To What Extent Do You Agree with the View That the Hazards Resulting from Volcanic Activity Have to Be Adapted to Rather Than Managed?
Autor: Nico11897 • March 23, 2015 • Essay • 1,040 Words (5 Pages) • 1,513 Views
To what extend do you agree with the view that the hazards resulting from volcanic activity have to be adapted to rather than managed? (40marks)
Adapting to a situation is when a person learns to live with and recovers after an event and deals with the consequences, whereas managing a situation is when it is prevented, altered or planning has occurred to prepare for the foredooming situation. Deaths from volcanic activity are estimated at about 300,000 since 1600. No volcanic hazard can be prevented but the value, the vulnerability, and the risk can be reduced ahead of time by actions taken to reduce loss of life, property, or money. There are a variety of volcanic hazards that can occur.
Volcanic gases rarely cause deaths, but when gases such as carbon dioxide fill the air, being heavier and denser than oxygen, it can flow down into nearby valleys and travel several kilometres, reaching villages intoxicating everything in its path. In 1986 over 1700 people died from suffocation in Cameroon when a large bubble of volcanic gas escaped from Lake Nyos. 3000 cattle died and all animal life in the area was killed. The cloud was largely carbon dioxide, which is heavier and denser than oxygen, so it swept down the volcano sides reaching a depth of about 50km. The gas flowed down into neighbouring valleys and travelled up to 25kms. The CO2 was released from the magma chamber and leaked into the waters of the lake; the cold dense water near the lakebed absorbed the CO2, which was held down by the weight of the over-lying water layers. The problem is that the waters of Lake Nyos, like many tropical lakes, are steady and still, with little annual mixing of the water layers. Eventually, the lakebed was disturbed, possibly by a deep volcanic eruption or an earthquake. This reduced the overlying pressure and the CO2 escaped into the surrounding area causing rapid death. To manage this, and prevent it recurring with such violent side effects an international team of scientists, supported by the U.S. Office of Foreign Disaster Assistance, have developed a plan to try to remove the gas from the lakes. The plan is to place large pipes in Lake Nyos and Monoun. These pipes, each about 13cms in diameter, will be placed on a floating platform and sent down to the lowest layers of water, creating a vent to the surface. Water will be pumped from the bottom of the lake, and the gas-water fountain that results releases the carbon dioxide harmlessly into the atmosphere. Currently, there is funding to place one pipe in Lake Monoun, which will slowly remove the gas stored in the lake over the next five years. A pipe will also be placed in Lake Nyos, which should be sufficient to prevent the further build up of carbon dioxide, but since the lake is considerably bigger than Monoun, six to ten pipes will eventually be needed to remove all the gas stored in the lake. This management method after the event shows that sometimes a situation has to occur once so people learn from it and then can create a successful management strategy so the same situation will never happen again.
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