Saturday 12 March 2011

Long-term Impacts Of Volcanoes

Disadvantages
THE PEOPLE
   There will be a massive decline of the country's population due to a large number of casualties. There will also be effects on the economy, depending on the area effected. If it is the financial district, than the wealth of the country will decrease.
   Also, when people revisit the spot where the volcano erupted, they may breathe in the coal dust still floating around the area. Coal dust in the lungs that mining authorities shrugged shoulders about, has been found to be able to kill.
   The area affected by the volcanoes will be barren for quite some time, which will affect the country's food supply, maybe even causing famines.

THE ENVIRONMENT 
   Ash and lava is very difficult to farm on, and it only becomes fertile after a long time, therefore, plant life would be limited, which would also affect the food chain. It may even cause animals to attack humans due to lack of food available or migrate, which will leave the area with little animals for awhile.
   There might also be silting in the rivers and lakes, which stops boats from navigating through, as the depth of water becomes much shallower.
   Eruptions can inject massive quantities of ash into the atmosphere, greatly reducing the solar heating of the Earth and potentially interrupting the global food supply for several years.
   Sulfur from volcanoes has the potential to cool the Earth. Sulfur reacts with water in the air to form sulfuric acid droplets that reflect sunlight hitting Earth, thus blocking some rays. The reduction in sunlight can reduce temperatures for a year or so, until the droplets fall out of the atmosphere.
   When pastures are subjected to ash falls and remobilization of ash by wind, evacuation of livestock to areas with good quality feed and water may be prudent. Even after evacuation, long-term inhalation of ash and exposure to fluorine may result in reduced productivity.


Advantages
THE PEOPLE
   Many people may want to see the spot where the volcano erupted, thus, the volcanoes may become a tourist attraction, thus improving the country's economy.
   The area around the volcano erruption would become fertile, thus increasing the quality of the goods harvested. This, in turn, will lead to an increase in the economy of the country.
   Also,   Volcanoes provide resources for energy extraction, also called geothermal resources.  Heat from the earth's crust is being converted to energy. The big advantages to this type of energy are that it is very clean and the resources are nearly inexhaustible.

THE ENVIRONMENT
   Not all volcanic phenomena are destructive. A lava flow may engulf and bury the land, but new soil and vegetation will eventually develop. In warm, humid climates, the recovery is rapid; a few decades will suffice to hide the rocky surface of solidified lava flows. In desert or Arctic climates, on the other hand, recovery is slower; flows more than 1,000 years old may still retain their barren appearance. Volcanic ash slowly weathers to form rich, loamy soils.

Case Study

Lake Toba is the site of a supervolcanic eruption that occurred 69,000-77,000 years ago, a massive climate-changing event. It is believed to be the largest explosive eruption anywhere on Earth in the last 25 million years. According to the Toba catastropher theory, to which some anthropologists and archeologists subscribe, it had global consequences, killing most humans then alive and creating a population bottleneck in Central Eastern Africa and India that affected the genetic inheritance of all humans today. This theory however, has been largely debated as there is no evidence for any other animal decline or extinction, even in environmentally sensitive species. However, it has been accepted that the eruption of Toba led to a volcanic with a worldwide decline in temperatures between 3-5 degrees C, and up to 15 degrees C in higher latitudes.

SOURCES:
http://library.thinkquest.org/17457/volcanoes/advantages.php
http://en.wikipedia.org/wiki/Lake_Toba

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