TEMPO.CO, Jakarta - The Meteorology, Climatology, and Geophysics Agency or BMKG detected at least 36 aftershocks in Tojo Una-Una regency, Central Sulawesi with a magnitude of less than 5.0 Richter scale as of Tuesday morning, July 2. These followed the mainshock measuring 5.9-Richter scale magnitudes on Monday, July 26, at 11:52 local time.
The number added to seven series of earthquakes that occurred throughout Monday. The strongest one was recorded on Monday night at 19:00 Western Indonesian Time (WIB) with a magnitude of 6.3 Richter scale.
“Hopefully, the condition will be stable soon,” said the agency’s earthquake and tsunami mitigation coordinator, Daryono, as quoted from his social media account on Tuesday.
Daryono explained the quake’s epicenter was located on the Balantak Fault, recalling that the last strong quake on the line occurred on March 15, 2015, reaching 6.1-Richter scale magnitudes. An earthquake with similar strength in the region was also detected in 1964.
The series of quakes that occurred in the Balantak Fault headed to the west-east. “But in-depth studies are needed to ensure the generator of the quake in Tojo Una-Una,” Daryono said.
The Palu Regional BMKG’s Geophysics Station Head, Hendrik Leopatty, suspected that the earthquake was triggered by a local cesarean which was not yet known in detail. He opined that the local fault divided from north to south of Tojo Una-Una regency.