Author Question: Explain how Earth's crust is similar to an iceberg and how this helps explain the principle of ... (Read 32 times)

newbem · **on:** Jul 13, 2018

Explain how Earth's crust is similar to an iceberg and how this helps explain the principle of isostacy.

Question 2

What are the three possible explanations for the distribution of paleomagnetic data? Which one of these explanations is correct?

hollysheppard095 · **Reply #1 on:** Jul 13, 2018

Answer to Question 1

Ice is slightly less dense than water, so it floats. An iceberg sinks in water until it displaces a volume of water whose weight is equal to that of the ice. When the iceberg has sunk to an equilibrium position, only about 10 of its volume is above water level. If some of the ice above water level should melt, the iceberg rises to maintain equilibrium with the same proportion of ice above and below the water.

Earth's crust is similar to the iceberg in that it sinks into the mantle to its equilibrium level. Where the crust is thickest, as beneath mountains, it sinks farther down into the mantle and it also rises higher above the surface. And because continental crust is thicker and less dense than oceanic crust, it stands higher than the ocean basins.

Answer to Question 2

(1 ) The continent remained fixed and the north magnetic pole moved; (2 ) the north magnetic pole stayed still and the continent moved; (3 ) both the continent and north magnetic pole moved. The correct explanation is that both the continent and north magnetic pole moved.