Failure Nepal earthquake could cause another big quake – PanamaOn

The April 25, 2015 a powerful earthquake of magnitude 7.8 shook central Nepal, killing more than 9,000 people and destroying entire villages. Scientists believe that a failure of the Himalayas, the Main Himalayan Thrust (MHT), is behind this geological phenomenon, which has already caused other major disasters in the region in previous years.

This is a reverse fault, where two layers of strata move over each other as a result of compressive forces in the earth’s crust. The potential of this fault to slide major earthquakes was already known.

The western part of the MHT failure should be monitored closely, as it has the potential to trigger another large earthquake

Now a group of scientists led by researcher Jean-Philippe Avouac of the University of Cambridge (UK) has used seismic and satellite data to reconstruct the evolution of this fault and the earthquake in Nepal or Gorkha (name well received by the Nepali district where most affected) during 2015.

The findings, published in the journal Nature Geoscience, reveals that the devastating earthquake triggered the movement of the lower edge of an area that was MHT locked in failure, but only released their pressure on one of its sides. Specifically, the data indicate that the earthquake was initiated northwest of Kathmandu and spread about 140 kilometers to the east below the city, but failed to reach the surface.

However, more parts west of the fault is not broken and were blocked. Added to this is that the earthquake may have transferred more tension in this regard and surface areas of the cortex, which may facilitate future breakdown of those regions. Research suggests, therefore, that the western part of this failure “should be monitored closely, as it has the potential to trigger another large earthquake in the future.”

Help GPS and radar

This week also published in Science magazine where Avouac another study, along with other colleagues at Caltech Institute of USA and several international centers, show the usefulness of GPS and radar systems to measure, continuously and in short distances, displacements of faults as MHT.

“The data provide the scientific community with a unique perspective on megaterremotos that occur when two tectonic plates converge and one of them is pushed under the other and can help teams improve risk assessment models earthquake risk, “the authors note.

Thanks to this technology has proven to Nepal earthquake it was triggered by a pulse breakdown of just 6 seconds, a fraction of the total of 70 seconds that lasted the quake. The measurements also reveal a shift of 20 km wide, with an extremely fast break of about 3.2 kilometers per second.