Posts Tagged ‘questions’

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Saturday, August 15th, 2009

Data Management: Almost like doing your taxes?

by Nick Wilkinson

Now that the field season is over, we can all just go home and not think about work until next summer, right? Not by a long shot. As fun as it would be to hang out at Pavilion Lake for a few weeks each summer, diving and watching (or piloting) subs as they’re used to explore the lake, we wouldn’t be contributing anything to the science or exploration communities unless we share the data we collect. While each of us on the project came away from the lake with great memories and a lot of anecdotal experience that will undoubtedly make next season that much better, it’s the analysis of the hard data that was collected over the course of the field season that will lead to research publications, ensuring that the work conducted at PLRP remains fresh and relevant.

Nick Wilkinson helping DeepWorker begin its mission. (Photo: Greg Slater)

Nick Wilkinson helping DeepWorker begin its mission. (Photo: Greg Slater)

But what is this “hard data” and how is it used? This summer, the various research groups working at the lake generated several terabytes of data that included digital video from each sub flight, pilot logs, sub tracking data, rock sample information, data from the Gavia autonomous vehicle, weather station data, water samples, photos and video of the lake bottom collected by SCUBA divers and much more. One of my roles on the team this summer was to help make sure that this information was gathered and stored in an organized fashion. This included tracking down the original source of the data (such as hard drives and voice recorders from the subs), making sure that all files were named and stored according to an agreed upon format, and ensuring that our network-enabled data storage was as up-to-date as possible. Of course, this was a team effort and many people spent long hours tracking down data and keeping things organized.

Spending so much time making sure that we’re keeping track of these details might seem like a lot of trouble to go through, but it’s important to realize that time in the field is always at a premium and researchers want to spend as much field time as possible gathering their data. Analysis of this data can sometimes take a long time or require access to special facilities that aren’t on site, so most of the analysis generally happens after the field season. Therefore, it’s important to make sure that the field data is organized in a structured way so that you can find what you’re looking for weeks or sometimes months after the field season.

Think of the post-season data analysis like tax-time: organizing your receipts and other paperwork year-round takes a bit of work, but in the end, it makes filing your return that much easier. If your paperwork is spread all over the place, tax-time, which can be pretty laborious to begin with, is made that much more difficult. Thankfully, data analysis is generally more enjoyable than filing taxes.

With the field season behind us, we’re moving into a new mode of operation. The data has been collected and archived, and soon it will be distributed among the entire research team for their perusal and analysis. Personally, I’ll be looking at new ways to help the team share and interact with that data, enabling them to zoom in on exactly what they’re looking for, quickly and easily. I’m excited about what new discoveries will be made during this period of analysis, and I’m looking forward to how these insights will help shape plans for next summer, and beyond.

-Nick


Sunday, July 12th, 2009

Sometimes you get some answers, sometimes you’re left with more questions

by Margarita Marinova

Coming back from a great flight in the subs, I am even more excited about the lake! What an amazing place!

I had a great flight – the goal was to fly a contour at 15m depth on the east side of the South Basin (north section). That was just fascinating! A specific objective was to identify rock slides, to enable the afternoon flight to document and sample some of these rock slides. Why? Well, one of our hypotheses is that microbialites need rocks to start their growth. The sediment around is so soft, that it seems hard for any large structure to just grow in it. Using video to image these rock slides, we find that at significant depth we just see the rocks. As we get shallower first there is a thin cover of microbialites on the rocks, and then with increasingly shallower depth the microbialites get bigger and bigger! At this point there is no sign of the rock that’s likely underneath. So does this prove that microbialites always need a rock? Well not really! Just nearby there were landslides with no microbialites on them. Why is that? It’s the same type of rock, likely the same lake chemistry, and likely the same biology. But there is such a difference! Then later in the dive I also found areas with scattered microbialites, which certainly didn’t look like they depended on rocks for their growth. Examples of these relationships are seen throughout the lake, but it is this field season that we are meticulously documenting them. And while we are certainly showing some relationships are true, what we see raises even more questions!

Another big question we are asking is if the microbialites are currently growing. On this dive it was sad for me to see that there was a lot of trash on the lake bottom. But this trash is also like a natural experiment to look at microbialite growth. In this case, we can look at whether there is anything growing on the trash, or also on trees that have fallen into the lake. In the case of trash, we know it got there less than ~100 years ago, and a lot of the trash in this area was covered with about 0.5 cm (1/5 inch) of microbialite growth! So we now know that the microbialites are currently growing, at least in that part of the lake. So then we ask why is there such a difference in sizes for different parts of the lake? Just a few hundred meters south of my dive, Mike Gernhardt was exploring unusually large structures: 2 meters tall, by 3 meters wide (6 ft tall, by 10 ft wide). Where I was flying, most of the structures were small: maximum height of 20 cm (8 inches). So why is there such a difference? Is microbialite growth constant, or does their growth effectively turn on and off? Do the microbialites grow faster in one area than another because of slight water chemistry differences? Or something else? We haven’t seen any of these chemistry differences yet, but it could be something we haven’t measured … yet.

We started out 5 years ago with so many questions. Now we have more and more questions, but it is also nice to see that some answers are coming in as well. As we analyze the wealth of data we are collecting with the DeepWorker submarines, we are sure to answer more and more of these intriguing questions.

-Mars