TOKYO, Sept. 17 (Xinhuanet) -- The Japan Meteorological Agency said Wednesday it will revise its method for calculating the magnitude of earthquakes starting September 25 to make the figures more accurate.

　　Based on the new method, the agency also corrected the magnitude of the May 26 quakes in northeastern Japan from 7.0 to 7.1 on the Richter scale and those that shook the same area on July 26 from 6.2 to 6.4.

　　Compared to now, the new calculation method will increase the magnitudes of big earthquakes, except for those whose focus is deep, by around 0.2 and decrease them by around 0.5 for smaller quakes of around 2 in magnitude.

　　In the current method, the agency calculates magnitude based onthe maximum values among numerical data obtained from ground movement. But in so doing, seismic waves were being whitewashed bynoise in the event of minor quakes.

　　In addition, the magnitude figures for major tremors have been smaller than they should be since 1994 when the environment in which seismographs are placed changed with the introduction of a system for early detection of earthquakes that could cause tidal waves. Enditem