What caused the Soufrire Hills Volcano to erupt?

What caused the Soufrière Hills Volcano to erupt? The Caribbean island of Montserrat is situated on a destructive plate boundary. A plate boundary occurs when two of the plates that make up the surface of the earth meet. Underneath Montserrat the Atlantic plate is slowly being forced under the Caribbean plate. This happens because the oceanic plate is denser than continental plate. Convection currents pull the dense Atlantic plate into the mantle where intense heat and friction cause the rock to melt. This molten rock is lighter than the surrounding rock, forcing it to rise through cracks in the in the rock towards the earth's surface. Molten rock or magma gathers under the volcano until the pressure is so great that it is forced up through a vent towards the surface of the earth. The Soufrière Hills Volcano produces a thick sticky lava called andesite. The lava is so thick that it builds up at the top of the volcano in a dome until it becomes too heavy and the dome collapses. When the dome collapses hot rocks, gases and ash are released from the volcano causing the following hazards. Pyroclastic flows are extremely fast-moving flows of lava, hot rocks and gas that flow down the side of the volcano. Pyroclastic Surges are fast-moving clouds of hot ash that travel with the pyroclastic flow. Tiny pieces of volcanic ash are blasted into the air forming a plume of ash. As it

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Why do similar kinds of hazards have different impacts in different places?

Why do similar kinds of hazards have different impacts in different places? Similar kinds of hazards can cause a different scale of impact in different places due to many factors, the main influence being the countries economy. A hazard is an unexpected event or process which affects people, causing loss of life or injury, economic damage, disruption to people's lives or environmental degradation. A natural hazard could become a disaster when is has serious effects such as a large loss of life or property. The disaster risk has many factors which could increase or decrease the risk. This can be shown in an equation; Disaster Risk = Hazard X Vulnerability Capacity Hazard relates to the frequency of the hazard or the scale of the hazard, for example the magnitude of an earthquake, or the height of a wave. Vulnerability is the conditions determined by physical, social, economic and environmental factors which increase the susceptibility of a community to the impact of hazards. Capacity is the combination of strengths and resources available that reduce risk. Hurricane Katrina, 2005, New Orleans. Hazard: Hurricane Katrina passed east of New Orleans and winds downtown were in the Category 4 range with a minimum central pressure of 902 millibars and frequent intense gusts and tidal surge. 80 percent of New Orleans was flooded, with some parts under 15 feet of water.

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Marine Pollution

Marine Pollution I am writing to convince the UK Government that it is time to take action to protect the seas around us. The harm being done to our oceans is damaging in many ways - not least because with increasing speed, we are severely depleting the world's stock of fish. For four centuries the seas have been considered on inexhaustible resource from which people could take as much as they wanted. Now we have to face up to the fact that our oceans are not limitless - more and more people competing for less and less fish are which is making the existing crisis worse. Many marine ecosystems are at the point of collapse and will be destroyed unless we act quickly to protect them from the most serious threats. Pollution from ships Ships can pollute waterways and oceans in many ways. Oil spills can have devastating effects. While being toxic to marine life, polycyclic aromatic hydrocarbons (PAHs), the components in crude oil, are very difficult to clean up, and last for years in the sediment and marine environment. Discharge of cargo residues from bulk carriers can pollute ports, waterways and oceans. In many instances vessels intentionally discharge illegal wastes despite foreign and domestic regulation prohibiting such actions. Ships create noise pollution that disturbs natural wildlife, and water from ballast tanks can spread harmful algae and other invasive

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Sea Defence. Which is better: hard or soft engineering?

Which is better: hard or soft engineering? Hard engineering options tend to be expensive, short-term options. They may also have a high impact on the landscape or environment and be unsustainable. Hard engineering is the controlled disruption of natural processes by using man-made structures. An example of hard engineering is a sea wall, these walls are built on the edge of a coastline and made to protect the base of cliffs and also to limit the amount of coastal erosion on a cliff-face were land is being absorbed by the sea. These walls could also prevent coastal flooding. This type of hard engineering is good as it has many aspects and is effective. Disadvantages of creating a sea wall are that it is very expensive to build; the curves in the sea wall reflect the wave's energy back to into the sea, therefore the waves remain powerful. Another disadvantage is that the walls erode after time and the cost of maintenance is high. Another example of hard engineering is groyne, a groyne is a wooden barrier built at a right angle to the beach. Groynes are built to prevent the movement of beach material along the coast by long shore drift. This allows the build-up of a beach; beaches are a natural defence against erosion and also an attraction for tourists. Disadvantages of building a groyne are that it can be seen as unattractive and is also costly to build and maintain. A

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Decision Making how will we manage the Essex coastline?

Decision Making - how will we manage the Essex coastline? In February 1953 disaster struck Essex. The North Sea flood, a combination of high spring tide and a severe wind storm caused a storm surge. With the tidal surge of the North Sea the water level locally exceeded 5.6 meters. The flood and waves overwhelmed sea defences and caused extensive flooding. Essex, an area hit by subsidence and sea level rise relies highly upon sea defences. Most of the casualties occurred in the province of Jaywick, in Essex 307 people were killed and 22,000 made homeless. This flood also hit the Netherlands, which suffered 1,800 deaths. As subsidence and sea level rise grow worse due to global warming, there is a large chance that Essex if hit by a storm surge again will be very vulnerable. Essex is made especially defenceless as it has also been hit had by isostasy. And this is why I eager you to make a decision upon who we will defend our Essex coastline. There are several areas in Essex becoming increasingly susceptible to flooding. In order to protect these areas action must be taken. This plan provides a long term strategic view on how the balance between losses and gains to Essex can be maintained in the light of rising sea levels, and the flood defence response to it. The plan concludes that Essex cannot be maintained in its present form. Maintaining the present levels of flood

