Why do people still continue to live near volcanoes ? (Section 3)

Why do people still continue to live near volcanoes?

At first it may seem odd that people would want to live close to a volcano. After all, volcanoes have a nasty habit of exploding, discharging liquid rock, ash, poisonous gasses, red hot clouds of embers, and generally doing things that kill people. Yet, throughout history, people have deliberately chosen to risk all those hazards and live near them, even on the slopes of active volcanoes that have erupted within living memory.

They chose to live close to volcanoes because they felt that the advantages outweighed the disadvantages. Most volcanoes are perfectly safe for long periods in between eruptions, and those that do erupt more frequently are usually thought of, by the people who live there, as being predictable.

In short, the main things that attract people to live near active volcanoes are minerals, geothermal energy, fertile soils and tourism.

Minerals

Magna rising from deep inside the earth contains a range of minerals. As the rock cools, minerals are precipitated out and, due to processes like the movement of superheated water and gasses through the rock, different minerals are precipitated at different locations. This means that minerals such as tin, silver, gold, copper and even diamonds can be found in volcanic rocks. Most of the metallic minerals mined around the world, particularly copper, gold, silver, lead and zinc are associated with rocks found deep below extinct volcanoes. This makes the areas ideal for both large scale commercial mining and smaller scale local activities by individuals and small groups of locals. Active and dormant volcanoes have the same mineralisation, so like extinct volcanoes, they are rich sources of minerals. Hot gasses escaping through vents also bring minerals to the surface, notably sulphur, which collects around the vents as it condenses and solidifies. Locals collect the sulphur and sell it.



Geothermal Energy

Geothermal energy means heat energy from the earth. It's unusual to use the heat directly, by building your house on top of a steam vent for example, because it's unpredictable, dangerous and messy. The heat from underground steam is used to drive turbines and produce electricity, or to heat water supplies that are then used to provide household heating and hot water. Where steam doesn't naturally occur it is possible to drill several deep holes into very hot rocks, pump cool water down one hole and extract steam from another hole close by. The steam isn't used directly because it contains too many dissolved minerals that could precipitate out and clog pipes, corrode metal components and possibly poison the water supply.

Fertile Soils

Volcanic rocks are rich in minerals, but when the rocks are fresh the minerals are not available to plants. The rocks need thousands of years to become weathered and broken down before they form rich soils. When they do become soils though, they form some of the richest ones on the planet. Eruptions produced very thick deposits of ash and broken rocks which have weathered to rich soils. Today, the area is intensively cultivated and produces grapes,vegetables, orange and lemon trees, herbs, flowers and has become a major tomato growing region.

Tourism

Volcanoes attract millions of visitors every year, for different reasons. As an example of the wilder side of nature, there are few things that can beat seeing an erupting volcano blowing red hot ash and rock thousands of feet into the air. Even the less active ones that are just puffing out steam and smoke are impressive sights and attract tourists from around the world. Around the volcano may be warm bathing lakes, hot springs, bubbling mud pools and steam vents. Iceland markets itself as a land of fire and ice, attracting tourists with a mix of volcanoes and glaciers, often both in the same place. The wild, raw and barren volcanic landscapes also attract tourists who want to see what the early planet may have looked like. Tourism creates jobs in shops, restaurants,hotels and tourist centres / national parks. Locals economies can profit from volcanism throughout the year, whereas skiing, for example, has only a limited winter season.

Instruments Used To Predict A Volcano's Eruption

For Volcanologists, they use many instruments to predict eruptions such as:

A seismometer / seismograph

 

A seismometer (or seismograph) is a sensor that detects the intensity of earthquakes caused by magma that is moving. It has been around for almost 2,000 years. The first seismograph was invented by a Chinese scientist. It looked like a large jar with dragon heads on every side. Each dragon had a metal ball in its mouth, and when an earthquake struck, one of the balls would drop into the open mouth of a toad sculpture below. By looking at which ball dropped, Heng (the inventor) said he could tell from which direction the earthquake came.

Luigi Palmieri invented a seismograph in 1856 while working near Italy's Mt. Vesuvias. He wanted a way to predict eruptions, and knew that tremors were usually felt before an eruption. The seismograph uses a pendulum to record movement of the ground below it. The squiggly lines recorded on paper by a seismograph are called a seismogram. A Gravimeter

Since magma gives off electric currents, electric meters are used tospot rising magma levels by measuring its electric current. Gravimeters can also detect flowing magma.

