The Chernobyl nuclear disaster took place all the way back on 26th April 1986 due to an accident at the power plant in Ukraine. It is often describe as the worst nuclear accident in the world. Chernobyl was located in the former Soviet Union which is now known as Ukraine. At present, Chernobyl is now known as a nuclear wasteland and people are believed to have evacuate the place, but however, there are still some settlements there even with the danger of mutation and radiation sickness those people are exposed to.
The nuclear disaster happened at 1.32am when the town slept very peacefully. A fire broke out at the nuclear power plant nearby. It was a bluish glow all over the power plant. Lieutenant Colonel Leonid Petrovich Telyatnikov was the head of the fire department at the Chernobyl power plant then, led the team of firefighters to the fire at reactor number 4 which had caused the outbreak of the fire. Despite the radiation level being extremely high at that time (even higher than the one after the Hiroshima atomic bomb), they still fought the blaze without a radiation suit and respirators. They only had their uniforms and gas masks. After about a few minutes of trying to put out the fire, Telyatnikov began vomiting and it was the sign of radiation sickness. Several days after that, Telyatnikov and his teammates began developing radiation burns all over their bodies. They were soon taken to a hospital in Moscow where they were kept in sterile units because their body immune system had been weakened. In 1987, Telyatnikov was named a Hero of the Soviet Union. He died of cancer at the age of 53. On April 25, 2006, the twentieth anniversary of the Chernobyl disaster, a monument was dedicated to him at the Baykove cemetery in Kiev where he is buried.
The causes of the explosion were a long list of problems with management errors being the main issue. The head managers who conducted the test at Chernobyl were electrical engineers but none were specialised in reactor plants. Is it said that there were a sudden loss of water to cool down the 1661 uranium fuel assemblies that were set in pressure pipes surrounded by 1700 tons of graphite blocks, causing the fuel rods to overheat. The zirconium alloy around the fuel assemblies, along with the pressure tubing, melted at about 3500 degrees Fahrenheit, overheating the graphite. This causes the temperature to increase even more. Soon, the uranium-oxide fuel began to melt at 5100 degrees Fahrenheit. When water was introduced into the fire, it immediately turned into a superheated steam which reacted with the graphite, fuel, zirconium to produce hydrogen, methane and carbon monoxide. Over several hours, the gases built up and combined with the oxygen released from the cracked pressure tubes which resulted in a massive explosion. Melted metal fissioned out of control, releasing radioactive isotopes that were sucked up into the smoke, creating dangerous cloud of deadly radiation. Since water cannot be used to put out the fire (as it would react with graphite to produce more methane which is a flammable substance), the only way to stop the fire was to wait for the flammable elements to have run out.
The worst part is that, The Soviet government did not informed other countries of the incident so that they would be well prepared with safety precautions and such. Instead, they covered up the incident and acted as if nothing had happened.They did not even bother to evacuate the area. The rest of the world found out of the incident in a rather shocking way. Sweden was the first that realised something when they saw signals indicating high levels of radiation in the area. At first the technicians involved thought that it might be a leaked in one of their power plant which contributed to the high level of radiation. They used a Geiger counter to test it on all of their worker's clothing and had found nothing. Similar reports then came from parts of Finland, Sweden and Norway. Soon they realised that it was coming from the Soviet Union. Evacuations had only started several hours after they had confronted the Soviet Union. However, several serious damage had already been done to the people.
Evacuations were also very discriminatory. According to Jessica Lee in USA Today, "Increased ethnic unrest threatens because Byelorussians were not evacuated immediately after the accident." As quote by Lemonick, "this angered many people along with the fact that the communist officials failed to evecuate nearby towns and cities rightaway, although they knew of the danger." Chernobyl now is common with human and animal mutation. Pregnant women living in these areas has a higher chance of giving birth to deformed babies or infants with genetic problems. After the incident in Chernobyl,many women were afraid to give birth because of the risk of getting a deformed child. Animals in the affected areas often deliver young that are stillborn or so deformed that they had to be destroyed. According to Gould, "the radioactive fallout resulting from Chernobyl was detected all over the world, from Finland to South Africa."
In 1995, over 125 000 people had died due to the accident. Many of these deaths could have been prevented had the Soviet Union taken responsibility in the first place and if the Soviet Union had nuclear power plant standards as high as the United States.
In "The 20th Century Plague" by Sharon Begley and Susan Katz, the effects of radiation on the body is laid out.
