“Would have swept”
The glaciers don’t melt overnight. It goes the course of thousands of years. Wooly mammoth time was the maximum extent of the last glaciation. We’re technically still in an ice age. Glaciations cycle up and back within ice ages. There have been 60 such events in the past 4 million years. Average 66 thousand years a cycle.
The press and climate “scientists” mischaracterize the last glaciation as “the last ice age” all the time.
It is a really interesting book. The geology shows these things happened and they were not just a slow thaw but the great ice sheets being undermined by warm salt water and breaking loose to slide into the ocean creating thus some really big tsunami and there were also some rather sudden effects of the immense glacial lakes that flowed out behind the glaciers and made for a rapid rise that in itself permanently drowned a huge continental shelf of previously dry forested and populated land in SEA.
The failure of the remaining glacial dams led to those floods, which are documented in formations like the Channeled Scablands.
During an ice age with mile thick ice over Seattle, I’m guessing that there would be opportunity for that ice to break and calve off like it does today. When a 100-foot chunk breaks off in some Alaska bay it will cause a water rise. One minute you are standing in the water with your rubber boots, the next the water is suddenly pouring over the tops.
Having a chunk of ice thousands of feet wide and thousands of feet tall break off would have been fairly common 15,000 years ago I would think. I’m not sure what the dimensions of that island out in the east Atlantic is - but there are articles written on the huge tsunami that it would cause if there was a huge landslide.
And landslides/ice falls can cause larger tsunamis than a large earthquake.