What's the 'half-cracked' scenario for predicted Nankai Trough megaquake off Japan?

The Mainichi Shimbun answers some common questions readers may have about a "half-cracked" scenario for a predicted megaquake along the Nankai Trough

What's the 'half-cracked' scenario for predicted Nankai Trough megaquake off Japan?
The Mainichi Shimbun answers some common questions readers may have about a "half-cracked" scenario for a predicted megaquake along the Nankai Trough