Ice sheet wall shape

[tedbarnett]

As it retreated the Laurentide Ice Sheet probably wasn't a single flat "wall" of ice. It likely had indentations and scallops where rivers later formed. Greenland today is a good example to look at (it has a retreating ice sheet). Example below. We should have indentations behind the Hudson and East Rivers, where then flowing water helps scour out the basins of those two rivers.

[tedbarnett]

https://www.google.com/maps/@60.3415291,-46.8358295,118213a,35y,33.7t/data=!3m1!1e3?entry=ttu

and

https://www.youtube.com/watch?v=qMcX0taQxtI

[tedbarnett]

Would also be awesome to add some tall waterfalls pouring off the edge of the ice sheet. Cheap particle effect?

National Geographic:

[tedbarnett]

Might also want some of the bay to be unfrozen but full of broken off ice chunks as in these shots from near Greenland:

[tedbarnett]

I love how the wall looks currently: very vertical and dramatic.

• In the long run though we have to go with what is accurate, to the extent science has figured it out. What did the Laurentide Ice Sheet look like as it receded?
• Best guess is something like Greenland, which is covered in an ice sheet that sometimes retreats. Similar rock underneath too. The "wall" (where the ice was 1km thick) was probably back from the front edge by 2-5km. Snow ramps up from the front edge back to that height.

This spot on Google Maps looks similar to the Hudson appearing as the Laurentide Ice Sheet retreats.

[tedbarnett]

3.7km from the front (ice-free) edge to what looks like the full thickness of this Greenland ice sheet.

[tedbarnett]

3.7km on our map would have the snow starting around the West Village (14th Street).