Japanese seismologists believe that nearly 99 percent of their predictions related to massive earthquakes in the Pacific off central and western Japan are likely to prove wrong, a survey conducted by Kansai University showed Sunday.

While the government estimates there is a 70 to 80 percent chance of a magnitude 8 to 9 quake occurring along the Nankai Trough within the next 30 years, the survey underscores the difficulty of precisely predicting the timing, location and strength of imminent quakes, based on observational data.

The survey covering 138 people, including members of the Seismological Society of Japan, received responses from 90 individuals.