Hery Susanto Wibowo, the head of the BMKG Geophysics Station, on Monday advised residents to check their buildings for sufficient earthquake resistance before returning home.
"Also make sure that there is no damage due to earthquake vibrations that could endanger the stability of the building," he stated in Banjarnegara, Central Java.
He noted that according to observations made by the BMKG Banjarnegara Geophysics Station from May 27-29, four earthquakes were felt by the residents of Salatiga and its surroundings, with magnitudes of 2.2 to 2.5.
He remarked that the series of earthquakes is similar to those recorded in 2021.
"From the distribution of the epicenters, they are close to the events from October to November 2021 that were likely caused by the Merapi-Merbabu fault," Wibowo explained.
He pointed out that in this case, there were three active faults—the Merapi-Merbabu fault, the Ungaran fault, and the Rawapening fault—around the earthquake site.
However, Wibowo did not rule out the possibility of new unidentified faults appearing near the earthquake epicenter.
Nevertheless, he admitted that a more in-depth study was necessary to determine whether the series of earthquakes in Salatiga was caused by these faults.
"Based on their distribution, the series of earthquakes that have occurred in the last few days are indeed more towards the Merapi-Merbabu fault, but further studies are needed," he said.
Moreover, based on the 1975 geological map, it is known that Salatiga, Ambarawa, and their surrounding areas are made of alluvial deposits that can magnify waves or earthquakes, although the magnitude is small, Wibowo explained.
Hence, the residents are encouraged to build earthquake-resistant houses to anticipate damage when an earthquake occurs, he stated.
The series of small-magnitude earthquakes in Salatiga and its surroundings is expected to reduce the possibility of larger-magnitude earthquakes, as the energy has been released through small earthquakes.
In addition to the series of earthquakes that occurred in 2021 in Salatiga and its surroundings, he said that based on data, the largest magnitude only reached 3.5.
He added that based on a macro survey or a direct survey on the ground, there was indeed damage, such as cracks in buildings.
"We must also check the structure of the building, whether they are earthquake-resistant or in accordance with the infrastructure development rules," he stated.
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Translator: Sumarwoto, Resinta S
Editor: Anton Santoso
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