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| Sunday, 3 October 2004 |
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Junior Observer |  |
| News Business Features Editorial
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The fiery beauty of volcanoes
However, mankind has contributed to some disasters like floods and earthslips by the haphazard and excessive cutting down of trees and environmental pollution. The Junior Observer starts a series under Geo Facts to highlight man-made as well as natural disasters. The focus of this week will be volcanoes.
We in Sri Lanka are fortunate enough not to have any volcanoes on our island. However, the same cannot be said for people in places such as Italy, USA and Indonesia. These countries are home to some of the most dangerous volcanoes in the world. A volcano is a mountain made of material that has exploded to the surface of the earth from deep inside its crust. Some volcanoes reach remarkable heights within days while others may take centuries to form. They could be cone- or dome-shaped. The movement of materials deep below the earth's crust sometimes builds up huge pressures and high temperatures. Gases which are formed come under pressure and seek to escape out through cracks or 'chimneys' that lead from the earth's core to the upper crust. When reaching the surface, they explode with a bang and flames, clouds of steam, smoke, ashes, cinders and molten magma are thrown out. Magma is the molten rock that lies beneath the earth's crust. When it reaches the earth after an explosion, it is called lava. Lava comes out as a hot liquid (around 1000 degrees C) and solidifies (becomes hard) on cooling. An active volcano regularly erupts lava, ash and fumes. Some volcanoes remain dormant (non-active) for many years while those which have not erupted for tens of thousands of years are called extinct. There are about 500 active volcanoes around the world not including those hidden by the sea. A few, such as Stromboli, the volcanic island off the north-eastern coast of Sicily are active nearly all the time. But most undergo long periods when they 'sleep' or are dormant. It sure does come as a terrible shock when they unexpectedly errupt again. As a result of volcano eruptions, trees are burnt to ashes; animals, birds and fish are killed.Vast areasmiles and miles away from the volcano could be totally devastated. Although as many people as possible are evacuated when authorities receive information that a volcano is about to erupt, thousands of people have been killed.Volcanoes are found in the ocean too. Some of them grow out of the ocean bed and become visible. The island of Surtsey is an example in the ocean south of Iceland. Although it suddenly appeared on the surface, scientists believe that it started erupting years ago, gradually forming a dome that reached sea level.
The friendly giant You may have heard of the eruption of Mount Etna a few weeks ago. This volcano in Sicily, Italy is such a beautiful sight with its top capped in snow. At 3350 metres, it is Europe's highest active volcano. The height of its summit changes with each eruption. Over 1200 square metres of Etna's surface is covered with solidified lava. To the ancient Greeks, Mount Etna was the domain of Vulcan, god of fire, and the home of the one-eyed monster known as the Cyclops. Its crater was believed to be the mouth of hell. Etna offers skiing during Winter and hikes in the woods during Summer. Its slopes are home to various species of plant and animal life. Despite its look during eruptions, Mount Etna is not a killer volcano and is nicknamed "the friendly giant" for this reason. Its explosive eruptions are rare and close to its top, and the lava moves very slowly down its flanks, giving people a chance to escape. In its entire recorded history, which goes back to 1500 BC, only 73 confirmed deaths can be directly attributed to eruptions.
Volcanoes around the world Some of the well-known volcanoes in the world are Vesuvius in Italy, Mount Etna in Sicily, St. Helens in USA, Krakatoa in Java, and Pinatubo in the Philippines. Have you heard of Pompeii, the ancient city in Rome, which was completely destroyed when Mount Vesuvius erupted? On August 27, 1883, the volcanic island of Krakatoa blew itself up. Did you know that the explosions were heard 4,700 km (2,920 miles) by Australian farmers from Perth to Alice Springs? It is said that in Singapore which is over 800 km (500 mile) away, window frames rattled. In big volcanic explosions, black clouds of dust and ash are hurled into the air. The volcanoes of Hawaii and Sicily's Mount Etna are called 'quiet volcanoes'. This is because they contain fluid, runny magma and therefore 'quiet' volcanoes do not explode. Instead they emit long streams of blazing hot lava which often flows over great distances before it cools and hardens.There are volcanoes in the solar system too. The largest volcano is Olympus Mons on Mars. At 600 km (375 miles) in diameter and 26 km (16 miles) in height, it is larger even than the volcanic islands of Hawaii on earth!St. Helens erupted on May 18, 1980 killing 60 people. Unlike many other eruptions, this had been forecast for it was the most carefully studied volcanic event of all time. Scientists were monitoring the volcano from 1969.In March 1981, a small eruption occurred and in April one side of the mountain started to swell. Then in May it exploded. After the eruption, the height of the mountain was reduced by 400m (1,313 ft) and 600 square km (230 sq. miles) of land was devastated. |
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| Politics | Produced by Lake House |
Humans have faced death and destruction at the hands of Mother Nature
for years. Volcanoes, earthquakes and earthslips, tornados and hurricanes
and floods have wreaked havoc on the human as well as animal population of
the world. Some disasters like volcanoes are natural phenomena and cannot
be controlled or prevented by us.
