A series of earthquakes, including one that was magnitude 7.5, triggered a powerful tsunami on Indonesia’s Sulawesi island on Friday evening local time. Early images and harrowing video shared on social media show water pouring into the city of Palu, as well as collapsed buildings and damage from the wave-and-quake combo.
Things first began shaking late afternoon local time, according to data from the U.S. Geological Survey. The strongest quake hit shortly after 5 p.m. about 50 miles to the north of Palu, and likely triggered the tsunami.
At least one person is dead and 10 more are injured in the wake of the earthquake, according to Indonesia’s disaster management agency. That number is likely to rise, as AP reports that a number of homes were swept away and entire families have been reported as missing in and around Palu, a city of around 330,000 that sits at the end of an inlet on the north side of the island of Sulawesi. That inlet may have funneled the water toward the city, increasing the damage.
“The situation is chaotic, people are running on the streets and buildings collapsed,” Dwikorita Karnawati, the head of Indonesia’s weather and earthquake agency, told Reuters. “There is a ship washed ashore.”
Indonesia is unfortunately no stranger to tsunamis, which are generally triggered by earthquakes and underwater landslides associated with them, owing to the fact that it sits on the edge of two tectonic plates that frequently smash or rub together. Palu was shook by an earthquake in 2005 that killed one person. The 2004 Indian Ocean tsunami generated by one of the strongest underwater earthquakes ever observed exacted a more dramatic toll, killing nearly 230,000 across the ocean (including 120,000 in Indonesia) and causing almost $20 billion in damage.
What caused this tsunami is still under investigation, though. Erik Klemetti, a Denison University geologist, wrote that the circumstances around where the earthquake occurred could offer some clues:
“This tsunami is somewhat unexpected as the earthquake does not appear to be similar to the massive 2004 Boxing Day earthquake, where the motion on the fault was caused by the collision of two plates. Instead, this appears to be strike-slip motion (side by side) similar to the San Andreas fault. [SPECULATION ALERT] However, with its coastal location, there may well have been undersea landslides that might have caused the tsunami [END].”
We’ll update this post with more information, images, and video as they become available. And as always, remember that not everything you see on social media is accurate so share anything carefully.