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What is like living near a volcano?. What is it like most of the time? What happens when it erupts?. Why do people live near volcanoes?. At first it may seem odd that people would want to live close to a volcano or any tectonic activity.
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What is like living near a volcano? What is it like most of the time? What happens when it erupts?
Why do people live near volcanoes? • At first it may seem odd that people would want to live close to a volcano or any tectonic activity. • 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. • Today, about 500 million people live on or close to volcanoes. • We even have major cities close to active volcanoes. Popocatapetl is a volcanic mountain less than 50 miles from Mexico City in Mexico. • In short, the main things that attract people to live near active volcanoes are minerals, geothermal energy, fertile soils and tourism. • Lets look at each one...
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. • Hot gasses escaping through vents of active volcanoes 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.
Countries such as Iceland make extensive use of geothermal power, with approximately two thirds of Iceland's electricity coming from steam powered turbines. New Zealand and to a lesser extent, Japan, also make effective use of geothermal energy. Iceland has over 200 volcanoes and 800 hot springs 26% of Iceland’s electricity comes from Geothermal Power. Reykjavik is said to be “the most unpolluted capital in Europe.” It’s true - the city is absolutely pristine. The air is crystal clear. The geothermal electricity generation has a lot to do with this. Geothermal Energy
Other uses of Geothermal power in Iceland • It is also used for recreational purposes • Blaa Lonio - The Blue Lagoon. In the middle of this huge lava field sits this pool of seawater naturally heated by the geothermal activity below the surface
Southeast of Reykjavik, the town of Hveragerdi serves as a geothermal farming centre for the capital. • Puffs of steam coming out of the ground all over the place. • There were greenhouses everywhere, often surrounded by steaming cracks in the ground. • The extreme climate of Iceland is actually able to produce much in the way of tropical fruits and vegetables with the help of geothermal steam.
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. • The Naples area, which includes Mount Vesuvius, has such rich soils thanks to two large eruptions 35,000 and 12000 years ago. Both 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. • Geysers are always popular tourist attractions, such as Old Faithful in the Yellowstone National Park, USA. Old Faithful is such a popular tourist feature that it even has its own 24 hour Old Faithful webcam. This one is in New Zealand
Tourism • 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. • In Uganda, a country trying hard to increase its tourist industry, the volcanic region around Mt Elgon is being heavily promoted for it's landscape, huge waterfalls, wildlife, climbing and hiking and its remote 'get away from it all' location.
Building Materials • Blocks of lava are used for building materials • Granite is a volcanic rock • Ash is used in cement to build with.
They stay there because there is nowhere else to go – it is home • Land is cheap in volcanic and earthquake zones. Some people are too poor to leave their home (especially in LEDCs) – also poor education does not explain why they should move further away • Even when people can afford to leave the area they may be too attached to their homes to leave. Their families have been there for generations. • And there are so many people living in these dangerous areas, that it would difficult if not impossible to re-house them, especially as many areas that provide food for so many other people.
So living near a volcano can have its advantages, but how do you cope with the danger? • Scientists can often find clues about past eruptions by studying the deposits left behind. Areas affected by lava flows etc can be mapped, making disaster planning more effective. • In addition to this type of long-range forecasting, scientists are becoming more and more skilled at spotting the warning signs of an eruption.
Warning Signs • Before an eruption, magma moves into the area beneath the volcano and collects in a magma chamber, or reservoir. • As it comes closer to the surface, the magma releases gases. • These events can offer valuable clues about the likelihood of an eruption. • For example, the movement of magma produces small earthquakes and vibrations • Magma gathering in a chamber causes slight swelling of the volcano's slopes. • Gases released near the volcano can be measured for changes in quantity and makeup.
Monitoring Methods • A number of tools can be used to record these warning signs. • Seismographs can detect small earthquakes, • while tiltmeters and geodimeters can measure the subtle swelling of a volcano. • Spectrometers can measure amounts of sulfur dioxide • a telltale gas that is released in increasing quantities before an eruption. • Using these and other tools, it's possible to closely monitor activity at an awakening volcano. • Volcanologists are becoming very skilled at predicting the likelihood of an eruption.
