Situated on the precarious Himalayan seismic zone, Nepal is a highly earthquake-prone country and its quake-battered western mountainous region is likely to face a threat of a bigger earthquake, a seismologist says. According to the government's post-disaster needs assessment (PDNA) report, Nepal is the 11th most earthquake-prone country in the world. So, when a powerful 6.4 magnitude earthquake hit Nepal's remote western mountainous region late on Friday night, it was not the first one for the day or for this month.