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Things To Know About Lightning Strike by labamo07(m): 4:32am On Apr 18, 2016
Lightning strike
A lightning strike is an electric discharge between the atmosphere and an earth-bound object. They mostly originate in the thundercloud and terminate on the ground, called cloud to ground (CG) lightning. A less common type of strike, called ground to cloud (GC), is upward propagating lightning initiated from a tall grounded object and reaches into the clouds. About 25% of all lightning events worldwide are strikes between the atmosphere and earth-bound objects. The bulk of lightning events are intracloud (IC) or cloud to cloud (CC), where discharges only occur high in the atmosphere.
A single lightning event is a "flash", which is a complex, multi-stage process, some parts of which are not fully understood. Most ground to cloud flashes only "strike" one physical location, referred to as a "termination". The primary conducting channel, the bright coursing light that may be seen and is called a "strike", is only about one inch in diameter, but because of its extreme brilliance, it often looks much larger to the human eye and in photographs. Lightning discharges are typically miles long, but certain types of horizontal discharges can be upwards of tens of miles in length. The entire flash lasts only a fraction of a second. Most of the early formative and propagation stages are much dimmer and not visible to the human eye. [ citation needed]
Panorama photography taken during a lightning storm over Bucharest, Romania
Strikes
Lightning strikes can injure humans in several different ways:
1. Direct
Direct strike – the person is part of the flash channel. Enormous quantities of energy pass through the body very quickly and this can result in internal burns and organ damage, explosions of flesh and bone, and a damaged nervous system. Depending on the flash strength and access to medical services, it may be instantaneously fatal or cause permanent injuries and impairments.
Contact injury – the person was touching an object, generally a conductor, that is electrified by the strike.
Side splash – branches form "jumping" from the primary flash channel, electrifying the person.
Blast injuries – being thrown and suffering
blunt force trauma from the shock wave (if very close) and possible hearing damage from the thunder.
2. Indirect
Ground current or "step potential" – Earth surface charges race towards the flash channel during discharge. Due to the high impedance of the ground, the current "chooses" a better conductor, often a person's legs, passing through the body. The near instantaneous rate of discharge causes a potential (difference) over distance, which may amount to several thousand volts per linear foot. This phenomenon is responsible for more injuries and deaths than the above three combined. Reports of "Tens of cows killed by a lightning strike..." are classic examples.
EMPs – the discharge process produces an electromagnetic pulse ( EMP ) which may damage an artificial pacemaker, or otherwise affect normal biological processes.
3. Secondary or resultant
Explosions
Fires
Accidents
Re: Things To Know About Lightning Strike by labamo07(m): 4:34am On Apr 18, 2016
Lightning's interaction with the body
Lightning strikes can produce severe injuries, and have a mortality rate of between 10% and 30%, with up to 80% of survivors sustaining long-term injuries. These severe injuries are not usually caused by thermal burns, since the current is too brief to greatly heat up tissues; instead, nerves and muscles may be directly damaged by the high voltage producing holes in their cell membranes , a process called electroporation.
In a direct strike, the electrical currents in the flash channel pass directly through the victim. The relatively high voltage drop around poorer electrical conductors (such as a human being), causes the surrounding air to ionize and break down, and the external flashover diverts most of the main discharge current so that it passes "around" the body, reducing injury.
Metallic objects in contact with the skin may "concentrate" the lightning's energy, given it is a better natural conductor and the preferred pathway, resulting in more serious injuries, such as burns from molten or evaporating metal. At least two cases have been reported where a strike victim wearing an iPod suffered more serious injuries as a result.
However, during a flash, the current flowing through the channel and around the body will generate large electromagnetic fields and EMPs , which may induce electrical transients (surges) within the nervous system or pacemaker of the heart, upsetting normal operations . This effect might explain cases where cardiac arrest or
seizures followed a lightning strike that produced no external injuries. It may also point to the victim not being directly struck at all, but just being very close to the strike termination.
Another effect of lightning on bystanders is to their hearing. The resulting shock wave of thunder can damage the ears. Also, electrical interference to telephones or headphones may result in damaging acoustic noise .
Re: Things To Know About Lightning Strike by labamo07(m): 4:37am On Apr 18, 2016
Prevention and mitigations