A Landsat Satellite

Scientists also take temperatures and gauge gas by using a Landsat satellite. The satellite uses infared sensors to detect temperatures and changes in volcanoes. Aircraft monitors the amount of gas released from the ground. An increase in sulfur dioxide and other gases usually means that there could be volcanic eruptions.

A Tiltmeter 

The tiltmeter is a sensor that uses a laser beam to find the rising or lowering of magma levels by measuring changes in ground elevation.

GPS

GPS (Global Positioning System) is a method to determine position of locations on Earth. It uses satellites that broadcast a signal and receivers that pick up and record the signal. GPS uses the relationship between velocity, distance, and time (velocity equals distance divided by time). With GPS, the velocity is the speed of light. Knowing the velocity and time (and the position of the satellite) allows the distance to be calculated. As magma moves up into a volcano the volcano swells and distances between points on the volcano increases (think of dots on a balloon) and the elevation at specific points increases. Such a change is a common occurrence prior to an eruption.

Volcanologists use these instruments to successfully predict eruptions which saves many lives. Scientists are trying to develop new ways to predict future eruptions.

    (Source:  http://library.thinkquest.org/J003007/Disasters2/volcano/predicting/predict.htm)

For the ordinary people, they can predict a volcano by:

1. Looking  for plumes of smoke or clouds of gas on or around the volcano that aren't typically there. As magma flows into the chambers beneath a volcano and rises to the surface, it can cause different gases to be released, which geologists keep a close eye on for changes in quantity or composition.

2. Looking out for any changes in seismic activity near the volcano. Many volcanoes continuously give off rumbles or tremors, but a sudden increase in the number or strength of these quakes can indicate impending eruption.

3. Taking note of strange activity that you may not immediately recognize as a tremor. While tremors may be obvious, rumbling and causing objects to rattle, they may also have seemingly no effect on a sturdy building and may just sound like a passing airplane or truck.

4. Observe any alterations in the shape or elevation of the ground in the surrounding area. Bulges, cracks or increased slope in the ground are all indicators of activity beneath.

5. Check with local rangers or members of the U.S. Geological Survey to see if the volcano has erupted in recent history. If it has, then geologists will have labeled it as an "active" volcano, which increase the likelihood of an eruption in the future.

(Source: http://www.ehow.com/how_2095755_predict-volcano-eruption.html)

- Points obtained by Charmaine Tan Wen Qian

- Vetted And Edited by Yap Way Shen Russell

Pictures Relating To Section 1

Location Of Mount Merapi

The Dead Bodies Left After Merapi's Explosion in 2010

Destroyed Houses After Merapi's Explosion 

Lightning strikes as Merapi Explodes

Make Shift Shelters Following The Aftermath of Merapi's Explosion

Merapi Releasing Volcanic Material Into The Air

Closer To Merapi as it explodes

Mount Merapi Spewing Smoke

Students Are Seen Playing In A Field Prior To Merapi's Explosion

This section (4) explains what more can be done to prevent the harms of a volcanic eruption

     In my section, I would be looking into what more can be done to reduce the negative effects of a volcanic eruption. I would firstly, be elaborating on what these negative effects are and will be explaining it on a general perspective. Then finally, I would be going into detail about what more can be done to reduce the harm that the volcanic eruption can cause.

    Onto my first point, as mentioned in our group's first section, one of the effects is that many lives can be lost as a result of a volcanic eruption. This is caused by the 'Lahars' which have been explained in Section 1's answers. As such, the hot lava and lahars can destroy settlements and clear areas of woodland or agriculture. Due to this, man-made and natural landscapes can be destroyed and changed forever (such as landmarks and ancestral homes etc).

    Next, when the hot ash hits the homes, the homes would collapse under the weight of the ash, leaving people homeless. Huge shanty-type refugee camps were set up and disease spread rapidly in them (especially diarrhea, chickenpox and malaria) leading to 600 deaths due to the proximity of close contact with each other. As such, the destruction of rice crops also led to food shortages. As a precautionary measure, the government would evacuate and shift the native villagers to somewhere safe to avoid the volcanic eruption for the time being. This as stated, in my team's first point, puts a strain on the government to support these people while the volcanic eruption and would be a threat over the long run.
    Finally, I would be now looking at what can be done to reduce the negative effects of a volcanic eruption on different sources of people. Firstly, we should encourage the government to not build anything expensive near active volcanoes. (ancestral homes, landmarks etc.) as the government would have much difficulty to cope with the financial burden of reconstructing these objects if they were to be destroyed by the active volcano. Next, we should warn people and evacuate them from the affected area(s) and vicinities upon receiving news that the volcano is most likely to erupt. This reduces the chances of them losing their lives as they would not need to perish and die if they were to be hit by the hot lava. In the event that the government is unable or unfortunately, is delayed in broadcasting to the village that they must evacuate prior to a volcano eruption, we should educate the native villagers on how to detect when a volcano is about to erupt. This way, it might save their lives as they would know when to evacuate due to the knowledge absorbed.
     Overall, I have summarized up the negative effects of a volcanic eruption and have explained what more can be done to reduce the harms that an eruption could possibly cause.


