Radium Springs Cave, Arkansas

This last spring I had the opportunity to go caving with a great group of cavers in Arkansas. This trip was into Radium Springs Cave in northern Arkansas, sort of a final small event during Hydro Days.

This is one of those great caves that's both large and explorable, but also protected with a lockable hatch, so only certain people are allowed to get in. Even more of a plus, this was not a "show cave", meaning we had no official guide, and we could only see what we shined our flashlights at.

A short walk into the cave we first came to the locked "entrance". This metal hatch was placed over a natural bottleneck. It was quite a small entrance, and a sign to come of the claustrophobic passages we would experience.

Most of the cave was made of large "rooms" that we would spend a while in looking at really great speleothems and cave structures. Between the large rooms, though, we often had to crawl through very narrow, low, and otherwise unnervingly small passages for long distances (I had to take my backpack off just to fit along this belly-crawl passage below. It went for a good 50 feet, and we went one at a time just incase someone had to back out). Since moving to Missouri I have gone on a number of cave trips, and they all had been building me up to be able to handle this level of claustrophobia.

One of the neat cave features are these "boxwork" features, named so because they form these honeycomb shaped features on the cave ceiling which look like old fashioned post office mail sorting boxes. While most ceiling features are formed from calcite dissolution, these are calcite veins from the rock which used to be there. The veins were more resistant to erosion than the surrounding rock, so are remnant features.

Aside from those, there were plenty of the garden variety cave speleothems, as seen below. Stalagmites are the spikes on the floor of the cave. Stalagtites are the spikes hanging from the ceilings. Where a stalagmite and stalagtite grow together they form a column. The large feature on the left (which I always think look like frozen waterfalls) is flowstone, which is formed the same way as the other speleothems.

Our group would often stop in some of the larger rooms and take some fairly spectacular pictures. My little camera was nothing compared to some of the great equipment some of us had.

One of the more interesting concepts of the karst bedrock system is the way in which water flows underground in these areas. While traversing through the cave we often had to hop or otherwise tred through small streams. Underground river systems are the norm in these areas.

One of the great things about this cave being locked off from just anyone is that vandalism and over-exploration would have probably destroyed some of the more delicate formations.

I had been caving before, usually bringing my own headlamp. This was the first time I had been introduced to a carbide lamp. These are flame lamps which are powered by adding little carbide lumps with water in the reservoir of the lamp. This combination gives off a flammable gas which is lit to ignire a small flame. The lever on top controls how much gas escapes and therefore the size and brightness of the light. A little carbide seemed to go a long way, so as long as you had a source of water you had light (handy in a cave).

Below, picture of my masters thesis advisor (left) and myself (right).

I also had the opportunity to go caving with Dr. Arthur Palmer (below, right), whose textbook many speleology classes use, and is well known in the karst world. Great guy!

Despite the lack of visible light there was still plenty of life to be found underground. Below, a cave cricket.

While delving deeper into the part of the cave which is home to a colony of bats we accidentally came across a whole cluster of them. I didn't have time to get a photograph, but I promise there was a huddle of hundreds of bats on the ceiling which became startled to our arrival.

If small spaces wouldn't get you, then maybe a fear of bats might. Personally, bats don't bother me much, but I admit what followed would have caused some issues for others. A piece of advice about bats: if they start flying around, don't freak out. If you stand still and don't move suddenly, they won't hit you. Although I could feel the wind from their flapping wings just barely inches away.

Catching photographs of these bats in flight was not difficult at all. I just kept taking pictures, and there were so many bats flying around that almost all of my pictures looked like these.

I wasn't sure how large the cave was, but we spent around 3 hours underground exploring, so a good hour and a half both ways. That in itself should give you a good idea about how extensive one of these caves can be.

We finally made it back to the surface. In our absence from the surface world it had begun to rain. I couldn't even begin to guess how much extra cave this water would explore that we were too big to fit.

Petrogenesis 1:1

Some of the weirdest ideas come to people that are up way too late and under stress. With that said, it's not a surprise that this following "passage" was the product of taking a Petrology class.

