Friday, November 25, 2011

Fall in West Idaho

In the past, I’ve waxed poetically (or, at least waxed on endlessly) about the beauty of the eastern Snake River Plain. But the more metropolitan western section is also quite lovely, especially in the fall!

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The whole western Snake River Plain at a lower elevation than the eastern half (check out this map from geology.com), which creates a warmer, more temperate climate than the western portion (about ~10 degrees difference.) This makes a great environment for agriculture, and gives the eastern section the nickname “The Banana Belt.”

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The name “Boise” is a bit disputed, but the word derives from the from the French “Le Bois,” or, “the trees.” Boise is situated in a wooded river valley, while the surrounding plain is fairly sparsely vegetated with sagebrush.

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I’ve never lived in a place with so many deciduous trees – Seattle has them, but the leaves quickly become sodden with rain. It’s quite lovely to walk along the bike path and crunch the leaves.

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There’s also some scenic construction equipment. (I’m quite fond of large, colorful machinery, frankly.)

Monday, November 14, 2011

Coring Trees

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This is not how you actually hold a corer – I was too busy posing to keep my hands in the proper position! You’re supposed to have one facing up, one facing down.

My hydrology class went out coring trees to study dendrochronology! Dendrochronology is the study of trees through time . To take a core sample, you gently screw this hollow tube into the tree, and then insert an extractor that much resembles a long-handled ice tea spoon, which grips onto the end of the core and pulls it out.

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Much as it seems really invasive, they’ve apparently figured out a way that this doesn’t harm the tree. I like to think of it like getting an ear piercing with a hollow needle, or a biopsy.

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Then we let the cores dry out in the lab, and our professor used a planer saw to flatten them out. Then the real work of counting and measuring rings began!

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The youngest rings are the smallest, because a tree grows from the inside-out. When the tree has grown larger, the total growth for the tree is spread out over a larger area – this results in smaller rings. In addition to marking the years on the core-holder, you also mark the core with a certain number of dots – one for a decade, two for a half-century, three for a century, etc..

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Once you get close to the tree’s center, the rings become much larger. In this picture, you can see how the rings near 1810 are curving, instead of being perpendicular to the core – this means that we missed the core. These rings aren’t very useful to measure, because it’s difficult to get a good reading on their actual width.

We correlated this data with historical precipitation data, to see how the growth reacted to precipitation. Our correlation was quite poor, since our measuring tools were fairly low-grade. (Plus, we’re newbs.) But, with the proper measuring tools, many more data points, and a lot more practice, a good correlation can be established. The relationship from this correlation can then be used as a proxy to establish possible precipitation values for the years before historical measurements exist. In addition to being a useful tool for looking at a particular region’s specific precipitation and plant growth patterns, this is one of the primary methods current climate change studies rely upon to establish past climate figures.

Friday, November 11, 2011

Jurassic Lantern

As a kid, “Jurassic Park” gave me nightmares. I would lay in bed, and think about how a Tyrannosaurus could totally hide behind my parent’s rhododendron bush. The only consolation was that my bedroom had round doorknobs - and thus was Velociraptor-proof.

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Perhaps a Parasaurolophus doesn’t have “a six-inch retractable claw, like a razor, on the middle toe. He doesn't bother to bite your jugular like a lion, oh no … he slashes at you here or here … or maybe across the belly, spilling your intestines.”

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Parasaurolophus really isn’t the scariest dinosaur around, even in lantern-form.

But when I was staring at a pumpkin, trying to think of something geological to carve for this month’s Accretionary Wedge challenge , Parasaurolophus seemed fitting:

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Especially since I spent Halloween watching Jurassic Park and enjoying some chocolate stout – the intersection of youth & slightly-less-youth.

I hope everyone had an exciting Halloween, filled with (possibly prehistoric) undead (cloned) creatures!