The blanket bogs known as 'featherbeds' on subantarctic Macquarie Island occur on raised marine terraces; they may be up to  deep, tremble or quake when walked on and can be hazardous to cross.
Macquarie Island's "featherbeds," a type of blanket bog found on elevated marine terraces, are deep and can shake or crumble underfoot, posing a safety hazard for crossing them.