Icebergs!

Icebergs are, "a large mass of ice floating at sea; usually broken off of a polar glacier" and are found usually near the pole regions of the world.
Below is an aerial view of the North Pole















Next is an aerial view of the South Pole

Below is a representation of an Iceberg, note that most of the iceberg is under the waterlevel

When an iceberg is stressed to the point that the water crystalline matrix cannot support the weight of the ice above it, This happens! (Note: Look for what seems to be a frozen ship in the video)  CLICK HERE!!!
The weight causes a shear in the matrix that cleaves in an almost straight  plane. 

Ice at the poles differs at certain times of the year. The picture below shows the pole at March (A) and September (B).