The long term result would be that the region where it has occurred will split and the two parts will move away from each other, the growing gap between them will be filled with water which in time will become sea, there will be significant climate changes, the one part that'll be moving into more isolated position will make life forms on it to evolve in a specific way and they will become very unique in time.
Fresh water and salt water together cover 3/4 of the earth's surface.
Answer: mid ocean ridges so I would go with the first one of at the spreading centers in the middle of the ocean
Explanation:
Not completely sure educated guess
