Holiday Ayo - The Meteorology, Climatology and Geophysics Agency (BMKG) emphasized that Indonesia could not avoid the megathrust earthquake. 

Researchers from the National Research and Innovation Agency (BRIN) also revealed the facts about this natural phenomenon and how to mitigate it. 

In Indonesia, megathrust earthquakes are nothing new. Based on data compiled by BMKG, there were many megathrust earthquakes that occurred in various regions. 

Expert Researcher at the BRIN Geological Disaster Research Center, Nuraini Rahma Hanifa, said that most of the megathrust earthquakes and tsunamis occurred along Sumatra, some in Java, and quite a lot in Eastern Indonesia. 

There are several locations that look empty, which actually does not mean there is no potential for a tsunami, but is referred to as a 'seismic gap'. 

This means, an area where a large earthquake could occur at any time. 

“The results of much research that has been carried out can contribute to efforts to reduce earthquake risk. Megathrust and its earthquake potential are real, but this is part of a natural phenomenon that must be faced with adaptation and mitigation," said Rahma, quoted from the BRIN website, Monday (2/9). 

According to him, megathrust literally means a very large rising fault. Indonesia, which is above the Ring of Fire, has a large area and is vulnerable to megathrust. 

“Megathrust earthquakes first became a major concern in 2011, with more and more research being conducted and the application of research results growing. Efforts to bridge research and policy are very important to build mitigation for megathrusts," said the Coordinator of the Geohazard Risk & Resilience Research Group. 

Rahma added, based on the 2017 earthquake map which is being updated and is projected to be completed by the end of 2024, megathrust locations in Indonesia are generally located on the west side of Sumatra to the south of Java. 

“This megathrust field is the size of Java Island. Imagine if it moved 20 meters simultaneously, the shaking would be very big," he explained. 

In southern Java, the megathrust stretches for 1,000 km with a contact area 200 km wide, plunges to a depth of about 60 km, and continues to accumulate energy ready to be released at any time.

"Under Java Island, there is the Indo-Australian oceanic plate which is thrusting beneath the south of Java, while above it is the continental plate. The meeting between the oceanic plate and the continental plate is what is called the megathrust field," said Rahma, a researcher who graduated from Nagoya University in 2014. 

This Rahma further explained that in the concept of disaster there are things that can and cannot be controlled, such as the movement of the earth and population growth. 

Disaster risk is a function of hazard and vulnerability, divided by capacity or adaptability. To be safe, Indonesians living above the megathrust must understand how to mitigate and adapt to disasters. 

“This vulnerability is related to exposure or population growth. Therefore, to reduce the risk of disaster from a potential megathrust, the population's adaptive capacity must be increased. If this is not improved, while we already know there will be a disaster but do not take any action, then Our capacity is low, and this will increase the risk of disaster," he said. 

Rahma emphasized the importance of a good understanding of megathrusts to increase adaptive capacity. 

“The threat from megathrusts is divided into primary threats such as surface earthquake shocks and surface rupture. Then there are secondary threats such as tsunamis, landslides, liquefaction and fire," he said. 

“We can live side by side with the megathrust phenomenon, and it is not something to be afraid of. We really have to live together with megathrusts, especially as we are in an island country," he concluded.