The average depth of the oceans is about 3.64 km, and oceans cover about 70% of Earth's surface.Make an order-of-magnitude estimate of the volume of water in the oceans. The

circumference of Earthis about 40 000 kilometers. 10^{15} \mathrm{~m}^{3} 10^{14} \mathrm{~m}^{3} 10^{18} m^{3} 10^{9} \mathrm{~m}^{3}