Today we talked about igneous rocks, the type of rock that forms when rock matter is melted down and then cooled. Igneous rock can form underground but when it comes out of the ground it forms volcanoes. The largest mountain in the world, if you’re looking at it from the bottom of the ocean floor, is Mauna Kea, an island in Hawaii (source). Whenever a volcano erupts it produces lava, which cools into different types of igneous rock.
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Research one of the following volcanoes and, in your own words, tell the story of how it erupted and what consequences it’s eruption had on the local environment. We will be using Wikipedia today (and today only!).
14 comments:
I chose Krakatoa, a volcanic island formed by lava. It is between the islands of Java and Sumatra and belongs to Indonesia. There was a volcanic activity there August 26-27 1883, and it had a VEI of 6. This meant that it was one of the most violent volcanic activities in recorded history and also meant that it was 4 times stronger than the largest nuclear weapon detonated by far. It impacted 21 Kilometers, cubed. Also, it could be heard almost 2,000 miles away, in Western Australia. 165 towns and villages were destroyed, and 132 were damaged seriously. 21,007 people died (approximately) and many died, most of them from following tsunamis. It destroyed two-thirds of the island.
Mount Vesuvius is found on the Bay of Naples Italy and is the only volcano within the European mainland to have erupted within the last hundred years. Mount Vesuvius is regarded as one of the most dangerous volcanoes since it's eruptions are explosive and has caused thousands of deaths in the past.
I chose to do my report on an icelandic mountain called Eyjafjallajökull a.k.a E15. E15 is a small ice cap in iceland in-between Skogar and Myrdasjokull. The climb to the summit is 1,666 meters. E15 flows into many outlet glaciers it flows through 3 more glaciers before reaching the final one named Steinholtslon which is the 6th largest glacier in Iceland. On the 15th of january in 1967 a large explosion happened on the glacier which people have timed with and earthquake on another volcano. E15 is nourished by a magma chamber which is located under the mountain. The volcano is part of a chain that go's across iceland the closest active volcano is Katla who's explosions normally follow the ones of E15. The first documented eruption of E15 started in 1821 and ended 2 years later in 1823 (altho there were 2 other eruptions before that in 920 and 1612). The eruption was only minor and caused little damage. The most noted factor of this was the ash that came out held a large amount of fluoride which can cause harm to bone structures for humans and animals such as horses and sheep. The first phase of eruptions began on December 19 1821 and continued over the next couple of days. The people described it as having very heavy ash falling around the south-west. The series of eruptions became less and less after the first one up until june when the next group of explosions happened and much more violently this time shooting columns to extreme hight. The only deaths that came out of this explosions were ones of sheep and cattle. Things calmed down, then sometime in 1823 there was a group of men who went up the side of the volcano and came across a fissure vent close to the summit. Then a few months later the next volcano exploded at the same time that steam was coming out of E15. Now fast forward to December 2009, over the years between 1823 and 2009 no real eruptions had been seen out of E15. So in December some seismic activity was noted around the area and thousands of mini earthquakes (most below the magnitude of 3) about 8 kilometers under the volcano. Then on the 26th of February more abnormal seismic activity was detected with extremely rapid expansion happening too along the Earths crust. Geophysicists found strong signs that magma had been leaking under the crust and had found its way into the magma chamber. The pressure from those actions cast causing very bad crystal displacement at Porvaldseyri farm. He activity of E15 continued to get worse and in between march 3 and 5th an estimate of 3,000 earthquakes took place at the epicenter of E15. People think that the eruption began on march 20th 2010 at about 8 kilometers east of the top of E15 on Fimmvorduhals the "neck in the middle of e15 and the ice cap "Myrdalsjokull". In a form of a fissure vent the first eruption happened but did not occur inter the glacier and was much small than was anticipated. After almost a month of relaxation of E15 on the 14th of April the volcano started to erupt again but this time from the top crater directly in the glaciers center this action caused meltwater floods that rushed into the closest rivers which caused 800 people to be evacuated. The April 14th eruption was about 15 times larger then the one before it tossed ash several kilometers into the atmosphere and that started air travel disruption around northwest Europe for 6 strait days. Another problem the eruption caused was electrical storms. so finally on May 23ed, 2010 the London Volcanic Ash Advisory Commission told the public that the eruptions had stopped yet they still are tracking the volcano with a close eye because E15 still has several earthquakes every day. Eyjafjallajokull (like every other volcano) is considered dormant after three months of no volcanic activity.
I chose Mt. Saint Helens, It erupted on May 18, 1980, The reason why it erupted was because it experienced a magnitude 4.2 earthquake on march 20th and started venting, by the end of April the mountain started bulging, on May 18th it experienced a 5.1 magnitude earthquake which is when it erupted, it destroyed a total of 3,900,000 cubic meters and destroyed some 200 homes.