The field of lightning protection systems is an enormous industry world-wide due to the impacts lightning can have on the constructs and activities of man. Lightning, as varied in properties measured across orders of magnitude as it is, can cause direct effects or have secondary impacts; lead to the complete destruction of a facility or process or simply cause the failure of a remote electronic sensor; it can result in outdoor activities being halted for safety concerns to employees as a thunderstorm nears an area and until it has sufficiently passed; it can ignite volatile commodities stored in large quantities or interfere with the normal operation of a piece of equipment at critical periods of time. The impacts of a lightning event are as varied and far reaching as the nearly infinite products and systems devised to mitigate the effects of lightning on our lives.
Most lightning protection devices and systems protect physical structures on the earth, aircraft in flight being the notable exception, however some attention has been paid to attempting to control lightning in the atmosphere, however all the attempts proved extremely limited in success. Chaff and silver iodide crystal concepts were devised to deal directly with the cloud cells and were dispensed directly into the clouds from an overflying aircraft. The chaff was devised to deal with the electrical manifestations of the storm from within, while the silver iodide salting technique was devised to deal with the mechanical forces of the storm.
Hundreds of devices, including lightning rods and charge transfer systems, are used to mitigate lightning damage and influence the path of a lightning flash.
A lightning rod (or lightning protector) is a metal strip or rod connected to earth through conductors and a grounding system, used to provide a preferred pathway to ground if lightning terminates on a structure. The class of these products are often called a "finial" or "air terminal". A lightning rod or "Franklin rod" in honor of its famous inventor, Benjamin Franklin , is simply a metal rod, and without being connected to the lightning protection system, as was sometimes the case in the old days, will provide no added protection to a structure. Other names include "lightning conductor", "arrester", and "discharger"; however, over the years these names have been incorporated into other products or industries with a stake in lightning protection. Lightning arrester, for example, often refers to fused links that explode when a strike occurs to a high voltage overhead power line to protect the more expensive transformers down the line by opening the circuit. In reality, it was an early form of a heavy duty surge protection device (SPD) . Modern arresters, constructed with metal oxides, are capable of safely shunting abnormally high voltage surges to ground while preventing normal system voltages from being shorted to ground.
Re: Things To Know About Lightning Strike by labamo07(m): 4:41am On Apr 18, 2016
Notable events of lightning incidents
All events associated or suspected of causing damage are called "lightning incidents" due to four important factors.
Forensic evidence of a lightning termination, in the best investigated examples, are minuscule (a pit in metal smaller than a pen point) or inconclusive (dark coloration).
The object struck may explode or subsequent fires destroy all of the little evidence that may have been available immediately after the strike itself.
The flash channel and discharge itself are not the only causes of injury, ignition or damages, i.e., ground currents or explosions of flammables.
Human sensory acuity is not as fine as that of the milliseconds duration of a lightning flash, and our ability to observe this event is subject to the brain's inability to comprehend it. Lightning detection systems are coming online, both satellite and land based, however their accuracy is still measured in the hundreds to thousands of feet, rarely allowing them to pinpoint the exact location of the termination.
As such it is often inconclusive, albeit highly probably a lightning flash was involved, hence categorizing it as a "lightning incident" covers all bases.
https://en.m.wikipedia.org/wiki/Lightning_strike
Re: Things To Know About Lightning Strike by seunlayi(m): 6:06am On Apr 18, 2016
Interesting post

2 Likes

Re: Things To Know About Lightning Strike by Flexherbal(m): 6:22am On Apr 18, 2016
OP: thanks for taking out time to educate us.
Re: Things To Know About Lightning Strike by Burger01(m): 6:32am On Apr 18, 2016
Na that kind of Cloud to Ground (CG) lightning I pray strike those corrupt endtime bast#£%s messing our nation up... May CG lightning strike all of them angry undecided
Re: Things To Know About Lightning Strike by labamo07(m): 7:35am On Apr 18, 2016
Burger01:
Na that kind of Cloud to Ground (CG) lightning I pray strike those corrupt endtime bast#£%s messing our nation up... May CG lightning strike all of them angry undecided
boss, na vex you carry come this morning o Lmaooooooooo...........
Re: Things To Know About Lightning Strike by Burger01(m): 7:50am On Apr 18, 2016
^^^ They deserve more than CG lightning self. We must enact laws to kill those thieves. I am are tired of them angry

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