One of the questions asked for a given rock sample is "what is its petrogenesis?", meaning, how did it form, and where did it come from? When given such a loaded question at 2am, the only thing you can do is go off on a complete tangent. The first couple lines were made on the spot between us 3 petrology students that late night, and the rest followed later:

_______


In the beginning, God created the heavens and the magmas. And the magmas were unfractionated and without form.

And God said, 'Let there be Bowen, so that the magma may fractionate, and order be had'. And there was Bowen.

On the second day, He spaketh unto Bowen, 'Seperate the magmas into two series, continuous and discontinuous, so that geologists may spend many hours with petrographic microscopes". And Bowen commanded it so, and there was olivine and anorthite.

On the third day, God spaketh unto Bowen, 'Thou shalst continue in the continuous series of plagioclase, replacing sodium for calcium. The Michel-Levy Method will guide the true of heart'. And there was much rejoicing.

On the fourth day, God spaketh unto Bowen, 'Thou shalst make pyroxene, which is like olivine but more complex and with cleavages' And thus the geologists did rejoice of single-chains.

On the fifth day, God spaketh unto Bowen, 'The geologists have grown arrogant in their memorization. Lo, you shalst create the amphiboles, which are complex with 60-120 cleavage'. And the geologists wailed, and there was much gnashing of teeth.

On the sixth day, Bowen prayed, and said 'I am out of calcium, what shalst I do?' and God said, 'Have faith', and there was albite.

On the seventh day, Bowen said unto God, 'May I have a rest?', and God was displeased with Bowen, and showered him with flakes of biotite and muscovite. And Bowen begged for forgiveness, and continued his series.

On the eighth day, Bowen recovered, his body having been pinched and swelled in tartain plaid. And there was microcline. And God forgave Bowen.

On the ninth day, Bowen prayed unto God, 'But I have nought but silica and oxygen left, what shalst I do?', and lo, God commanded him to take up thine rock hammer, and strike upon the earth. And forth sprang quartz, and God said, 'Its hardness shall be 7". And it was good.

Hundred Dollar Hamburger

One of the things I had always heard about when I started flying was the concept of the “hundred dollar hamburger”, or “cheeseburger”, or whatever-food you prefer. Why so expensive? Because you fly somewhere to eat it.

“Is a cheeseburger really worth that?” you might ask. Well, no. But that’s not the point. It’s just an excuse to fly.

A few years ago, while thinking of places to go and build flying time, my friends and I brought up the idea of getting a hundred dollar hamburger up at Grandma’s Restaurant in Duluth, Minnesota. I had yet to fly northward from my home base, so I might as well check off that cardinal direction. The thought of flying around Lake Superior was another appeal.

I was going to fly up in the trusty Piper Warrior along with my friend Garrett who had started training recently. My other friend Alex was going to leave just before us in the Cessna 172. It was basically a straight shot north for 170 nautical miles, so would have been just under two hours if it wasn’t for the 40 knot headwind.

Alex stayed a few miles ahead of us the whole time, staying in plane-to-plane radio contact. In our plan to be sneaky we had decided on the code word “pickle barrel” to be said to let the other know we were on the same frequency. I don’t think we ever ended up using it, but while listening in on the major local channels I was fully expecting to hear a quick “pickle barrel” shout out from Alex, followed by a confused center controller.

Once getting close to Duluth I started hearing that Alex was having a bit of a directional disagreement with ATC. An aircraft comes with two direction indicating instruments; a magnetic compass, and a heading indicator. The heading indicator operates on a gyroscope, which maintains one directional orientation and is more stable and less susceptible to bumps than the magnetic compass. But the heading indicator only knows what direction it is when you adjust it to the magnetic compass (usually before takeoff). It is prone to drift in the long run, and after a while of flying it might drift off a few degrees, giving the pilot the perception that they are flying in the correct direction when in fact they are a few degrees off.

This must have happened to Alex, because air traffic control would tell him to fly a certain heading and notice that he was, in fact, not flying it, so they would tell him to “turn right 15 degrees” to adjust. Soon after they would give him a new heading, and again he would go off in a different direction, so air traffic control would again tell him to “turn right 15 degrees”. I could tell both Alex and the controller were getting a little flustered when the controller asked him what heading he was flying, Alex responded “I’m all over the place”.

