The Eruption of Toba Essay Example | Topics and Well Written Essays - 2000 words

The Eruption of Toba - Essay Example Some geologists believe that the volcanic eruption also resulted in the extinction of the human race that existed at that time. However, there is a belief that this theory does not hold true because many of the species of the animals that are said to be sensitive to the change in temperature did exist at that time. The other belief is that it caused a change in the genetic setup of the human beings that lived in the area at that time. This volcanic eruption is considered to be the largest known eruption in the last 25 million years and caused a major change in climate at that time. The volcanic winter which occurred as a result of the eruption resulted in decrease in temperature to around 3 to 5  °C (5  to 9  Ã‚ °F), and up to  15  °C  (27  Ã‚ °F)  in higher latitudes (Causey 48-59). TOBA CATASTROPHE THEORY According to this theory the winter caused because of this super volcanic eruption lasted for around 6-10 years and the cooling of the lava was a long process that stretched around 1000 years. It was suggested by Ann Gibbons that the super volcanic eruption that took place resulted in a bottleneck in the human race. A few other scientists suggested the same but then again many other scientists subsequently failed to identify any link or develop enough evidence to support the theory. According to a theory there were not just one but a series of three eruptions that spanned over the period of 1 million years. The crater that was formed because of the super volcanic eruption was  100 ? 30 km2 area wide. The crater is known as the Caldera Complex and the volume of the eruption was estimated to be around 2,000  km3  and  3,000  km3. The mass that was collected after this eruption was estimated to be larger than the erupted mass that had been ever collected in the past 100 years of volcanic eruption history. The ash layer that was deposited from the Toba eruption that took is said to be around 15cm thick and it was spread over the whole o f South Asia. A layer of ash was also deposited over the Indian Ocean, and the Arabian and South China Sea. Even the deep sea rocks that were later retrieved from the South of China sea are said to have the after effects of the volcanic eruption and this has proven that the estimation that was done about the spread of the volcanic mass was an underestimation. And therefore the mass was estimated to have even more far reaching effects than had been calculated (Gunn 40). Some of the scientists believe that the eruption happened at the time when the last of the glacial period was setting in. They believe that the super volcanic eruption that occurred was not responsible for the cooling effect on the climate, but it acted as a trigger for the glacial period. The glacial period was setting in was at a very low speed, but when the super eruption at Toba occurred the whole process was quickened and the glacial period occurred. There are many conflicting opinion about this theory but the ge neral assumption is that the super eruption at Toba caused a lot of dramatic changes in the weather and the temperatures dropped dramatically thereafter. There were also a lot of ash deposits found in the atmosphere as well as in the ocean. The ice samples that were found from the Greenland also showed abnormality in the temperatures and the deposition that had