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Development is hazardous to natural and build environments

Developing country areas will decrease the amount of poverty throughout all of Asia, including the assistance to the countries economic growth. The development of road built infrastructure, water availability and aid will assist in the reduction of poverty. "Infrastructure development is a driving factor that can affect poverty negatively and positively. Infrastructure is important for poverty reduction. This can be the case where development aid, road construction or water and sanitary investments have been made with poverty reduction in mind." - (Environmental Knowledge of Change) The increased development and aid from more developed countries would help reduce the amount of poverty in many developing countries, also helping the population's health while helping to deteriorate the amount of poverty driven families. Economic growth can be helped by increasing the amount of contact within inland areas around Asia. "Rapid economic growth in recent years has put enormous pressure on Asia's transport, energy, and communications infrastructure. Unless these can be improved, they will continue to be a bottleneck to growth...Better connectivity with inland areas, for instance, would boost trade and economic growth in both coastal areas and inland...Following the 1997-1998 Asian financial crisis, countries with significant investments in infrastructure recovered faster than

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Describe and explain the economic and social costs and benefits of ageing and youthful populations

Describe and explain the economic and social costs and benefits of ageing and youthful populations Ageing populations usually shows that a country is an MEDC, which of course is a good thing. It shows that medical care is very good, diseases are low, diets are nutritional and that there is a good standard of living. The benefits of having lots of elderly people is that the death rate is lower, some provide a service for the country if they are still working and often they are involved in politics using their wisdom to help the country, so in an MEDC an ageing population can be a good thing. However if they are too many elderly then problems start to develop. After all the elderly are part of the dependant population and most, although some do, don't have jobs and contribute to the country and its economy. They do not pay taxes because they are not earning and so just take money from the country in the form of state pensions and other social security benefits. The young and active population therefore has to work hard to support the dependant population so that they can obtain their pensions. However if there are too many elderly people then the country, for example the United Kingdom, which has an ageing population will become very strained. They are too many elderly dependant people to support, this occurs when the active population cannot equal by working the amount of

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Why did so many people die in the Kobe Earthquake?

Why did so many people die in the Kobe Earthquake? Kobe is a major city in central Japan, its population is 1,528,948. It is situated on a minor fault, the Najima fault line. It lies above a destructive plate margin, hence why Japan has so many volcanoes. At 5.46pm, 17th January 1995 an earthquake measuring 7.2 on the Richter scale and lasting for 30 seconds, struck Kobe. This colossus earthquake was caused by "The Philippines plate" and the "Pacific plate", (Oceanic Crust) getting forced downwards when pressure was applied to it by the Eurasian plate (continental crust). The seismic waves caused by the plates rippled through the earth's surface. As well as causing earthquakes these events can cause Volcanoes. The magma rises out of the earth and out of the cracks which have been formed. Although this earthquake may seem big, it is still relatively small compared to the ones that the American people have to endure in San Francisco and California. These one's reach 8-9 on the Richter scale! They are located on the "Ring of fire", which also lies above a destructive plate margin. As you may or may not know, Japan is basically an island made up of volcanoes sticking out of the ground. This means there is very little flat land other than at the base of the volcanoes. Due to this, it is very crowded and congested. Believe it or not the population Of Japan is 124

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Earthquakes in MEDC's and LEDC's

A well-known principle states that the impact of earthquakes in LEDC's or Less Economically Developed Countries is generally more severe when compared with MEDC's or More Economically Developed Countries. This shall be illustrated by comparing the Kobe Earthquake in Japan of 1995 with the Kashmir Earthquake of 2005. The Kobe Earthquake occurred on Tuesday, January 17, 1995, at 05:46 JST in the southern part of Hyogo Prefecture, Japan. It measured 7.2 on the Richter scale and lasted for 20 seconds. The duration of the tremors was around 20 seconds long. The focus of the earthquake was located 16km below the epicentre, on the northern edge of the Awaji Island, approximately 20km from Kobe. The proximity to the city was a major factor of its widespread devastation. The ground moved 18cm horizontally and 12 cm vertically. The Kashmir Earthquake was caused by the Eurasian and Indian tectonic plate boundaries colliding. Its epicentre was located in Azad Kashmir near the city of Muzaffarabad. It occurred at 08:52:37 Pakistan Standard Time (03:52:37 UTC) on 8 October 2005. According to the authorities, 79000 people died. A major factor in the severity of the earthquake was the poor construction - a salient feature of LEDC's. The Indian Plate which was moving 40 mm a year north collided with the Eurasian plate and was forced beneath it. It measured 7.6 on the Richter Scale. As is

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Debden Brook Rivers Cousework Analysis and Conclusion

Analysis and Conclusions In this section I intend to analysis my results and state whether my hypothesis were verified (proved correct) or nullified (proved incorrect) I will provide reasons as to why by showing a detailed analysis of actual figures from my graphs. In the second part of this section I will evaluate the results by looking at factors that could have affected the accuracy of my results and conclusions i.e. limitations. I shall look at ways in which my methods might have been improved. I must also look at the Bradshaw model and see if the characteristics of this specific river follow the general trend of his model. Hypothesis 1 - The Width of the River Increases with Distance Downstream This hypothesis was proved correct because figure one shows that the width of the river steadily increases with distance downstream. The water width of the river increased from 0.83m at site 1 (Debden Brook) to 1.95m at site 2 (Debden Brook) and 8.53m at site 3 (The River Roding). This is because streams generally carry more water in their channel as distance from the source increases because water is added to them from tributaries, however there are some exceptions (e.g. The River Mersey due to human activity). This will also increase lateral erosion as the water will be moving faster and carrying more load. As a result, the width increases. This hypothesis corresponds

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