Flying into the Duluth area was great. Clear skies above the North Shore, all the pine forests below. Because of the wind coming out of the west, we were directed to come in from the east, right over Lake Superior. I had never flown over a large body of water (ok, it wasn’t the ocean or anything). It was fun seeing the tanker ships from above, they looked so small, like toy boats in a bathtub.

Alex made it and landed just fine, but I was trailing behind. On final approach I was asked to go around because my little Piper was quickly getting overrun by an NWA airliner which was on a long final approach. I forgot this was a large airport. I made a traffic pattern to come back around and decided to land long to stay above any wake turbulence from the MD80 landing. I also noticed the halting cable at the front of the runway used for breaking fighter jets. Even aiming for the halfway point of the runway, I still had more remaining runway than I’m used to landing on (Duluth’s runway is about 2 miles long).

I taxied up to the FBO, past all the fancy Cirrus aircraft (this is their HQ) and the NWA airliner which I got out of the way for.

They gave us a courtesy car and we went to find Grandma’s Restaurant. I recall having been there before. The cheeseburger was good, but I almost choked on it while Alex was recounting his directional problems on the way in.

The whole trip was a 3-pointer. Instead of heading back to Winona directly we made a pit stop at Anoka airport just north of Minneapolis. We had taken a little more time than expected with our burgers, so we were in a little rush.

The headwind became a tailwind which pushed us quickly down to the Twin Cities region, leaving Duluth behind. Oh, the joys of dealing with Class B airspace, hoping I wasn’t poking up into somewhere I wasn’t supposed to be, staying below the upside down wedding cake shaped airspace layering. On this leg of the trip, I got to Anoka before Alex, he had gotten stuck behind a few Cirrus aircraft. I was on the ramp shutting down when I heard Alex coming over the radio, for some reason feeling it important to state his intent to land, to “get a few drinks and leave”. We were both newby pilots. Sometimes weird things are unintentionally said to airway authorities. Because it was getting late, we decided not to get out, but got underway leaving so we would get back before sunset.

 Flying back to Winona from the Cities is always a breeze, following the Mississippi River the whole way down. It was getting into the twilight hours when we arrived, enough justification to turn on all the runway lights by clicking on the radio (it’s always fun doing that). Soonly afterward we saw a pair of red and green lights coming towards us on the horizon, Alex finally catching up. We were all safe on the ground and still full.

Total flight distance: 370 nautical miles, just to grab some lunch

Price of cheeseburger: way more than $100, but worth it!

Finding Patterson Spring

For part of a recent dye trace I’ve been searching the area for more springs to monitor. One spring, Patterson Spring, shows up on historical dye tracing records but didn’t seem to be at the location indicated (it was an old dye trace so location coordinates were general; location was listed as being near a bridge crossing the James River, but there are 2 bridges in this area).

I was feeling especially adventurous so I went down to figure out where the spring really was. There’s a lot of overgrowth surrounding the river and the river has carved a decent valley for itself.

I parked just at the intersection of S Farm Road 141 and W Farm Rd 190 by the northernmost bridge, as the bridge provided a good way to reach the river. Pictured below - my trusty field vehicle. In the background is a good exposure of the rock unit in the area which is prone to caves, springs, and sinkholes (in fact there is a cave within that hillside that was preserved when the highway department discovered it while blasting through to build that road).

My one regret is wearing shorts instead of pants. Apparently Mother Nature has created her own version of barbed wire in the form of vines with incredibly sharp barbs. Also, the spiders in Missouri continue to amaze me. There is this type of large yellow spider which I’ve seen a number of times while tromping through the woods around here which I’ve been told is nonpoisonous but it provides no comfort to me. It also likes to spin its spider webs at face-height. Photo below courtesy of me (note those are inches on the bottom part of the scale).

After making it down to the river we began walking upstream as this appeared to look more promising for a spring location. After about 80 feet of walking along the bank I looked down and saw water flowing into the river through a bedding plane in the bedrock. As I wasn’t actually expecting to find the spring so it was exciting to “re-discover” it.

