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Emma Watts (7316) Arthur Mellows Village College (22315) Introduction This dissertation is going to discuss the possibility of predicting volcanic eruptions, and how accurate the predictions could be. Predicting a volcanic eruption is very important as they can cause devastation through loss of life, loss of livelihood, and damaging the environment. However they aren’t as easy to predict as some people may think. Many factors come into the prediction of an eruption, which makes it very hard to predict, so each factor will be looked at individually using the following questions: How does the type of volcano affect prediction? What are the current prediction methods used across the world? How does the development of the country change how a volcano is predicted? How do peoples opinions affect the prediction of an eruption? Will predictions change with time? The dissertation will first look at how the type of volcano affects how an eruption would be predicted. However, due to each type of volcano having its own ‘fingerprint’ the study will focus on composite volcanoes, because overall many volcanologist believe (maybe find a quote to back it up?) they pose the most threat and therefore need to be predicted the most. As the dissertation I is focusing on composite volcanoes it will use specific case studies as examples throughout, including: Mt St Helens, Vesuvius, Nevado del Ruiz and the Aleutian Islands. It will then discuss all the current prediction methods and how they help professionals to predict the volcanic eruptions at the moment, using the different proportions of a variety of equipment in the United States, as an example to show which methods are more widely used. Then the study will go on to discuss how the development of a country can affect how a volcano is predicted, as previous eruptions have shown changes depending on the country, causing questions about whether some countries may predict volcanic eruptions more accurately or effectively. Following that the study will continue to look at how peoples opinions can change the outcome of predictions and what impact this can have on the environment and people in that area. The study will then explore why this happens. Finally it will discuss the possibility of how things may change in the future and if this could either develop or damage the prediction of a volcanic eruption. 1 Emma Watts (7316) Arthur Mellows Village College (22315) There are many questions to consider when looking at a volcano: what’s going on inside it, if or when will it erupt and how many people could it affect. These questions are all very simple to ask but unfortunately the answer is not as simple to find. However trying to predict the answers is very important as it could prevent fatalities and also help decrease the devastation it causes. By previous monitoring it is possible to predict an eruption in the near future due to professionals recognising a volcano being more active than usual. This then provides the volcanologists time to monitor the volcano and measure the potential threats that an eruption may pose to the public. According to Gislason et al. (2011) another reason why predictions are vital is the tephra (mainly ash) can cause mechanical problems within aircrafts. Being able to put out a warning to aircraft companies may not only prevent economic losses (due to machine malfunction) but also the possibly of death due potential crashes of aircrafts. A recent example of this being a problem is the eruption of the Icelandic volcano Eyjafjallajokull in 2010 ‘where some 10 million travellers were affected’ (Rincon, 2011). This means that prediction is more and more vital within the current times as it now not only affects people in the traditional ways but also affects people further afield due to technological advances. How does the type of volcano affect prediction? Different types of volcano can affect prediction of an eruption as each behaves differently. Some types, for example shield volcanoes, behave in an effusive way and some volcanoes such as Mt St Helens erupt in an explosive way (Dinwiddie, R., et al. 2011). Dinwiddie et al. then go Tephra is a term for relatively fine grained fragmented volcanic rock (Parfitt and Wilson, 2011:XX) and describe how effusive volcanoes tend to occur on a divergent plate boundary, whereas explosive volcanoes tend be on constructive plate boundaries. All volcanoes form on a plate boundary or hotspot and the distribution of these plate boundaries can be seen on figure 1. It then is explained how many of the volcanoes on the earth are situated around ‘the Ring of Fire’. This is an area where there is high volcanic and seismic activity. ‘The Ring of Fire’ isn’t quite a circular ring. It’s shaped more like a 40,000 kilometer (25,000-mile) horseshoe. A string of 452 volcanoes stretch from the southern tip of South America, up along the coast of North America.’ (National Geographic, 2013). 