Institute says tested device bigger than Hiroshima bomb

TOKYO, May 12 Kyodo - The measurements of seismic waves from India's underground nuclear tests Monday indicated an explosion equal to that of a 20 to 30 kiloton device, slightly larger than the 15-kiloton bomb that was dropped on Hiroshima, the University of Tokyo Earthquake Research Institute said Tuesday. The resulting seismic waves were equivalent to those of an earthquake with a magnitude of 4.9 on the open-ended Richter scale, institute officials said. According to Katsuyuki Abe, a specialist in seismology, the measurements were typical of those originating from nuclear tests, as only longitudinal waves were detected from the blast. The explosion was estimated at 20 kilotons but could have been as large as 30 kilotons, depending on the nature of the rock formations surrounding the blast site, he said. Abe added that only one set of seismic waves was detected, indicating that the three tests may have been conducted simultaneously. Meanwhile, the Meteorological Agency reported that an earthquake observation center in Nagano in central Japan recorded the seismic waves at 7:23 p.m. Monday Japan time, and that they lasted for about 10 seconds.