Презентация на тему "Экология"

The Tunguska Explosion

Borzenkov Stas

• A little over 100 years ago, on the morning of 30th June 1908, there was a huge explosion in the sky above the Tunguska River in Siberia. It was as if a giant bomb had gone off over the area. In fact, the explosion was so powerful that it killed 80 million trees, destroying a natural area of over 13,000 square kilometres in size.

People who saw the explosion back then all gave similar descriptions of the event: an extremely bright light, as if the sky were on fire, followed by a deafening crashing sound and strong wind. This wind was so strong that it brought down buildings, uprooted trees and knocked people to the ground. Everyone spoke of a giant fireball splitting the sky in two. In fact, the effects of the explosion were so powerful, that they spread as far as Central Asia and Northern Europe.

There are many ideas about what happened.

These ideas range from the extremely unlikely (a UFO exploded)

The unlikely (a black hole passed through the Earth).

But there is one idea that many scientists think may be right.

This is that a meteorite (which is a rock from outer space) about 35 metres in length and weighing millions of kilos, entered the Earth’s atmosphere that day and exploded

Still, not all scientists think that this explanation can be correct. They pay attention to the fact that no one has ever found a piece of rock from a meteorite on the ground in Tunguska. They also wonder why trees in the area now grow extremely quickly. Not only this, but whatever it was that exploded over Tunguska left no mark behind.

In truth, Tunguska remains as much a mystery today as it was 100 years ago. Nevertheless, scientists intend to carry on examining the Tunguska forest and the surrounding area in the hope that one day they will discover the answer to this fascinating mystery.

The End ?