2 Emma Watts (7316) Arthur Mellows Village College (22315) Figure 1- Map showing tectonic plate boundaries (Simkin, T. et al., [2006a]) Effusive volcanoes erupt on a more regular basis and are rated very low on the VEI (Volcanic Explosivity Index), so prediction is more used to predict explosive eruptions rating around 5 on the VEI out of a possible 5, as the explosivity of them means that there tend to be more impacts. Many of these explosive volcanoes are situated around ‘the Ring of Fire, and as it VEI (Volcanic Explosivity Index) is a single number between 0 and 8 giving a combined measure of the magnitude and intensity of a volcanic eruption. (Parfitt and Wilson, 2011: XX) Destructive/ Convergent plate boundary - Eggar (2003) explains the destructive plate boundary, also called convergent is where two plates are colliding (an oceanic plate and a continental plate) and the oceanic plate gets forces under the continental plate as it is less dense and therefore weaker. This then causes pressure within the asthenosphere so the rock above begins to fracture and the magma rises; eventually it will fracture so much that there is a ‘path’ through the lithosphere to the surface, our ground. Slowly the magma (now called lava as it has broken the surface) builds up, cooling to form rock and over years a volcano is formed. Lithosphere is the outer part of a planet where the rocks behave as brittle solids, consisting of the crust and the upper part of the mantle (Parfitt and Wilson, 2011: XVii) Asthenosphere is the layer of the mantle immediately below the rigid lithosphere. It is sufficiently nonrigid to flow slowly in a solid state and plays a key part in allowing the movement of tectonic plates (Dinwiddie, R., et al. 2011: 346) 3 Emma Watts (7316) Arthur Mellows Village College (22315) consists of mostly convergent boundaries, composite volcanoes tend to form here. By knowing the type of volcano we can also look at the surrounding rocks, and by analysing these we can see what hazards have previously occurred and compare it to the type of volcano. After looking at these aspects, professionals can get to know the common hazards, magma and style of eruption, which enables them to look out for more specific signals before an eruption, as well as preparing for the hazards that usually occur with the particular type of eruption. This could prevent loss of lives and any other damage. This then helps the government predict an eruption as the more that is known about the past, the more the information can help predict what may occur now; this then means signs can be identified to help make predictions more accurate. Magma Magma is looked at, and judged on the rock type and its viscosity. Viscosity is affected by three main things: silicon content, temperature and gas content. Each factor affects the viscosity in a different way, as explained below (Dinwiddie, R., et al. 2011). They then go on to say that there are four different main rock types when looking at magma: Basalt, Andesite, Dacite, and Rhyolite, each forming in different places, creating different types of rocks once cooled. Magma can help predict a volcanic eruption as if the normal type of magma is known we can monitor it and compare it to samples that may be taken. There are a number of things that can be compared to help us predict a volcanic eruption. Viscosity is resistance to flow, in fluids (Dinwiddie, R., et al. 2011: 348) One of the things that are looked at is the magma temperature. As magma becomes liquid by increasing its temperature it therefore decreases the viscosity making it appear more ‘runny’. As you can see from figure 2, Basalt has the highest temperature, and also has the lowest viscosity, whereas rhyolite is the coolest and has the highest viscosity. 4 Emma Watts (7316) Arthur Mellows Village College (22315) Figure 2 - Classification and Flow Characteristics Of Volcanic Rocks (Johnson, 2009) Temperature is used as an indicator, if magma changes so would the temperature, the movement of magma to the magma chamber would raise the average temperature, so by looking at the change in temperature you could get a rough idea of how high the magma was in the volcano. This indicates whether an eruption is imminent. It is also used to predict hazards that may occur as the magma would be more dangerous if its viscosity is low as it can travel quicker and further so scientists and governments would be able to assess the viscosity of the magma beforehand and produce warnings to the people that it may affect. The water content also makes a difference in the prediction of an eruption. Water content in magma is very important when looking at a volcano. Schutt (2013) states that water enters the volcanic system when one plate (oceanic) is forced beneath another plate (continental). The oceanic plates are made up of sediment (which includes water), so as the pressure and temperature increases, new rock is formed and the water is released as steam. The gases begin to buildup, as they are trapped in the conduit, so this causes the pressure begins to increase. The pressure will suddenly be released (in an eruption) and the larger the change in pressure the more explosive the eruption will be. Due to different types of magma containing different amounts of water, the knowledge of how water affects a volcano helps us predict an eruption, as there is now an understanding where a change in gas pressure in a volcano can be seen before an eruption. This means that now we can monitor this, and not disregard it as just a coincidence, but actually analyse it and use the information constructively. 