What is the volume of ice that has melted (in cubic kilometers)? Since 1960, sea level has risen 30 mm due to added water from melting glaciers. If the ocean area is 361 million square kilometers, what is the volume of ice that has melted (in cubic kilometers)?

Then the area added is base times height, or, in this case, area of the ocean, or $361,000,000\cdot(1000\ \text{meters})^2$, times the height added ($30\cdot 10^{-3}$ meters).