Last week, Japan issued its inaugural “megaquake advisory” following a magnitude 7.1 earthquake off the southeastern coast of Kyushu's southern main island. Although the quake caused no fatalities or significant damage, the advisory has sparked widespread confusion and concern in a nation accustomed to frequent seismic activity, leaving many anxious about the potential for future large-scale quakes.
Understanding the Megaquake Advisory
The Japan Meteorological Agency (JMA) issued the advisory after determining that the recent 7.1 quake near the Nankai Trough raised the likelihood of another major seismic event. The JMA warns of a 70-80% chance of a magnitude 8 or 9 quake associated with the Nankai Trough within the next three decades, with the probability now deemed “higher than normal” post the recent quake.
Insight into the Nankai Trough
The Nankai Trough, an undersea trench stretching from Hyuganada to Suruga Bay, poses a significant seismic threat. The interaction between the Philippine Sea Plate and the Eurasian Plate in this region could trigger a megaquake and subsequent tsunami, as seen in the devastating 1946 Nankai Trough quake off Shikoku.
Potential Impact of a Megaquake
A government report from 2013 highlighted the catastrophic consequences of a magnitude 9.1 Nankai Trough quake, projecting a tsunami exceeding 10 meters and estimating casualties, building destruction, and economic losses on a massive scale.
Government Preparedness Efforts
Prime Minister Fumio Kishida has taken charge of the government's response to the advisory, emphasizing preventive measures and public communication. The Fire and Disaster Management Agency has instructed at-risk municipalities to review their emergency plans, while experts stress the importance of preparedness without causing undue alarm.
Public Reaction and Precautionary Measures
The advisory has left many Japanese citizens perplexed and concerned, leading to stockpiling of emergency supplies and disruptions to travel plans. While some have adjusted their routines and made necessary preparations, others struggle to grasp the advisory's implications and the appropriate response.
Local businesses and authorities have taken steps to enhance readiness, with hotels, resorts, and transportation services implementing precautionary measures. Despite the challenges posed by the advisory, efforts are underway to ensure public safety and minimize potential risks in the event of a megaquake.
As Japan grapples with the aftermath of the recent quake and navigates the uncertainties surrounding future seismic activity, the nation remains vigilant and resilient in the face of its seismic vulnerabilities.
