Yogyakarta, BRIN Public Relations. An earthquake with a magnitude of 6.7 that rocked Banten on Friday (14/1) at 16.05 West Indonesia Time is the sign that Indonesia is within area prone to earthquakes and tsunamis. “The earthquake that occurred in Banten is a reminder of threat potential in Southern Java, the Sunda Strait, Sumatra, with its megatrust potential,” said Widjo Kongko, Engineer at BRIN’s Port and Coastal Dynamics Infrastructure Technology Center in an interview with the media on Sunday (16/1/ 2022).

According to him, the Banten earthquake with epicenter in the Sunda Strait Friday (14/1) did not cause a tsunami. “The earthquake occurred in an area known as seismic gap, which is the zone that so far has not shown any seismic activity,” said the Doctor, who has studied the potential of megatrust earthquake and tsunami in South Java.

He added that the potential of megatrust earthquake in the Sunda Strait is M8.7 in magnitude, but it can be released along with the segmentation above it, namely the Enggano megathrust, and to the east the West-Central Java megathrust. If this happens, the earthquake magnitude can reach 9 or higher. “Such potential energy is similar to the 2004 Aceh earthquake and tsunami. However, as in general the sea depth in the earthquake source area is deeper than that in the 2004 incident, based on model calculation, scientifically the tsunami that occurs could be higher than Aceh,” he added.

Nevertheless, Widjo urges the public not to panic, but together with the Authority (Regional Government/BPBD) step up mitigation efforts. “On the downstream side, we must prepare the necessary disaster mitigation programs, such as preparing detailed threat maps and risk maps in each area, providing disaster education to the community, preparing proper evacuation sites, and routinely conducting tsunami simulations. On the upstream side, studies on earthquakes and tsunamis need to be carried out continuously,” he asserted.

He added that several important things that we need to know are the characteristics of tsunami threat in Indonesia. “The source of tsunami in Indonesia is generally very close, about 100 km offshore, so that the time it travels to the mainland is very fast,” said Widjo.

He emphasized the mitigation aspect that the community needs to do with regard to the concept of self-evacuation and not relying too much on current technology.

Widjo said further that Indonesia is an archipelagic country, but thus far we concentrate on large islands, in the future mitigation programs in small islands also need to be considered. In addition, Widjo hopes that the development of InaTEWS that has been running, for example the BRIN OR-PPT Buoy facilities which have been set up off the coast of Bengkulu to Sumba island and are still functioning, need to be used optimally, so that it can help the community to receive tsunami early warnings more effectively and accurately through BMKG. (An/Mn)