But …. • ……. it's very difficult to pinpoint exactly when an eruption will happen. • Often, moving magma doesn't result in an eruption at all, but instead cools below the surface. • Monitoring potential eruptions is expensive. • With many volcanoes erupting only every few hundred or thousand years, it's not possible to monitor every site. • Volcanic eruptions don't occur without warning, however. If we set up monitoring devices, we should not be caught off guard by disastrous eruptions.
So you are living in a volcanic zone? What can you do to stay safe?
Your plan should include 4 parts • What do I need to know and have ready in case an eruption should happen? • What will I do if an eruption is predicted? • What will I do during an eruption? • What will I do after an eruption?
OK – you live in a volcanic area What do you need to know and have ready in case an eruption should happen?
Suggestions include • Learn about your community warning systems. • Be prepared for these disasters that can be spawned by volcanoes. • Earthquakes, Flash floods, Landslides and mudflows, Thunderstorms, Tsunamis • Make evacuation plans. You want to get to high ground away from the eruption. Plan a route out and have a backup route in mind. • Develop an emergency communication plan. • In case family members are separated from one another during a volcanic eruption, have a plan for getting back together. Ask an out-of-state relative or friend to serve as the "family contact." Make sure everyone knows the name, address, and phone number of the contact person. • Have disaster supplies on hand. • Flashlight and extra batteries, Portable, battery-operated radio and extra batteries, First aid kit and manual, Emergency food and water, Non-electric can opener, Essential medicine, Cash and credit cards, Sturdy shoes, A pair of goggles and a throw-away breathing mask for each member of the household.
The volcano alert has been madeTV and Radio are telling people to evacuate URGENTLY The eruption could be any time soon! You have a plan – but what could go wrong with it?
Some ideas • Although it may seem safe to stay at home and wait out an eruption, doing so could be very dangerous. The rock debris from a volcano can break windows and set buildings on fire. Stay safe. Follow authorities' instructions and leave the area before the disaster begins. • Follow the evacuation order issued by authorities. - Avoid areas downwind of the volcano. • Mudflows or Lahars : are powerful "rivers" of mud that can move faster than people can walk or run and occur when rain falls through ash-carrying clouds or when rivers are dammed during an eruption. • When you approach a bridge, first look upstream. If a mudflow is approaching or moving beneath the bridge, do not cross the bridge. The power of the mudflow can destroy a bridge very quickly.
If eruption happens before you get away • If caught indoors: • Close all windows, doors, and dampers. • Put all machinery inside a garage or barn. • Bring animals and livestock into closed shelters. • If trapped outdoors: • Seek shelter indoors. • If caught in a rock fall, roll into a ball to protect head. • Avoid low-lying area where poisonous gases can collect and flash floods can be most dangerous. • If caught near a stream, beware of mudflows. • Protect yourself: • Wear long sleeved shirts and pants. • Use goggles to protect eyes. • Use a dust-mask or hold a damp cloth over face to help breathing. • Keep car or truck engines off.
Afterwards • Listen to a battery-powered radio or television for the latest emergency information. • Stay away from volcanic ash fall. • When outside: • Cover your mouth and nose. A number of victims of the Mount St. Helens volcano died from inhaling ash. • Wear goggles to protect your eyes. • Keep skin covered to avoid irritation or burns. • If you have a respiratory ailment, avoid contact with any amount of ash. Stay indoors until local health officials advise it is safe to go outside. • Avoid driving in heavy ash fall. Driving will stir up more ash that can clog engines and stall vehicles. • Clear roofs of ash fall. Ash fall is very heavy and can cause buildings to collapse.
Homework • Imagine you are an advertising executive and you want to attract people to visit or live on your volcano (you might like to use your volcano from last week?) • In a 3-slide PowerPoint • Explain • why it is really the one place they would like to come to • how they will protected by monitoring • how they can prepare to survive any disaster • Keep it brief and punchy – this is an advert remember – • Don’t let the font size go below size 24