It is gravity. So, the effect ofgravitational waves is to form the solar system in the first place and form the Earth as part of our solar system. They do this by dragging atoms towards one another and creating a sphere of untold numbers of atoms. We call it Earth because we have evolved to live here.

Explanation:

Gravitational waves are 'ripples' in space-time caused by some of the most violent and energetic processes in the Universe. ... The strongest gravitational waves are produced by cataclysmic events such as colliding black holes, supernovae (massive stars exploding at the end of their lifetimes), and colliding neutron stars.

yes it can also effect the earth.