I was too preoccupied examining and recording the location of the spring with my trusty eTrex GPS that I failed to see the “rest” of the spring.

For about 100 feet upstream along the bank of the river there was water coming out of the bedding plane into the James River. It wasn’t a large volume at any given spot, flowing at around 1-2 feet per second, but the “thickness” of the sheet of water flowing out of the spring was about 4 inches, and was around 100 feet in width. Rough estimates of discharge put the whole spring at around 30-40 cubic feet per second, which is considerably more than the other springs I’ve been studying in the area (usually 1-5 cubic feet per second).

The observation that the water flows out along a widened bedding plane is important to understand for the way water is flowing in the area (it's one of the major research questions I'm trying to address). The river seems to prevent vegetation from growing on a large section of the bedrock and has exposed the fractures in the rock, which allowed us to look down and see the water flowing. These little “windows” were a good place to put a charcoal packet to see if the dye makes it down into this spring.

To do or dye

As part of my masters degree I recently performed a dye trace to better understand how the groundwater flows in my study area. This is especially important in areas like mine known as karst topography, where the groundwater flows through caves and fractures in the bedrock along specific paths and in specific directions, almost like underground river systems. This I opposed to other types of ground water flow which usually involves water flowing slowly in all directions, which is usually easier to predict and monitor.

Sinkholes in these areas are often controlled by the way groundwater flows, so understanding groundwater flow can provide some insight into sinkhole formation and hazard, such as this sinkhole which formed (in a matter of hours) only a few miles south of my study site and destroyed a house.

Dye traces in theory are very simple. A type of fluorescent dye, either as a powder or a liquid, is dumped into a sinkhole or sinking stream, which act as inputs into the groundwater system. Springs nearby act as groundwater outputs and are monitored afterward to see if the dye begins to show up in the spring water. If the dye is found coming out of the springs, or when it doesn’t (which is also important), then connections can be made between the sinkhole and spring, giving insight into what the ground water is doing.

A dye trace can also be taken further. Measuring how much dye is recovered from can see if dye is being pirated away to other springs. Finding out exactly when the dye starts coming out of the springs relative to when it is dumped into the sinkhole will show how long it took the dye to travel underground. With the distance known between the sinkhole and spring the groundwater velocity can be calculated. Measuring dye concentration spikes in the spring can show if the dye is traveling as one “slug”. Multiple spikes would show dye splitting along different paths and rejoining before exiting through the spring.

My field site includes a number of sinkholes (numbers #1-3), springs (#5,6), and even a sinkhole in a stream (#4), which allow for a few dye tracing opportunities. Previous studies show that, generally, the groundwater flows southward. One of the sinkholes (#3) has just opened up in the last few months in the middle of a retention basin near a major highway.

Rhodamine WT dye was injected into the stream sink (#4) using a small pump. The idea behind this is it causes the dye to come out of the other springs at a constant, level rate. This getup was a special pump and reservoir system which we installed under a cart path.

Lissamine FF dye was dumped into the newly formed sinkhole and flushed in using a garden hose which was installed into a nearby fire hydrant. This was one of my more unique research experiences, rolling out 300+ feet of hose from a fire hydrant across a street and down into the sinkhole. Opening the fire hydrant was actually kind of frightening as it made a lot of low rumbling noises before finally opening up.

We flushed in the dye using about 250 gallons of water. This took about a half an hour, based on the rate of the hose. The whole process took about two hours to set up and complete. Unfortunately for myself and my field assistant we had no shade to rest in. As a side note, this was during some of the hottest days so far this summer in Missouri.

The dye from the newly formed sinkhole was detected at both of the springs to the south, which was expected but important to find out. One of the more important observations, though, relates to the dye injected at the stream sink. Although that dye shows up at both of the springs, it shows up at unequal concentrations. More specifically, it shows up as a higher concentration at spring #6 than spring #5. What this shows is that some of the dye is diverting to another path before it reaches spring #6 and mixing with another source of ground water which is diluting it before it reaches spring #5. Spring #6 is also farther away than spring #5 which explains why it shows up later.