Mt. Etna is unlike other volcanoes in the fact that it has numerous eruption points. One of the most common eruption points is the summit but those aren't very dangerous. However when there is a 'flank eruption' lava can appear in areas very close to cities or towns from one of 300 vents. There has been only one case when Etna has proved dangerous. On November 1928 vents appeared very low on the volcanoes flank. Downhill of the vents was a town called Mascali. It was destroyed in two days. Along with the town a section of a near by railroad and Mascali's train station was also destroyed.
The island of Krakatoa is located in the Sundra Straits between the islands of Java and Sumatra off the southwestern coast of Indonesia. Krakatoa is one of many active volcanoes along the Indonesian Island Arc, including the famous Tambora volcano. This arc, containing over 130 active volcanoes, is produced by the subduction of the Indo-Australian plate as it moves northward towards mainland Asia.
The island of Krakatoa itself is lies next to two other islands: Lang and Verlaten. These three islands together are the remains of an ancient volcanic island. Ancient Krakatoa, as it is called, exploded in an enormous eruption around 416 A.D., according to Javanese scriptures. In that eruption the majority of the island collapsed into a 7km long caldera beneath Rakata on Krakatoa forming the three present day islands.
The map on the right shows Krakatoa as it was before the great eruption of 1833. Three major volcanoes existed on the island, Perboewetan, Danan(not shown but in the middle), and Rakata. Since the eruption and collapse of Ancient Krakatoa the chamber beneath these three volcanoes had begun to fill, heat up, and create enormous pressure. Of late, Perboewetan had been the most active.
Mount Pelée is in the northern tip of the French "overseas département" of Martinique in the West Indies, Caribbean. The volcano was formed subduction zone, were one tectonic plate goes under another tectonic plate. In 1902 on may 8th Mount Pelee exploded, killing about 30,000 people. Mount Pelee exploded near a small town called St. Pierre destroying everything with in minutes of the eruption, only three people survived! In the beginning of october 1902, a volcanic spine started to grow, reaching the maximum height of 1,000 ft, it became unsteady and collapsed. Even before then in the 1900 the volcano would have volcanic ash come out, nobody thought it was a big deal because it did this many times. Today mount Pelee is being watched very closely by volcanologists, it is still active, and likely to erupted again.
I chose Mount Vesuvius not only cause it is a cool subject to study but that I went to Spain and saw the volcano in person.
In AD 79 Mount Vesuvius erupted and complete buried the city of Pompeii 600 sheep were killed because of the poison gas and ashes that were hoovering around the area. The eruption caused massive destruction on the Naple Bay area. Mount Vesuvius had not erupted since 1944.
I chose mount st. Helen it had been famous for its catastrophic eruption and had killed a good number of 57 people and 250 homes.
This mountain has erupted over 50 times since the eruption in 79 A.D. The volcano repeated to erupt every 100 years until about 1037 A.D. In 1631, the volcano killed an extra 4000 innocent inhabitants. Before Mount Vesuvius erupted on Pompeii, Italy, it erupted in an even more powerful explosion that affected the area opccupied by present-day Naples. It left the region a desert wasteland for centuries. it covered everything in ash and left plants and animals to die but not only plants and animals but people practically everyone died in this eruption.
Mount Vesuvius
By the 1st century Mount Vesuvius, had number of towns located around the base of the volcano, including Pompeii. Many people lived at Pompeii because of the good agricultural soil. By coincidence the eruption was the day after Vulcanalia, the festival of the Roman god of fire.
When Vesuvius erupted at surrounding towns heat was the main cause of death of people, previously supposed to have died by ash suffocation. Exposure to at least 250 °C hot surges at a distance of 10 kilometers from the vent was sufficient to cause instant death, even if people were sheltered within buildings. I think this was one of the most famous eruptions of all time.
Mount Etna is an active volcano.it is the Largest active volcano in Europe.its about 10,922 ft. this volcano is very active. It has multiple eruption points. There have been at lease 60n flank eruptions since 1600 A.D. In 1669 violently erupted and destroyed villages. it killed 15000 people.IN 2007 erupted spiting lava into the air.lasting for 6 hours. this eruption was caused by the Southeast Crater.
Located in Skamania county Washington
Mount st Helens is most well know for its exspotion may 18 1980
The deadliest most destrctive in history
The expotion killed 57 people, and destroyed 250 homes 47 brideges 15 mils of railrde and 185 miles of highways
all because of mout st helen
Mt Etna is located in Sicily, Italy. It has multiple eruption points. The most violent eruption occurred in 1669 when it destroyed small local villages and part of a town. The eruption killed 15,000 people. Also in the 1970s and the 2000s the mountain erupted smoke rings. Footage of some eruptions was captured by Lucasfilm and used in the landscape of Mustafar in star wars Episode III:Revenge of the Sith.
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