- Krypton 85 affects the entire body and can increase a person's chances of getting cancers like leukemia within two years of exposure. It has a half life of 10.7 years.
- Cesium 137 can attack the entire body, centering on the liver, spleen and the muscles. It has a half life of 30.2 years.
- Barium 140 gathers in the bnes and can cause tumors as late as thirty years after exposure. It has a half life of 12.8 days.
- Iodine 131 gathers in the thyroid. It can trigger cancer there decades after exposure. It has a half life of 8 days. Most radioactivity disappears from the body after only two months.
The Chernobyl accident has cost a lot of money so far and will cost even more if Ukraine ever wants to use the land again. This incident should be remembered so as to not be repeated in the near future. As the saying goes, people learn from studying history so as to not repeat the same mistakes again.
References:
1. Barnathan, Joyce and Steven Strasser. "The Chernobyl Syndrome." Newsweek. 12 May 1986: 22-30.
2. Begley, Sharon and Susan Katz. "The 20th Century Plague." Newsweek. 12 May 1986: 36-37.
3. Lemonick, Michael D. "The Chernobyl Coverup." Time. 13 November 1989: 73
4. Lee, Jessica. "14,000 at Chernobyl to Evacuate." USA Today. 24 April 1990.
5. E.S., 4/01/99, for History and Thought of Western Man, Rich East High School, Park Forest, Illinois, United States of America. Retrieved from http://www.richeast.org/htwm/chernobyl/chernobyl.html
6. Wikipedia, the free encyclopedia. Leonid Telyatnikov. Retrieved from http://en.wikipedia.org/wiki/Leonid_Telyatnikov
Tuesday, August 21, 2012
Eruption of Mount Vesuvius
Have you ever wondered what it'll be like to watch a volcano erupt in real life? To watch it up close and not through a television screen, through the internet or in pictures posted in the papers. To watch in awe as one of nature's most spectacular yet deadly occurrences takes place before your eyes.
Regarded as one of the most dangerous volcanoes in the world today, Mount Vesuvius is most 'renowned' for its catastrophic eruption in the year of 79 AD with the exact date and time unclear but believing to have lasted for about two days. The eruption obliterated the two Roman cities of Herculaneum and Pompeii which were located to the West and Southeast of Vesuvius respectively. The estimated death toll was put around 16,000 lives with ash and dust clouds covering most of its southern regions. Almost everyone in Pompeii and Herculaneum was unable to flee for their lives and were killed.
Preceding to the great eruption of 79 AD, a major earthquake struck the Bay of Naples adjacent to Pompeii 17 years beforehand. It is common knowledge that seismic activity within the vicinity of volcanoes are usually either directly or indirectly related to volcanic activity. The movement of deep underground seismic plates located many kilometers beneath the surface coupled with magma flow causes tremors that reverberate in all directions. On the surface, major tremors shake the very earth thus disturbing the volcano and causing an immense release of pressure from volcanoes. In the case of Vesuvius, the pressure build up was due to ground water seeping from the surrounding into faults within the volcano. The water heated up and formed pockets of extremely hot gas with lots of energy just waiting to be released into the open. Needless to say when the chance for the volcano to 'let loose some steam' came, it did not hold back.
A majority of the lives lost and damage done are actually not due to the eruption itself or lava. An occurrence known as pyroclastic flow which succeeds the volcano eruptions cause the largest percentage of human casualties in any volcanic eruption. Pyroclastic flow is a current of superheated gas and rocks that is thrown out by the volcano when it erupts. The currents can reach speeds of up to 700 km/h and temperatures of up to 1000°C. These devastating currents stay close to the ground and spread outwards from the mouth of the volcano.
Within one day after the eruption, pyroclastic flow from Vesuvius began engulfing the city of Herculaneum. Although the temperature of the currents from Vesuvius was relatively low, about 300°C, the density of the clouds were thick enough to knock down entire buildings. The next three surges reached the city of Pompeii and destroyed it. Those unlucky enough to be caught in the streets when the currents hit were instantly burried under rocks or suffocated to death due to ash inhalation. Anybody hiding in buildings or structures could not have escaped as the city was surrounded by gases of incinerating temperatures, meaning that they were either killed when the buildings collapsed on them or were 'cooked' to death.
