Answer:
0.018 km³
Explanation:
Area of land
[tex]A=72\times 10^4\ m^2[/tex]
D = Depth of land = 25 m
Volume is given by
[tex]V=AD\\\Rightarrow V=72\times 10^4\times 25\\\Rightarrow V=18000000\ m^3[/tex]
Converting to cubic kilometers
[tex]1\ m=\dfrac{1}{1000}\ km[/tex]
[tex]1\ m^3=\dfrac{1}{1000^3}\ km^3[/tex]
[tex]18000000\ m^3=18000000\times \dfrac{1}{1000^3}=0.018\ km^3[/tex]
The volume of Earth removed is 0.018 km³