Equipment Near Pothole

[ScubaRob]

While diving this weekend at Peacock we noticed a piece of equipment tied to the line near Pothole. Does anyone know what this piece of equipment is? It think I was labeled CDT Diving.

[Daphne]

I noticed that too, a rod correct? If it is what I am thinking Jill told me it was part of a study to measure ...water quality (?) salinity?... cant remember what, I was interested at that moment but senility has taken over now... Either way, nice to know there is research going on down there.

[stairman]

There was some gadget tied to the back of the sign at the start of the pothole tunnel as well. Some survey or test equipment I presumed.

[Kelly Jessop]

Yes,this is part of a water quality analysis.

[jason]

well.... my last shot at this didn't make it, so here goes round two. There are sensors installed in several caves (Peacock and Madison being the most popular) that are part of our (UF geology - Jon Martin lab) study of how river intrusion/reversals affects nutrient and geochemical cycling in as well as formation of underwater cave systems. The sensors on the signs measure temp, depth, the amount of 'stuff' dissolved in the water, tubidity, dissolved O2, acidity and a few other things that aren't likely to mean much to most people. The other sensors further in the caves measure temp, depth and the amount of stuff dissolved in the water. Using these sensors, we're able to track flood water as it enters the cave systems. We also sample water from the cave systems during floods from the surface using pumps and hoses. I'm planning to write up a layman's version of our findings of this study (and a couple of other ones) just as soon as I finish my PhD defense next month. I've just been too busy traveling for research and working on my defense that I haven't been able to get around to it. But to summarize the results of three floods..... Peacock is very unlikely to have a conduit connection to the river, all the water appears to come in fractures and the aquifer matrix. Flood water during reversals flushes out of Madison quickly because it has a conduit connection to the river. Flood water stays in Peacock for a very long time. Flood water has a lot of natural organic carbon in it, so when it gets 'stuck' in Peacock, the bacteria eat it and consume all of the O2. This causes the water to go anoxic and all the 'surface' fish die. The cave organisms go further into the aquifer and are able to get to places with some O2 in it (I got the idea for the study after talking with Kelly Jessop about his cave fauna surveys at the NSS convention in Florida a couple of years ago). Over a period of weeks to months, the residual flood waters are pushed out of Peacock, the dissolved oxygen levels slowly increase and the cave critters come out to eat all the dead stuff (and probably the bacterial mats). The chemistry results indicate the caves are not getting any bigger during normal flow conditions, however, A LOT of dissolution is happening during floods. If you dive Little River, you'll notice the scallops on the walls. Those scallops indicate the flow of the water was INTO the cave when the form. Same with downstream Cow. I haven't done too many dives in Peacock or Madison on account of the no solo rule - so there might be scallops in there too (if anybody knows where I can go find some, please let me know).... If there are - I'm sure they point into the cave as well. So, while I know a lot of people think of the river water as 'dirty' or 'bad', river reversals are a crucial part of cave formation and enlargement, the life cycle of cave organisms and they are a major source of recharge to the aquifer.

Jason Gulley

[Howie]

Thank you Jason, very informative. It's nice to see this info in a way I can understand it

[Bobby]

Jason,
Thanks for the information it is very interesting. If you want to do dives in Peacock or Madison to gather information I don't mind just hanging out to satisfy the no solo rule.

Bobby

[jason]

Thanks for the offer Bobby - I'll keep that in mind.

[Daphne]

Hey Jason you have a PM.

[ScubaRob]

Thanks Jason. Excellent explanation.