Centaurus:
I believe that ice absorbs radar waves and that ice covered mountains would not show on older airborne weather radars. I vaguely recall this point was made during the original investigation. If correct, it would suggest that relying on weather radar for terrain clearance in the Antartic is risky.
True, but within the ice of Erebus is a volcano, and while there will be some absorption, much of the signal will pass as if through air, and reflect off the rock.
GB