IMD,US data on Sikkim-Nepal earthquake at variance

The Pune observatory data released earlier put the magnitude of the earthquake at 6.8 on the Richter Scale along the Sikkim-Nepal border and the depth at 10 Km at 12:40 universal time co-ordinate (UTC) or 6:10 pm Indian Standard Time (IST). However,the USGS data shows that the depth of the Sikkim earthquake was 19.7 km and the magnitude was 6.9 on the Richter Scale at 12:40 UTC. Latur earthquake measured 3.9 on the Richter Scale.

Assistant meteorologist M T Jadhav said the observatory data varied with the USGS data as the “initial calculations were not correct.”

However,senior scientist at IMD’s instruments division and director of Seismological Observatory Pune,P N Mohanan,said the variation in the US and IMD data is owing to the USGS link with dense network of seismic stations. “Our initial collection is based on the data of few stations. We calculated the data with the help of satellite linked seismic stations. The USGS has a large number of digital seismograph stations,” he said.

Jadhav,however,said the depth of the aftershocks recorded along the Sikkim-Nepal border was lesser. “The depth of the second tremor decreased to 5 km later. The magnitude of the third tremor was much lesser on the Richter Scale,” he said.

Jadhav added the tremors of lesser magnitude have been felt regularly at Latur after 1993 earthquake.

“The shallow faultline has been generated at Latur in 1993 following which the earthquakes have been frequent. After 1993 continuous tremors are being felt in Latur,” he said. The earthquake in the Latur region on Monday was also felt in the adjoining areas of Osmanabad and Solapur districts.