A new government-issued map shows that Tokyo and its surrounding areas as well as Pacific Coast cities in Japan remain at high risk of suffering strong tremors in the next 30 years.
An expert panel updates the map every year based on the latest studies of faults and mega-quakes linked to marine trenches.
It shows each area's probability of being hit in the coming 3 decades by tremors registering 6-minus or above on the Japanese intensity scale of zero to 7.
The latest version issued on Tuesday shows a significant rise in risk in eastern Hokkaido.
This follows a revised assessment of the Chishima Trench off Japan's northernmost main island. Experts now say that an earthquake of magnitude 8.8 or more could occur along the trench.
The probability of being hit by massive tremors is 78 percent in the city of Nemuro. That's 15 points higher than on the previous map issued in April of last year. The city of Kushiro now faces a 69 percent probability, up 22 points.
The cities surrounding the Tokyo metropolitan area remain at high risk, as do those on the Pacific coast of central and western Japan along the Nankai Trough.
The figure for the city of Chiba is 85 percent, while it's 82 percent for Yokohama and 81 percent for Mito. The city of Shizuoka is slightly lower at 70 percent, while the risk for Tokyo's Shinjuku district is 48 percent, and Nagoya 46 percent.
The probability is 56 percent for the city of Osaka, which suffered 6-minus tremors last week.
Panel chair Naoshi Hirata says there's no place in Japan that has zero probability of 6-minus or stronger tremors, so everyone should be prepared for powerful quakes.