Cave Pearl Data Loggers at GSA 2015

We had two presentations at the Geological Society of America conference last weekend in Baltimore.  Trish spoke in the Karst Processes and Speleogenesis session about the challenges of new instrument development, and presented a snapshot of our growing long-term record which includes ocean sensors,  surface precipitation & cave drip monitors, with flow sensors inland and at coastal discharges:

Cave Pearl Logger deployment Record to Sept 2015

You can see attrition of the early prototypes pretty well in a graph like this.  We lost units from the 3rd generation of flow sensors due to epoxy failures, and much of the fourth failed due to pressure effects on our temperature sensors.  Despite having to wake for several hundred thousand processor interrupts,  the drip sensors are faring much better overall.  But I have been replacing them anyway, as the recent builds have much better power consumption. Even with improvements to each logger, you still reach a point where field logistics put a limit on how many units you can deploy with a small two person team.

While we aren’t at the whole catchment/watershed scale yet, we hope that our little DIY monitoring network will grow into the kind of coverage you see in Critical Zone Observatories.  Trish ended her talk by walking through some data from a very large storm event to show how it impacted the different monitoring stations. You could see the effect on people as they watched the individual sensor records building into a system wide picture of the hydrology.

Presenting the Cave Pearl loggers at the GSA conference 2015

There was a a lot of interest from younger academics, as they understand the potential for open source kit to help them compete with senior colleagues who can afford $5-10k for each piece of equipment.

That interest spilled over to the poster session the next day where I had a selection of different builds on display. I was a little embarrassed as many of these were rough early prototypes & bookshelf calibration units. (because all the really good loggers are currently out on deployment 🙂  There was a steady stream of people with questions that kept me at the poster all day and both of us were on deck for the huge crush of people at the end of the day. All that positive feedback was great for the ego, and it was especially nice to talk to people from other research groups working with the Arduinos. Each of us is tackling different questions, leading to a good diversity of hardware builds and approaches.

I think things are reaching critical mass because at this point many of the smaller independent projects people have been working on have seen enough field trials to cross the tipping point from rough prototypes to capable research equipment. DIY instrumentation will have a much larger presence at future conferences, and some of us have even started scheming about a whole session dedicated to it. If we can wedge it in between the teaching and the fieldwork schedule, perhaps next year we will bring the Pearls over to the AGU.


The conference generated enough interest to show up on the blog’s traffic: not so much as a change in the number of visitors, but as an increase in the number of pages being read:

I think pages per visitor is probably a better metric of interest, though I am sure humble stats like these don’t even count as a drop in internet bucket. But hey, you’ve got to start somewhere…

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4 thoughts on “Cave Pearl Data Loggers at GSA 2015

  1. Dave B

    This is really interesting work you’re doing. I’m interested in helping with projects like this, where’s a good entry point for folks with no current ties to the water community?

    1. edmallon Post author

      I would say first start with a part of the world you love: perhaps its a mountain stream in the Rockies, perhaps its a tropical coastline, perhaps it’s the historic river flowing through your downtown urban center. It does not matter which one you are drawn to because every environment in the world depends on water. Then do a little bit of research, and I guarantee you will find that in some way or another, we are putting pressure on that water resource. Often you also find that there are groups of concerned citizens already working to solve problems that have been identified. Talk to them to discover what you really want to work on.
      There are plenty of grass roots groups
      [like PublicLab or those listed at Scistarter ]
      and often there are large scale Gov/Academic projects that welcome volunteers once you filter your way through the administration hierarchy to the people with boots on the ground in your part of the world:
      [eg: ]
      [eg: ]

      Finding a good problem to work on is really the key step because it’s the thing that keeps you going through the frustration of failures, and having to teach yourself the electronics from scratch. But thanks to the strong Arduino community you really can pick all that up as you go along. So find an issue that really resonates with you first.

  2. Dave B

    Thanks for the pointers. I know the electronics, it’s the environmental issues I need to start digging in on.

    Anyone in the Chesapeake Bay Area doing water monitoring work?



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