The great eruption of 79 AD had rather permanent effects on the geography of the mountain and its immediate vicinity. After that eruption, the summit of mount Vesuvius had been changed considerably and was more deformed with a larger crater. The Sarno River nearby the volcano had also been affected with its river being redirected in a slightly different direction and most of its river basin being burried during that period. The city of Pompeii was very well preserved underneath the pumice, ash and layers of earth that covered it in the many years after that until its accidental discovery in the 18th century.
Due to its past history, the Italian government has put in place an emergency evacuation plan should an eruption occur. The plan is tailored for an eruption of the worst kind similar in scale to that of the 79 AD eruption with 14-20 days notice prior to an eruption. The plan comprises of the emergency evacuation of 600,000 people in the immediate danger zone in the event of an eruption by means of ferries, trains, cars and buses. The government has also put in place ongoing policies in order to reduce the population of people around the presently inactive volcano. Among these are the establishing of a national park reserve around the volcano to prevent further development closer to it and to provide financial assistance for those who wish to move away from the region. The purpose of these policies are to reduce the number of people needed to be evacuated and the time required to evacuate the overall population. After all, better safe than sorry.
Today the region around Mount Vesuvius is home to around 3 million people and is one of the most densely populated volcanic regions in the world. The most recent eruption of Mount Vesuvius took place in the spring of 1944 during World War 2 where the fallout from the dust and debris damaged a USAAF airfield in Italy. With a period of roughly 7 decades since the last eruption, it has been the longest period of inactivity from Vesuvius in over 400 years.
Regarded as one of the most dangerous volcanoes in the world today, Mount Vesuvius is most 'renowned' for its catastrophic eruption in the year of 79 AD with the exact date and time unclear but believing to have lasted for about two days. The eruption obliterated the two Roman cities of Herculaneum and Pompeii which were located to the West and Southeast of Vesuvius respectively. The estimated death toll was put around 16,000 lives with ash and dust clouds covering most of its southern regions. Almost everyone in Pompeii and Herculaneum was unable to flee for their lives and were killed.
 |
| Artist impression of the eruption of Mount Vesuvius from Pompeii. |
A majority of the lives lost and damage done are actually not due to the eruption itself or lava. An occurrence known as pyroclastic flow which succeeds the volcano eruptions cause the largest percentage of human casualties in any volcanic eruption. Pyroclastic flow is a current of superheated gas and rocks that is thrown out by the volcano when it erupts. The currents can reach speeds of up to 700 km/h and temperatures of up to 1000°C. These devastating currents stay close to the ground and spread outwards from the mouth of the volcano.
Within one day after the eruption, pyroclastic flow from Vesuvius began engulfing the city of Herculaneum. Although the temperature of the currents from Vesuvius was relatively low, about 300°C, the density of the clouds were thick enough to knock down entire buildings. The next three surges reached the city of Pompeii and destroyed it. Those unlucky enough to be caught in the streets when the currents hit were instantly burried under rocks or suffocated to death due to ash inhalation. Anybody hiding in buildings or structures could not have escaped as the city was surrounded by gases of incinerating temperatures, meaning that they were either killed when the buildings collapsed on them or were 'cooked' to death.
The great eruption of 79 AD had rather permanent effects on the geography of the mountain and its immediate vicinity. After that eruption, the summit of mount Vesuvius had been changed considerably and was more deformed with a larger crater. The Sarno River nearby the volcano had also been affected with its river being redirected in a slightly different direction and most of its river basin being burried during that period. The city of Pompeii was very well preserved underneath the pumice, ash and layers of earth that covered it in the many years after that until its accidental discovery in the 18th century.
Due to its past history, the Italian government has put in place an emergency evacuation plan should an eruption occur. The plan is tailored for an eruption of the worst kind similar in scale to that of the 79 AD eruption with 14-20 days notice prior to an eruption. The plan comprises of the emergency evacuation of 600,000 people in the immediate danger zone in the event of an eruption by means of ferries, trains, cars and buses. The government has also put in place ongoing policies in order to reduce the population of people around the presently inactive volcano. Among these are the establishing of a national park reserve around the volcano to prevent further development closer to it and to provide financial assistance for those who wish to move away from the region. The purpose of these policies are to reduce the number of people needed to be evacuated and the time required to evacuate the overall population. After all, better safe than sorry.
