Question

If you went to Greenland and drilled a hole in the ice sheet, then came back later and surveyed the hole, you would find that the shape of the hole had changed. If you asked Dr. Anandakrishnan why the shape changed, he would tell you that the ice sheet was flowing. He would be correct. What does he mean by this?

A) Your drill has melted the ice, the water flowed away and refroze.
B) Your drill has shaken the ice, which settled downward, changing the shape of the hole.
C) The ice is not too much colder than its melting point, and deforms something like hot rocks in the mantle or a chocolate bar in your pocket.
D) Your drill compresses the ice, turning it into a denser type in an implosion-style earthquake that deforms the hole.
E) Your drill woke up the ice from a nice nap, but the ice then settled back down to "going with the flow"

Answer 1

C) The ice is not too much colder than its melting point, and deforms something like hot rocks in the mantle or a chocolate bar in your pocket.

Step-by-step explanation:

Materials heated near their melting point can deform without breaking or melting. In fact, the ice has been warmed from almost zero to the melting temperature. As a result, the stress from gravity can cause the ice to distort or move steadily.