Coastal Subsidence Induced Several Tsunamis During the 2018 Sulawesi Earthquake

Abstract

The height of the tsunami caused by the Sulawesi earthquake in 2018 was higher than that estimated from the magnitude of the earthquake, and its cause is not well understood. Although it is conceivable that tsunamis originated from landslides in several cases, it is not known whether landslides were occurring in the coastal area at the time. This report describes the results of a field survey conducted to investigate the traces of subsidence and the characteristics of the tsunami incidents in the bay far from the epicenter. Subsidence was observed at a minimum of seven points along the coast; in accord with the reports of eyewitnesses, this suggests that subsidence might have generated tsunamis.