Garut Earthquake Reveals Minimal Mitigation of Residential Buildings in West Java

The M 6.2 earthquake in Garut affected 17 areas in West Java.

KOMPAS/MACHRADIN WAHYUDI RITONGA

Residents are observing the damaged kitchen area of their house due to an earthquake in Sukamenak Village, Sukarame District, Tasikmalaya Regency, West Java, on Sunday (28/4/2024).

BANDUNG, KOMPAS — An earthquake measuring 6.2 magnitude at a depth of 70 kilometers occurred in the offshore area of ​​Garut Regency, Saturday (27/4/2024) last week, causing damage in 17 areas in West Java. This reveals the condition of people who have not prepared earthquake-resistant house structures or public facilities.

The Coordinator of Data and Information at the Meteorology, Climatology, and Geophysics Agency (BMKG) Station Class I in Bandung, Virga Librian, explained on Tuesday (30/4/2024) that the earthquake in the offshore region of Garut was not caused by a fault movement. However, it was caused by rock deformation activity within the Indo-Australian Plate that is being subducted beneath the Eurasian Plate in southern West Java.

Virga stated that the earthquake that occurred was a moderate type of earthquake due to its depth being above 60 kilometers and its strength only reaching 5 MMI. According to him, strength at that level should not trigger damage to buildings, ranging from minor to severe.

"The earthquake that occurred was not at a shallow depth. This indicates that the mitigation efforts in West Java, by preparing earthquake-resistant buildings, have not been optimal," said Virga.

KOMPAS/FABIO MARIA LOPES COSTA

Coordinator for Data and Information at BMKG Bandung Class I Geophysical Station Virga Librian when met by Kompas on Tuesday (2/1/2024).

Virga revealed that many residential buildings do not meet earthquake-resistant standards based on findings from the earthquake incidents in Cianjur District in 2022 and Sumedang District in late 2023. For instance, the buildings lack concrete or reinforced concrete foundations.

Also read: Garut Earthquake: Injured Victims and Damaged Buildings Increase

He believes that the economic conditions of residents are a contributing factor to the construction of houses that are not earthquake-resistant in terms of materials and construction. This is what leads people to build their homes with makeshift materials.

"This should be a concern for various parties in preparing earthquake-resistant housing mitigation in the southern region of West Java. Because, the earthquake location last Saturday was close to Megathrust Zone, which is the intersection of two plates at a shallow depth with a high potential for earthquakes," he said.

Head of the Geological Agency of the Ministry of Energy and Mineral Resources, Muhammad Wafid, explained that the location of the earthquake that occurred at 11:29 PM was located at sea at a medium depth, causing tremors to be felt in a fairly wide area in West Java. The morphology of the southern coastal region of West Java is generally in the form of a coastal plain bordered by undulating hill morphology to steep hills in the northern part.

HUMAS POLRES GARUT

One of the residents' houses in Garut Regency, West Java was affected by an earthquake measuring 6.2 magnitude on Saturday (27/4/2024).

Wafid revealed that the earthquake event was caused by thrusting activity, also known as intraslab earthquakes with a fault uplift mechanism. "According to the Geological Agency's records, the source of intraslab earthquakes in South West Java has caused several disasters, namely in 1979, 2007, 2017, 2022, and 2023," he said.

He also recommends that houses and public facilities in the South West Java region be built using earthquake-resistant construction. In addition, areas on the south coast of West Java are prone to earthquakes and tsunamis, so mitigation efforts must be increased through structural and non-structural mitigation.

17 regions

Based on data from the West Java Regional Disaster Management Agency (BPBD), there are 17 areas affected by the earthquake in Garut. The affected areas include Tasikmalaya Regency, Tasikmalaya City, Garut Regency, Sukabumi Regency, Ciamis Regency, Bandung Regency, Cimahi City, and West Bandung Regency.

Other areas include Sukabumi City, Sumedang Regency, Majalengka Regency, Bogor Regency, Pangandaran Regency, Purwakarta Regency, Subang Regency, Banjar City, and Cianjur Regency.

KOMPAS

The Indo-Australian Plate to the Garsela Fault, which triggered a number of earthquakes in Garut.

Hadi Rahmat Hardjasasmita from the Public Relations of the West Java Regional Disaster Management Agency stated that 254 houses across 17 areas were damaged due to the magnitude 6.2 earthquake. A total of 620 residents were affected, with 13 of them suffering injuries.

"As many as 28 public facilities buildings have been damaged. We have coordinated with the BPBD officials in these 17 areas for handling the impacts of the earthquake," said Hadi.

Also read: Thousands of houses damaged by the Sumedang earthquake were built not according to standards