We live on a planet that is continually moving and changing. The earth’s surface is cool and solid but deep in the belly of our planet is a thick layer of hot, molten rock (Magma) that is always churning. Some of the most dramatic features of our planet are volcanoes, named after Vulcan The Roman god of fire. They are among the most powerful and spectacular forces on earth. They can build or destroy but where do they come from? There are two main ways that volcanoes are formed. First, volcanoes may form at the boundaries of tectonic plates. Such plates are sections of the earth’s crust that float on the layer of magma beneath, known as the mantle. Where two plates meet they may either pull apart allowing magma from the mantle to come up, or they may push together shoving some of the crust beneath to be melted into magma and pushing other pieces of the crust up to form new mountains. The new magma beneath the crust starts creating pressure, and once enough pressure has built up it can burst through the crust as an erupting volcano. The second way volcanoes may form is due to ‘hotspots.’ Scientists believe that when a volcano forms away from the edge of a tectonic plate, it is either because the mantle beneath is unusually hot or the crust in that area is unusually thin, allowing the magma to melt its way through to the surface. Magma that reaches the surface is called ‘Lava.’ Either way the result is the same, volcanoes.
THE FIVE BIGGEST VOLCANIC ERUPTIONS IN RECENT HISTORY ARE AS FOLLOWS:
Tambora
April 10, 1815
The Tambora eruption was the largest in modern history. According to the Global Volcanism Program, it was the only eruption in at least 1,000 years to rate a VEI (Volcanic Explosivity Index) 7. The eruption of Mt. Tambora in what is now Indonesia cast a veil of ash around the world, lowering global temperatures by more than 5 degrees Fahrenheit. The result was the “year without a summer” in 1816. A foot of snow fell in Quebec City, Quebec, in June. Crops failed worldwide in what historian John Post called “the last great subsistence crisis of the Western world.” The eruption is also tangentially credited with the invention of the bicycle, as the cost of maintaining horses rose, both because of the cost of oats and the death of many horses.
Krakatoa
Aug. 27, 1883
The obliteration of the Indonesian island of Krakatoa in a series of eruptions ending on Aug. 27, 1883, is, in many ways, the most famous modern volcanic cataclysm. The sound of the explosion was heard some 3,000 miles away, across the Indian Ocean on Rodrigues Island. The VEI 6 eruption created a tsunami 150 feet tall, and a ship 50 miles away reported being blasted by hurricane-force winds from the eruption. Volcanic ash blown high into the earth’s atmosphere circled the earth in two weeks, and its lingering effects for years afterward caused brilliant sunsets that inspired artists from North America to England. In recent years, some experts have posited that the dramatic sunset in Norwegian artist Edvard Munch‘s “The Scream” was inspired by the effects of the Krakatoa. Scientific study into how the Krakatoa’s ash spread, later led to the understanding of atmospheric winds worldwide, including the jet stream.
Novarupta
June 6, 1912
The largest explosion of the 20th century happened in such a remote area of the Alaska Peninsula that scientists trying to identify exactly which volcano erupted were mistaken for nearly a half-century. Only through studying local geology were they eventually able to pinpoint the eruption to Novarupta. The VEI 6 Novarupta eruption threw out more material than all other Alaskan eruptions in history – and 30 times more than Mt. St. Helens – a VEI 5 eruption. Across the Shelikof Strait on Kodiak Island, ash fell for three days, accumulating one foot in the main town. The eruption also caused the top of Mt. Katmai, some six miles away, to collapse. As the magma chamber under Mt. Katmai emptied through Novarupta, the weight of Mt. Katmai made it fall in on itself, forming a crater two miles wide and 800 feet deep.
Pinatubo
June 15, 1991
As the most recent VEI 6 eruption, Mt. Pinatubo demonstrated the role that science can sometimes play in limiting the damage of eruptions. Located in the Philippines on the island of Luzon, Mt. Pinatubo had not seen any major activity for at least 500 years. But thousands of earthquakes and minor eruptions through April and May of 1991 suggested that Mt. Pinatubo was likely to erupt. Further readings suggested that gases were building within the volcano, raising the possibility of a major eruption. Three evacuation zones were drawn up around the peak, and by the time the major eruption happened, some 66,000 people had been evacuated. Some 850 people were killed in the eruption, as compared with an estimated 92,000 after Tambora. Curiously, direct observation of the eruption was hampered by the fact that typhoon Yunya hit the island on that same day.
Santa Maria
Oct. 24, 1902
The least powerful of the VEI 6 eruptions recorded since the beginning of the 1700s, the Santa Maria eruption hit the Pacific coast of Guatemala. The 1902 eruption was the first in the recorded history of the mountain, spewing ash that was detected as far away as San Francisco. (THE CHRISTIAN SCIENCE MONITOR: The Five Biggest Volcanic Eruptions In Recent History, by Mark Sappenfield, April 18, 2010).
No serious student of history would be ignorant of the erupting volcano on the Island of Pompeii.
Around noon on August 24, 79 CE, a huge eruption from Mount Vesuvius showered volcanic debris over the city of Pompeii, followed the next day by clouds of blisteringly hot gases. Buildings were destroyed, the population was crushed or asphyxiated, and the city was buried beneath a blanket of ash and pumice. For many centuries Pompeii slept beneath its pall of ash, which perfectly preserved the remains. When these were finally unearthed, in the 1700s, the world was astonished at the discovery of a sophisticated Greco-Roman city frozen in time. Grand public buildings included an impressive forum and an amphitheater; lavish villas and all kinds of houses, dating back to the 4th century BCE, were also uncovered. Inside were some preserved remains of people sheltering from the eruption; others lay buried as they fled; bakeries were found with loaves still in the ovens. The buildings and their contents revealed day-to-day life in the ancient world—and stirred 18th-century interest in all things classical. (BRITTANICA: Pompei, Ancient City, Italy).
Scientists believe that right here in the USA, there is a dormant monster, the sleeping giant supervolcano of Yellow Stone National Park. That can erupt at any time and snuff out all life on planet earth. First, it would destroy America, and the Volcanic ash spewed into the atmosphere along with the poisonous gases produced would lead to the death of all wildlife and the destruction of vegetation. This cataclysmic event would block out all sunlight world wide thus enveloping our world in a nuclear winter that would last for at least a decade. Under such circumstances, no human life would survive. Scientists also believe that there is an Alaskan version of the Yellowstone supervolcano. Namely, the mountains of Cleveland, Carlisle, Herbert, Kagamil, Tana, and Uliaga are all tips of one gigantic magma chamber. If this supervolcano were to erupt it would also lead to worldwide catastrophe. “If their predictions are right, Alaska’s Aleutian Arc – the line of islands stretching across the Bering Sea towards Russia’s coast – could be harboring a monster on the scale of Yellowstone’s mighty supervolcano. The entire chain contains around 80 volcanos in total. Dozens of them have erupted repeatedly in recent history, too, so it’s no secret that it’s a geologically active part of the planet.” It is also believed that the eruption of this Alaskan supervolcano brought about the downfall of the Ptolemaic dynasty in Egypt and also the fall of the Roman Empire. (SCIENCE ALERT, Geologists Think They have Found An Alaskan Version of Yellowstone’s Supervolcano)
(TO BE CONTINUED)
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