5 Emma Watts (7316) Arthur Mellows Village College (22315) Gas content tends to be the final component of magma that is accessed. Gas content is slightly linked to the viscosity of the magma but is linked closer to the explosivity of a volcanic eruption. In terms of viscosity; as the gas content increase so does the viscosity (Nelson, 2011).Nelson (2011) also explains that the explosivity is determined by gas content as gases tend to try to expand when pressure is decreased. This then means that if the gas is pushing outwards and there is a sudden release it will cause an explosion. This means by knowing the gas content of the magma contained within the volcano, it can affect predictions as it indicates how cautious to be during prediction (the more gas the more explosive and possibly the more prominent the eruption may be, meaning that people may be in more danger going to the crater to get data). It may also affect prediction as if it has a high gas content it may be leading to an eruption with a high VEI, which tend to be more destructive and dangerous, so may be looked at with more precision and more methods may be used to enable the best prediction possible. Prediction is affected by many factors and how these factors shape the prediction of an eruption is done in different ways. Some may be focused on when an eruption is predicted, others may persuade more in-depth assessments to be carried out or just whether continued monitoring is needed. Conversely, all these factors may interlink, with monitoring in turn leading to complex assessments being carried out and an eruption being more precisely predicted. What are the current prediction methods used across the world? Monitoring volcanoes is possibly one of the most important ways to predict a volcanic eruption; however this is not the only use for monitoring. The two main reasons for monitoring a volcano are to learn more about the internal structure of the volcano and look for signs of activity (Parfitt and Wilson, 2011). We have different prediction methods because not all volcanoes show the same warning signs as others. This is one of the reasons why it is very difficult to predict an eruption as we have to get to know each individual volcanoes’ warning signs. However the warning signs often change because a volcano doesn’t always erupt in the same way (Sparks, 2003). A variety of different equipment and machines may be needed to monitor one volcano as opposed to another. The United States is a great example of a country that uses a variety of monitoring instruments.Research by Guffanti et al.(2009) has shown the USA has around 1321 active instruments, as of December 2008, to monitor around 170 volcanoes. The United States uses 6 Emma Watts (7316) Arthur Mellows Village College (22315) 38 different types of monitoring equipment, as each tells us something slightly different, or has been made to suit specific locations. Guffanti et al. (2009) state there tends to be about ‘6 different categories’, all the types of instruments/methods can be arranged in. These categories are: ‘Seismic, Deformation, Geochemical, Hydrological/Metrological, Other Geophysical, and Visual’. The proportion of each different monitoring method used within the United States can be seen below in figure 4. Figure 3 -Percentages of instrument types used in United States in December 2008 (Guffanti et al., 2009) Figure 4 shows it is clear that there are many ways in which a volcano can be measured and observed. The majority of the instrumentation used is seismic (over 50%), second deformation (28%) (Guffanti et al., 2009) and then hydrological/ meteorological (14%). This percentage distribution could be due to cost, how simple they are to install or the detail of information they give. There are many reasons why people pick specific types of techniques and equipment and each depends on the type of volcano. The report will discuss some of the major methods, including what they tell us and how they help predict an eruption. 