Sunday 20 March 2011

Long-term effects of volcano eruptions by Vivian (;

Lots of people would be left homeless. There would be a massive decline of the country's population due to large amount of casualties from the hot lava and or the suffocating volcanic ash emmited, which is caused by inadequate information on the eruptions.
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.

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.
The ash and lava that rains over the land and buries it is also a problem. 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.
There might also be silting in the rivers and lakes, which stops boats from navigating through, as the depth becomes much shallower.

Mount Tambora
It created a long-term effect on global climate.
The 150 cubic km of ash that erupted during the explosion not only rained down on the terrestrial surface, but was also projected into the atmosphere, entering the troposphere and, possibly, the stratosphere. The ash covering the Earth’s surface was responsible for lowering many of the plants’ productivity. The ash in the atmosphere only quickened this process, for upon reaching the troposphere and stratosphere it quickly spread, eventually encompassing the entire planet. In turn, the ash particles in the atmosphere reflected incoming solar radiation or absorbed the light waves.

The Tambora volcano in Indonesia erupted in April 1815, but North America and Europe did not notice its effects until months later. In 1816, known as "the year without a summer", gases, ashes and dust arrived over the Iberian Peninsular and reached the stratosphere, where they remained long enough to create "an enormous sun filter".

The period 1812 - 1817 was one of unusually intense volcanic activity. This activity
reached its peak in April 1815, when Mount Tambora (sometimes spelt Tamboro) on the
island of Sumbawa, Indonesia, erupted in one of the most explosive volcanic events of
the last 10,000 years. Although this eruption was much bigger than the 1883 Krakatoa
event, it was less well-documented. Estimates of the size of the eruption vary, although
Christopherson (p 105) quotes one such estimate that 150 cubic km of material was
released. To put this into pespective, this would be 25 times the volume of material
released by the 1980 Mount St. Helens eruption. Before Mount Tambora erupted, it is estimated to have been about 4,000m high. The eruption reduced it to 2851m, and left behind a caldera 7 km across. 

The concussions produced by the explosions are said to have been felt for
1,000 miles all around, and the sound was reported to be heard 1,700 miles distant from
the volcano. In European settlements 200 and 750 miles away the sounds of the eruption
were thought to be cannon fire, and ships and soldiers were despatched to investigate
what were assumed o be attacks on nearby outposts. In Java, some 300 miles west the day
was darkened by the ash, which fell several inches deep. Closer to ground zero, the
rooves of houses 40 miles from the eruption collapsed under the weight of ash. All
vegetation on several nearby islands died, significant masses of pumice were reported in
the ocean off the western coasts of Sumatra, and the immediate area death toll was
around 92,000. 10,000 died from the direct effect of the explosion, lava flows, falling
debris and pyroclastic flows, with another 82,000 dying subsequently through starvation
and disease. The eruption generated an hour long and extremely destructive "whirlwind",
and the sea rose 12 feet above its high tide mark, causing widespread flood damage. It
was 5 years before new vegetative growth returned to the area within 250 miles from the
eruption.




Sources: http://www.sciencedaily.com/releases/2009/02/090225161422.htm
http://www.orangutan.lombok-lintrack.com/mount-tambora-info.htm
http://en.wikipedia.org/wiki/Year_Without_a_Summer
http://www.ehow.com/facts_7184416_mount-tambora-interesting.html
http://en.wikipedia.org/wiki/Mount_Tambora

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