I always wondered where the floods came from and i found this weird area on google earth. So in this picture (you might want to download it so it's bigger) the rocky mountain on the lower left side of the picture is a Nunatek (a mountain completely surrounded by ice). On the right side you see two completely different tounges of ice slam into each other head on. Two lines in the middle make a cross and concentric rings of crevaces emanate outward away from the cross. This is a big bulge in the ice. Above it you can see a lake.
What is interesting is that the main Skilak glacier is on the far left and continues flowing in that direction for miles downhill. The lake and where the the two glaciers meet is in a a natural depression where three valleys meet. I don't know why there would be a depression in that spot but if there was no ice the whole area would be a big lake.
So what happens is that the depression fills with water until the water makes the ice float, which is that bulge you see. Then the water can get all the way under the ice, which you can see on the right edge of the Nunatek. At some point it must fill up and float enough of the glacier that it ruptures some subsurface barrier and then it all violently escapes downhill and out the mouth of the glacier, killing people who may be eating lunch on a rock.
