TREGGALEK, Indonesia, June 27 — A magnitude 5.2 earthquake struck 114 kilometers south-southwest of Trenggalek, Indonesia early Saturday morning, according to the U.S. Geological Survey. The quake occurred at 07:47 UTC at a depth of 65.584 kilometers. The USGS, which detected the event through its real-time global seismic monitoring network, classified this as a shallow earthquake.
Shallow events less than 70 kilometers deep typically produce stronger shaking at the surface than deeper ones of the same magnitude, the record shows. No tsunami warning was issued following the tremor.
At least four people reported feeling the earthquake, according to USGS data.
Moderate magnitude, shallow depth
Earthquakes in the magnitude 5 range are considered moderate and can cause minor to moderate damage near the epicenter. The depth of 65.584 kilometers places this event in the shallow category, meaning the rupture occurred relatively close to the Earth’s surface. Seismologists note that shallow earthquakes of this size tend to produce more noticeable shaking compared to deeper events of identical magnitude, though damage typically remains limited to areas directly around the epicenter.
The region south of Java is seismically active. According to USGS records, at least 123 earthquakes of magnitude 5.0 or greater have been recorded within approximately 300 kilometers of this location over the past two decades.
The strongest during that period was a magnitude 6.3 event in 2006.
Aftershocks expected
Seismologists note that aftershocks are common following an earthquake of this size and may continue for days or weeks. People in the affected area are generally advised to be prepared for further shaking, according to standard seismic guidance. The USGS monitors global seismic activity continuously through its network of sensors.
The agency detected the event as part of its routine monitoring operations. The data provides researchers and local authorities with information about the earthquake’s location, depth, and magnitude, which helps in assessing potential impacts.
The earthquake struck in a region where the Indo-Australian tectonic plate subducts beneath the Eurasian plate, generating frequent seismic activity along the Sunda Trench. This tectonic setting produces both shallow and deep earthquakes, with shallow events like Saturday’s posing a greater risk of surface damage due to their proximity to populated areas. At a depth of 65.584 kilometers, the earthquake released energy that propagated through the crust and was felt by a small number of people who reported their experience to the USGS.
The agency collects felt reports from the public to supplement its instrumental data, providing a fuller picture of an earthquake’s impact. The USGS continues to monitor the region for any additional seismic activity.
Aftershocks, if they occur, are typically smaller than the main shock but can still be felt and may cause additional damage to structures weakened by the initial earthquake. The timeline for aftershocks can extend for days or weeks following the main event, seismologists note.
