What is Megaquake and why Japan has issued advisory on it

On August 8, 2024, Southern Japan experienced a 7.1 magnitude earthquake, prompting the country’s first ‘megaquake’ alert due to the danger posed by the Nankai Trough. The warning centers on the possibility of a magnitude 8 or 9 earthquake happening soon. Citizens have been advised to stay informed and prepared for immediate evacuation if necessary.