- Points provided by Mok Jinrong
- Grammar & Construction by Yap Way Shen Russell

Section 1: The Long Term Effects Of A Volcanic Eruption

     In 2010, Mount Merapi, one of the world’s most volatile and dangerous volcanoes, erupted with much force, causing much damage and losses to many. In this section, I’ll be investigating about what are the long term effects of this eruption.

     Prior to the eruption, thousands of people living on the volcano’s fertile slopes began evacuating as Merapi started erupting and sending hot ash and rocks high in the air.

     As such, the lives of many people living in the region of the volcanoes were disrupted as they had to evacuate in order to save their lives from this potentially dangerous disaster.

     Based on the evidence provided from the different individual sources and interviews with different renowned geologists from different parts of the world, I hereby present the different long-term effects posed to different audiences depending on the perspectives that we would be looking at. I would be talking about this on two main levels, firstly on the positive benefits it would bring to people and lastly, the negative effects that the volcano eruptions would cause.

      So now, on to my first substantive. Considering the fact that there are many paddy fields surrounding the exterior of Mount Merapi, many of the peasants decide to settle there and adopt farming as their career. As such, upon the release of the ash from the volcano, it would travel down to the city and hit the paddy fields. Due to the time required for the ash to travel, the temperature of the ash would not be as hot as what it was extruded as but in a cooler temperature. The ashes would travel down and end up resting on the paddy fields. Due to the nutrients that the ashes contain, it would be able to fertilise the land and make it fertile and suitable for farming. Due to the benefits posed as such, the people would choose to settle in the nearer regions of the volcano as they see the potential chance of the land becoming fertile for their farming purposes.

     Next, moving on to my next substantive on about the negative aspects on how different audiences would be negatively affected by the volcanic eruptions of Mount Merapi. Due to fact that Merapi is surrounded by many paddy fields and they are heavily populated by people who lived in the region of Merapi. One of the negative threats posed to them would be that they might eventually suffer from respiratory problems due to the exposure and breathing of smoke into their health systems. As the volcano would spew out smoke frequently due to the fact that Merapi is an active volcano, the villagers who reside on the vicinity of the volcano would be exposed to smoke and inhale the smoke into their health systems. In such events, after a period of time due to the inhaling of smoke, they would eventually have respiratory system problems and would pose a threat to their lives. This is especially dangerous as they might die or become seriously ill due to this.

     Next, as the pyroclastic flow would roll down from the volcano, native animals who are unable to escape from the hot larva would be killed in a matter of seconds, while some may escape to other places to take refuge. Over time, food chains will also be altered as the animals, who are the main source of food for the native villagers, are now gone, and the food chain and left unbalanced, many insects will have grown rampant in the city, and if there are still inhabitants, many of them will succumb to Malaria and other diseases. Over time, as many of these animals continue to perish, the population of these animals would suffer a tremendous dip into productivity.

     Lastly, there will also be a huge problem concerning 'Lahar', every time it rains. When the pyroclastic materials mix with large amounts of water, 'lahars' (which is a type of mudflow) are formed, which can flood and bury not only houses but also towns. This is an aftermath result of a volcanic eruption. Due to the burying of houses and towns, many villagers would be left homeless and would have to reside in makeshift shelters for the time being. The long term effect of this would be that it would put a strain on the governments to reconstruct the properties of these people. Over time, the government does not have the ability to provide for everyone in the country that is affected by this.

      To clear the air about the financial district(s) being affected, the area where Merapi resides is not a huge contributor to the financial economy, it would be not necessarily devastating to the financial economy but the main strain is still on the government as they would need to provide for the people who are affected by the volcanic eruption.

      To sum up my case, I have presented the long term effects of a volcanic eruption using Mount Merapi in Indonesia as my case study.


- Written And Vetted By Yap Way Shen Russell