Register to reply

Lightning while at the beach

by vivesdn
Tags: beach, lightning
Share this thread:
vivesdn
#1
Apr2-07, 03:01 PM
P: 104
It is generally accepted that under lightning risk, it is not safe to be on open areas, and if in such a situation, better to lay on the ground to avoid being the higher feature.

But what if you are on a beach. Is it safer to keep inside the water than laying on the sand? At the end, the water is better conductor that skin and electricity would be semi-spherically dissipated.

What do you think?
Phys.Org News Partner Physics news on Phys.org
Step lightly: All-optical transistor triggered by single photon promises advances in quantum applications
The unifying framework of symmetry reveals properties of a broad range of physical systems
What time is it in the universe?
cesiumfrog
#2
Apr2-07, 04:52 PM
P: 2,051
I'm betting that's not the safest time to be swimming, for various reasons.
vivesdn
#3
Apr2-07, 05:11 PM
P: 104
okay, but as of lightning, what is riskier or more dangerous, remaining on the sand or inside the water?

berkeman
#4
Apr2-07, 05:44 PM
Mentor
berkeman's Avatar
P: 41,104
Lightning while at the beach

I'm not a lightning expert, but in the water you are at risk for the electric current going through your body because of the water being in contact with you. I think your best bet would be to squat down on the dryest and lowest piece of sand you can, and only touch the sand with your feet and keep your feet together touching. That way if there is a ground current, it won't be inclined to go up and around through your body.
CPL.Luke
#5
Apr2-07, 05:48 PM
P: 444
actually if lihnig is going to hit anywhere near you here's not much you can do to stop it. if the current has gone through a mile of air that extra 6 feet isn't going to make much of a difference.
lpfr
#6
Apr3-07, 04:01 AM
P: 388
Lie flat on dry sand or better, on a trench in dry sand. This diminishes the risks but not eliminate them.
Chaos' lil bro Order
#7
Apr3-07, 07:12 PM
P: 683
Water increases the conductivity of skin 5-fold. So 10,000 volts becomes 50,000 making it much worse of a lightning strike. Also, water is a much better conductor than SiO2 sand. I'm no expert on the chemistry of sand-to-glass conversion, but glass is a good insulator, which inclines me to believe that sand is likely also a good insulator. For all these reasons, stay on the beach to be safest.
hayzie
#8
Apr4-07, 11:13 AM
P: 5
Iv been studying the effects of lightning for years. The safest possible way to avoid being struck is to squat down (not lie down) with feet together as Berkeman has already stated above.

Safer on dry sand than in the water.

you have a few seconds warning before you get struck, as lightning doesnt travel from the cloud to the ground it actually meets together between the cloud and ground.

the warning will be a fizzing sound with your hair standing on end the strike will either be extremley close to you or it will hit you. Depends if you generate an electron streamer or not. If u do there isnt much you can do, just brace for it and hope you survive.
vivesdn
#9
Apr4-07, 01:04 PM
P: 104
As water is better conductor than air, and we are better and higher conductor that land, the undelying supposition to the question was that may be in water the lightning would prefer any wave than us.

So, now, it's clear. Thanks a lot. Hopefully we won't need this new knowledge...
Chaos' lil bro Order
#10
Apr5-07, 01:51 PM
P: 683
Quote Quote by hayzie View Post
Iv been studying the effects of lightning for years. The safest possible way to avoid being struck is to squat down (not lie down) with feet together as Berkeman has already stated above.

Safer on dry sand than in the water.

you have a few seconds warning before you get struck, as lightning doesnt travel from the cloud to the ground it actually meets together between the cloud and ground.

the warning will be a fizzing sound with your hair standing on end the strike will either be extremley close to you or it will hit you. Depends if you generate an electron streamer or not. If u do there isnt much you can do, just brace for it and hope you survive.

In fact, before every lightning strike, several dendrils extend from the ground upwards and the lightning from the clouds comes down to reach one of these dendrils, sometimes only 10 feet above ground level. All the dendrils that don't make contact with the cloud lightning, dissipate and return their electric potential to the earth.
Unicyclist
#11
Apr10-07, 03:23 AM
P: 42
Quote Quote by hayzie View Post
you have a few seconds warning before you get struck, as lightning doesnt travel from the cloud to the ground it actually meets together between the cloud and ground.

the warning will be a fizzing sound with your hair standing on end the strike will either be extremley close to you or it will hit you. Depends if you generate an electron streamer or not. If u do there isnt much you can do, just brace for it and hope you survive.
Would it help if you stood on the tip of one foot, to minimise the contact with the ground?

