Joe Barta wrote:

It's an earth auger ANCHOR...

I'm changing my mind. The thing that bothered me was the length...
50". That just seems too long for an anchor. And the diameter of the
bit just isn't big enough for much of a post hole digger. Plus it just
seems too flimsy to be used to dig deep holes into earth or anchor
anything that requires such a deep anchor.

My final answer is one that was given by others... an ice auger for
ice fishing. It's the right length, has a removable handle for easy
carrying and drills a hole just big enough to set a line into
(although if you catch a huge fish you might have a problem ;-)

Seems to me that the cutter should pretty easily carve a nice hole
into ice without much torque required.

Is that your FINAL answer?

Yes... ice auger.

Joe Barta