True. Good point.
I guess I pictured in my mind a glacier, where sand, rocks and boulders had
been pushed and collected over time. In the ice fields of Earth's North and
South poles, is there debris like we're talking about?
There is no ice field on Earth's north pole. It's pack ice there, and sometimes, particularly of late, that pack ice melts all the way through to open water. In recent years, it has literally been possible to sail a boat right to the North Pole. Ice in the North is generally collected on Greenland, the major islands in Northern Canada, and Alaska.
Antarctica is a different tale. There, the ice is about 1 1/2 miles thick in some places.
This is a key factor why I was pushing for using the Harding Ice Field. It is a giant 'bowl' valley, filled with OLD ice, that is, snow distributed over 12,000 years, that has compressed to ice. In other words, no rocks, such as you find in a glacier, which typically grinds up dirt, rocks, trees, and anything else in its path as it works its way over the land.
For now, our initial test site is likely to be a couple of conduits bolted together, or later, a 50' depth drop into a Colorado glacier. For a deep, rock-free dive, we would need a significant ice field, such as in Alaska, Greenland, or Antarctica.
-- JHB
Maybe the only thing that would be present on Europa's poles is anything
that may have fallen from the sky.