This is just a mad suggestion, but what do you think?
lpfr
#12
Apr10-07, 03:44 AM
P: 388
No. Not at all.
Integral
#13
Apr10-07, 07:25 AM
Mentor
Integral's Avatar
P: 7,320
Quote Quote by Unicyclist View Post
Would it help if you stood on the tip of one foot, to minimise the contact with the ground?

This is just a mad suggestion, but what do you think?
It depends... If YOU are the lightning rod then no, it will not help. However, if the strike is near by then standing on 1 foot could help. Lighting causes a large voltage gradient in the ground surrounding the area of the strike. If you are standing with your feet on a radial line from the strike your body will bridge different potential lines, causing you to be come a conductor...not good. If you are on 1 foot or standing so you face the strike your feet will be closer to the same potential thus, lower currents will flow through your body.
dimensionless
#14
Apr10-07, 08:49 AM
P: 464
Quote Quote by hayzie View Post
you have a few seconds warning before you get struck, as lightning doesnt travel from the cloud to the ground it actually meets together between the cloud and ground.

the warning will be a fizzing sound with your hair standing on end the strike will either be extremley close to you or it will hit you. Depends if you generate an electron streamer or not. If u do there isnt much you can do, just brace for it and hope you survive.
Nothing I can do? If I thought a lightning bolt was about to hit me, I estimate I could move 50 feet in three seconds. If I was standing next to a tree, would running not be worth the effort?
hayzie
#15
Apr11-07, 01:49 AM
P: 5
Quote Quote by Unicyclist View Post
Would it help if you stood on the tip of one foot, to minimise the contact with the ground?

This is just a mad suggestion, but what do you think?
No this would not help, you are still earthed to the ground.

Quote Quote by dimensionless View Post
Nothing I can do? If I thought a lightning bolt was about to hit me, I estimate I could move 50 feet in three seconds. If I was standing next to a tree, would running not be worth the effort?
There isnt much you can do if you are producing a step streamer or step leader from your body, thats what i ment, you wouldnt even have time to think about it.

examples of this phenomenon can be seen here http://www.treecareindustry.org/imag...ningStrike.jpg

This is a famous shot taken by Johnny Autery which shows a tree being struck, as you can see there are 2 other leading streamers that did not manage to find the connection with the main stroke, one from the tree and one from the tv tower.

If you are on the beach, a number of objects around you may produce one of these streamers. If you are one of them running wont help, you migth be lucky enough not to be directly hit.
Unicyclist
#16
Apr11-07, 06:17 AM
P: 42
What are the chances of surviving a direct hit by a lightning?

What are the usual health hazards/body impairments for the survivors?

Also, how exactly does a lightning damage you? Does it fry you up, because of body resistance? I hear different people have different body resistance values: would that affect the chances of being hit and the chances of surviving a hit by a lightning?
lpfr
#17
Apr11-07, 06:32 AM
P: 388
Some people survive, but maybe not to a direct hit. Lightning and other electric chocks produce heart and/or lung paralysis. This is the reason why you can try to give heart massage and artificial respiration to victims.
The other possibility is to be fried. Current heats and burns parts of the body. If the current do not goes through the heart, people may survive, seriously impaired.
People differ on the skin resistance. Mostly due to dry or wet skin. But inside, we are all a very good conducting electrolyte (salted water).
Danger
#18
Apr11-07, 08:50 AM
PF Gold
Danger's Avatar
P: 8,964
This might sound a bit off the wall, but it's a legit question. I never even thought of it until I read this thread.
Assuming that you're in the proper crouched position, would it be a good idea to stick your fingers in your ears? I've read several times that the most common complaint of strike or near-strike survivors is deafness from the overpressure. Or would that action increase the chance of the current going through your brain?


Register to reply

Related Discussions
3rd right foot washes up on BC beach General Discussion 86
Waves approaching a beach General Physics 4
Lovely day at the beach. General Discussion 12
Scores of Fish Beach Themselves in N.C. General Discussion 0
Not Just Another Day at the Beach General Discussion 5