7 Emma Watts (7316) Arthur Mellows Village College (22315) Seismic Seismic equipment is used because normally there are always earthquakes leading up to an eruption, however, this isn’t always due to plate movement (USGS, 2013). Around a volcano there are normally around four seismometers all within a 20km radius of the crater. Generally earthquakes caused by a volcano will have a magnitude of around 2-3 and they are normally only around 10km from the earth’s surface. The IRIS (2012) state that the amplitude on a seismogram can be affected by three things: magnitude of the earthquake, the direction that the waves hit the seismometer, and the medium the wave travelled through.In soft rock (sediment) the wave is amplified, and in hard rock it isn’t. This then could help professionals identify where the tremor began and also helps them learn about the structure of the volcano, including the different layers of rock. There are many types of recognised waves some of which are shown below in figure 5. Figure 4 - Types of Volcanic Tremors (Montserrat Volcano Observatory, 2013) Volcanic-tectonic tremor These tremors are also known as an ‘A wave’. Chouet (1996) discovered them after looking at the Nevado Del Ruiz seismograms. He came to a conclusion which is now accepted worldwide that these tremors appear as high frequency, quick and sudden (see figure 5). Chouet stated these are waves from rock fracturing within the volcano. This happens due to the magma slowly pushing its way up the vents within the volcano, and even making new vents, which is why there are rocks breaking, causing tremors. These tremors often occur at the start of an eruption as the magma slowly makes is way up from the mantle into the volcano. This data can be used to help 8 Emma Watts (7316) Arthur Mellows Village College (22315) estimate how high the magma is within the volcano as the higher the magma the more prominent an eruption may be. Long period tremor Also discovered by Chouet, the long period tremor tends to be a quick starting, long lasting and low frequency tremor, see figure 5. He explained that what it shows us is that there are gases building up within the volcano and vibrating due to the pressure. This then might help determine how explosive the volcano may be as the more of these tremors the more gas there is within the volcano; the sudden release of this gas is what determines the explosivity of an eruption. Hybrid Earthquake Figure 5 shows hybrid earthquakes have a very sudden start but quite a low frequency. These are thought to be caused by magma forcing its way towards the surface. They indicate that a lava dome may be forming or even indicate that a current lava dome may collapse (Montserrat Volcano Observatory, 2013).This then helps identify what type of eruption may occur making the assessment more educated. There are also other types of tremors that have been discovered, indicating things including rock fall and mudflows, but the report has discussed the three above as they could help the most when predicting an eruption as they provide the best indications on how explosive it may be, how long it may be before an eruption and also whether a lava dome may be forming. These all play a vital part in the prediction of an eruption; however not enough is known about these tremors yet to just use this information to make the most accurate prediction possible. This is due to each volcano showing different amounts of seismic activity before an eruption and some showing very little at all, which means other information from different monitoring techniques can help give a clearer indication. Deformation Another aspect considered is ground deformation. It is when the ground tilts outwards, showing swelling, due to an increase in magma within the volcano. However this data can be tricky to use at times as sometimes the ‘movement of magma within a volcano may cause one part to deflate as another part is inflating’ (Parfitt and Wilson, 2011: 174). This then means that volcanologists may miss interpret the data and think that magma within the volcano is 9 Emma Watts (7316) Arthur Mellows Village College (22315) increasing when actually it isn’t, it is just moving. As with any measurement there is away a possibility of inaccuracies. Other methods of deformation include Global Positioning System (GPS) but a different type of GPS to what one would think, they actually use a Continuously Recording Global Positioning System (CGPS). This type of device is used worldwide but is used persistently in the United States, 292 were being used in 2008 (Guffanti et al., 2009). CGPS gives volcanologists a constant view of the volcano being monitored and as they are easily accessible over the internet. Volcanologists do not have to be there in person, which means they can monitor the volcano in a safer way than watching it up close. With CGPS it is possible to see changes in colour, texture or reflection this could be due to changes in the vegetation around it or something similar (Parfitt and Wilson, 2011). This will help prediction as the more the ground changes shape and moves, the higher the possibility that magma is rising. This means that it can help predict the size of the eruption, how prominent it is and also if it will affect mostly one side, for example the cryptodome of Mt St Helens 1980, erupting towards the north (USGS, 2013). Cryptodome is a body of magma that rises from depth and intrudes into the edifice of a volcano, but does not erupt on the surface. Cryptodome formation