The poles do flip magnetically, but it has not happened for tens of thousands of years.
Had it happened 3,600 years ago, there would be nothing on the planet right now more sophisticated than a simple bacterium.
You can observe the history of polar magnetic disturbances in the magnetic patterns of the ocean bed. There is no evidence that proximity of a planet to small to easily spot would cause Earth's field to change at all, never mind flip. There is also no evidence that magnetic shifts affect continental drift or volcanic activity.
My question was really about the flood itself - how did it spread, how long did it last, how deep was it? etc.