(File Photo)
The Japan Broadcasting Corporation (NHK) reported on Sunday that a team of researchers from Tohoku and Hokkaido universities, along with the Japan Agency for Marine-Earth Science and Technology, have issued a warning regarding the accumulation of unreleased stress energy at an undersea trench off northern Japan.
According to their findings, this energy could potentially trigger a magnitude 9-level earthquake.
The researchers, who have been studying the Chishima Trench near Hokkaido for the past five years, released their findings yesterday (Mar 9).
They noted that similar seismic activity in the 17th century led to a massive earthquake in the region.
The government’s earthquake panel estimates that there is a 7 to 40 percent chance of an earthquake of at least magnitude 8.8 occurring in this area within the next 30 years.
In 2019, the research team installed GPS observation stations on the seabed around the point where an oceanic plate subducts beneath a continental plate.
Data from these stations showed that parts of the oceanic plate are moving approximately 8 centimeters per year towards the continental side. Interestingly, a station located on the continental plate, where the two plates meet, also recorded a movement of about 8 centimeters per year in the same direction. This movement suggests that the plates are tightly joined, leading to an accumulation of strain.
If the plates have been interlocked in this manner since the 17th-century earthquake, the researchers believe that the accumulated strain could be equivalent to the energy released during a mega-quake.
Assistant Professor Tomita Fumiaki from the Tohoku University International Research Institute of Disaster Science stated that memories of the 2011 Great East Japan Earthquake and Tsunami have been fading.
He highlighted that public awareness and preparedness are crucial, as there is a real possibility of another mega-quake occurring in the region.
The research team is planning further studies at another location off Hokkaido to gather more data on this significant seismic threat.
AloJapan.com