The Geological Agency of the Ministry of Energy and Mineral Resources\n(ESDM) has mapped the potential for secondary hazards such as ground\ncracks and liquefaction following the Magnitude 6.7 earthquake in\nCentral Sulawesi. The mapping is based on subsurface geophysical\nanalysis that identified intensive activity on the Palolo Graben\nstructure.<\/p>\n
The agency explained that the tremor, centred 42 kilometres southeast\nof Palu City, had a normal fault mechanism. Field teams are closely\nmonitoring the distribution of more than 150 aftershocks recorded with\nvarying magnitudes between 2.5 and 5.1 up to 18 June 2026.<\/p>\n
\u201cThe occurrence of the main earthquake followed by numerous\naftershocks indicates complex geological conditions, with diverse\nlithology types in terms of rigidity and hardness, as well as\nintensively developed geological structures in the affected area,\u201d the\nGeological Agency stated.<\/p>\n
\u201cThe earthquake may be followed by secondary hazards such as ground\ncracks, land subsidence, landslides, and liquefaction. The public is\nurged to remain alert and avoid cliff areas that are prone to\nlandslides,\u201d the agency stressed.<\/p>\n
According to the agency\u2019s data, there are differences in the\nearthquake\u2019s strength parameters from various international\ninstitutions, with the USGS recording Magnitude 6.99 at a depth of 11.5\nkm, while GFZ reported Magnitude 6.66 at a depth of 10 km. Nevertheless,\nthe ground shaking was felt very strongly, reaching intensity IX MMI,\ntriggered by soft soil conditions in residential areas.<\/p>\n
\u201cAnalysis shows a normal fault mechanism triggered by the Palolo\nFault (graben), not the Palu-Koro or Sausu faults which have strike-slip\nmechanisms. We also found no indication that the Palu-Koro Fault was\nactivated by this earthquake,\u201d the agency continued.<\/p>\n
It was emphasised that the rise in sea water followed by a receding\nwave was not due to a tsunami, but rather the effect of physical changes\nto the coastline caused by the strong shaking, including land\nsubsidence. \u201cIt was not an indication of a tsunami,\u201d the agency\nstated.<\/p>\n
Physical impacts in the field show land subsidence that caused sea\nwater in Palu Bay to temporarily recede after the tremor. In addition,\nslope instability on Mount Kamarora triggered landslides and subsidence\non the access road to the Napu area.<\/p>\n
The affected area, classified as having medium to high disaster risk,\nhas soil classifications ranging from soft rock to very soft soil (Vs30\nclasses C, D, and E). This condition triggers the potential for\nliquefaction in Sigi Regency, Palu City, Parigi Moutong Regency, and\nparts of Poso Regency.<\/p>\n
The Geological Agency recommends that all buildings in vulnerable\nareas be designed according to earthquake-resistant standards and\nequipped with adequate evacuation routes.<\/p>\n
The public is also urged to always check the structural condition of\nbuildings to ensure safety before resuming activities indoors, to avoid\nthe risk of being struck by debris from aftershocks.<\/p>\n
Regarding the potential for liquefaction, which is also influenced by\nthe level of shaking and soil type, the Geological Agency stressed it\nwill continue to conduct strict field monitoring.<\/p>\n
\u201cAlways follow the directions and information from local BPBD\nofficials, and remain alert to the possibility of aftershocks. Do not be\ninfluenced by irresponsible information regarding earthquakes or\ntsunamis,\u201d the agency stated.<\/p>\n
\u201cStay calm, do not panic, but remain vigilant. Because aftershocks\nare normal, avoid cracked buildings. Do not easily believe rumours or\nhoaxes, and always refer to official information from BPBD, BNPB, and\nthe local government,\u201d the agency concluded.<\/p>", "url": "https:\/\/jawawa.id\/newsitem\/latest-facts-on-the-m6-7-palu-earthquake-beware-of-liquefaction-and-ground-cracks-1781938268", "image": "" }, "sponsor": "Okusi Associates", "sponsor_url": "https:\/\/okusiassociates.com" }