2018 Sulawesi earthquake and tsunami

2018 Sulawesi earthquake and tsunami
Devina Andiviaty · CC BY-SA 3.0 · source
Title	2018 Sulawesi earthquake and tsunami
Caption	Damage in Palu after the event
Date	28 September 2018
Magnitude	7.5 M_w
Depth	10 km
Location	off the coast of Palu, Central Sulawesi
Type	Strike-slip on the Palukoro–Koro fault/whip
Affected	Indonesia, especially Sulawesi, Palu (city), Donggala Regency, Sigi Regency
Casualties	Thousands killed, thousands injured, many missing

2018 Sulawesi earthquake and tsunami The 28 September 2018 event struck near Palu, Central Sulawesi and combined a large plate‑boundary earthquake with a destructive tsunami, triggering widespread landslides, liquefaction, and urban collapse. The disaster affected cities and regencies across Sulawesi, prompting national and international responses from agencies and organizations including Badan Meteorologi, Klimatologi, dan Geofisika, Indonesian National Board for Disaster Management, United Nations, International Red Cross and Red Crescent Movement, and numerous governments. The catastrophe reignited debates in seismology, coastal engineering, humanitarian law, and disaster risk reduction led by institutions such as United States Geological Survey, Australian Government, European Union, World Bank, and Asian Development Bank.

Background

Central Sulawesi lies within the complex tectonic framework of the Pacific Ring of Fire, bordered by the Sunda Arc, Philippine Sea Plate, Australian Plate, and numerous microplates including the Molucca Sea Collision Zone and the Banda Arc. The region has a history of seismicity including the 2004 Indian Ocean earthquake and tsunami, the 2010 Mentawai earthquake and tsunami, and recurrent activity recorded by the United States Geological Survey, Global Seismographic Network, and regional centers such as BMKG. Coastal towns like Palu (city), Donggala Regency, and Sigi Regency sit on alluvial plains and river deltas vulnerable to liquefaction documented in academic studies from Institut Teknologi Bandung, Bogor Agricultural University, and international research teams from University of Tokyo, Columbia University, Imperial College London, and University of Oxford.

Earthquake

The mainshock occurred on 28 September 2018 at local time; seismograms from USGS, BMKG, Geoscience Australia, and the Incorporated Research Institutions for Seismology recorded a 7.5 M_w event with a shallow hypocenter. Focal mechanism solutions published by USGS and analyses by researchers at University of Auckland, ANU, and GFZ German Research Centre for Geosciences indicated strike‑slip rupture on a local fault system often associated with the Palukoro–Koro fault and nearby structures. Numerous aftershocks were recorded, cataloged by BMKG, USGS, and international networks; notable strong aftershocks prompted comparisons to sequences like the 2010 Maule earthquake and investigations by teams from Caltech, Massachusetts Institute of Technology, Johns Hopkins University, and University of California, Berkeley.

Tsunami and Impact

The earthquake generated a tsunami that reached the western coasts of Palu Bay and inundated areas of Donggala; wave heights varied due to bay geometry and submarine landslides. Observations by BMKG, eyewitness reports from residents of Talise Beach, Pantoloan, and Wani' and tide gauge data compiled by IOC-UNESCO highlighted anomalous arrival times and run-up patterns inconsistent with simple fault‑displacement models. Investigations by scientists from INAGTA, LIPI, Kagoshima University, University of Tsukuba, Seoul National University, and Monash University suggested that submarine landslides, local sediment failure, and basin‑resonance amplified tsunami generation, echoing mechanisms discussed after the 1998 Papua New Guinea tsunami and the 2011 Tōhoku earthquake and tsunami.

Casualties and Damage

The combined effects of shaking, coastal inundation, liquefaction, and landslides devastated infrastructure. Buildings including hotels, markets, hospitals, schools, and the Jalan Trans-Sulawesi corridor collapsed or were rendered unusable; iconic sites such as the Palu IV Bridge (often called the Palu IV Bridge) were damaged or collapsed, while neighborhoods in the Balaroa and Petobo districts experienced catastrophic lateral spreading and subsidence. Death toll estimates reported by BNPB, International Federation of Red Cross and Red Crescent Societies, WHO, and media outlets like BBC News, The New York Times, Reuters, Al Jazeera, and The Guardian varied over time; thousands were confirmed dead, many more injured, and tens of thousands displaced. Archaeological sites and cultural heritage in Central Sulawesi, monitored by Ministry of Education and Culture (Indonesia) and regional museums, also suffered damage.

Response and Relief Efforts

The national response was led by BNPB and TNI (Indonesian National Armed Forces with police support from Polri; search and rescue teams from BASARNAS, SAR teams, and international urban search and rescue units from Australia, Singapore, Malaysia, Japan, United States, Canada, and South Korea participated. Humanitarian coordination involved United Nations Office for the Coordination of Humanitarian Affairs, WHO, UNICEF, WFP, IOM, UNHCR, International Committee of the Red Cross, Médecins Sans Frontières, Save the Children, Palang Merah Indonesia, and NGOs such as Mercy Corps, Oxfam, CARE International, and Plan International. Donor support and reconstruction financing were announced by the World Bank, Asian Development Bank, Asian Infrastructure Investment Bank, bilateral partners including Australia Department of Foreign Affairs and Trade, USAID, DFID (now FCDO), and emergency supplies were staged at ports such as Bitung and Makassar.

Recovery and Reconstruction

Long‑term recovery involved resettlement planning for liquefaction zones like Petobo and Balaroa, reconstruction of transport links including sections of the Trans-Sulawesi Highway, restoration of healthcare facilities coordinated with Ministry of Health (Indonesia), and rebuilding of schools in collaboration with Ministry of Education and Culture (Indonesia) and international partners such as UNICEF and UNDP. Scientific research projects by LIPI, BMKG, USGS, Leicester University, and regional universities informed updated building codes and early warning proposals advocated by IOC-UNESCO, GNS Science, and disaster risk organizations including Global Facility for Disaster Reduction and Recovery and Resilience Alliance. Legal and policy reviews in the DPR and provincial assemblies addressed land‑use, zoning, and compensation schemes, while memorials and commemorations in Palu and surrounding districts involved civil society groups, faith organizations, and cultural institutions.

Category:Earthquakes in Indonesia Category:2018 disasters in Indonesia