[Retric]

The Empire State buildings base is almost 2 acres x 443.2 m tall and a square km is 247 acres. 2 * 443m * 37 million / 424 million (424,000 thousand) / 247 ~= 0.3m so covered to the depth of 1 foot. Which seems more reasonable.

ED: Ahh, they had wrong area for California. It's 424,000 square kilometers not "424,000 thousand square kilometers"

[dmurray]

That 424million should be 424,000, so we are back at 300m deep. Except the ESB doesn't fill anywhere near all of the (2 acres x 443m) cuboid, so 100m is closer.

[Retric]

Yea, I was thinking they where off by 1000 somewhere. Checking https://en.wikipedia.org/wiki/California gives (423,970 km2).

And yea, 1/3 of the volume is a better approximation but the numbers where so far off that seemed less useful.