A tsunami as high as 34 metres could be triggered by an earthquake with a magnitude of 8.9 in and around Indonesia’s Java and Sumatra islands, according to a report recently released by Indonesian researchers, although no timeline was given.
The researchers discovered high seismic activity on the southern coast of West Java province and the southeastern part of Sumatra Island that could unleash a “megathrust” quake, said the report published last Sunday in the journal Natural Hazards.
If a quake of this scale occurs, the tsunami could be comparable to one that followed a devastating quake in 2004.
Aceh province, also in Sumatra, was struck by a magnitude 9.1 quake and tsunami on Dec 26, 2004, leaving around 180,000 people dead. It was the deadliest disaster in Indonesian history.
The researchers assessed the height of a potential tsunami using a map of more than 1,000 epicentres with quakes measuring a magnitude of four or more based on data from 2009 to 2020.
They said that “magnitude is only one factor in determining the maximum tsunami height.” They put the average tsunami height along the coasts of Sumatra and Java at 11.8 metres and 10.6 metres, respectively.
A separate study has shown that a “megathrust” quake southwest of Java may occur once every 500 years.
Indonesia is one of the most active seismic regions in the world, sitting on the Pacific Ring of Fire, where many earthquakes and volcanic eruptions occur.