<P> A complete hierarchy showing which seas belong to which oceans, according to the International Hydrographic Organization (IHO) and for the whole planet, is available at the European Marine Gazetteer website . See also the list of seas article for the seas included in each ocean area . Also note there are many varying definitions of the world's seas and no single authority . </P> <P> The Arctic Ocean covers much of the Arctic and washes upon northern North America and Eurasia and is sometimes considered a sea or estuary of the Atlantic . </P> <P> The International Hydrographic Organization (IHO) defines the limits of the Arctic Ocean (excluding the seas it contains) as follows: </P> <Dl> <Dd> <Dl> <Dd> Between Greenland and West Spitzbergen (sic)--The Northern limit of Greenland Sea . </Dd> </Dl> </Dd> </Dl>

Where does the pacific ocean end and the indian ocean begin