TEMPO.CO, Jakarta - This week's eruption of Mount Tangkuban Perahu did not trigger the motion detectors of Cimandiri and Lembang Faults, stated Supartoyo, a researcher of the Energy and Mineral Resources Ministry's Center for Volcanology and Geological Disaster Mitigation (PVMBG) on Sunday.
Therefore, local people living in the areas of West Java Province where the Cimandiri and Lembang Faults exist do not need to be worried about an occurrence of an earthquake because it was not triggered by the eruption of Tangkuban Perahu, said Supartoyo.
He further explained that the faults may be potentially triggered by an earthquake with tremors measuring up to VIII on the Modified Mercalli Intensity(MMI) scale, and also adding that the faults' motion detectors could also be likely to be triggered by a vulcanic eruption.
However, a strong earthquake might not make a volcano become active as revealed in the Aceh earthquake in 2004. At that time, the nine-magnitude earthquake that jolted certain parts of Aceh did not trigger the volcanoes there, he said.
Instead, in the occurrence of Yogyakarta's earthquake several years ago, it had triggered the eruption of Mount Merapi though its magnitude was lower than that of the Aceh quake, Supartoyo further added.
So for for those living in areas of the Cimandiri and Lembang fault lines, including Cianjur District, they should remain calm and rely on information circulated by credible and competent sources, he reassured.
Mount Tangkuban Perahu, which is located around 27 kilometers away from Bandung, one of Indonesia's most densely-populated cities, erupted on Friday (July 26).
The PVMBG has made a statement based on analysis that further eruptions of this 2,084-meter high volcano might possibly occur as ongoing tremors are still being recorded.
Head of the Sub-Section of Volcano Mitigation for Eastern Region Devy K. Syahbana expounded that Friday's eruption was caused by magma steam interacting with the hydrothermal system of Mount Tangkuban Perahu followed by a change below the surface.
"Several mountains too can experience this condition, and it is not only in Tangkuban Perahu. The same also took place at Mount Papandayan and Mount Dieng. This usually does not start with a clear sign and can occur at any time," Syahbana stated on Saturday. However, he noted that based on the eruption that occurred, the threat exists only in the areas around the crater, while those outside the crater will not be too perilous.