SIPRE corer blues

I had my first truly difficult field day this month, the kind of day that leaves you questioning your life choices that brought you to this place and moment in time.  Okay, perhaps a little melodramatic, but I am choosing to not curb my vitriol, so fair warning – a bit of hyperbole is about to happen.

SIPRE core hole #1So at this point in the year I’m doing once-monthly gas sampling of my soil collars (the ground is frozen so there is theoretically less gas being produced, and conditions are harsh = less sampling).  The sun set permanently in Utsjoki on November 24th (sunrise should happen again on January 16th), but there are a few hours a day of what Laplanders call the ‘twilight’ or ‘blue light’ hours, which are exactly how they sound, and afford a period of semi-illumination for working in (between about 11am-1:30pm).  A good, streamlined gas sampling of all 24 collars takes me 6 hours, so darkness is an inescapable part of any field day.  It means that I end up doing most of my work with this type of view:

headlamp view of the transect post-measurement snowI try to make the bulk of my work coincide with the ‘blue light’ hours, because pretty much everything is easier when you can see (you feel me?).

Light and gas issues aside, this is the month when the ground is (theoretically) frozen enough to begin soil sampling using a SIPRE auger/corer (stands for Snow, Ice, and Permafrost Research Establishment).  These are essentially giant drill bits that allow you to extract a 3″ diameter frozen soil core.  I have used a SIPRE corer in Alaska before (see picture below), and felt semi-confident in what to do, and what I’d get.

SIPRE in AK 2010There are a few differences in the SIPRE coring unit I have access to here, mainly that it’s smaller in diameter, and the coring drill bit is much shorter (only about a foot and a half, as opposed to about a meter), and so requires extenders to reach deeper soil depths.  I was aiming to take approximately six, 50- to 70-cm deep soil cores from around the landscape at my field site.  These cores will be used to measure some basic soil parameters (nutrient and mineral contents, soil compaction and density, depth of organic matter/mineral layers, etc.).  These cores will also be the source of soil materials to be used in the stable isotope incubation experiments I’ll be doing in Kuopio next February and March.  Long story short: I need these cores for the science I need to do while here in Finland.

SIPRE cores can be taken by hand, but attaching the equivalent of a weed-whacker motor makes things much faster and “easier”.  Kevo had the SIPRE drill bits and extenders, but no motor, but thankfully Minna helped my find a person here in Rovaniemi that had a motor I could borrow, and then it was only a matter of Esa (master of the welding torch) making me an adapter to attach the motor to the drill bit:

SIPRE adapterOkay, SIPRE unit built and ready!  Esa also strongly advised me to take a propane tank into the field so that I could lightly fire the outside of the corer in the instance that the soil core froze into the corer during extraction.  This is a totally valid concern, as the friction of the coring thaws the outside edges of the core, and when you pull the corer (with a core inside it) out into the sub-freezing air, it instantly freezes to the inside of the coring bit.  Anyways, it meant that I was lugging around a propane tank (which freaks me out), the motor, and the SIPRE kit (core bit, extenders, adapters and giant wrenches to tighten/loosen it all).To help me carry all these really heavy things, I was provided a plastic sled, which I can loop around my body and drag (it’s at this point I was wishing I’d bought a live reindeer).

December sledOkay!  Into the field I went.  Step 1: I remembered to bring a snow shovel with me, so I shoveled my own parking space this time, rather than relying on the good nature and preparedness of fellow E75-drivers!  Step 2: load up all equipment and drag it out to the field transects.  First hiccup: I forgot the G-D snowshoes again, so this was another unnecessarily difficult slog through thigh-deep snow while dragging the super-heavy sled behind me (yeah, yeah, I know this is whiney).  Step 3: Do my gas sampling (this means a continuous cycle of 10 minutes of activity, and then 15 minutes of waiting.  Step 4: Because light is limited and gas sampling is easier to do in the dark than working propane tanks and motors, I took a break in the gas sampling and started trying to take the SIPRE cores early (noon).  You can extract the part of the core closest to the ground surface without an extender, so I extracted a core about 7-inches long with almost no fuss (and without needing to use the blowtorch!). Also, this configuration has the added benefit of being shorter than me.

SIPRE corer without extenderAnd then I took it all apart and inserted an extender so I could reach farther into the soil.  This was where the trouble started.  Spoiler alert: I got the corer frozen and stuck in the ground.  Turns out that the despite the -26°F temperatures, the ground is not actually fully frozen!  Only the first 8-inches or so is frozen, so after only a few seconds of working the SIPRE corer with the extender on, the drill bit broke through the frozen layer and promptly dropped about 2 feet through the non-frozen squishy peat.  This was somewhat shocking, as I essentially face-planted into the motor.  After shaking that off, I tried to pull the whole apparatus back out of the ground, because I’d clearly not gotten a core, I’d just compressed a core-sized section of really cold peat.  Two factors combined to make this nearly impossible: (1) the SIPRE corer with an extender on is almost as tall as me, so I can’t actually lift it from ground level all the way over my head without severely straining my back; and (2) the extender section is smaller in diameter than the actual drill bit, and the frozen-soil layers had re-frozen around the extender bit, which meant it’s a much smaller hole than needed to pull the SIPRE bit out.

SIPRE corer with extenderSo there I was, in the semi-darkness, with the SIPRE corer half frozen into the ground, and the exact height at which it needed a burst of power to force it through the frozen lens just so happened to be the exact height when the motor was at my standing-height chest, so power was nearly impossible to get.  Thus commenced the Free-Willy-style leaping.  Then I tried the combo of pouring hot tea from my thermoses into the hole, immediately followed by my frantic breach move.  There was also a lot of manual digging, to try and see the problem, and possibly get at it from above.  I also stopped for a few minutes to call and ask for advice from Esa, who told me that he’d bring out 30 liters of hot water (!) and we’d be able to get it out.  I decided to try for a few more minutes before calling in that type of reinforcement, and just when I was about to bust out the propane tank and fire the darn hole into giant-sized proportions with a blowtorch, one of my tea+breach moves actually worked!!  Here’s a shot of the post-extraction area:

post-SIPRE-extraction destructionAnd then the kicker: after all that, the rest of my gas sampling, the sled-dragging back to the car, the re-digging myself out of the snowbank, and the drive back to the station, I discovered that I’d lost one of my gas vials!  So the next day, I trekked back out to the site and spent an hour hand-digging into the snow in every possible place I thought it could have dropped, all to no avail, unfortunately.  So the combination of my lost sample, my SIPRE corer battle (resulting in a thrown-out back and no cores), and my forgotten need for snowshoes, and I’m starting to understand why there’s a dearth of deep-winter Arctic science.  I think I need a field buddy next month, so I’m going to do some serious baking-bribing to enlist help and hopefully make this my last terrible winter-sampling experience.  And when all was said and done, even though I didn’t get any cores, almost everything else was fixable with a washing machine and ibuprofen.

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