> If it happened over centuries then it’s a slow creep and hardly a flood They probably flooded increasingly regularly before being abandoned and eventually su

> If it happened over centuries then it’s a slow creep and hardly a flood They probably flooded increasingly regularly before being abandoned and eventually subsumed, no unlike Venice today. Some could have been much quicker though, there are fault lines through the region though, so it's entirely possible a small tsunamis could have knocked out villages that sea level rise made vulnerable.