Tundra Travels

I've spent the last 8 days on the Slope. More precisely, I've been on the tundra. Hauling around several hundred pounds of geophysical equipment. We had sun, rain, wind, and mosquitoes. Weather holds, wildlife (no bears, luckily, although we did have a bear guard), a very friendly caribou, dry tundra, wet tundra, big tussocks, small tussocks, deep holes, bogs, water over topping our xtra tuff's, and, miraculously, no equipment problems.

We did some ERT (electrical resistivity tomography) mapping all over a predetermined area. ERT can be used to generate continuous land surveys and is often used to identify the location of mass ice. We're interested in the soil exploration applications, so went to a site with lots and lots of boreholes. Lots of boreholes means lots of ground truth (we know what soils are present), and the hope is we'll be able to correlate the different resistivities to soil properties. We set up the project as a blind study in conjunction with Logic Geophysics, an awesome geophysics outfit out of Anchorage, and I picked the lines we measured based on the geotechnical data available, which, for once, was copious. Over the next couple weeks, I'll compare the processed ERT results to the actual soil profiles and see what, if any, relationships can be identified. 

ERT works by injecting electrical current into the ground via electrodes and measuring the resistivity at the surface. We laid down 240 meters of cable at a time and placed electrodes every 5 meters. This was a lot of electrodes. I started off using a hammer to put them in, but it turned out to be faster to just push them in by hand, since the permafrost is basically right under the tundra mat. 

I would like to note that walking across the tundra hauling a sled with 150 lbs of gear in it is a pretty good workout. Also, tussocks are evil and a threat to ankles everywhere. Amazingly, I didn't roll one or fall down traipsing around for a week.

Yeah, I'm surprised, too. 

We had enough gear (mostly electronics plus aforementioned 240 m of cable) that it was transported to the site in a sling. Did I mention we had to be dropped off at our site in a helicopter? This was the first I've flown in one. It was pretty cool, except for the whole dislike of heights and confined spaces thing I have going on. 

If you live in Alaska (or a northern region), you hear all about patterned ground, pingos, and ice wedges when people start talking about the Arctic. You see pictures, even understand the processes that cause them and implications for engineering applications. You walk over miles of tundra, through the boggy bottoms of polygons, over the pingos, spotting the occasional exposed top of an ice wedge. But there's something special about flying across the tundra and seeing those polygons, pingos, and thousands of lakes from above. It gives you a sense of scale, the monumental scope and forces at work to create the landscape. It's powerful and humbling and beautiful.  

Beautiful, at least, until you have to navigate 240 m of tussocks while pulling 150 lbs of gear.