Geography-volcanoes 04

WHAT MORE CAN BE DONE TO REDUCE THE IMPACT OF VOLCANIC ERUPTIONS

Geographers can use hazard mapping to outline the possible impact of eruptions on local communities and the effects so that they will know what have to be done.

-People can also use barrier walls to penetrate the flowing lava and use diversionary lava channels to divert the lava away from the nearby village/town.

-Locals must also have volcanic activity warning and evacuation drills and emergency food so that when a volcano erupts, they will know what to do. Geographers are using technology to predict when a volcano is erupting by monitoring heat through satellites.

-Activities of the volcano round the area should be closely monitored at all times.

-Effective warning and evacuation procedure should also be planned by the government when volcanic eruption happens.

Acknowledgements:
http://wiki.answers.com/Q/You_do_to_reduce_the_negative_impact_of_volcanic_eruptions

http://wiki.answers.com/Q/You_do_to_reduce_the_negative_impact_of_volcanic_eruptions

http://en.allexperts.com/q/Geography-1729/volcanoes.htm

Geography-volcanoes 03

Mount Ruiz
Mount Ruiz also known as Nevado del Ruiz, is located in central Colombia, 130km West North West of Bogata. The Nevado del Ruiz was produced by the subduction of the oceanic Nazca Plate beneath the continental South American Plate. It is the northernmost of some two dozen active volcanoes scattered along the Cordillera Central.

Its eruption on 13th November 1985 created history’s fourth largest volcanic disaster. The eruption although small, produced an enormous lahar which consists of mud and debris flow, which pose a threat to human life and environment. The lahar completely buried a desolated town called Armero causing an estimated 23,000 deaths.
The high death toll was the result of the lack of preparation. The government officials were responsible for this tragedy as they chose to ignore the warnings by volcanologists. The villagers were warned about the possibility of the disaster however because of past false information about it happening and the false statements from other officials who say that the volcano was not going to erupt. Thus, the villagers did not believe the warnings.


As the town of Amero was built on old mudflows, it was in the hazard zone if lahars were to avalanched down the mountain. The people of the town were told to stay inside and avoid the falling ash, not thinking the mudflows would bury them.
Several years later, the sides of the creeks along which the lahars flowed were clearly visible from commercial airplanes. In the mid 1990s, the town was still buried up to 20 feet of ash and debris. The local villagers who harvested stones for building work. They would often still discover human bones and would place it on the shrines around the area.
Survivors who fled to other towns in the area were gradually housed in new government schemes, but problems for the displaced population occurred for many years after.
The eruption cost Columbia 7.7 billion dollars.



http://www.britannica.com/EBchecked/topic/512533/Mount-Ruiz
http://www.websters-online-dictionary.org/definitions/Nevado+del+Ruiz?cx=partner-pub-0939450753529744%3Av0qd01-tdlq&cof=FORID%3A9&ie=UTF-8&q=Nevado+del+Ruiz&sa=Search#922
http://www.volcanolive.com/ruiz.html
Picture from : http://www.websters-online-dictionary.org/definitions/Nevado+del+Ruiz?cx=partner-pub-0939450753529744%3Av0qd01-tdlq&cof=FORID%3A9&ie=UTF-8&q=Nevado+del+Ruiz&sa=Search#922

Geography-Volcanoes 02

People live near volcanoes for many practical reasons, namely because of minerals, the fertile soil, geothermal energy, not being able to afford moving away, and tourism.


An example of people living near volcanoes
(http://environment.nationalgeographic.com/environment/natural-disasters/volcano-safety-tips.html)

1. 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.
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 to earn money.






A gem found inside volcanic rocks. Sulfur deposits at Kawah Ijen Volcano in Eastern Java.
(http://www.smartminerals.com/pakistan/articoli/occurrence.htm)
(http://www.hilo.hawaii.edu/~csav/gallery/decker/indonesia_kawah_ijen.php)

2. Volcanic rocks also produce very fertile soils. Volcanoes, after erupting, produce very thick deposits of ash and broken rocks which weather to form rich soils. People from less developed countries who live near the volcanoes would be able use the soil for growing crops. Places such as the African Rift Valley, Mt Elgon in Uganda, and the slopes of Vesuvius in Italy all have productive soils thanks to the breaking down of volcanic rocks and ash.




Farming near volcanoes.
(http://scienceray.com/earth-sciences/weird-and-wonderful-of-nature-the-volcanic-eruptions/)

3. The cost of moving. It is expensive to move away from volcanoes. In less developed countries, there are people who cannot afford to move away. Most of them are in denial and hope that these volcanoes nearby them will not erupt again. After all, when a volcano has long been dormant, it is easy to assume and hope that it will not erupt why you live near it.

4. Volcanoes also provide geothermal energy.Geothermal energy means heat energy from the earth.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. Many countries with active volcanoes ( Iceland, New Zealand and Japan) make use of geothermal energy and convert it to use as electricity.




(http://www.energyrant.com/geothermal-energy/)

5. Volcanic sites can also be very effective tourist attractions. Even the less active ones that are just puffing out steam and smoke are impressive sights and attract tourists from around the world. Warm bathing lakes, hot springs, bubbling mud pools and steam vents are often present around volcanoes, drawing in tourists.Geysers are also popular tourist attractions, such as Old Faithful in the Yellowstone National Park, USA.Tourism creates jobs in shops, restaurants,hotels and tourist centres / national parks. Locals economies can profit from volcanism throughout the year.






Hot springs near volcanoes.
(http://www.chinaculturecenter.org/chinaguide/regions/yunnan/)

Some wealthy people even choose to live near volcanoes because areas with volcanoes are beautiful, full of wilderness. People who love to ski and snowboard enjoy living near volcanoes because of the atmosphere and scenery.

credits:
http://www.plate-tectonics.org/volcanoes/why-do-people-choose-to-live-by-volcanoes.html
http://www.geography-site.co.uk/pages/physical/earth/volcanoes/why%20people%20live%20near%20volcanoes.html

Bold; less developed countries.

Geography-Volcanoes

Section2:Ways on how volcanic eruptions can be predicted.
-Sudden earthquake activity & change in temperature, ground tilt &gas compositions
-Use of seismographs, tiltmeters, geodimeter, magnetomers & gravity meters are also helpful because changes in magnetic and gravity measurements around the volcano can indicate whether magma body is rising into it (hence the volcanic eruptions)

Seismographs:



Seismic activity (earthquakes and tremors) always occurs as volcanoes awaken and prepare to erupt and are a very important link to eruptions. Some volcanoes normally have continuing low-level seismic activity, but an increase may signal a greater likelihood of an eruption.
(above is the picture of a seismograph)

Tiltmeters:



A tiltmeter is designed to measure very small changes from the horizontal level, either on the ground or in structures. Tiltmeters are used extensively for monitoring volcanos, the response of dams to filling, the small movements of potential landslides, the orientation and volume of hydraulic fractures, and the response of structures to various influences such as loading and foundation settlement. They may be purely mechanical or incorporate vibrating-wire or electrolytic sensors for electronic measurement. A sensitive instrument can detect changes of as little as one arc second.

Magnetomers:

Magnetometer is a scientific instrument used to measure the strength and/or direction of the magnetic field in the vicinity of the instrument. Magnetism varies from place to place and differences in Earth's magnetic field (the magnetosphere) can be caused by the differing nature of rocks.




credits: www.wikipedia.com
www.photobucket.com