21/12/11 at 12:38 am
A volcano is a pyramidical hillock; formed by the solidification of lava; the molten rock, oozing out of earth, under great pressure. Volcanoes are considered as extinct if they have no potential to erupt again, while they are regarded as dormant if they erupted in last 2000 years and are classified as active if they have potential to erupt any time in future. Both ‘Lava’ and ‘Magma’ are molten rocks of almost similar chemical composition containing minerals like; potassium, Sodium, Magnesium, Aluminum, manganese, Silicon, Iron and other trace elements. Lava and magma differ physically in that, ‘Magma’ is underground molten rock while ‘Lava’ is erupted red hot molten liquid or it may be gaseous at times. Depending upon the shape of volcanoes and their material composition, they are categorized into a few groups known as; Strato Volcanoes, Shield Volcanoes, Cinder Cones, Spatter Cones and Complex Volcanoes.
, located near Naples in Italy is the most known volcano on account of its catastrophic eruption in 79Ad. The eruption wrapped in volcanic ash, the whole ancient city of Pompeii, and mummified the city into a museum of sculpture. So sudden and severe was the calamity that people could not find time, even to change the postures. Time waits for none, except at Pompeii, where it stands still, in state. Pompeii was covered in huge layer of volcanic ash, preserving whole the city, for more than 2000 years
; the volcanic island of Indonesia, erupted in 1883, causing instant death of 36,000 people. It generated the loudest; recorded sound in history measuring 180 Decibels, which was heard in locations as far as SriLanka, 4500 miles away from the site of eruption. The volcano was situated at an elevation of 2,667 ft .high and sunk to 820 below sea level after eruption. Intensity of the explosion was estimated 13,000 times more than the atomic bomb which destroyed Hiroshima.
Located at a distance of about 100 kilometers, south west to Tokyo, Mount Fuji is the highest multi layered, and most picturesque Volcano of Japan. On account of its location at high altitude (12,389 ft), its peak remains covered with snow for many months of the year. Highest recorded temperature at the peak is 17.8 C, while the temperature falls below zero to the extent of _38 C in winter. The mount is visible from Tokyo and on a clear day be seen from as far as Yokohama. On account of its picturesque beauty, Mount Fuji is iconic to Japan and had been subject of arts since long.
Mount St. Helens
Named after the British Diplomat, Lord St.Helen; Mount St.Helen is an American, Volcano comprising of many layers of solidified lava. It is situated at about 96 miles from Seattle, Washington. It is known for its big eruption on May 18, 1980 at 8:32 am, instantly killing fifty seven people and destroying 250 homes, 47 bridges, 15 miles of railways and 185 miles of highways. The eruption; triggered by an earthquake of 5.1 degrees on Richter scale, caused lowering of the summit of the mountain from 9,677 to 8365 ft.
Located in the Italian island; Sicily at an altitude of 10,991 ft, Mount Etna is, for most of its part a shield volcano while some of the upper part is stratovolcano; comprising of different strata of solidified lava. Its height varies on account of eruptions and the consequent deposits. It is the largest active volcano in Italy and is about 2.5 times larger than the famous Mount Vesuvius. Its circumference at base is 140 Km. the Roman poet Virgil painted Etna, in the unsurpassed poetry ‘Aeneid’ stating the fury of Etna as, ‘To all invading storms; and Aetna’s throat with roar of frightful ruin thunders nigh…’.
Located in the South American province of Cotopaxi, the volcano is named after the name of the province and it is about 17 miles from Quito, Ecuador. It is 19347 ft high with 14 miles wide base. Historically, it is one of the most disastrous volcanoes and has erupted intermittently in the years 1534, 1742, 1768 and 1853. The1768 eruption destroyed the provincial capital Latacunga.Its most famous eruption however, occurred in June 1877. Smoke from volcano was seen from as far as Quito and the eruption caused the melting of glacier with consequent flow of Lahars, which comprised of ice and dirt. Mudflow was so fast that within 18 hours it reached the coastal town Esmeraldes.
Llullaillaco; located at the border of Salta province of Argentina is one of the tallest active volcanoes in the world. It has huge deposits of avalanche covered with snow around it. Last time it erupted in 1877.Three intact frozen mummies of children were explored from the 22,000 ft. high summit of Mount Llullaillaco in 1999 and amazingly their internal organs were found intact. It is believed that Incas sacrificed the children to please their gods and left them at the mountain top to freeze; to be unearthed after 500 years.
Kilimanjaro is a 19,710 feet high, snow-covered mountain. Kilimanjaro is the tallest mountain in Africa and if seen from freestanding point of view; it is the highest mountain in the world. The mountain peak; summit of Kibo, was completely covered with snow in 1880 however it is constantly depleting and it is estimated that with current rise in global warming, the peak will be deprived of snow completely by the year 2030.
Kilauea volcano is situated at the southeastern side of Hawaii at an elevation of 4,190 ft. It covers 13.7 % area of Hawaii. Mauna Loa volcano is situated in its immediate vicinity. It is considered one of the most active volcanoes of the world. In Mythology, it is regarded as the home of the Volcanic goddess; Pele. An eruption of the volcano that started in Jan 1983 continued for long time and produced 1.9 cubic kilometers lava, which covered 102 square kilometers area.
Mount Tambora is located on the island of Sumbawa in Indonesia, Its eruption in the year 1815 brought a catastrophic disaster, killing 117,000 people. Size and volume of Tambora was greatly reduced due to the discharge of huge quantity of lava from it, causing a huge crater on its peak. The eruption impacted the environment adversely, and to the extent that the volcanic smog destroyed the crops in the areas far and wide. This caused famine in Indonesia and on account of the volcanic smog, the year 1816 is remembered as the year without summer in Europe and North America. This event is taken as the worst disaster due to volcanic eruption in the recorded history.
Ever since the emergence of this world, it has been continuously subjected to natural calamities, mostly involving the volcanic eruptions. In fact the modern human beings are as vulnerable to the natural disasters as were the ancient human beings. There is lot of difference between the ‘protective equipment’ of both, but little; if any, in respect of ‘protection’. Nature keeps on showing its might and that it can exercise its authority, at will, when and where it considers necessary. The only way to prevent or at least minimize such occurrences is not to disturb nature, which unfortunately we are bent upon doing currently.