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. Ash clouds are explosive eruptions that blast solid and molten rock (called tephra or pyroclastics) into the air with tremendous force. Ash clouds pose a considerable threat to aircraft, can cause buildings to collapse and can also cause death by asphyxiation. Pyroclastic flows are a potential product of volcanic activity; clouds of incandescent gas, ash and rocks with temperatures up to 800°C and speeds of over 200kph. They can cause widespread destruction, such as the 1980 eruption of Mt St Helens.
To what extent to you agree with the view that the hazards resulting from earthquakes and volcanic activity cannot be managed but merely adapted to. Earthquakes and volcanic activity are both nature disasters that human can’t control when or where it will happen and it may cause lots of death and economic loss. There is no way that we can stop it from being happened but we can definitely try to adapt it by many different ways. Firstly, volcanoes are found at destructive and constructive plate margins. 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.
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 .
Secondary Vents are extra vents that the lava seeped through Secondary Cones are built by lava and are on the volcano. The risks to people and property from volcanic eruptions are being destroyed by lava. Some risks to people are suffocation to the gas cloud. You can predict volcanic ruptures because there will be ground shaking, increase in temperature and the Earth’s surface will began to bulge. What role have volcanoes played in the evolution of life on the planet?
A natural hazard is a natural event that has the ability to adversely affect people and their property. In an earthquake the primary hazard is the ground shaking which leads to injury or loss of life. Although humans have no control over the duration of time that
Damage: 2-3 specific examples of structural damage (earthquakes); areas covered with volcanic debris (volcanic eruption); any other types of damage 9. Were there any mitigation methods in place (building codes or warning systems)? 10. How did the government respond to the event? International aid?
The scale or better known as magnitude of the earthquake effects these characteristics and determines the physical destruction. The local geology of the area such as whether building on reclaimed land can have huge toll on building destruction and impact on hazards. Along with this the proximity of the earthquake to the coast can have a huge impact on the hazards. If the earthquake occurs out at see the tsunamis can be just as devastating if not more destructive than the earthquake. It would result in services being unable to reach areas due to the flooding and many more lives could potentially be lost.
Analyse the factors that cause differences in the hazards posed by volcanoes around the world (40 marks) A hazard is a situation that poses a level of threat to life, health, property or environment, all of which can be compromised by a volcano. A volcanic eruption can cause many deaths, illnesses, destruction of property, crops, and livestock, also the economy of an area may be affected, amongst other things. However, there are many factors involved which can cause differences in the severity of destruction caused by a volcano such as, settlement, monitoring, plate boundaries and the economic status of a country; which would be different for every single volcano around the world. One factor that would cause differences in the hazards posed by volcanoes is settlement, which includes where people chose to live in relation to a volcano. For example, in Indonesia many people settle near Mount Merapi because of the rich and fertile soil favoured for farming.
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.
They grow by piling up lava and ash into cones with steep-sided slopes, which are prone to collapse as massive landslides known as debris avalanches. The 1980 debris avalanche at Mount St. Helens literally opened a new chapter in the study of volcanic hazards. Debris avalanches were an under-appreciated hazard prior to 1980. More than 200 prehistoric debris avalanche deposits around the world were recognized because of observations of processes and resulting geologic features at Mount St. Helens. For example, the origin of puzzling, hilly volcanic deposits near Mount Shasta and Mount Rainier became clear.