Megathrust Earthquake Discussions Intensify: When Will It Occur? The Geological Agency Responds
Recently, megathrust earthquakes have become a frequent topic of discussion on social media. Public attention towards this issue has intensified following several earthquakes in Indonesia and the eruption of Mount Anak Krakatau.
As many citizens begin to seek information regarding the potential for megathrust earthquakes, including when they might occur, the Geological Agency of the Ministry of Energy and Mineral Resources (ESDM) has issued a statement. Through its official Instagram account, the Geological Agency provided several important pieces of information regarding the potential for megathrust activity.
The Geological Agency explained that a megathrust is an earthquake source formed at the meeting point of two tectonic plates, where one plate descends beneath another (a subduction zone). “This zone can cause large earthquakes if the energy accumulated in the subduction zone is released,” the agency stated on its Instagram account.
It was explained that megathrust zones have the potential to trigger both earthquakes and tsunamis. The resulting earthquakes could have significant magnitudes, ranging from a maximum of M8.0 to M9.2. Meanwhile, the western coast of Sumatra and southern Java face a high potential for tsunamis. Tsunami heights along the coastline are estimated to potentially reach more than 3 metres, and in some locations, they could exceed 10 metres.
Regarding when a megathrust earthquake will occur, the Geological Agency clarified that, currently, science cannot precisely determine the day, date, time, exact location, or magnitude of future earthquakes. “We study megathrusts not to predict the date of an earthquake, but so that we can identify the source of the danger and prepare for mitigation,” the agency continued.
There are several recommendations provided by the Geological Agency regarding megathrust potential. Below is a summary of actions to take before and after such an event.
Before a megathrust event occurs:
Familiarise yourself with your surroundings, such as potential geological hazards (landslides, tsunamis, etc.), and understand self-protection efforts and designated evacuation zones.
Prepare an emergency disaster bag (drinking water, long-lasting food, torch, spare batteries, first aid kit, whistle, cash, and copies of important documents).
Organise room interiors, such as avoiding placing heavy items on high shelves and keeping beds away from large glass windows.
Ensure that your house or building has an earthquake-resistant structure and immediately repair any cracks in foundations or walls.
Implement risk-based urban spatial planning.
Familiarise yourself with disaster-prone area maps.
Participate in regular socialisation and evacuation training.