2 mile cave passage opened to reveal many dead bats

[mgmills]

you mentioned in another post that rocks fell (for at least ten seconds)???? that should be about a 3200 pit . Maybe you should let a more seasoned caver drop that first before you or your (guys) end up a recovery

10 seconds may result in 3200 feet in the physics world but 10 seconds in the real world with air resistance, rocks bouncing off of other rocks and rolling off of a muddy slope that resulted in no sound to our ears meant it was in freefall. Of course it wasn't and it resulted in a 40 foot pit.

Recently there was a thread about "measuring the depth of a pit" and several formulas for calculation were posted there. The thread can be reviewed at
viewtopic.php?f=26&t=7548&p=62903&hilit=depth+of+pits#p62903

Based on the formulas the depth would not be 3200 feet. I'm too brain dead from work and holiday celebrations with family to do the calculations but I think it would come out to less that 1400 feet for a 10 second rock fall.

That said, in the past I've tried to count seconds on a rock fall and it is real easy to count too fast and over estimate . . . unless you are timing with stop watch your best bet is to expore it and actually measure the depth. If there is a slope involved where the rock you drop is rolling, all calculations are going to be inaccurate.

[WVCaver2011]

That's what my conclusion was when I found out the pit was only 40 feet when I thought that it would be at least 100 feet. Thanks for your help!!

[Scott Shaw]

Could this be a reason why the NSS is seeing a drop off in membership? Instead of offering to help you have to cut him down? Shame on you who are so quick to judge when you should be offering guidance!

I notice that the two folks who have cut him down are also from WV. Coincidence? Or jealousy? Keep the reports coming.

[driggs]

Edit: Deleting response and ignoring Scott Shaw's "fightin' words".

[wyandottecaver]

LOL and here I just thought we were talkin about dead bats :)

[tncaver]

Everyone should consider that rocks can fall for 10 seconds and only fall a few feet. The source of the rockfall
can be feeding rocks for 10 seconds even if they are only falling 10 feet. It totally depends on how much rock
is loose above a weak space below, and not necessarily how FAR they are falling.

[wyandottecaver]

TNcaver thats Great!

[WVCaver2011]

So, back to the dead bats! I figured out what I believe to be the reason for them dying! Upon ventureing back into this cave I figured out that there was another hole just behind thehole I opened. Beyonfd this hole is a room that leads back around and up a small pit that leads into the passage! So, this hole plugging up had nothing to do with the bats becoming trapped because they had another hole that they could have escaped through. So, why did they all die? Well, I just recently visited the cave and found it to be flooded to it's highest level that i've seen thus far. The water doesn't need to be that high to plug off the holes with water. So, when I entered the cave this last time I noticed that the holes would have been sumberged with 2 feet of water above them. Therefore, this back passage is a death trap for bats and needs to be plugged off somehow after the water resides to omit any bats from going into this back passage and die again! This is why there were so many bats dead back here. Constant water fluctuation will do that. I noticed that when this passage floods to its highest level I've seen it takes many days to reside if there's no precipitation during that time. Let me know what kind of plug I could put in to allow water movement but no bat flow. I have a feeling that this may not be easily resolved!

[tncaver]

Let me know what kind of plug I could put in to allow water movement but no bat flow. I have a feeling that this may not be easily resolved!

Try chicken wire or something similar that will allow lots of water through but nothing as large as a bat.

[WVCaver2011]

Good idea, and I actually have some of that laying around my house. Thanks!!

[wyandottecaver]

another alternative is eliminate the bottleneck, i.e make the drain big enough to better handle the water flow. Now that both the lower and upper holes are open my guess is that water will reach the upper hole far less often and for less time. Being trapped for a few days once or twice, even in summer, would not be great, but would also probably not be lethal either.

[WVCaver2011]

another alternative is eliminate the bottleneck, i.e make the drain big enough to better handle the water flow. Now that both the lower and upper holes are open my guess is that water will reach the upper hole far less often and for less time. Being trapped for a few days once or twice, even in summer, would not be great, but would also probably not be lethal either.

Yea, that would be a good thing if it were possible but it isn't unless you make 30-40 feet of passage 2 -4 feet taller. That would require lots of work and would damage all the formations within that area! I believe it would work better and be way less costly to do the chicken wire trick! What I'm working with beyond this hole for the 30- 40 feet is a small 3 feet tall tunnel that drops about 2 feet at the end making things even more costly to blast through. Even then there's lots more passage that drops even further most likely meaning that it floods to the ceiling as well. Doing this would also reqiure blasting all of that open as well. I mean I'm not for sure if this other part of the cave floods completely or not but It's definately likely!. Do you have any ideas that I could use to test and see if it floods to the ceiling? I'm almost certain that this cave is one of those "wall of water" caves when it floods!

[wyandottecaver]

Remember that unless you have a LOT of water all at once, the hole itself is all you should need to enlarge. 2-3ft of tunnel can carry a lot of water, its making sure the hole itself is big (and making sure any downstream drain is big enough) thats the important part. That being said, if the flow is big enough to overwhelm the passage itself, there are numerous ways to check flood depth. There is in fact a thread on this.

In summary, my favorite is a hollow tube with a few holes drilled in it (plastic tubes are best) filled with crushed cork and anchored to the wall. As the water rises the cork powder floats and when it goes down the little pieces stick to the tube sides showing max height. A less intensive method is to place ping pong balls at various heights and see which ones go missing after a rain :)

[tncaver]

Look for water marks on the wall after a rain event is over long enough for you to go back into the cave.
Usually there are water marks on the walls/ceiling or leaves and/or debris from a flood event in a cave.
I discovered one cave that had leaves and debris almost 60 feet above the floor and it was plainly visible.
Usually that only happens when there is a debris plug or very small drain at the lower end of a passage
that accepts a lot of water. However, it is amazing how much water can go through a 6 inch hole. If you
see no water marks or debris, then it is likely the passage does NOT flood.

[WVCaver2011]

I'll see what I can do! This will be an interesting test to prove the height of water flow during flooding events! I believe there is a lower drain in the cave which is noticable and there were also pools of water in this passage that we had to walk/crawl through. I went into this area twice and noticed that the water level had risen a little in this part of the cave! I was skeptical of going any further and decided to turn around before things got ugly! Thanks for your help guys!