The two mile tall glaciers and the 400 foot sea level rise over the last 10,500 years make a complete liar out of you.
I doubt ice can be piled up that high and still maintain a 'cliff-face'. How much of that depth was created by snow that used the Gulf Stream for the moisture. Would a 'ocean-effect snowstorm dump 20 ft at a time, how about 100ft.. The alternative is the ice from the interior was even a few miles taller in order to flow across uneven ground. When ice does fill that the hole remains filled with the same ice that sheers itself in a line that gust grazes the highest parts of the land.
The 400ft would have happened many times. The 40,000 miles of oceanic crust has taken 200m years to get to the shape it is today. All that water would have moved onto the land that may have been at least at the 4,000ft level and there were no mountains and no deep crevices.
10.5 is when the 400ft rise would have been completed rather than that is when it started. That ice-age was supposed to be a very long one but I have found no actual dates and the mini-iceage pattern seem to go back quite a ways. A long term ice-age would put more water in the Nile and Northern Africa, that same shift would mean the Dead Sea would have been a body of fresh water. If it went back 400,000 years that is when live would have been easy and we are 'struggling' once the desert belt showed up. It should show up every time an ice-age ends. The changing patterns should be predictable so people can avoid the floods and the droughts, today the elite would sent the poor into areas that will kill them and they would buy all the poor land that will become the best land once the rains return. That is a money making opportunity for them, many people die because the deceptions are believed.