Therefore, local people living in the areas of West Java Province where the Cimandiri and Lembang Faults exist need not be worried about an occurrence of earthquake because it was not triggered by the eruption, the center's researcher, Supartoyo, said.
Instead, the faults potentially trigger an earthquake with tremors measuring up to VIII on the Modified Mercalli Intensity(MMI) scale, he said, adding that the faults' motions could likely trigger a volcano's eruption.
However, a strong earthquake might also not make a volcano become active as revealed in the Aceh earthquake in 2004. At that time, the nine-magnitude earthquake that rocked 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 said.
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 added.
Mt 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 Mt 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.