TEMPO.CO, Jakarta - The Meteorology, Climatology, and Geophysics Agency (BMKG) explained that the series of earthquakes striking Java Island’s northern and southern parts on Tuesday, July 7, were not interconnected.
“They were all different in terms of source, depth, and mechanism,” said BMKG head of earthquake mitigation Daryono on Tuesday.
Following the earthquakes in South Banten and South Garut that were only hours apart, many questioned whether it was related to each other and feared it would lead to a larger magnitude quake. Asked whether people’s fears are justifiable, Daryono said: “That is an aspect that we must be aware of.”
Daryono explained that the South Banten earthquake is due to the deformation in the Indo-Australia slab within the ‘Benioff zone’ at the depth of 87 kilometers. Meanwhile, the other one was caused by deformation at the same slab but specifically came from the ‘megathrust zone’.
The series of earthquakes started when the northern Java Sea shook at magnitude 6.1 at 05:54,44 Western Indonesia Times (WIB), which was followed by the earthquake in Rangkasbitung on the southern side of Banten recorded at magnitude 5.1 at 11:44,14 WIB. This was then followed again bay a magnitude 5,0 earthquake at south Garut and moved to the magnitude 5.2 south Sunda Strait earthquake at 13:16 WIB.