Answer:
1. The major crustal plates involved in the Atlantic mid-ocean are the North American Plate and the Eurasian Plate on the west side, and the South American Plate and the African Plate on the east side.
2. The tectonic boundary presented at the Atlantic mid-ocean is a divergent boundary, where the plates are moving away from each other.
3. The movement at the Atlantic mid-ocean results in the formation of new crustal material, which eventually leads to the widening of the ocean. The volcanic activity along this boundary also contributes to the creation of new islands and archipelagos. On the other hand, this movement may also cause earthquakes and tsunamis in the nearby coastal areas.
4. In another million years, the Atlantic Ocean is predicted to continue to widen, with the distance between the Americas and Europe/Africa increasing by several more centimeters per year. The volcanic activity and the formation of new islands may also continue, although at a relatively slow pace.