Okay so i asked a question about antarctica and now i have another one?

those who answered stated that there is no population nor government...so of the scientists who live/work/study/visit there - say one kills another...since there is no government and i would presume no law what happens to the person who commits the murder?...are they governed by whatever country they are from? what if it is a intercountry murder? say an american kills a person from another country...whose laws govern then?