An estimated 5.8 magnitude earthquake struck the seas south of Java on Thursday evening, triggering tremors across Indonesia’s most populous island and increasing fears over a recent wave of local earthquakes.
The Event: Precision Data and the Local Impact
The quake came sometime around 18:06 GMT (Friday, 1:06 AM local time). And although the US Geological Survey (USGS) and GFZ German Research Centre had initially estimated its magnitude to be 5.8, Indonesia’s Meteorology, Climatology, and Geophysical Agency (BMKG) recorded an initial value about 6.2 or 6.4 in a follow-up alert.
- Epicenter: Approximately 89 km southeast of Pacitan, East Java.
- Depth: A shallow 10- to 58-kilometre descent, shallow enough to indicate most seismic activity is occurring on the surface.
- Tsunami Status: Officials say they know there had not been an immediate tsunami threat, although residents in coastal areas were briefly thrown into panic, and many fled their houses and offices in Yogyakarta and Surabaya.
A Pattern of Instability
This latest jolt follows a series of earthquakes across the archipelago this week. Up until that point this morning about the area of Modisi, North Sulawesi, there was a 4.5 magnitude foreshock. The beginning of February witnessed tremendous tremor in Maluku and West Papua, signalling deeper-reaching activity involving the Sunda Megathrust the interface of the Australian plate moving below the Sunda plate.
Recent activity comes at a time of sharp volcanic fissures, including some recent eruptions of Mount Semeru in East Java, some experts say.
A Call from the Government and Safety
Joko Widodo, the country’s president, sounded an alert to citizens to be careful but calm. “Indonesia is sitting on the Ring of Fire, so we have to be ready for how this very natural phenomenon of our geography works,” he said, urging local authorities to fast track damage assessments. Despite reports of minor falls and stampedes causing injuries in the immediate aftermath, no significant, structural failures or deaths have been confirmed as of Friday morning.