can results in a bulge or welt on the surface of a volcano. (USGS 3, 2013) Geochemical Geochemical tends to be the monitoring of gases, in particular CO2 (carbon dioxide) and SO2(Sulphur dioxide). There are a few ways to monitor these including someone going down to fumaroles and taking a sample of gas into a container and then taking it back to the laboratory for analysis (Parfitt and Wilson, 2011). Fumaroles are places where volatile components being released from the interior of a volcanic deposit reach the surface and settle to form deposits on the ground as they cool (Parfitt and Wilson, 2011: XV) However this can be extremely dangerous as the some of the volcanic gases are poisonous and also as they have been released from the surface they tend to be extremely high 10 Emma Watts (7316) Arthur Mellows Village College (22315) temperatures. This means people have to be willing to risk their health for the data. Parfitt and Wilson (2011) describe some technological advances in how to monitor gases released from a volcano. There is a method using mass spectroscopy and have been some new advances in this method in 2001. You can set a mass spectrometer to find many different things, including molecular mass, fragmentation patterns and also even to identify an unknown compound (Gent and Ritchie, 2007). The rise in gases emitted is thought to be related to how prominent an eruption is; as the more gas released the quicker the magma is moving within the volcano. Unfortunately this is quite time consuming, therefore only a small amount of readings can be taken over a period of time. Geochemical monitoring also includes fluid analysis. This means that crater lakes, hot springs, and even streams are monitored as quite often gases dissolve into them, so we can analyse the chemical makeup of the samples and tell if there has been a change (Guffanti et al., 2009). This then indicates whether there has been magma movement. Guffanti (2009) states the two reasons geochemical monitoring is used: to help predict an eruption, but also because the gases released are poisonous, and the health and safety of the local people needs to be taken into account. When monitoring a volcano, by using just one of these methods gives an indication on what is happening within a volcano When multiple data is considered, coming from different instruments and techniques professionals can gather a better view on what is actually happening, especially if they show similar things. This is why a number of different techniques are used and therefore the more techniques we discover and the more that is learnt about the previous eruptions and the warning signs before precursors (and how to spot them) the more accurate our predictions will become. How does the development of the country change how a volcano is predicted? There are many countries that monitor their volcanoes. However some do not and this can affect how well volcanic eruptions are predicted. LEDC’s (Least Economically Developed Countries) e.g. Columbia, can only monitor their volcanoes to a certain extend as they don’t have the money to get lots of equipment or to pay for volcanologists to monitor the volcanoes. This then means that the social affects tend to be a lot worse in an LEDC as there is no/very little prediction. Without prediction people don’t have any idea how imminent and what threats an eruption poses to the area, this means areas 11 Emma Watts (7316) Arthur Mellows Village College (22315) around the volcano aren’t warned so people don’t evacuate the area, often causing more loss of life and other social impacts such as loss of crops. MEDC’s (Most Economically Developed Countries) e.g. USA, Italy etc. monitor most if not all their volcanoes to an extraordinary level, using a variety of equipment. USA, being on ‘the Ring of Fire’, has around 170 volcanoes, and in 2008 it had about 1321 active instruments to monitor these (Guffanti et al., 2009). On average that is almost 8 instruments per volcano. This does mean that not all the volcanoes can be monitored to the same degree as some equipment needs around 8 of each located at different places around the volcano to give a clear result. This must mean that they decide to concentrate on some volcanoes more than others. As mentioned previously some volcanos erupt much more commonly than others so equipment can be transferred over to specific areas which show signs of change and activity. Overall, by not all countries looking at the same amount of data for each volcano, it reduces the understanding of the volcanoes around the world and also reduces the likelihood of finding a common link in triggers or signs before an eruption. This shows that the level of development within a country changes how an eruption is predicted as the more developed a country has more money and better education, meaning a higher understanding of Volcanology and more specialists within that area possibly leading to more advances in the prediction of volcanic eruptions. How do peoples opinions affect the