'The extent to which volcanic processes represent hazards depends on where and when they occur.' Discuss this statement. Volcanic processes become a hazard when they impact upon the human and built environments, killing and injuring people, burying and collapsing buildings, destroying infrastructure and bringing agricultural activities to a halt. Volcanic hazards are influenced by several factors including location, time and frequency of eruptions, and the materials ejected. It is the viscosity of magma that largely determines the nature and power of an eruption and the resultant severity of the hazard.
I will be discussing factors that cause differences in hazards posed by volcanoes. I believe the most important factor is the location of a volcano and the type of volcano. The most explosive and therefore dangerous volcanoes are found on destructive plate boundaries (Over 80% of the worlds volcanoes occur at these boundaries) for example the eruption of the Nevado del Ruiz in Colombia on the 13th November in 1985 which killed over 25000 residents of Arenas and Armero. At destructive plate margins, the oceanic crust is denser than continental crust and is therefore subducts under the continental crust. 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 .
A risk assessment shows that the chances of a volcanic eruption in the next 10,000 years is 1 in 10, 0000 ("Volcanic hazard at," 2002). This region has had some volcanic activity within 12 miles of the Yucca Mountain. Some of the eruptions have caused some levels of magma. Because of the level of volcanic gases contained in the magma the eruptions have been explosive ("Volcanic hazard at," 2002). This could be a problem if an eruption was to take place at the Yucca Mountain or close by.
Discuss the Extent to which Tectonic hazards can be Monitored 40 marks Monitoring tectonic hazards involves being able to predict when they will occur and the extent of the damage they may cause and in this way we can prevent maximum harm taking place. When predicting volcanoes it’s important to look at their history of previous eruptions and the type of volcano. The most recent research was in time prediction using shock waves that are produces as magma reaches the surface which expands cracks or breaks the surface of the volcanic rock. This was partly successful in a Mexican eruption in 2002 of Popacatapelt. Using the history of eruptions allows us to assess what is likely to happen in the future, for example, in the eruption of Mt.
What is "summit deflation"? (page 94, para 2 to page 95) Summit deflation, which is measured by tilt meters in parts per million, is when the slope of a volcano changes usually relatively prior to an eruption. 4. How does Kilauea's magma move upward
7. The most recent major eruption of Mount Saint Helens was May 18, 1980. The eruption was so large, the whole north face of the volcano slid away. I can tell it was the north face, because the compass points north and that is where the face slid away. This eruption was an explosive eruption.
These include creating an exclusion zone around the volcano, being ready and able to evacuate residents and having an emergency supply of basic provisions, such as food. A study of the previous eruption history of a volcano is important in prediction, along with an understanding of the type of activity produced. At present, research is being conducted to see if it is possible to predict the time of an eruption accurately using the shock waves that are produced as magma
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.
DEMONSTRATE UNDERSTANDING OF A SIGNIFICANT EVENT IN THE CLASSICAL WORLD In the year 79 AD, a mountain in Italy called Mount Vesuvius erupted, the eruption is one of the most catastrophic and famous of all time. Surrounding Roman cites; Pompeii and Herculaneum, which were two densely populated towns located in the Bay of Naples were obliterated by the eruption. It is not known how many people the eruption killed. LOCATION OF THE AREAS AFFECTED BY THE ERUPTON This map shows the cities surrounding Mount Vesuvius, Pompeii, Stabiae, Oplontis and Herculaneum which were all destroyed during the eruption. This map also shows the area of the smoke plume from the eruption.
Where is the park located and what are its' dimensions? The base of the Cascade Range was constructed as the Earth's crust folded and uplifted, pushing the seas westward. Molten rock pushed toward the surface, creating both violent eruptions and forcing an incredible amount of lava upward through enormous cracks. Within the past 750,000 years these explosive eruptions built a string of volcanoes on this plateau base. This Cascade Range of volcanoes extends from Canada's Mount Garibaldi to Lassen Peak in northern California.