ini Penyebab Gempa dan Tsunami di Palu & Donggala Menurut Ahli Gempa UNHAS #BreakingNews

Summary

The transcript discusses a recent 7.4 magnitude earthquake in Palu, Central Sulawesi, which prompted residents to stay outdoors due to aftershocks and the threat of a tsunami. Dr. Ardi Arsyad, a geophysicist from Hasanuddin University, explains the causes of the earthquake, including the Palu-Koro fault's tectonic activity. The conversation explores the unpredictability of aftershocks, the geological characteristics of the fault, and the need for better earthquake preparedness and risk mapping in eastern Indonesia. The discussion also touches on historical seismic cycles and the challenges of predicting earthquakes in this seismically active region.

Takeaways

• 😀 A recent earthquake of magnitude 7.4 struck Palu, Central Sulawesi, causing widespread panic and power outages.
• 😀 Many residents in Palu are staying outdoors in anticipation of aftershocks and potential tsunami threats, using makeshift shelters.
• 😀 Earthquake expert Ardi Arsyad suggests that the earthquake could be linked to the ongoing tectonic movements in the region, including past seismic events in Lombok.
• 😀 The Palu-Koro fault is highly active, with a movement of 20 to 40 mm per year, contributing to shallow earthquakes that can cause significant damage.
• 😀 Historically, similar earthquakes have occurred in Donggala in 1927, 1968, and 1996, showing a 30-40 year cyclical pattern.
• 😀 It is difficult to predict earthquakes due to the limited data on the region's minor faults, although there is potential for aftershocks in the future.
• 😀 The Palu-Koro fault exhibits strike-slip behavior, where parts of the fault move horizontally rather than vertically, which can cause complex seismic events like tsunamis.
• 😀 Tectonic activity in Sulawesi is unique, with multiple active shallow faults that require detailed mapping and early warning systems to mitigate risks.
• 😀 Indonesia is focusing on microzonation mapping for seismic risks, which could help inform building codes and disaster preparedness plans in earthquake-prone areas.
• 😀 The recent 7.4 magnitude earthquake is considered a main shock, and although the energy release seems to be decreasing, there are concerns about further aftershocks or seismic gaps in the region.

Q & A

What was the immediate impact on the residents of Palu after the earthquake?

After the earthquake, many residents of Palu, Central Sulawesi, remained outside their homes, fearing aftershocks. The area was also left in darkness due to power outages, with some residents using generators for lighting.

What did the expert say about the potential link between the recent earthquake and the Lombok earthquake?

The expert, Pak Ardi, mentioned that there could be an indirect link between the recent earthquake in Palu and the Lombok earthquake due to the movement of the Indo-Australian plate. However, this needs further study to confirm the connection.

What is the Palukoro fault and how does it contribute to the seismic activity in the region?

The Palukoro fault is an active fault in Central Sulawesi, moving at a rate of 20 to 40 mm per year. This fault causes shallow earthquakes, with significant seismic events, including the recent earthquake with a magnitude of 7.7.

Can future earthquakes in the Palu region be predicted based on historical data?

While historical data indicates periodic earthquakes every 30 to 40 years in the Donggala area, Pak Ardi explained that predicting specific earthquakes is difficult due to limited studies of the Palukoro fault and its minor segments.

What makes the Palukoro fault's movement different from other faults like the one in Lombok?

The Palukoro fault is a 'strike-slip' fault, where the plates slide horizontally, rather than moving vertically as in normal faults. This results in a unique type of tectonic activity compared to other regions like Lombok.

How does the tsunami associated with the Palu earthquake occur despite the fault being a strike-slip fault?

Although the Palukoro fault is a strike-slip fault, a tsunami could still be triggered by underwater landslides or secondary normal faults in the seabed. This could explain the tsunami observed in the region.

Is it possible to predict aftershocks or subsequent earthquakes after a major earthquake?

It is challenging to predict aftershocks precisely. However, Pak Ardi noted that after a major earthquake, the release of energy may cause further movement along other segments of the fault system, potentially leading to additional seismic activity.

What is the potential risk of future earthquakes in Sulawesi based on its tectonic activity?

Sulawesi's tectonic setting, with multiple active shallow faults, poses a significant earthquake risk. The region requires thorough earthquake risk mapping and public awareness to mitigate the potential impact of future seismic events.

What are the recommended actions for residents in areas like Palu to prepare for future earthquakes?

Residents in earthquake-prone areas should be educated on earthquake preparedness, including the importance of evacuation to higher ground during tsunamis and understanding local seismic risks based on updated maps of fault zones.

What are the challenges in implementing earthquake mitigation strategies in Central Sulawesi?

One major challenge is the lack of comprehensive seismic hazard maps and limited public awareness. Additionally, building infrastructure in earthquake-prone areas needs to comply with updated earthquake-resistant building codes, which are still under development in some regions.