My habit of blogging about things I experienced several months ago leads to weird "blog time warp" situations. Case in point: my last post was a very recent picture and an abrupt departure from all the glorious Alaskan goodness that I have been sharing for several weeks now. Then, to top if off, Tammy and I took a trip to Asheville, NC this past weekend, which gave me a great excuse for not posting anything at all.
Now that we have returned from our trip (with a few pictures in tow), I am refreshed and ready to boldly resume the blogging bonanza. There are still, I think, some very interesting photos to share from the Alaska adventure, so I am going to push through those before sharing anything from this weekend's trip. And to continue through the Alaska photos means that I need to give a blogger's wave goodbye to Seward - it is time to move on to another location. And the perfect
segue for that exit is a post about
Exit Glacier, the location that served as the exit for the first recorded crossing of the
Harding Ice Field.
As you drive out of Seward (or into Seward...there is only one road), you pass a spur that will lead you to Exit Glacier. This spur is the only road that lies within the
Kenai Fjords National Park. As you drive down this spur you pass several odd signs that show nothing but four digit numbers. We later learned that those four digit numbers were years, and they marked where Exit Glacier terminated at various points in the past. I cannot remember what the exact year was on the first sign we passed, but it was somewhere in the late 1800's. Once we learned what the numbers represented, we immediately wondered how they knew where the glacier terminus was that long ago?"
Part of the answer turns out to be forest succession. As Exit Glacier recedes it leaves bare ground. Eventually, that bare ground is covered by plants, and then over time, different plants replace the previous plants. It turns out that the order in which plants cover that bare ground and replace each other is fairly predictable. By looking at what is growing at various distances from the current terminus of Exit Glacier, and how old those things are, you can estimate how many years it has been since the terminus was at that point. If my slim explanation of forest succession leaves you wanting more, you can read better explanations of forest succession
here and
here (PDF).
This next picture was my attempt at capturing evidence of forest succession. On the opposite ridge, you can see "lines" in the vegetation that draw a crude outline of where the edges of Exit Glacier were at some point in the past. As you follow the opposite ridge from right to left, near the left edge of the photo the height of the vegetation suddenly increases, giving a clue to where Exit Glacier previously terminated. Also, as you go up the opposite ridge the type of vegetation changes, giving a clue to the height of Exit Glacier at some point in the past. If you are not sure what I am referring to, then click the picture (or
here) and it will take you to my Flickr page for this photo where I used the "note" feature of Flickr to point out these "lines".
At the end of the spur road, there is a visitor center and a couple trail heads (the National Park Service provides an interesting birds eye view
map (PDF) using an aerial photograph). One
trail leads you to the top of the ridge where Exit Glacier slowly oozes out of the Harding Ice Field. That sounded immensely interesting, but we did not have the time to invest for that hike. Instead we chose the very easy and quick trail to the terminus of Exit Glacier. Although they do not allow you to walk up and touch the glacier (too much risk of a chunk of ice breaking off and landing on you), you can get close enough to feel the cold of the ice.
Here are two more photos, these with the glacier at my back. The first shows a nice sized chunk of rock that was left by the glacier. The second shows the outwash plain (or
sandur) of the glacier.
