Laharic flow characteristic of post 2010 Merapi Volcano eruption, Indonesia
Penulis/Author
Dr.Ing. Ir. Donatus Hendra Amijaya, S.T., M.T., IPM. (1); Prof. Dr. Ir. Sugeng Sapto Surjono, S.T., M.T., IPU., ASEAN.Eng. (2)
Tanggal/Date
2011
Kata Kunci/Keyword
Abstrak/Abstract
It is estimated that 1.5 to 2 million cubic meter of volcanic material has been produced by Merapi Volcano in Central Java, Indonesia upon its recent eruption in October-November 2010. Laharic flow which significantly brings volcanic material to the surrounding area occurs very frequent. This study is aimed to characterize the laharic flow of Merapi Volcano. Observation was done along Putih River, one of ten main rivers flowing from the peak.
Density current and debris flow mechanism have been observed. Both type of mechanism has enormous energy which is able to transport up to 10 km of volcanic rock fragment with about 5 m in diameter. At the upstream part, density current vertically eroded intensively the channel of about 5 -10 m deeper. Those process not only bring the volcanic sediments from recent eruption, but also eroded those from previous volcanic activity.
At the downstream part, vertical erosion is ceased, but the rivers need bigger channel to accommodate the sediments to deposition.
