divergent boundarys
theses boundarys are way diffrent then the others this proccess in when all the plates move away from eachother. So when these plates move they will cause some of the earths countries like africa and russia ec will move apart so thats why the earth looks like that. Also Divergient boundarys occur also in the sea they will spread the sea floor which is spreading of a divergent boundary. In the middle of the atlantic in the atlantic ridge is a good example of a divergent boundary.