38
votes
What should one do when climbing if someone above you yells ROCK?
How you react will depend on the situation.
If you're climbing and you hear someone yell "ROCK" then your default reaction should be to hug the rock, brace for impact, and hope the rock misses you, ...
- 53.5k
37
votes
Will a compass work underground or underwater?
Compasses are good equipment both spelunking and diving. Even the deepest cave you could go to is still near the earth's surface, geologically speaking. The earth's magnetic field is also essentially ...
- 4,219
33
votes
Would a gunshot echo in a cave?
It turns out that gunshots can be used to map caves,
The decade-long search might have gone a little differently, though, if soldiers had access to a new system that can use sound waves from a ...
- 69.2k
24
votes
Accepted
Why does suspension trauma happen?
Most climbing harnesses support the majority of your weight, if freely suspended, around the tops of the thighs. While the waist belt may be designed to take the brunt of loads in a fall once you are ...
- 6,202
21
votes
Accepted
Can I record my route electronically when underground?
How would GPS trackers work when underground?
Poorly
I have no personal experience with Alltrails, but the GPS apps which I have used in the past mostly did not cope well with GPS reception being ...
- 12.8k
17
votes
Can I record my route electronically when underground?
Assisted GPS is different from inertial navigation. It uses ground stations to transmit GPS almanacs and ephemeris for faster GPS start-up. There are also wide-area augmentation services such as ...
- 4,662
15
votes
What should one do when climbing if someone above you yells ROCK?
You have no idea how much time you have before you might take an impact, no matter how far above you the call is made because you don't know the delay in calling ROCK. Therefore, I think the answer ...
- 1,766
12
votes
Accepted
How to escape a cave in an emergency situation?
Assuming you have no way of safely and reliably leaving the cave to get help, your first priority is not to become a casualty yourself as well.
Even if the Guide needs urgent medical attention, it ...
- 5,980
12
votes
Accepted
What is the warning call for falling rocks in your area?
North America
English Canada / United States
"ROCK!" (pronounced /rɒk/)
French Canada
"ROCHE!" (pronounced /ʁɔʃ/)
Europe
European Alps
"CAILLOU !" (pronounced /ka.ju/...
8
votes
Accepted
What is a lava tube, as a place to see bats? Are there any in the United States?
Basically, a lava tube is formed when a underground lava flow stops flowing, leaving behind a long tubular cave.
A lava tube is a natural conduit formed by flowing lava which moves beneath the ...
- 69.2k
8
votes
Accepted
How to get rid of illegal artificial paints on historical monuments?
When I've had to clean spray paint from remote destinations, we've used chemical paint removers in spray bottles and scrub brushes.
Do not do this on a historic site without permission from whoever ...
- 4,219
7
votes
Why does suspension trauma happen?
The main problem is the disruption of the normal blood circulation. The blood pressure generated by the heart alone is not able to persistently pump back the blood from the feet, it needs the venes ...
- 1,451
7
votes
What should one do when climbing if someone above you yells ROCK?
As climber, your options are usually limited: get close to the wall, grab a good hold and/or a sling/pair when nearby. One possibly bad result of the rockfall might be that you'll be short a rope or ...
- 71
7
votes
Can I record my route electronically when underground?
GPS and similar technologies do not work at all underground, they can be blocked fairly effectively by dense tree-cover or being deep in a valley, even with clear views of the sky. Any thickness of ...
- 9,729
7
votes
When cave diving, if one sees an air pocket, how can one know whether the air is safe to breathe?
There isn't an easy way of telling if the air in air pockets are safe to breathe, especially in short sumps where cavers might free dive (i.e.dive through by just holding their breath with no air ...
- 5,980
6
votes
Accepted
How fast does suspension trauma happen?
The wikipedia page you quote should be right, of course this may vary by situation and person. So The asnwer to "how fast" is "about 20 minutes".
This is indeed not a whole lot of time. When it is ...
- 1,451
6
votes
Would a gunshot echo in a cave?
From my experience in caves, I'd say you could expect the gunshot to reverberate for just a second or two in passages that are barely more than walking size. In larger passages, maybe longer. Around ...
- 163
4
votes
Will a compass work underground or underwater?
Magnetic compasses work well in caves (both dry and submerged), with the usual caveat that iron-rich minerals can cause deflections. In mines, consider using regular back-bearings for confirmation.
...
- 4,662
4
votes
Minimum safe rappel rope diameters?
I also agree that 8mm rope is pretty safe. I've done pretty close to straight vertical rappels up to 160ft on it while canyoneering (8mm rope is very common in canyoneering). I'm assuming you've ...
- 190
4
votes
Headlamp with open flame
What you're looking at is a carbide lamp, and it looks to be a Petzl Aceto. What you can't see in this photo is the generator, which is a round canister with two parts. The upper part contains water,...
- 4,662
4
votes
Would a gunshot echo in a cave?
So the answer is that the other person will almost definitely be able to hear the gunshot in the absence of background noise. Will it echo? That sounds like it would depend a lot on how much the walls ...
- 59
4
votes
Accepted
How do I distinguish a dirt floor in a cave from a floor formed of very old coprolites?
No, there are no risks, assuming you're asking abput biohazards. This is poop so old it has petrified, become stone and/or sand. The only microorganisms that actively live in there are ones that can ...
- 1,923
4
votes
Can I record my route electronically when underground?
As others have stated, the way to keep track of your position when you can't use GPS is inertial navigation, also known as dead reckoning. This uses various sensors, such as accelerometers, ...
- 141
3
votes
How to escape a cave in an emergency situation?
If someone is seriously hurt deep in a cave, and only hours away from dying, chances are they are going to die.
You have a map, but do you know how to read it? Cave maps don't read like a topo map, ...
- 53.5k
3
votes
How to escape a cave in an emergency situation?
Get lucky
If you don't know where the exit is, getting out of a cave is a matter of luck. If you have watched T.V. you have seen people using a flame to check for a breeze, but in reality, there is ...
- 30.3k
2
votes
Can I record my route electronically when underground?
To supplement @fgysin answer:
Modern smartphones contain enough sensors (acceleration, gyro, compass) to do inertial navigation.
These sensors are not of a great precision, so I think the integration ...
- 407
2
votes
What precautions are needed for caving?
Great answers here. This news piece seems to be relevant to your question, now probably 3 years old now.
Grade Point
Student survives three days in a cave after college spelunking group leaves him ...
- 2,343
1
vote
Would a gunshot echo in a cave?
Would a gunshot echo in a cave...
It depends on the cave. To echo a sound wave needs a smooth surface to reflect off of.
Most caves aren't giant smooth caverns but are relatively convoluted or ...
- 1,086
1
vote
Good places to go potholing in the UK
I recommend the Mendips with an organised group. Could do a morning session in the dry Goatchurch Cavern and an afternoon session in the wet but superb Swildon's Hole. Around there there's loads of ...
- 1,086
Only top scored, non community-wiki answers of a minimum length are eligible