Sulawesi Earthquake and Tsunami: The Deadliest Earthquake of 2018

The earthquake and subsequent tsunami that struck the Indonesian island of Sulawesi on Friday, September 28, has already claimed the sinister accolade of being the deadliest earthquake in the world this year.

According to local authorities, there have so far been 1,374 reported fatalities, but this figure is set to rise as rescue efforts spread out from the main cities. At this stage, thousands of people are believed to still be trapped under the rubble of collapsed buildings, and at least 60,000 people are displaced with limited food and water supplies.

The 7.5 magnitude earthquake struck the island of Sulawesi on Friday, September 28, approximately 48 miles (78 kilometers) north of Palu, a coastal city with around 330,000 residents. The earthquake triggered a ten foot (three meter) high tsunami, that impacted the coastal areas of western Central Sulawesi, including Palu City and Donggala, a regency with a population of around 275,000.

Sulawesi is the eleventh largest island in the world, around ten percent smaller than Great Britain in terms of area.

Reports show that the devastation in the region is extensive. Satellite imagery and photographs released by the Indonesian National Board for Disaster Management (BNPB) show widespread damage. Thousands of buildings are reportedly collapsed and destroyed from the earthquake and resulting tsunami, and according to local officials and media reports, the city of Palu has been devastated. Several districts, including Petobo, a district in the southeast of Palu City, and Balaroa neighbourhood in the west of the city have been destroyed from ground liquefaction and landslides.

Communications and power outages continue to impact the whole region, which are hampering relief efforts. The main airport east of Palu — Mutiara Sis Al Jufri Airport, was closed after it sustained damage from the tsunami, with the runway now acting as a mobile treatment center.

With its long, narrow bay, local reports suggest that the Palu bay acted as a funnel for the tsunami waves. Many of the early fatalities from Friday’s tsunami were on Talise Beach in Palu, with a launch event for the annual Palu Nomoni Festival which was attended by hundreds of visitors. Questions are also being asked about the regions tsunami warning system, with warnings cancelled soon after the earthquake happened, and reissued after the waves struck the coast. After another tragic tsunami event, authorities across the world will again reexamine whether they have sufficient infrastructure and awareness training to help their citizens react when a tsunami is identified.

This is a region that is very familiar with seismic events. According to local researchers, Central Sulawesi is the most prone area in Indonesia to tsunamis, and including this event, the area has seen at least 19 such occurrences since 1820.

At the time of writing, more than 170 earthquakes have affected the region since Friday’s Mw7.5 earthquake. To add to these problems, on Wednesday, October 3, the Soputan Volcano in northern Sulawesi erupted, spewing volcanic ash up to 4,000 meters into the air. Local volcanologists have suggested the recent earthquakes could have triggered the eruption. No casualties or damage have been reported.

Indonesia has experienced at least eight events with a moment magnitude of Mw 5.0 or greater so far in 2018. Just two months ago on August 5, a magnitude 6.9 earthquake struck the island of Lombok, around 31.8 miles (51.2 kilometers) northeast of Mataram City, killing over 500 people, injuring at least 1,300, and damaging more than 50,000 buildings.

The nearby island of Sumatra experienced tsunamis after earthquakes in 2009 and 2010, with these events killing around 400 and 1,100 people respectively. Many will remember events in Indonesia on December 26, 2004, when the magnitude 9.1 Indian Ocean earthquake and tsunami resulted in an estimated death toll of around 170,000.