10 Topics for exams
8. Freak weather Freak weather has been introduced by the scientific community and the media as the term that encompasses all potential changes in climate. Hundreds of scientists from many different countries are working to understand strange phenomena. As freak weather is the result of extremely complex interactions, scientists still cannot predict the exact impact on the Earth of these phenomena and find the explanation of them. El-Nino is one of these phenomenon. Every few years something mysterious happens in the Pacific. Vast areas of the surface of the Pacific begin to warm up. As a result, the wind weakens. A great sweep of warm water sloshes eastwards. These warm waters usually arrive off the coast of South America shortly after Christmas. That is why they are known as El- Nino, which is Spanish for the Chist-Child.It seems rhat El-Nino affects the weather of North America and the Atlantic, too. In 1983 severe storms caused havoc in the United States and Europe, these and severe drought in Africa, India and Europe could be traced back to El-Nino. Scientists call El-Nino world weather upset. Crop circles phenomenon is not a modern one. They are mentioned in academic texts of the late 17th Century. Since then some eighty eyewitnesses from as far away as British Columbia have reported crop circles forming in under twenty seconds; cases are often accompanied by sightings of incandescent or brightly-coloured balls of light, shafts of light or structured flying craft. Serious attention was given to the simple circles in 1980 in southern England. The designs appeared primarily as simple circles, circle with rings, and variations on the Celtic cross, they developed straight lines and created pictograms, Research and laboratory tests suggest that microwave or ultrasound may be the only method capable of producing such an effect. There are a lot of other unusual weather phenomena such as flying saucers, tornadoes, blood rains about which people think they are God signs.