Being land-locked has spared us Nature’s worst fury

In this region, we love Nature. But do we appreciate how kindly She has been on us this far? Nature sustains us but can wipe us off this earth in a jiffy with little change in Her temperament.

Sunday, August 12, 2012

In this region, we love Nature. But do we appreciate how kindly She has been on us this far? Nature sustains us but can wipe us off this earth in a jiffy with little change in Her temperament. We have had our fair share of Her anger but that’s no reason to gripe. Many times She has used wind, earthquake, volcano, drought, flood, fire – and a host of others – to show us who pulls the punches around here. But all the times She has never unleashed their full destructive power.For instance, She has never visited the full wrath of tornadoes or hurricanes on us. Both are awesome forms of wind-power that represent Nature at Her fiercest. But which is meaner, deadlier and which the worst atmospheric force on earth? Compare for yourself!Packed into tight, swirling spirals, the winds of the most powerful tornadoes can reach speeds approaching 515 km per hour. That’s wind’s violence at its worst. It’s faster than a Formula One race-car. Faster than many planes can fly. And almost half the speed of sound. At that speed, wind can fling cars across areas the size of Amahoro Stadium and reduce the sturdiest house to rubble. And while the majority of tornadoes rage at less than 322 km per hour, that’s still fast enough to uproot trees and destroy your average Nyarutarama home.A strong hurricane whips up sustained winds of over 241 km per hour, with gusts that top 322 km per hour. At hurricane wind speeds, loose debris becomes a barrage of flying missiles. Even if you could stand up straight in a hurricane wind, you wouldn’t be throwing a wise challenge.Tornadoes’ funnel width at ground-point usually ranges from a few dozen to several hundred metres across. Some tornadoes reach more impressive widths – more than 1.6 km at ground-point. Yet because tornadoes move rapidly along the ground, they can cause damage over a larger area than their size might suggest. Larger, longer-lived tornadoes can cut a swath of destruction through Musanze to Rusizi.Hurricanes are huge. They can cover the entire country. The average hurricane is 322 to 483 km in diameter, and massive hurricanes can span 1,127 km or more. The size of a hurricane, however, is not directly related to its wind speed or destructive force. Relatively small ones can pack an incredible punch, while much larger ones can be relatively mild. So, tornadoes may dominate the sky, but hurricanes swallow it whole. Tornadoes require the tropical ocean to maintain their intensity, hurricanes quickly lose their strength when they make landfall or move into cooler climates. This greatly limits the number of places they can strike. The same factors that spawn hurricanes also limit their frequency. Like tornadoes, hurricanes tend to strike in season. Tornadoes pack quite a wallop. When they strike near populated areas, the damage can be severe. They are notorious for destroying houses on one side of the street while leaving those on the other untouched. Because of their longevity and immense size, hurricanes can wreak tremendous havoc. The combined effects of wind, rain, and surf can destroy homes, erode seashores, and flood entire regions. Luckily for us in hinterland Rwanda, most hurricanes spend the majority of their lives in the open ocean. How much damage a hurricane does is determined as much by when, where, and how it strikes coastal areas as by the magnitude of the storm itself. Despite greatly improved weather tracking and warning systems, tornadoes still kill an average of 100 people in the United States each year. Although they can lift humans into the air and hurl them long distances, flying debris and collapsing buildings cause most deaths. And not every place has such modern tools. In 1991, a typhoon (as hurricanes are called in the western Pacific and Indian oceans) struck low-lying sections of Bangladesh and killed almost 140,000 people. Hurricanes kill more, especially worldwide, even if they do it less often than tornadoes.Metre for metre, tornadoes pack the most destructive force of any atmospheric phenomenon, possessing a pinpoint violence unmatched by any other force of nature. In fact, a good-sized twister releases energy at a rate equal to that of two large nuclear reactors. Don’t be too impressed, though. The "super-cell” thunderstorms that spawn tornadoes typically have a total energy output thousands of times greater than that.The sheer size of a hurricane allows it to unleash massive amounts of destructive power on anything unfortunate enough to be engulfed by it. And unlike tornadoes, which rarely last for more than an hour, a hurricane can rage for days. All of that adds up to staggering energy levels. By some calculations, a typical hurricane generates power at a rate equal to that of half of the electrical production of the entire world at any given time. So, even though tornadoes produce an impressive display of ground-churning power, they lack hurricanes’ size and stamina. If that’s not enough to convince you, consider this: hurricanes are so powerful that they can spin off tornadoes and get rid of them. I don’t know about you. But if I’m to be victim, I’ll pick a tornado anytime.