Dewi Elvia Muthiariny, Bandung – The Meteorology, Climatology, and Geophysics Agency (BMKG) Bandung Geophysics Station recorded a total of 147 earthquakes in the West Java region throughout September 2024. According to the Head of the Bandung Geophysics Station, Teguh Rahayu, the majority of these tremors, 132 in total, originated from shallow depths, less than 60 kilometers.
Fifteen quakes were recorded at medium depths between 60 and 300 kilometers. "Regarding magnitude, the largest recorded quake was 5.0, and the smallest was 1.2," Teguh said on Monday, October 14, 2024. In terms of location, 75 quakes were centered in the sea, while 71 others occurred on land.
Out of the 147 quakes, 14 were felt by residents, including a destructive 5.0 magnitude quake on September 18, 2024, at 9:41 a.m. local time. Centered at coordinates 7.19 degrees south latitude and 107.67 degrees east longitude, this quake, originating from a depth of 10 kilometers, was generated by the activity of the Southern Garut Fault (Garsela). It was followed by 34 aftershocks in the subsequent two days.
Daryono, Head of the BMKG Earthquake and Tsunami Center, confirmed the connection between the 5.0 magnitude earthquakes in Bandung Regency and Garut to the activity of the Southern Garut Fault.
"The quakes were undoubtedly triggered by the Garsela Fault," he said to Tempo on Friday night, September 20, 2024.
Daryono further explained that the quake source mechanism was aligned with the northeast-southwest orientation of the Garsela Fault line. The series of aftershocks confirmed that the tremors were shallow crustal earthquakes caused by a sinistral strike-slip fault mechanism.
"To date, the 5.0 magnitude quakes in Bandung Regency and Garut remain the largest quakes triggered by the Garsela Fault," he added.
Prior to these events, destructive quakes triggered by the Garsela Fault included a 4.2 magnitude quake on November 6, 2016, and a 3.9 magnitude quake on July 18, 2017. These tremors resulted in damage to several buildings and houses in Pangalengan and Kamojang.
Based on updated data from the West Java Regional Disaster Mitigation Agency (BPBD), as of Friday, September 20, 2024, the number of affected residents was 11,352 families or 45,753 people. The majority of those affected were residents of Bandung Regency, with 10,101 families or 39,135 people. In Garut Regency, 1,246 families or 6,601 people were affected.
A total of 35 people, all residents of Bandung Regency, suffered severe injuries, while 98 others sustained minor injuries. In Garut, five people were injured. The most significant building damage occurred in Bandung Regency, with 720 severely damaged houses, 875 moderately damaged units, and 2,979 lightly damaged residences.
Apart from Bandung and Garut, residents' houses in other areas were also reportedly damaged. One house each in West Bandung Regency and Purwakarta experienced severe damage. Additionally, one house in Cimahi City and one in Bogor Regency suffered moderate damage.
– Anwar Siswadi (Contributor)