Science-ish Questions

May 10, 2011 Leave a Comment

Welcome to questions part two!  These are mainly related to science/field work.  Things like that.   With some other stuff thrown in for fun. 

When you take samples of soil from a given area, how many do you take? (From cgbookcat)
Generally, the only time we collect samples is when we dig out a site.  This is different from our normal everyday mapping, which are just "observations," or small holes that we dig to get a basic idea of what we're looking at.  Site descriptions are done in much more detail and the holes are bigger, so we can see better and describe it in more depth.  Each person on the crew does about 3-4 of these per year.  We take one set of samples at each site, which are collected in special cardboard boxes with separate partitions for each horizon.  These are kept on hand in our office mainly for reference purposes, so that we can run color and pH tests.  For pH, I use indicators.  Various indicators are mixed with the soil, and then drained.  The color that comes out in the liquid indicate what the pH of the soil is. This can be done at the office and don't require a lab.  Honestly, I prefer a pH meter.  It's much more straightforward (if it's not broken), but unfortunately we don't have one of those.

Do you do cores so you can see layers? 
We do not take core samples and the main reason for that is the soil here is much too rocky.  I've used an auger before, in training.  They're really nice and way easier than digging a 100 cm soil pit, but it just doesn't work in this climate and soil type.  The best place to use them is in the Midwest where there is a lot of agricultural land, glacial till, stuff like that.

What kinds of tests get run on them? 
There are a variety of tests that we can run on soil samples, for various purposes.  If we just need to do basic property tests, like I described above, we use the box samples.  If we need to do more complex tests, they get sent out to a lab.  For this, we'll collect a larger sample, like in a ziploc bag or something.  Examples of tests that would be run are calcium carbonate equivalent and cation exchange capacity, which basically tell you how much carbonate or clay-type molecules are in a sample.  We can also get a more accurate percentage on particle size using the hydrometer or pipette method (which I have learned about a little but it's been a while). However, sending samples to the lab is extra time and money that we don't particularly want to spend, so it doesn't happen too often.

How much analysis can easily be done from the site, and what proportion of them need to be brought back for lab tests? 
Most analysis is done directly from the site.  We analyze physical soil properties and plant characteristics right there in the field.  This gets documented and we use that documentation and its interpretations to make our maps.  We use lab data mainly to confirm soil taxonomy, which often requires things like a specific particle size ratio or a percentage of a certain mineral or something like that.  A lot of times we can just infer a lot of it from previous data or other information that we've been given, and the lab data is more of just a back-up. 

What kinds of stuff are you looking for?
What we do is called Terrestrial Ecological Unit Inventory, or TEUI.  The name, Inventory, says a lot about what we do.  It is mainly about collecting data and creating a map from it.  We look for patterns in the landscape, vegetation and soil type within a certain geology or parent material so that when we make our maps, we have some consistency in our data and how our maps come together.  The final product is entered into a database so that land managers, researchers and other staff can look at our data and use it as necessary.

First question: What is an ANZAC? :) (from off-black)
Oh oh, I know this one!  ANZAC is Australia New Zealand Army Corps.  Yep, I'm so smart.  Haha.  Thanks for the info.  Americans seem very hesitant to teach much more than American history.  I learned that in England when some little kids were spewing off a bunch of info about the Iron Age and I had no idea what they were talking about.  You learn something new every day. 

Just kidding, actual question: Weirdest/most unusual thing you have had to do in the field?
Hmmm... the weirdest thing?  I think I've been doing this so long, nothing really seems weird and unusual anymore.  I asked Matt if he remembered me telling him about anything and he said, "tell them about the poop sack." Which doesn't even have to do with field work.  It's for caving.  You're not supposed to go number 1 or 2 in a cave, because people crawl around in there and that would be gross.  So you bring ziploc bags, and go in them.  You can also use a "pee bottle"  or a bag that holds a material that will convert your pee into a weird gel-like substance.  The poop bag is also called a burrito bag, in case you were wondering about that.  I guess, in general, using nature as facilities was one of the main things I had to get used to when I started doing regular field work. But it's just one of those things you have to do, you know?  There's even a plant called mullein, aka Indian toilet paper, that you can use for such occasions, but apparently it will give you a rash if you use it too much.  Sorry if that's TMI, but you asked  ; )

If, after this, you're like totally WTF, well... I was too at one point.   Until I became a geologist.  I will explain how that happened in the next Q&A post.


  • Off-Black said:  

    Nah, I'm pretty much TMI proof most of the time, but especially at the moment after literally catching my new girl as she was born a few days ago (childbirth isn't really a spectator sport). The point about toileting in caves is one of those obvious things one never thinks about in abstract. I'll bet it wasn't in the brochure anyway (just like pitchforking frozen beef livers off the floor onto a cutting table at 4am on a winter's morning wasn't part of my applied science brochure...).

  • Maureen said:  

    Haha! That is the best comment ever.

  • Jessica said:  

    I love hearing about what you do! You have of THE most interesting jobs ever, I think. I'd be you for a day, is what I'm sayin :)

  • Rachel said:  

    Your job sounds great! I love science!

    Pooping in a bag wouldn't be so great though!! Love this post.

  • Maureen said:  

    hmm, all the comments for this post got eaten. That is sad. Oh well, they will live on in spirit...

  • Off-Black said:  

    Wasn't just you, I had a comment from my blog disappear as well. Blogger was having issues last night. I was trying to post just so I could have friday the 13th as a post date but couldn't sign in.

  • Maureen said:  

    I figured it probably had something to do with that. Guess the Friday the 13th joke was on us!

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