B.M.G.L.

Yesterday I posted a little photo of me at Glacier Bay in Alaska. Taken back in 2005 BMGL (before my geology life) and honestly I wrote exactly what I thought back then. That glaciers were big, beautiful "hunks of ice" that I wanted to climb. Back then if you were to ask me what I thought about the landscape around a glacier, I probably would have answered something like "it looks a little on the tattered side, but for the most part it is - interesting". Interesting was my word for "I dunno, leave me alone".

Today, my viewpoint is very different. I now read the landscape instead of seeing it.

What do you see in this photograph? Big beautiful hunk of ice right? Well, okay I will give you that but do you see the "flow" of the glacier, or the horns in the mountains, the lateral moraines or the cirques? If you are like me (a rock minion who lives in textbooks) then you probably do see those glacial features. Maybe you think I am speaking a different language...that's all right because technically I am.  

In this second picture look to the highest part of the mountains in the background. It looks kind of like an inverted "V"...that my friend is called a horn. It is created by the snow (firn) and ice of glaciers that over the glaciers lifetime strip away some of the loose, or not-so-stable rock materials. This leaves behind a rugged, sharp looking peak.  Next, if you look above the treeline dead-center of the picture you see a gray bar-like feature, that is the lateral moraine. It is boulders, rocks, gravel, and soil that is being shoveled to the edges by the glacier. Last are the cirques. A cirque is a circular space at the top of the mountain where glacial ice begins.

If you are fortunate to live in California or Nevada, you can see glaciers and all these features in the Sierra Nevada. Go to your local library and check out Mary Hill's book on the Sierra and take a drive up there for a day or two. Oh, don't forget your camera!