prediction of an eruption? It is not always about just monitoring and predicting a volcano, this is pointless unless you are able to do something with it; save lives, habitats, wildlife etc. This means that even if we are are able to predict an eruption, unless we can make a difference with the information then there is no point in it. Some past eruptions when we have predicted an eruption to a fair degree of accuracy the information wasn’t used to benefit people as the government didn’t put out a warning or the information wasn’t taken seriously enough. A prime example of this is the Nevado del Ruiz eruption, Columbia. Columbia is an LEDC so didn’t have any monitoring equipment. This meant that volcanologists and geologists from other countries had to come in. A report was then made where it was stated that a moderate eruption would produce ‘…. A 100 percent probability of mudflows’. The government didn’t like this report however and said it was to alarming, and authorities did not want to evacuate until completely necessary, so no action was taken. This then cost 23,000 people their lives as lahars swept down the slopes and into villages and towns beneath (Mileti et al., 1991). This example shows that even if there is 12 Emma Watts (7316) Arthur Mellows Village College (22315) prediction and even a hazards assessment it does not mean that action will be taken, it then all comes down to the authorities to make a difference to the situation’s outcome. Will predictions change with time? Since Pliny the Younger witnessed the first recorded volcanic eruption in 79AD, where he recorded earthquakes occurring before the eruption there have been many changes in prediction (Oregon State University, 2013), but the recording is something that has not changed, other than now doing it in more detail. However, many more prediction methods are changing and being created throughout time, as technology and knowledge evolve. One of the latest advances would be Bernard Chouet’s discovery of the ‘A’ and ‘B’ wave. This has meant that volcanologists not only are able to understand what is going on within the volcano, but can also use their new knowledge to help predict when a volcano may erupt. By combining this with other data, their predictions become more accurate. As technology changes prediction methods become more accurate such as GPS has become more and more accurate over the years, so this means that changes on the volcano can be seen in more detail, helping further prediction as well as keeping the volcanologists safe. Decade Volcanoes As well as methods changing, committees may change the way we monitor volcanos. This could then change how different volcanic eruptions are predicted. An example of how time has changed which volcanoes are monitored is the decade volcanoes. The International Association of Volcanology and Chemistry of the Earth’s Interior (IAVCEI) have chosen sixteen volcanoes as ‘worthy of particular study’. These are also known as decade volcanoes. To be one of these volcanoes they had to fit into one of the following categories (Newhall et al., 2012). The chosen decade volcanoes are shown below in figure 6. Decade volcano qualifying categories (Newhall et al., 2012): 1. Must have more than one major hazard 2. Must be geologically active 3. Must be in a highly populated area (threatening over 10,000 lives) 4. Must be support for local work 5. Must have the basic requirements for someone to work there 13 Emma Watts (7316) Arthur Mellows Village College (22315) Figure 5 –The Decade Volcanoes, (National Geographic 2, 2013) These volcanoes were picked as they each fall into one of the categories mentioned previously. However many of them fall into more than one category, this means that if they erupted and the area wasn’t ready it could cause more damage than some other volcanoes so the IAVCEI believe it is important that we focus on these. Prediction is always going to be changing as the world around us changes meaning that different things are created and there need to be different areas of focus. Therefore we never know what may come when it comes to the science of tomorrow. What factor to look for before an eruption could be discovered that will enable us to pinpoint the minute it will erupt but then again it might never be known, it all depends on what happens in the future. Conclusion Volcanic eruptions are very complex, as there are many factors and things that can alter the system. With all of these variables, each volcano seems to be very unique: some change their eruption style (e.g. Vesuvius goes from Pilinian style to effusive), which changes the hazards that accompany the eruption. Some change physical factors e.g. a lava dome may grow as it did in Mt St Helens (1980), which then means different signals/signs of an eruption may occur; and some volcanoes just have no pattern at all (that we know of); which makes analysing the data from monitoring very difficult. 