How Much Does the Ocean Weigh? Water does weigh something; about
8.3 pounds per gallon. In research published this week,
scientists from the National Oceanography Center and Newcastle
University have proposed an idea that will assess the mass of
the world ocean by weighing it at a single point. But there is a
catch. Global sea level is currently rising at about 3 mm per
year, but predictions of rise over the century vary from 30 cm
to over a meter. There are two ways global sea level can
increase. The water in the oceans can warm and expand, leading
to the same weight of water taking up more space. In other words
water density can vary which must be taken into account.
Alternatively, more water added to the ocean from melting of
land ice will increase the ocean’s weight. The National
Oceanography Centre’s Prof Christopher Hughes said: “We have
shown that making accurate measurements of the changing pressure
at a single point in the Pacific Ocean will indicate the mass of
the world ocean. And we know where to