The Forums

.

How Would a Major Nankai Trough Earthquake Affect the Maglev? — Symposium in Iida Explores Risks Like Falling Debris and Fires

## Overview of the Event

A symposium was held in Iida City, Japan, where experts and local residents discussed the potential impacts of a massive Nankai Trough earthquake on the Linear Chuo Shinkansen (maglev train), with particular focus on risks such as falling objects and fires.

## Background: Nankai Trough Megaquake

- The Nankai Trough is an ocean-floor trench off Japan’s Pacific coast, where the Eurasian and Philippine Sea tectonic plates meet. This region is known for generating some of the world’s most powerful earthquakes, with magnitudes that can exceed 9[7].
- The Japanese government has recently raised the probability of a magnitude 8–9 megaquake occurring along the Nankai Trough within the next 30 years to approximately 80%[5]. Such an event could cause widespread shaking and massive tsunamis, affecting a broad area of Japan’s Pacific coast[5][7].

## Symposium Topics

**1. Impact on the Linear Chuo Shinkansen (Maglev Train)**
- The symposium addressed how a Nankai Trough megaquake could affect the maglev line, which is a major infrastructure project running through central Japan.
- Concerns include:
- The risk of structural damage to elevated tracks and tunnels.
- The danger of falling objects within tunnels or onto tracks during strong shaking.
- The possibility of fires breaking out, especially in enclosed spaces like tunnels, and the challenges of evacuating passengers safely.

**2. Earthquake and Disaster Preparedness**
- Experts highlighted the need for robust disaster impact evaluations and emergency response planning, especially for high-risk infrastructure such as the maglev line[3].
- The unpredictability of the earthquake’s timing and the potential for long-period ground motions (which can affect large structures) were emphasized[2][3].

**3. Community Involvement**
- Local residents participated in the symposium, expressing concerns about safety and evacuation procedures in the event of a disaster.
- The event aimed to foster collaboration between technical experts and the community to improve disaster resilience.

## Context and Significance

- Japan’s experience with large earthquakes, such as the 2011 Tohoku quake, has driven efforts to reassess and strengthen disaster preparedness for major infrastructure[2][3].
- The symposium in Iida City reflects ongoing efforts to address the unique challenges posed by the Nankai Trough, particularly for new transportation systems that traverse seismically active regions.

## Summary Table: Key Points

| Topic | Details |
|---------------------------- |------------------------------------------------------------------------|
| Earthquake Risk | 80% chance of M8–9 quake in next 30 years[5] |
| Main Concerns for Maglev | Falling objects, fire risk, evacuation in tunnels |
| Symposium Participants | Experts, local residents |
| Broader Context | Lessons from past disasters; focus on resilience and emergency planning |

## Conclusion

The symposium in Iida City underscores the urgent need for comprehensive risk assessment and disaster preparedness for critical infrastructure like the Linear Chuo Shinkansen, given the high probability of a devastating Nankai Trough earthquake in the coming decades[5][7].

Citations:
[1] https://www.sciencedirect.com/science/a ... 1X19306788
[2] https://www2.jpgu.org/meeting/2013/sess ... 35_O_e.pdf
[3] https://www.mdpi.com/2076-3417/11/15/7041
[4] https://agupubs.onlinelibrary.wiley.com ... 15JC010995
[5] https://sj.jst.go.jp/news/202501/n0123-01n.html
[6] https://lisamultiverse.com/the-role-of- ... -outcomes/
[7] https://www.cnn.com/2024/08/12/asia/jap ... e-intl-hnk
[8] https://al-takdir.com/lifestyle-page/ma ... n-trojena/
[9] https://www.unizulu.ac.za/unizulu-disse ... lum-issue/

---
Info based on: https://www.shinmai.co.jp/news/article/ ... 5052500046 Accessed: May 25, 2025

Specific Information on the Iida City Symposium on May 24, 2025.

Expert Presentations: Specialists in earthquake engineering and disaster prevention presented scenarios of how a Nankai Trough megaquake could affect the maglev line. They highlighted concerns such as the risk of falling objects inside tunnels, fire hazards, and the challenges of evacuating passengers safely in the event of a disaster.

Evacuation and Safety: The symposium emphasized the importance of robust evacuation plans, especially considering the maglev route includes long tunnels through mountainous terrain. Experts noted that, in the event of a fire or tunnel collapse, rapid and coordinated evacuation would be critical.

Community Involvement: Local residents participated actively, voicing concerns about how the maglev project might increase disaster risks in their communities. They called for greater transparency and stronger collaboration between the railway operator, government agencies, and the public to ensure safety measures are adequate.

Disaster Preparedness: The event underscored the need for ongoing disaster drills, clear communication channels, and up-to-date emergency protocols tailored to the unique risks posed by both the maglev infrastructure and the potential scale of a Nankai Trough earthquake.

Context: The symposium took place amid heightened awareness, as recent government reports have raised the estimated probability of a magnitude 8–9 Nankai Trough megaquake within the next 30 years to about 80%. Such an earthquake could cause catastrophic damage across a wide area, including Nagano Prefecture.

Conclusion:
The symposium in Iida City highlighted the urgent need for comprehensive disaster planning and community engagement as the Linear Chuo Shinkansen project advances. Experts and residents alike stressed that anticipating and preparing for worst-case scenarios is essential to safeguarding lives and infrastructure in this seismically active region.