Here are some explanations that may help. Your question is extremely broad, though, so further searches on your part at www.google.com would probably help you.
http://regentsprep.org/Regents/earthsci/units/introduction/index.cfm
http://www.enviroeducation.com/majors-programs/earth-sci.html
http://www.usgs.gov/
Traditionally,how have different fields of earth science been studied?
3 answers
science is the study of all things science.
science is when you si and then ence