Megathrust Earthquakes: Indonesia Braces for Potentially Catastrophic Events
- 14 AUGUST 2024
Indonesia’s Meteorology, Climatology, and Geophysical Agency (BMKG) has issued a warning about impending megathrust earthquakes that could lead to massive tsunamis, stressing the urgent need for preparedness.
A megathrust earthquake occurs in the shallow, angled subduction zones where one tectonic plate is forced under another. These zones can produce the most powerful earthquakes and potential tsunamis, especially in highly seismic regions like Indonesia.
Understanding Megathrust Earthquakes:
BMKG highlights the particular danger from the Sunda Strait Megathrust M 8.7 and the Mentawai-Suberut Megathrust M 8.9. These faults have not released significant energy for centuries, accumulating stress that could lead to catastrophic earthquakes and tsunamis.
Historic Inactivity Raises Concern:
The last major releases along these megathrust zones were hundreds of years ago—Sunda Strait in 1699 and 1780 and Mentawai-Siberut in 1797 and 1833. This long inactivity increases the potential for a high-magnitude earthquake.
Indonesia’s Vulnerable Megathrust Zones:
Three key megathrust regions in Indonesia pose a significant threat:
– Sunda Megathrust covering Sumatra, Java, Bali, Lombok, and Sumba.
– Banda Megathrust which includes parts of Maluku and Sulawesi.
– Northern Papua and the Philippine Sea Plate.
Comprehensive List of Threat Zones:
Based on the 2017 Indonesia Earthquake Source and Hazard map, the following are detailed as high-risk megathrust segments:
– Sunda Strait-Banten Segment: Potential magnitude up to 8.8, historical quakes in 1699 and 1780.
– Java Western Segment: Notable for a M 8.1 quake in 1903.
– Central and Eastern Java Segment: Recorded a M 7.8 quake in 1994.
– Bali Segment: The highest potential with a magnitude up to 9.0, no historical quakes recorded.
Read More: Indonesia Launches Seismic Investigation Mission Across Megathrust Zones
BMKG’s Mitigation Efforts:
To counter the potential disaster, BMKG has enhanced its monitoring and early warning systems. The Indonesia Tsunami Early Warning System (InaTEWS) plays a crucial role in disseminating rapid alerts, combined with community education and evacuation drills.
The threat of megathrust earthquakes is a pressing concern for Indonesia and its neighbors, including Singapore. Effective mitigation and preparedness strategies are essential to minimize potential damage and ensure rapid response to safeguard populations in these high-risk zones.
BMKG warns of the imminent threat of megathrust earthquakes in Indonesia, capable of generating devastating tsunamis. Historical gaps and the buildup of tectonic stress underline the urgency for regional preparedness and robust early warning systems to mitigate the impact on millions living in vulnerable areas.
Sources: Detik.com, CNN Indonesia (2024)
