Don't let the word "Geology" make you think this post is going to be anything short of a near-death experience.
It only took a week for the rest of Lake Superior to freeze over. This NOAA link shows you lots of graphics about ice thickness and even more things that I really don't understand. But after venturing out to Porter's Island a couple days ago, I now understand a bit more about how land formations form and shift.
I don't know why I didn't think of snowshoeing out to Porter's Island before. I mean, I even skated to it this winter. As I beelined from the Harbor Haus ramp past a couple shanties, over the uneven snow, a couple patches of clear black ice caught my eye. Because I didn't have an auger myself, the only way to see how thick the ice was was to look at the cracks in the clear ice. This is what I saw.
Thick ice on the Harbor
Well, it was so deep, that I couldn't really see how far it went. I suddenly felt sorry for those ice fishermen because I knew they had a looooooong way to drill. As I took this picture, I heard Her Majesty stirring.
Blub blub. Blub. Blub.
(Take an old gallon milk jug, fill it with water and turn it perfectly upside down. The sound the jug makes as it retracts back to it's normal shape is similar to the Blub sounds the lake made.)
What the heck? I laid there bewildered. How can I hear the water move when the ice is so thick and the lake is frozen over? How can it still move?
I had a couple answers at the moment.
1) The ice fishing holes create an area for pressure to be released. If the fishermen were throwing bait and catching fish, the volume of the lake would fluctuate -- only slightly -- but if enough people were doing this all over Lake Superior, this transferring of matter could create a shift enough to make those blubbing air bubble sounds.
2) We may not always realize it, but the earth we live on is constantly shifting. Someone digs a mine, the earth rebalances to accommodate this loss of density. A company blows up mountains on one part of the world to build Dubai in another part of the world, the earth recalculates so it can still spin on its access without us noticing the giant offset.
Lake Superior covers a significant area where volcanoes erupted, fault lines shifted and glaciers passed. Any trepidations in the surrounding land will lead to continuing vibrations through the water -- even if it's covered in ice. And, I did see recent cracks in the ice along the shoreline, so these reverberations are big enough to crack the ice of a solidly frozen lake around the edges. Especially the edges because that is where different elements meet: ice meets rock.
I could ramble on, but back to the adventure!
I wasn't quite ready for the splendor I saw on the north side of Porter's Island. The ice cliffs were so big that I had to search for a spot where I could get down without dropping from a foolish height, unable to climb back up.
Ice cliffs on Porter's Island
I found a spot to drop down because I absolutely had to check out this terrain I saw in the distance, perhaps 200 yards north of the island. It looked like a pristine ice rink. Aha! More proof that the ice is pulling and shifting.
The hiking was not easy. Broken and refrozen ice chunks composed the ground. Here are some examples.
Blue ice chunks looking toward East Bluff
Modified sheet ice looking toward Brockway Mountain
Now here's where it gets sketchy.
I really wanted to check out that ice rink spot. Really, really bad. And you know me, my curiosity usually gets the best of me. But I have been studying the ice for eight winters here. I learn from my mistakes, and I know what to look for.
I was out by myself, so I couldn't screw up.
I found a patch of clear ice, and realized it was only two inches thick. When I heard the fissure next to me crackle, I pounced like a cat on prey to a thicker section. Whew.
By this time I began having visions of all the people who would be let down if I never came back. Aaron wouldn't even know who to call to cancel all my meetings and assignments. Who would publish my next book waiting on the computer???
And since this is the terrain I would have had to cross, I decided not to go.
The death trap before the rink... see that rink?
Defeated, but still alive, I walked back across the harbor. This reminded me of another story of how the Lake moves without us knowing.
"Aaron, isn't your shanty going to be stuck in the ice out there? It's been there for weeks!"
"No. It'll be fine." Such a man.
So he went out there with our friend Cody. They hopped in the shanty and drilled a hole through the trap door in the floor.
"Holy $#!*" I'm sure they exclaimed as the water began flooding out of the lake and toward the shanty floor. Their outside wind flaps were stuck in the ice, so all the water that was pouring out was actually penned in and on its way up the door and into their posh little shanty.
They worked to move that thing as fast as they could, as the drink engulfed them up to their shins. They finally removed the shanty from its sunken location, but the wind flaps are still in the ice. I really wish I could have recorded that, but if I was there, I know I would have been forced to help instead of document.
Aaron moves his shanty more often now.