Wednesday 17th March 2004
I swam all the way to Mexico and boy are my legs tired.
Big things come in little packages.
Cenote Kaibab continues to provide surprises. 600 feet/180 meters of new line off another room at the base of the cenote and leads they are a everywhere. It is amazing to see just how beautiful this cave is. It has so many different types of speleothemes (cave decorations) and different looks. We hope to have a good deal of images after Saturday of the cave itself.
Cave diving is like swimming inside a big jigsaw puzzle or maze. Except this one has a bit more time pressure and the fact that you cannot breath if you run out of gas. Part of the allure of expedition work for me is trying to figure out where the water goes.
Cave formation begins with rainwater falling on the surface. It is quickly absorbed into the ground. Limestone is extremely porous. Basically, the ground acts like a big dry sponge. The water as it leaves the surface picks up carbon dioxide. This makes it slightly acidic. This water that is now a mild carbonic acid dissolves the limestone as it travels through it. As more water enters the ground, pressure is developed that drives the water to flow, eventually ending at the ocean as a vent.
Imagine if you were to take a dry sponge and pour water into the middle of it. As the sponge fills up, it cannot hold the water any more, so the water begins to flow out of the sponge. Not all areas of the sponge have water flow that looks the same. As more water is added the flow picks up. The more water being added, the stronger the flow (hydrostatic pressure). The water flows where it has the least resistance to its movement.
The YucatanPeninsula has a high water table. It is currently right near the surface. This has not always been the case. The caves here have been above water several times. Speleothemes can only form in dry caves. So, it is clear that all of the passage in Systema Camilo were at one time at least partially dry.
The rainwater that made its way into the system tens of thousands of years ago ate away at the rock. As this water found its way into the aquifer, it carried with it the dissolved limestone it had picked up in its journey. When this water interacted with air, it lost some of the dissolved limestone, known as calcium carbonate. This depositing of the limestone after it had been dissolved is what created all of the decorations we see today in all the systems here.
The current water table has risen back to where almost all of the caves are completely below water. So, now the water is actually slowly dissolving all of the decorations that were formed while the cave was dry. No worries, this will take a very long time.
Anyway, figuring out where to go in a cave that no one has ever been in can be challenging. You really do not think about it much until you are faced with the challenge for the first time. However, experience is a good start, but how do you learn without going out and trying? Well, you don’t. The proof is in the pudding as they say. There are characteristics that we look for when we explore. Cracks in the ceiling of the passage are a good sign. Since the water begins on the surface and makes its way down, cracks can be a sign of softer limestone. Of course, softer limestone means more water will tend to go there.
As the passages get bigger, they often cannot support the weight of the rock above them and you will see a collapse (not while you are actually there, just called that). This might sound scary, but you quickly realize that the block of stone that looks like it just fell yesterday has decorations on it, so it is over ten thousand years old. It is not likely that anything will happen in the very short time we visit. These areas of breakdown often offer up more leads and continuing passage.
There are many more things we look for, but you get an idea that exploration is far more like a mystery than a straightforward action adventure movie. As Forrest Gump said, “Life is like a box of chocolates, you never know what you are going to get.” No truer words when it comes to cave diving and exploration.
Today Terrence, Renee and I each swam five bottles. We were in the water for five hours, diving for four of those. We secured a GPS fix on Cenote Kaibab and looked at multiple leads. Certainly, not a bad day, but boy am I tired.
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