> measures about 600,000 cubic kilometers — roughly the volume of water that would fill 240 billion Olympic-sized pools. The second zone, off the coast of Central America, is roughly three times larger.<p>You see this a lot with anything involving a description of a volume of liquid. It inevitably ends up using an Olympic-sized swimming pool as a yardstick for the laymen. To me, especially in this case involving hundreds of billions of those pools, this is meaningless to the average reader. It implies that the reader is familiar with or has a good mental image of how much water an Olympic-sized pool will hold. While I do watch the Olympics and have a rough idea of how large they are I find it a bit ridiculous in this case to make this particular comparison.<p>Most people are not going to have any idea what 240 billion Olympic-sized pools looks like. Maybe it would be better to rephrase in terms of how many pools every one of us could have if this water was all contained in Olympic-sized pools. In that case lets just round the global population to the nearest billion, so ~8 billion people, divide this water equally amongst us so that we can all share in the bounty of oxygen-depleted seawater - so that gives everyone on earth about 30 Olympic-sized pools of water. That is just from the first zone. Including the water in the second zone they describe as being about 3 times larger than the first gives everyone on earth about 90 Olympic-sized pools of oxygen-depleted seawater.<p>Then you can flip that into terms more recognizable, say acres or hectares or something else.<p>I think for most of us, that volume is easier to picture than the 240 billion Olympic-sized pools they use in the article.