For Marvel Odin creating Earth and humanity is a factual truth.  In the past at least, Odin has been considered the ruler of Earth.   As crown prince, Thor as at least some authority derived from him and stands to inherit all of it.

Then you have Gaea who IS the Earth personified.  Thor is her child and at least shown to be one of her favorite children.  Given how she was here before anything else and infused her life in all things and has guided life since.  She is higher up on the order of things than Thor ans possibly Odin.

Finally, you have Thor who at times has been considered an embodiment of all storms on Earth.  

Or is this a matter of how enforceable laws are?  Stark tried forcing Thor and Asgard to register for the SHRA only to back down when he realized Thor  was too powerful.  So he tried to find a politically expedient compromise.