It is the viscosity of magma that largely determines the nature and power of an eruption and the resultant severity of the hazard. Basic magma has a high proportion of dissolved gases and low silica content, making it very fluid. On the other hand, acidic magma is very rich in silica and has a relatively lower temperature, making it very thick and slow moving. The more viscous the magma, the greater the potential for explosive eruptions and these represent the greatest potential hazards. Non-explosive eruptions tend to produce mostly lava flows, which do not represent a particularly serious hazard to people, however they will destroy farmland and buildings.
At destructive plate margins, the oceanic plate goes under the continental plate due to it’s more dense, which is a process known as subduction. The oceanic plate moves down into the mantle entre the benioff zone where it’s melted and destroyed because a pool of magma formed. The magma then rises through the cracks in the crust called vents and it erupts on the surface forming a volcano. There are also different types of volcano for examples composite volcanoes, shield volcanoes and dome volcanoes. For constructive plate margins, the magma rises up into the gap that created by the plate move apart to form a volcano.
Due to high temperatures in the mantle of around 3000 degrees centigrade, this oceanic crusts melts and then rises due to the convection currents in the aesthenosphere . As it joins with trapped seawater and sediment, it melts the overlying continental crust, and the magma plumes rise to the surface. They contain more silica so are more viscous, which plugs up the volcano, meaning pressure build up. This is why these volcanoes are so explosive. Another type of plate boundary are constructive, which is the margin between two diverging plates where new magma
This eruption was an explosive eruption. 8. At first, the surrounding area experienced many small earthquakes, which suggested possible magma movement. The magnitudes of the earthquakes increasingly got higher as the volcano got closer to erupting. Then, explosions of ash, rock, and ice became common everyday occurrences.
These include.... * The eruption had left destruction in its wake, it created a ‘Pyroclastic Flow’ or ‘Nuée ardente’ (Glowing Cloud). This is a cloud of volcanic debris, made up of solid, semi solid and hot, expanding gases. The cloud behaves like a liquid, flowing down the slope of the volcano. It can reach up to and above 100Km/h and so destroys everything in its path. The pyroclastic flow from Mt.
Less rainfall means there is less water to enter into the facility and transport radioactive waste. On the negative side there are three things which cause me an unsteady feeling. First, the mountain is in an area where there has been volcanic activity. Because of the activity strong gases have entered into the ground which could cause explosions to be destructive. Secondly, the area has several faults running through the area where the proposed facility was to be built.
Viscosity can be affected by three main factors, Firstly, the higher the temperature, the lower the density of the magma, causing it to flow more easily. Secondly, the greater the amount of dissolved gases in the magma, the less viscous it will be, and lastly the higher the silica content, the more viscous it will be. Thicker, more viscous magma has a greater potential for explosive eruptions and therefore represent the greatest potential hazards. The thickest type of magma is known as Acidic Magma. Its relatively low temperature, high silica content and leads to blockages and powerful eruptions.
Hoses can be undone, gaskets can fail, pits leak and liquids always hit the ground, repeatedly in large quantities. Fracking needs a lot of work to be done before it can begin obtaining oil. The fracking fluids have a lot of toxic chemicals and become even more contaminated when pumped down a hole as they travel through rock formations before returning to the surface as flow back. The liquids can cause ground contamination and even in small portions can contaminate shallow aquifers with hydrocarbons, toxic chemicals, heavy metals and radioactive
As the plate descends it causes earthquakes in the Benioff zone, and volcanoes occur here because of melting of the plate in the asthenosphere. These are the causes of this volcano, which is explosive because the lava is Rhyolitic, has high gas pressure and high Silica
Frequent collapses of lava-dome complexes, most recently in 1964, have produced large debris avalanches whose deposits cover much of the floor of the breached caldera. During the 1990s, intermittent explosive eruptions took place from a new lava dome that began growing in 1980. The largest historical eruptions from Shiveluch occurred in 1854 and