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 increasing 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.

Respondents were asked whether the four stages necessary to release a prediction could be cleared: that there is abnormal activity in advance; that the abnormality is observable; that heightening risks could be quickly assessed; and that such an assessment could be announced immediately.

The questionnaire found an average of 5.8 percent of predictions could go all the way to release, while only 19.7 percent of those were likely to contain accurate information.