Deadly Indonesian Tsunami was Triggered by Landslide, Study Suggests

Deadly Indonesian Tsunami was Triggered by Landslide, Study Suggests

Until recently, scientists were puzzled why an earthquake of only 7.5 magnitude caused a devastating tsunami that killed over 2,000 people on the island of Sulawesi in Indonesia in September of 2018.  The earthquake didn’t even trigger the tsunami early warning system as normally a tsunami of the size (wave height up to 11m or 36 ft) would require an 8.4 or higher magnitude earthquake. A new study published in the journal Pure and Applied Geophysics has found that the cause of the tsunami was actually a marine landslide in Palu Bay on the west coast of Sulawesi. A combination of computer modeling and observation of the actual sea level data from the event was used to reach their conclusion.  They observed a wave period that was very short, consistent with the 3 to 4 minutes expected based on the modeling of a marine landslide compared to the 15 to 60 minute periods for an earthquake-induced tsunami.

Source: Deadly Indonesian tsunami was unleashed by landslide in Palu Bay, study suggests