'c' (abbreviation for 'circa').
'island' becomes 'i' (geographical abbreviation).
'climbing' is a reversal indicator (in a down clue, letters climb up).
'pace'+'c'+'i'='paceci'
'paceci' in reverse letter order is 'ICECAP'.
Can you help me to learn more?
(Other definitions for icecap that I've seen before include "north polar region?" , "Polar expanse" , "Frozen top of mountain etc" , "Cold sort of headwear found in Greenland" , "Permanent coating of white on a mountain-top" .)
