|when volcanoes erupt, causing the magma to rise above the earth's surface. When magma appears above the earth, it is called lava. |…
Volcanic eruptions happen all across the surface of the globe, many argue that if controlled and monitored they would have little effect on the population. However others argue that some volcanic events are too powerful or unpredictable to control.…
Coupled with these episodes were hundreds of small bursts or explosions of gas and steam. Mt. St. Helens has had four major eruptions and lots of minor ones. Volcanoes erupt due to the pressure of the magma and earth, and then erupts if a plate moves. Here is an image of the volcano before and after the eruption in…
The type of magma affects the severity and type of volcanic processes that occur because where there is basic (basaltic) magma, that is low is silica thus has a low viscosity, trapped gas bubbles are allowed to expand freely as they rise to the surface. This means the eruption fluid is free-flowing and therefore cannot suddenly erupt explosively. On the other hand, where there is acid (andesitic and rhyolitic) magma, the silica content is high therefore it has a high viscosity meaning gas bubbles struggle to expand and the magma often solidifies before it reaches the surface. These solidified sills and dykes cause a blockage that leads to a build up of pressure and eventually to a violent explosion.…
A volcano is an earth hazard that occurs on faults between tectonic plates on a destructive boundary and an eruption is a natural disaster. A primary impact happens immediately after the disaster and before any response like death or collapsing or destruction of buildings. A secondary impact occurs later after the disaster, such less farm produce or a reduction in tourism. The severity of these impacts will differ considerably in a MEDC and LEDC where volcanic eruptions have taken place. These may be seen in the Mount St. Helen volcano eruption as well as in the Iceland volcanic eruption. They may also show that the impacts vary from volcano to volcano, place to place.…
Mount st Helens caused fifty seven deaths compared to the Bam earthquake which caused over 25,000 deaths and 30,000 injuries. The earthquake in Bam in 2003 was the worst earthquake in Iranian hisrory and was situated in an overpopulated poor city in Iran therefore more people lost their lives. The eruption of Mount St Helens in 1980 Washington was situated in the Cascade mountain range so the area was very sparse therefore less lives were lost and also people were more prepared for this event because it is in a MEDC unlike the area in which the earthquake in Bam struck.…
On May 18th, 1980, in Washington State, the volcano, Mount St. Helens erupted. This eruption caused widespread terror throughout the towns surrounding the mountain. The magma from the volcano burned up the forest and killed most of the animals in the area. It affected the wildlife greatly because, after the eruption, the ecosystem was burned and smoldered thus killing thousands of animals in the region. This eruption was the deadliest of all the volcanic activity in the United States, and the people who live near the mountain are still affected by what the eruption did to this day.…
Volcanoes are formed on land near coastal areas when a continental plate and an oceanic plate converge. The oceanic plate submerges, due to its higher density, and is pushed deeper and deeper beneath the surface. The high temperature and pressures below melt the rock which creates hot, buoyant magma. Ultimately this magma rises towards the surface and accumulates in a reservoir, known as the magma chamber. The eruption occurs when the pressure within in the chamber surpasses the pressure of the upper rock, magma forces its way through the cracks in Earth’s crust. Magma that is low in gas and silicon dioxide produces thin quickly spreading lava which has a low viscosity, while a magma that is heavily composed of gas and silicon dioxide will yield a thick, viscose magma. The thicker magma builds up and because of this pressure, will cause a large…
Firstly, one place where tectonic activity occurs is at oceanic to oceanic constructive plate boundaries. Here two plates diverge or move away from each other, pushed apart by huge convection currents In the earth’s mantle. These convection currents are initiated by heat energy produced from radioactive decay in the earth’s core. As the convection currents move the plates away from each other, there is a weaker zone in the crust and an increase in heat near the surface. The hotter, expanded crust forms a ridge. Magma rises up from the mantle in the gap. The lava cools, solidifies and forms a chain of volcanic mountains thousands of miles long down the middle of the ocean eg. Atlantic. There are transform faults at right angles to the ridge. The movement of these faults causes rift valleys to occur. Examples of these landforms created by constructive plate margins are the Mid Atlantic Ridge (MIR) , and the Great African rift valley (GARV). The MIR is the result of the North American plate and Eurasian plate diverging in the middle of the Atlantic ocean. Here, volcanic islands such as Iceland, the Canary islands and ascension island have been created by the rising magma from the mantle. The GARV is an example of where the crust has dropped down between parallel faults to form rift valleys. As the crust subducts into the mantle it melts causing igneous activity below, magma to rise and therefore volcanoes erupt on the surface as a result. Evidence of this volcanic activity is shown by Mount Kenya and Mount Kilimanjaro.…
When volcanos form they form just like a regular mountains actually they are they are just regular mountains.That is why when they erupt it shocks many people because they all thought the possibility was rare.When the tectonic plates shift they cause a dramatic change in the mountain it causes molten rock to shoots up from the top of the mountain the molten rock just builds up and up until the top of the mountain erupts!It shoots out chunks of…
Scientist Ben Kennedy begun a very lengthy quest to solve the mystery of the shrinking pumice. This quest would eventually change the way scientists think about volcanoes-forever. One of the things (out of many) that he and his colleagues found out while on the road was that not only the rock was shrinking, the pores that make up the rock were shrinking as well. They think that this was due to the heating of the rock, and the molten rock's surface tension. What the scientist found was how some volcanoes function on the inside. In past years, volcanologists believed that flowing lava sinks back down and settles after an eruption, pressing on the magma below and crushing all of the bubbles, which makes pressure build up under the compacted lava. This leaves the lava sitting there...Until it explodes. Pow! This hints at why some volcanoes will go through cycles of flowing and explosive eruptions.…
Write an essay that explains how the Electoral College works. How does the Electoral College shape the strategy of candidates? Why is it harder to win presidential elections post 1968?…
Imagine you're one of the people that decide to ignore the officials warnings of an eruption on Mount St. Helens. It's May 18, 1980, 8:32 a.m. and you hear a rumble and feel the earth move. Behind you, you hear a thunderous noise. When you turn around, you see a humongous landslide headed your way. Mount St. Helens in Washington State has erupted, immediately a cloud of gas, rock, and hot ash shot up in the air and race down the mountainside at an unimaginable speed. The eruption created a mass of destruction, which effected many people locally and worldwide. The environment in the area was forever changed.…
While in class, we have learned many things about the earth and its elements that are within it. One thing about the earth that we have learned about is volcanoes. The text describes a volcano as a hill or a mountain that is constructed by the extrusion of lava or rock fragments from a vent (Plummer, 2007).…
Volcanic activity happens across the surface of the globe and naturally hazards occur too. It can be said that it’s easier to predict an event than prevent it, however prediction does have a positive impact on the effects of a volcanic hazard.…