今日のテキスト NEW SCALE FOR ACTIVE FAULTS

The recent powerful quakes in southwestern Japan are a reminder of how the country remains exposed to natural disasters, with nearly 100 major active faults nationwide. Seismic experts are about to change the way they tell people how dangerous each fault is.
Currently, members of a government task force give the probability of the active faults triggering an earthquake within the next 30 years. But these figures tend to be small because such quakes usually occur over a span of thousands of years.
The experts are now planning to rank the faults on a new four-level scale that uses letters instead of numbers.
"S" will mean the probability of the fault triggering a quake within 30 years is quite high ― greater than three percent. "A" will stand for a range of between 0.1 and three percent. The rank of "Z" will signify a probability of less than 0.1 percent. Finally, "X" will be used when the probability of a quake occurring is unclear but cannot be ruled out.
The members say that about one-third of the country's 97 faults will be ranked "S," the highest level of threat.