In the Baltic, it did happen rapidly, and the lake level variously fell and rose as glaciers melted and flowed and moraines dammed the narrow strait that separa

In the Baltic, it did happen rapidly, and the lake level variously fell and rose as glaciers melted and flowed and moraines dammed the narrow strait that separates it from the North Sea. https://en.m.wikipedia.org/wiki/Baltic_Ice_Lake https://en.m.wikipedia.org/wiki/Baltic_Ice_Lake