The recent earthquake in Bhutan was the ripple of the severe earthquake in Nepal. Experts long warned of a severe earthquake in the Himalayan region based on the movement of the tectonic plates.
Theoretically the Indian plate is moving under the Eurasian plate thus giving rise to the Himalayas. Scientist belief the plates to move by about 15 to 20 mm in a year. When the plates glide over each other smoothly earthquake are rare but when they rub against each other and the movement stops the pressure starts building along the fault line. When this pressure is released and the tectonic plates fall back to their normal position a huge amount of energy is release in the form of earthquake.
The Himalayan region is believed to be very active tectonically and it fall in severe earthquake zone. Scientist say that the himalayan region is built of three seismic gaps, Kashmir gap, Central Gap and Assam Gap. The recent earthquake in Nepal (central Gap) was of 7.9 magnitude but some experts believe that the full tension wasn’t released and Nepal might be facing for another bigger earthquake.
Bhutan falls in the Assam Gap and Assam Gap might experience a big earthquake of around 8 magnitude anytime in the future. The last severe earthquake occurred in Bhutan some 1500 years.