Today the region around Mount Vesuvius is home to around 3 million people and is one of the most densely populated volcanic regions in the world. The most recent eruption of Mount Vesuvius took place in the spring of 1944 during World War 2 where the fallout from the dust and debris damaged a USAAF airfield in Italy. With a period of roughly 7 decades since the last eruption, it has been the longest period of inactivity from Vesuvius in over 400 years.
Thursday, August 16, 2012
Hydrothermal Vents
Although 70% of the earth's surface is covered by water with vast and deep oceans, a large portion of it still remains uncharted. The seabed itself is one of the most isolated and unexplored places on earth with much of what goes on down there remaining as a mystery. Yet, it is here that many of the most intriguing orders of nature occur. Many of them complex and difficult to understand and just as many of them simple yet with interesting effects that kindle the interests of researchers everywhere.
Unbeknown to man until very recently, underwater hydrothermal vents located in the deepest parts of the sea have been actively spewing out hot water into the oceans and seas. Up till 1977, these vents would not have been discovered if not for a deep see underwater submersible named 'Alvin' which made this amazing discovery while diving in the East Pacific Rise near the Galapagos Islands in the Pacific.
Hydrothermal vents can occur up to 5,000 metres underwater where tectonic plates on the sea bed move apart and the sea water is free to flow into underlying layer of molten lava. The lava in turn heats the almost freezing cold water, usually around 2°C, and the water bursts back out in fumes from below the seafloor. The superheated water travels upwards now laden with dissolved minerals. As the extremely hot water makes contact with the chilling water of the deep ocean, the minerals in the fumes harden thus forming long cylindrical-like structures which come to be known as hydrothermal vents. Some of these structures are known to be 6 kilometres long. They hold some similarities to volcanoes and logically thinking, if they can occur above water, why not underwater too? Just on a smaller scale.
Essentially there are two types of vents. The black smokers and the white smokers. Black smokers, as the names suggests, release plumes of black material into the sea caused by high levels of sulphur in the dissolved superheated water. Black smokers are also considerably hotter than white smokers. White smokers on the other hand, emit particles which are lighter and brighter. Another difference is that white smokers result in alkaline conditions whereas acidic conditions exist for black smokers.
The long cylindrical structures of hydrothermal vents that resemble volcanoes are metal sulphide ore deposits and their rich mineral content like zinc, copper, lead and sulphur have been highly sought after by resource and mineral companies because of their value to them. The race between these companies have produced some impressive results with many new and advanced mining techniques applied in modified ways to mine and transport the minerals on a large scale. However, the act of carrying out this economic endeavour has its detrimental effects on the ecosystem in the sea. The increase in the frequency of movement around these vents has the potential to stir up dust particles, reopening 'dormant' vents or sub-oceanic landslides.
The amazing thing about these vents is that once the activity on them has died down and they lay 'dormant' for the time being, they become hosts to a large variety of aquatic life. They form a temporary community of organisms with an organism density of over 10,000 times higher than that of the surrounding sea floor. The transformation of the bare fields of underwater vents into gigantic underwater communities is a miraculous spectacle to behold and is another one of nature's many wonders.
Hydrothermal vents can occur up to 5,000 metres underwater where tectonic plates on the sea bed move apart and the sea water is free to flow into underlying layer of molten lava. The lava in turn heats the almost freezing cold water, usually around 2°C, and the water bursts back out in fumes from below the seafloor. The superheated water travels upwards now laden with dissolved minerals. As the extremely hot water makes contact with the chilling water of the deep ocean, the minerals in the fumes harden thus forming long cylindrical-like structures which come to be known as hydrothermal vents. Some of these structures are known to be 6 kilometres long. They hold some similarities to volcanoes and logically thinking, if they can occur above water, why not underwater too? Just on a smaller scale.
Essentially there are two types of vents. The black smokers and the white smokers. Black smokers, as the names suggests, release plumes of black material into the sea caused by high levels of sulphur in the dissolved superheated water. Black smokers are also considerably hotter than white smokers. White smokers on the other hand, emit particles which are lighter and brighter. Another difference is that white smokers result in alkaline conditions whereas acidic conditions exist for black smokers.
The amazing thing about these vents is that once the activity on them has died down and they lay 'dormant' for the time being, they become hosts to a large variety of aquatic life. They form a temporary community of organisms with an organism density of over 10,000 times higher than that of the surrounding sea floor. The transformation of the bare fields of underwater vents into gigantic underwater communities is a miraculous spectacle to behold and is another one of nature's many wonders.
Subscribe to:
Posts (Atom)