[tshaddox]

I'm an American, and I like to think that I can comprehend liters, but I think for enormous volumes like this it's easier to visualize distances cubed.

Like for a million cubic miles, I know that's a cube with 1,000 mile sides. That's like New York to Miami (don't ask me about cities in Europe...okay I'll go out on a limb: Paris to Rome?). I can visualize that cube of water on a globe.

But how many liters or gallons is that? A lot! But billions? Trillions? I probably would instinctively say billions, but with a tiny bit of mental arithmetic I'm suspecting it's up in the trillions.

edit: I came back to confess that indeed I am an ignorant American who has no intuitive sense of exaliters. My SI volume comfort zone doesn't extend much past teraliters.