Devastating floods, rampaging cyclones, damaging tsunami and tragic landslides may hit headlines year after year as natural calamities, but it is lightning and heatstroke that have turned out to be the deadliest. About 3 lakh lives were lost in 2014 owing to human error-induced (unnatural) accidents, which are mainly due to drowning, fire, and road and rail accidents. A total of 20,000 people died in natural calamities.
Rainy seasons come with occasional lightning and thunder, which will be at its peak during November-December. Many people get affected by lightning. Latest data from National Crime Records Bureau (NCRB) show that lightening killed over 2,500 people in 2014, while heatstroke claimed over 1,200 lives, and cold wave claimed 900 lives. So let us examine what safety precautions we can take during lightning though it is not possible to escape completely from lightening hazard.
Lightning strike is a sudden high-voltage electric discharge that occurs within a cloud, between the atmosphere and an Earth-bound object or between clouds, or between a cloud and the ground. Globally, there are about 40 to 50 flashes of lightning every second, or nearly 1.4 billion flashes a year. These electrical discharges are powerful and deadly. They mostly originate on the ground and terminate in the thundercloud, called ground-to-cloud (GC) lightning.
Upward-propagating lightning is initiated from a tall-grounded object and reaches into the clouds. About 25% of all lightning events worldwide are ground-to-cloud. The bulk of lightning events are intra-cloud (IC) or cloud-to-cloud (CC), where discharges only occur high in the atmosphere. Some lightning strikes go from cloud-to-ground (CG). Lightning strikes are known to occur as far as 60 miles (96 kilometres from the storm. Cloud-to-ground lightning is possible in dry or wet weather and occasionally well in front of the cloud formations of the storm.
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 – 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. Some forms of lightning can strike at great distances either in advance or behind the centre of a thunderstorm – anywhere from 5 to 10 miles away. That means that people sometimes believe that they are at a safe distance when they are actually well within range of lightning activity.
There are no solid statistics on the number of people killed by lightning in India, because incidents often are not reported. It is estimated by scientists that every year, lightning kills roughly 24,000 people around the world, and, In India, the number is over 3,000 a year, injuring 240,000 people in the world – many of whom end up suffering from lifelong medical problems.
Lightning is a bigger killer in India than one might think. Lightning is responsible for at least 10% of the total deaths caused by nature in most years in India.
The average lightning bolt carries about 30,000 amps of charge, has 100 million volts of electric potential, and is hot at about 50,000 degrees Fahrenheit – 5 times hotter than the Sun. Lightning is the third leading weather-related cause of death.
(Read the full article from the November Issue of Safety Messenger Magazine 2015)