Technology I’ve Used To Do Geoscience

This month’s Accretionary Wedge is hosted by Professor Charles Carrigan and calls for posts on geoscience and technology.

There is no question that technology has played an enormous role in the furthering of geoscience, and I’d like to assemble a series of posts from the geoblogosphere that describes the relationship.  So, fellow geobloggers, how do you perceive technology impacting the work you do?

Hardly anyone I know in geoscience can get work done today without a computer and telecommunications. So, let’s look at some other things. What follows is some technology I’ve used as a geoscientist. I do this for three reasons:

1) Bet you I can use an Illudium Q-36 Explosive Space Modulator on this. To promote getting hands-on experience with solving the same and different problems with a wide assortment of tools. This is so that if you’re faced with a situation that requires one of them, you will know to go to what tool works best and possess a certain sense memory of having used it or, at the very least, good notes, online references and human contacts to fall back on.

2) Marshall McLuhan said, “Obsolescence never meant the end of anything, it’s just the beginning.” Technology is ever-changing and increasingly obsolete. But, being in the habit of tinkering with new things is to your benefit.

3) “Hey, even chewing gum used at the right time is technology,” quoth MacGyver. Again, this word “technology.” It is different things to different people and it took me working with various types of technology – physical experiments, application-focused computer programming, data acquisition with electro-grav-mag tools, seismic interpretation on paper and screen, 3D visualization equipment and field gear – to really make me appreciate what science requires. A curious mind and a metric crap ton of devices to gather and analyze the ever-important data.

User! (from Cartoons I Drew by Andrew Fraser)

Speaking of curiosity, I took apart my father’s manual typewriter when I was 15 and still regret it. It was in a hundred pieces, I was in tears and no one in the family knew how to put it back together. Sure, Dad had moved onto a portable word processor and the whole place was ransacked only a few months later, but I monkeyed with a piece of technology paying no attention to how to put it back. I destroyed and learned nothing (except never to do that again without a manual). But, wow, can I type at the speed of light, and work my way through any technology placed in front of me to wondrous ends. This is just my way of saying at the outset that I have great respect for technology and am unafraid of it, but all I am is a well-educated user. I utilize technology to do and share geoscience and my hat is off to the instrument makers.

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Well Log Analysis As part of an undergraduate structural geology project, I picked six markers on fifty paper well logs to constrain the timing of Paleozoic deformation along the Divide structure in Southern Illinois. Logs examined were SP, gamma ray and resistivity. This was invaluable experience as many geologists and drillers still use paper logs to this day – it is easier to compare stratigraphic markers and patterns between wells on paper and show the big deposition/deformation picture at a better scale. Zaki Bassiouni’s Theory, Measurement and Interpretation of Well Logs is also one of the best investments I’ve made.

Physical Experiments. For my first MS, I performed physical experiments of transtensional folding using a custom-machined apparatus. Experimental modeling using physical materials is a useful method to study the kinematics and dynamics of deformation in 3D, in this case the formation of folds in a combination of shearing and extension. The apparatus was essentially a solid metal platform with two metal strips and a latex sheet attached to the two strips. One of the metal strips was fixed and another free to move along the horizontal surface of the metal platform controlled by a motor. The idea was to place various deformable materials like plasticine and silicone on the latex strip and deform them in any combination of opening, closing and wrenching. There’s nothing like physically witnessing the long axis of the horizontal strain ellipse rotate through the fold hinges during transtensional deformation to understand the relationship between observable structures and the physics that made them. Again, like well logs, experimental models only grow in importance. Research labs increasingly conduct physical experiments (AGL’s salt tectonics animations, for example) to make conceptual models of the subsurface which can be used at the exploratory phase or in the absence of sufficient well penetrations.

Here’s a line drawing I drafted of the experimental apparatus:

Lacoste Romberg G-1 gravimeter Also as part of the first masters, I used the first LR G-series gravimeter to measure the morphology of geologic basement west of Loreto in Baja California Sur, Mexico. Location and local topography measurements were conducted with a Total Station device and used to correct for free air and Bouguer anomalies. It took about a week and long days of careful back-bending (literally!) gravimeter adjustment to collect data for four east-west transects. The gravity measurements were then interpreted to determine the effects of the transtensional opening of the Gulf of Mexico on basement deformation and sediment deposition.

Handheld rock drill to core rock samples for geochemical and magnetic analysis. That was a lot of fun and I felt like Ash walking around with the drill in hand. It took me more than an hour to drill out the one-inch sample of Baraboo quartzite shown at the start of the post, while a two-inch sample of St. Peter sandstone was acquired in under five seconds. Learn your Mohs hardness scale, kids!

MagnetoTelluric Data Measurements Milk is everything in Wisconsin. Back in the late 1990s, dairy farmers around the state were convinced that stray voltage from farm electric lines resulted in their cows’ decreased milk production. (my pet theory is that the cows were merely recovering from the last Packers Superbowl win.) In the summer of 2001, I worked as part of a University of Wisconsin geological engineering team installing EMI magnetotelluric MT24 systems at two farms and one remote monitoring site in southern Wisconsin. You can read more about the magnetotelluric method and experimental setup in the report referenced above. While the results of the study were inconclusive, it taught a lot about the interference provided by manmade structures and cultural noise to signal. And that it’s really weird to properly install and orient a probe in the ground with a 1-ton animal strolling by you.

Ground-Penetrating Radar Another enjoyable experiment was riding in a boat collecting ground-penetrating radar data of the western shoreline of Lake Michigan to measure shore erosion all the way from Milwaukee to Kewaunee County. GPR acquisition is a lot like seismic but uses high-frequency radio waves instead of sonic explosions to image the subsurface and is perfect for shallow, high-resolution surveys. Another difference between GPR and seismic is that GPR images permittivity/conductivity contrasts while seismic picks up acoustic impedance contrasts at material interfaces. Here is a good primer on GPR and pictures of Bryn Mawr students conducting a basic “marine” GPR study.

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Writing this post forced me to pull up documentation on these various tools and it was very instructive simply looking at what I did then with what I know now. It also reminded me how much fun and physical and intellectual pain came with each of these experiences. This is how you learn and come to understand how much is required to collect scientific data.  Try it all, I say. Don’t ever give up a chance to learn how to use a tool, even if you will never use a non-telescoping basin wrench or a gas chromatograph again in your life.