14 Emma Watts (7316) Arthur Mellows Village College (22315) This means that it is necessary to find as many monitoring techniques and study volcanic data, as we may find some triggers that have not been discovered yet. Then this could help us increase the accuracy of our predictions, just as much as Bernard Chouet’s discovery of the ‘A’ and ‘B’ waves did after the 1985 Nevado del Ruiz eruption. This one discovery revolutionised Volcanology and enabled prediction of an eruption to be a lot more accurate than previously thought possible. Therefore if we were to combine this data from seismograms with data from a new discovery (that also increases our accuracy of prediction) it could mean that we could possibly predict an eruption to the day. However this all comes down to technological advances and people spending time studying data. This then means the time before possibly predicting eruptions accurately depends on: the amount of volcanologists working on triggers to be found within the data; the time it takes for new technology to be produced, tested and then data to be collected from it; but it also depends on how many volcanoes are looked at and studied in detail. As there about 1500 active volcanoes in the world (Smithsonian Institute, 2013) and therefore it would take a very long time to study each one individually. This means if volcanologists what to be able to predict and eruption to a high degree of accuracy, they must make focus on specific volcanoes. However how these volcanoes are chosen is not always the most appropriate way as often it all comes down to which volcanoes are in countries with a high GDP (Gross Domestic Product) as they often have more money to put into research. This can spark up some ethical issues and discussions about whether the decisions on what volcanoes to monitor should be based on money or the possible impacts (for example loss of life, environmental problems health issues etc). Overall from the data analysed and by looking at past discoveries, it is very possible we may be able to predict volcanic eruptions to the day, whether that be in a year or one hundred years. However it does all depend on how much time is put into volcano measurement and what new technology comes along over the years. It may only need one mind to find a new way to predict an eruption but it may take thousands. This may never be known until an eruption is predicted accurately. From this study one way we to be able reduce the time before this happens is to concentrate on certain volcanoes, although this does bring the question of which volcanoes do we focus on. This has to be made by the leading volcanologists on which they think are the most important to monitor and which they think could bring the most information. All these things influence whether an eruption will ever be predicted to the day but on the whole so many things can happen in the future that nobody could know, and 15 Emma Watts (7316) Arthur Mellows Village College (22315) science is always changing and developing, and ever is such a long time that it is almost certain that accurate prediction is highly possible in the future. 16 Emma Watts (7316) Arthur Mellows Village College (22315) Glossary Asthenosphere is the layer of the mantle immediately below the rigid lithosphere. It is sufficiently non-rigid to flow slowly in a solid state and plays a key part in allowing the movement of tectonic plates (Dinwiddie, R., et al. 2011: 346) Conduit - A subterranean passage through which magma reaches the surface during volcanic activity (USGS 4) Cryptodome is a body of magma that rises from depth and intrudes into the edifice of a volcano, but does not erupt on the surface. Cryptodome formation can results in a bulge or welt on the surface of a volcano. (USGS 3, 2013) Destructive/ Convergent plate boundary - Eggar (2003) explains the destructive plate boundary, also called convergent is where to plates are colliding (an oceanic plate and a continental plate) and the oceanic plate gets forces under the continental plate as it is less dense and therefore weaker. This then causes pressure within the asthenosphere so the rock above begins to fracture and the magma rises; eventually it will fracture so much, that there is ‘path’ through the lithosphere to the surface, our ground. Slowly the magma (now called lava as it has broken the surface) builds up, cooling to form rock and over years a volcano is formed. Fumaroles are places where volatile components being released from the interior of a volcanic deposit reach the surface and settle to form deposits on the ground as they cool (Parfitt and Wilson, 2011: XV) Lithosphere is the outer part of a planet where the rocks behave as brittle solids, consisting of the crust and the upper part of the mantle (Parfitt and Wilson, 2011: XVii) Tephra is a general tem for relatively fine grained fragmented volcanic rock (Parfitt and Wilson, 2011:XX) VEI (Volcanic Explosivity Index) is a single number between 0 and 8 giving a combined measure of the magnitude and intensity of a volcanic eruption. 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