Thursday, March 24, 2011
Lake Toba
It is estimated that Lake Toba explosion occurred at about 73000-75000 years ago and an eruption Supervolcano (super volcano) the most recent. Bill Rose and Craig Chesner from Michigan Technological University estimate that volcanic materials spewed out of the mountain as much as 2800 km ³, with 800 km ³ of rock Ignimbrite and 2,000 km ³ of volcanic ash which is expected in the wind to the west for 2 weeks. Volcanic dust in the wind has spread to half the earth, from China to South Africa. Explosion occurred during 1 week and throw the dust up to 10 km above sea level.
This incident caused mass death and the extinction of some species also followed. According to some DNA evidence, this eruption also reducednumber of of people to about 60 % of the total human population of the earth at that time , which is about 60 million people . The eruption was also contributed to the occurrence of ice ages, although the experts still debate.
After the eruption, the caldera formed which is then filled with water and became what is now known as Lake Toba. Pressure upward by magma that has not come out cause the emergence of Samosir Island.