It is raining hard. The rain is going to make the ice-burg pieces fall off. When they fall of it is called weathering. weathering is when a rock gets broken down by rain or hail.
The dotted line is where it will weather , because of the rain. the part that comes off will fall into the ocean and will go back to shore. That is called erosion that is when the rocks that got weathered go into the ocean and back out.
The ice burg will break ,and the parts will get hit by the wind and make more layers of mountains.