This is a somewhat close-up view of a glacier as it meets the water from our recent Alaskan trip. The big blue columns of ice form a wall at the water's edge. The best I could estimate the size is that the columns are about 200 to 300 feet high. Periodically, a sliver will fall into the water and create a big splash. You can see that splash at the bottom center of the photo -- I think that splash is about 30-50 feet high. The process is called calving.