Analyse the factors that cause differences in the hazards posed by volcanoes around the world
Analyse the factors that cause differences in the hazards posed by volcanoes around the world (40 marks)
Your main factors can be put into two simple categories. Human and physical. From there you can then further explore the factors. In my essay I will mainly focus on viscosity, location, settlement and perception and explore how the physical and human factors intertwine with each other through one simple idea that physical factors dictate the hazard while human factors exacerbate the hazard. From here we must define a hazard. A hazard is a situation that poses a level of threat to life, health, property or environment in this case caused by a volcano. I will now analyse how the factors affect the hazards.
One factor that must be considered is the viscosity of the magma. The viscosity can determine how violent the eruption is and what shape the volcano becomes. Viscosity can be affected by temperature, dissolved gases in the magma and its silica content. High temperatures can make the magma less dense allowing it to flow more easily. The amount of dissolved gases lowers the viscosity. Lastly a high silica content will make the magma more viscous. Magma of a high viscosity can cause very violent eruptions. These pose the greatest threat as there very destructive. This is because it has a tendency to plug the volcano, trapping gasses which build pressure and eventually erupt violently. This can mean that the eruptions caused by thick magma can be less frequent and more difficult to predict, meaning that when an eruption does occur, it is usually with little or no warning, which can lead to catastrophic consequences as any nearby settlement will be relatively unprepared for the effects of a violent volcanic eruption. It also more likely to produce clouds of smoke and ash which can lead to suffocation and is a big killer during eruptions. You then have your thinner, less viscous magma such as AA or pahoehoe. It has a very high temperature, 950 C. It moves quickly due
Your main factors can be put into two simple categories. Human and physical. From there you can then further explore the factors. In my essay I will mainly focus on viscosity, location, settlement and perception and explore how the physical and human factors intertwine with each other through one simple idea that physical factors dictate the hazard while human factors exacerbate the hazard. From here we must define a hazard. A hazard is a situation that poses a level of threat to life, health, property or environment in this case caused by a volcano. I will now analyse how the factors affect the hazards.
One factor that must be considered is the viscosity of the magma. The viscosity can determine how violent the eruption is and what shape the volcano becomes. Viscosity can be affected by temperature, dissolved gases in the magma and its silica content. High temperatures can make the magma less dense allowing it to flow more easily. The amount of dissolved gases lowers the viscosity. Lastly a high silica content will make the magma more viscous. Magma of a high viscosity can cause very violent eruptions. These pose the greatest threat as there very destructive. This is because it has a tendency to plug the volcano, trapping gasses which build pressure and eventually erupt violently. This can mean that the eruptions caused by thick magma can be less frequent and more difficult to predict, meaning that when an eruption does occur, it is usually with little or no warning, which can lead to catastrophic consequences as any nearby settlement will be relatively unprepared for the effects of a violent volcanic eruption. It also more likely to produce clouds of smoke and ash which can lead to suffocation and is a big killer during eruptions. You then have your thinner, less viscous magma such as AA or pahoehoe. It has a very high temperature, 950 C. It moves quickly due