Was this the big earthquake predicted in the Himalayas?

The main fault in Nepal marks where the Indian and Eurasian tectonic plates crash into each other -- also known as the Main Frontal Thrust (MFT) fault. Recent studies have shown that this fault has a rich history of evident and not-so-evident quakes, and was ripe for another major one.

In an interview to The Hindu in May 2013, Vinod Kumar Gaur, seismologist with the Centre for Mathematical Modelling and Computer Simulation, had said: “Calculations show that there is sufficient accumulated energy [in the MFT], now to produce an 8 magnitude earthquake. I cannot say when. It may not happen tomorrow, but it could possibly happen sometime this century, or wait longer to produce a much larger one.”

In a study published in the journal Nature Geoscience in December 2012, a research team led by Nanyang Technological University (NTU) discovered that massive earthquakes in the range of 8 to 8.5 magnitudes on the Richter scale had left clear ground scars in the central Himalayas

High resolution imagery and dating techniques showed that in 1255 and 1934, two great earthquakes ruptured the surface of the Earth in the Himalayas. The 1934 earthquake broke the surface over a length of more than 150 km.

Other than these “surface rupture” quakes, scientists have also found evidence of multiple “blind thrust” quakes that did not break the surface. These records indicate that the region has a rich history of quakes in the past centuries.

The leading scientist of the NTU study had then said that the existence of such devastating quakes in the past meant that quakes of the same magnitude could happen again in the region in future, especially in areas which have yet to have their surface broken by a temblor.

Surface rupture quakes are not only extremely violent, but also they tend to release most or all of the accumulated strain in the fault. “Blind thrust” quakes are ones that do not break the surface, and tend to be more frequent.

A series of studies earlier predicted that a massive earthquake in the South Asia is overdue.

Researchers recently said tremendous underground stress built up in the 1,250-mile Himalayan fault could force a rupture soon -- in geological terms -- and produce a great quake of 8.1 to 8.3 magnitude.

Such a quake could affect some 50 million people in India, Nepal, Pakistan, Bangladesh and Bhutan, they said, and kill at least 200,000.